Map of the world with countries coloured according to their immigrant population as a percentage of the whole population, based on the UN's World Population Policies 2005 data. Enlarge graphic to view legend.
The immigrant paradox in the United States is an observation that recent immigrants often outperform more established immigrants and non-immigrants on a number of health-, education-, and conduct- or crime-related outcomes, despite the numerous barriers they face to successful social integration.
According to the UN, the number of first-generation immigrants worldwide is 244million. These large-scale population changes worldwide have led many scholars, across fields, to study the acculturation and adjustment of immigrants to their new homes. Specifically, researchers have examined immigrant experiences as they pertain to educational attainment, mental and physical health, and conduct/crime.
Researchers have tried to understand why later generations seem to perform less well than their forebears. They have found that it can be explained by non-optimal methodology and differences in the way generations are modified by the host culture.
Challenges faced by immigrants
Immigrants face many challenges as a result of migration, stemming from the fact that the nations and communities they settle in are culturally unfamiliar. As a result, they find themselves in an unwelcoming environment lacking in the infrastructure necessary to ensure a simple transition. Additionally, because general attitudes of the host society are often hostile and xenophobic,immigrants are doubly vulnerable. Discrimination and prejudice are common and dictate daily experiences with individuals and organizations within the host society. For example, although cultural sensitivity training is increasingly a required component of medical education, immigrants have historically faced and continue to face discrimination in the health care system. An added barrier to equitable access to health care comes as a result of many immigrants' limited English proficiency. Many health care facilities have inadequate interpretation services, and culturally sensitive health care providers are also scarce. In addition, many immigrants are uninsured, making the financial burdens of adequate health care insurmountable.
Many immigrants also settle in de facto segregated, low-income neighborhoods and ethnic enclaves, especially during periods of high immigration. Although the benefits of living in such communities include increased social support, positive in-group relations, and the virtual elimination of cultural and language barriers in daily interaction, often such neighborhoods are targets of institutional violence, such as stop and frisk. Further, due to public education funding policies in the United States, funds are often allocated to schools based on neighborhood property taxes. As a result, many immigrant children attend schools that are understaffed, underfunded, and lacking in resources in comparison to the schools of their more affluent peers. This is known as the opportunity gap, by which low-income and marginalized groups have disproportionately low access to the opportunities and conveniences afforded to societally privileged groups, resulting in group-wide disparities in academic achievement, wages, and political power. In direct relation to these obstacles, immigrants also face challenges in the workplace, including poor and dangerous working conditions, unemployment, and the employment of highly skilled individuals in low-skill jobs.
To compound all of these issues, the burden of acculturation is an added stressor. Navigating the divide between the heritage culture and the culture of the new society is difficult, as the traditions, beliefs, and norms of these two cultures are often in direct conflict. This challenge is only compounded by the other obstacles immigrants are faced with, and has deleterious consequences for mental health, particularly because many migrants and refugees are already susceptible to elevated levels of psychopathology, due to the trauma associated with interpersonal conflict, acculturative stress and/or political unrest in their countries of origin.
In light of these obstacles, it is expected that recent immigrants would have outcomes inferior to those of their native-born or non-immigrant peers.
Paradoxical findings
Despite the numerous challenges facing early generation immigrants, research on the mental and physical health, educational, and conduct-related outcomes of these populations has demonstrated a paradoxical pattern.
Mental health outcomes
Research with Filipino Americans has demonstrated that first-generation immigrants had lower levels of depressive symptoms than subsequent, US-born generations. First-generation Mexican immigrants to the United States were found to have lower incidences of mood disorders and substance use than their bicultural or subsequent generation counterparts. Similarly, immigrant youth in general are less likely to engage in risky behaviours and substance use, including alcohol and marijuana consumption. Other research with Latino populations shows that immigrants are less likely to suffer from any mental disorder than non-Latino whites. Research with Asian populations has supported this apparent paradox, with first-generation Asian Americans reporting lower levels of lifetime symptoms of depression and anxiety than US-born Asian Americans. One study inclusive of immigrants to the United States from Asia, Africa, Latin America, and Europe found that immigrants, regardless of place of origin, exhibited less violent and nonviolent antisocial behaviour than US-born individuals.
These findings have been replicated outside of the United States, with Canadian researchers finding that foreign born youth are less likely to display emotional and behavioural problems than their native-born peers, despite experiencing similar levels of poverty. Research conducted in the Netherlands has also found evidence of an immigrant paradox, with first- and second-generation Muslim immigrants reporting fewer psychological problems and higher self-esteem than Dutch nationals.
Physical health outcomes
The immigrant paradox also extends to physical health, with recent immigrants having better outcomes than US-born individuals. One study of several thousand health records in Southern California found Asian and Latina women had better perinatal outcomes than both white and Black women. Specifically, Asian and Latina women had lower infant mortality, higher birth weight, fewer Caesarean sections, fewer medical diagnoses during delivery, and shorter hospitalizations. This finding has also been replicated in Spain, with immigrant mothers, barring those of Sub-Saharan African origin, having a lower frequency of low birth weight than native Spanish mothers.
With respect to overweight and obesity, it has been found that first-generation Mexican American women had healthier diets than both non-Latino whites and second-generation Mexican American women. Further, second-generation women had the poorest dietary intake, consuming even smaller amounts of necessary nutrients than non-Latina white women. US-born immigrants (i.e., second-generation immigrants, and subsequent generations) have also been found to engage in more overweight-related behaviours, such as poor diet, smoking, and little physical activity, in comparison to foreign-born immigrants. For Cubans and Puerto Ricans, increased length of stay in the United States was also associated with increased presence of overweight. These findings were replicated in a later study, which showed that with increased length of stay in the United States, immigrant health levels decreased significantly, approaching the levels of US-born individuals. Although immigrant men and women entered the US with lower BMIs than their US-born counterparts, within 10 to 15 years of arrival, there was no significant difference between the BMIs of immigrants versus US-borns. These findings apply to Asian American immigrants as well, with second- and third-generation Asian American adolescents being 100% more likely to be obese relative to their first-generation peers.
Educational outcomes
Among Latino populations, first- and second-generation Latino adolescents report high levels of effort in school, with effort declining across generations. They also place a greater value upon education, with the same downhill trend being observed. First-generation Mexican American adolescents, specifically, have more positive attitudes towards academics and skip school less than subsequent generations and non-Latino US-born Whites. They are also more involved in high school STEM coursework and have higher GPAs. With respect to Asian Americans, first-generation Asian American youth have more positive attitudes towards academics and skip school less than subsequent generations and non-Latino US-born whites. Further, first- and second-generation Asian American youth report higher levels of effort in school. Other differences in educational outcomes include superior reading achievement for first- and second-generation immigrant children, in comparison to their third-generation counterparts. First-generation Latino, Asian, and African youth have greater overall educational attainment and are less likely to drop out of high school than subsequent generations of each community. There are also differences in susceptibility to stereotype threat across generations, with second-generation Afro-Caribbean youth more at risk than first-generation youth.
Conduct-related outcomes
There is also evidence that the immigrant paradox extends to differential outcomes in conduct and/or crime. For example, rates of intimate partner violence are lower among non-Latino first-generation immigrant families. Immigrants are also less likely than non-immigrants to engage in many kinds of lifetime criminal and violent antisocial activity, including drunk driving, speeding, purposeful physical violence, and weapon use, with first-generation immigrants the least likely to engage in criminal behavior, followed by second-generation immigrants, then third-generation. These effects can be seen at the neighborhood level, with increases in first-generation immigrants resulting in decreases in neighborhood-wide violence over time. Further, among undocumented immigrants, drug-related crime is even less likely than it is among non-immigrants.
With respect to criminality among adolescents, first-, one-and-a-half-, and second-generation Asian American, African American, and Caribbean American adolescents are all less likely to engage in illegal or delinquent behavior than non-Latino US-born White adolescents. Immigrant neighborhood concentration was also negatively correlated with recidivism for Latino youth.
A special case: the immigrant paradox in refugees?
There is a general consensus that refugees are at a particular disadvantage when it comes to successful resettlement in the host society, as the same challenges voluntary immigrants face are generally aggravated for refugees. However, some research has found evidence of a paradox, with refugees at least three times less likely to engage in substance use than non-immigrants. Other research has found refugees to Denmark to have a lower likelihood of stroke and breast cancer compared to Danish natives, but higher likelihood of lung cancer, HIV/AIDS, and tuberculosis. Notably, levels of all of these diseases among refugee populations eventually converged to the same levels as Danish natives with increased length of residency.
There may also be an immigrant paradox for the perinatal outcomes of refugees, with the majority of refugee women studied having a lower crude birth rate, infant mortality rate, maternal mortality rate, and percentage of low birth weight than women in both their host country and their country of origin.
Conflicting evidence
There is some doubt among scholars as to whether or not the phenomenon actually exists, with some findings conflicting with the body of research on immigrant outcomes. For example, among Asian Americans, limited English proficiency was consistently associated with worse physical and mental health outcomes. In addition to language proficiency, age at time of immigration is also an important factor, with older first-generation Mexican American youth more likely to drop out of school than their US-born and younger, first-generation counterparts. In further support of this conclusion, data from the CPS shows that immigrating as a teenager is associated with completing less schooling than immigrating before or after adolescence. CPS data also shows that second-generation immigrants completed more schooling than both foreign-born immigrants and non-immigrant US-born individuals.
In international research on the phenomenon, Europe's SHARE data demonstrated no evidence of a paradox, with immigrants having poorer health outcomes than native Europeans. A study in Canada found that recent and non-European immigrant women were more predisposed to developing postpartum depression than non-immigrant Canadians.
Immigrants from North Africa and the Middle East, on average, have higher levels of education and are more likely to be proficient in English and to be naturalized. Their industries tend to be more similar to those of workers born in the United States than to those from other countries, with relatively higher shares of workers in management, business, science, and the arts. Yet North African and Middle Eastern immigrants are more likely to live in poverty than other immigrants from other countries. They are also more likely to obtain legal permanent residence in the United States, through humanitarian protection or the diversity visa lottery, than other immigrants.
Explanations
Acculturation and the erosion of protective factors
The most common hypothesis for the immigrant paradox considers recent and first-generation immigrants' comparative access to cultural and social protective factors. Despite being confronted with the many challenges arising from immigration and acculturation, first-generation immigrants have greater social and cultural capital than subsequent generations. These include stronger social networks and highly adaptive cultural practices concerning religion, diet, substance use, and parenting style. Researchers also posit that first-generation immigrants are more likely to place high importance upon academic success due to fear of limited employment opportunities in the host society. These protective factors result in superior lifetime health, educational, financial, and conduct-related outcomes. Additionally, by having access to multiple cultural frameworks, recent immigrants are able to code-switch between frameworks or engage in downward social comparison as methods of self-protection.
In comparison, subsequent generations may not have access to such social and cultural capital, having been socialized into the norms and expectations of the host society (i.e., consuming more processed and unhealthy foods, having a smaller network of same-ethnicity peers, increased substance use). Further, intergenerational conflict is more likely between first-generation immigrants and their second-generation children due to differing cultural practices, with parents being accustomed to the norms of their culture of origin and children having been socialized into the norms of the host society. This type of conflict has been linked to poorer outcomes for children.
A third cost of acculturation is linked to immigrant children's cultural socialization. A strong sense of ethnic identity and pride in one's cultural heritage is generally understood to be protective from negative mental health outcomes. However, with increased length of stay in the host society, subsequent generations are likely to report decreasing levels of involvement in culturally important traditions and practices. With this comes decreasing strength of ethnic identity. Second-generation immigrants are also less likely to endorse meritocratic views, which is similarly correlated with decreasing strength of ethnic identity. These attributes are all associated with poorer mental health.
First-generation immigrants often settle in ethnic enclaves, which carry a host of advantages. Residents of these neighborhoods have access to a strong and supportive network of same-ethnicity peers and potential access to culturally sensitive healthcare providers that may allow for increased financial gain and better physical and mental health outcomes. Ethnic enclaves also eliminate the challenges associated with language barriers, with residents often sharing linguistic similarity.
Healthy immigrant selection
Another common explanation for the immigrant paradox is that the vast majority of superior outcomes among early generations of immigrants can be accounted for by a selection effect. Proponents of this hypothesis argue that only the most psychologically and physically healthy individuals migrate from their country of origin, and therefore have superior outcomes to begin with.
Methodological concerns
Much of the literature on the immigrant paradox in mental health relies on self-report data. This may be problematic in that certain populations may differentially interpret questions in ways that are meaningful and result in significant disparities between groups. Similarly, many measures view mental health solely through a Western lens, accounting only for the types of symptoms commonly expressed in Western societies. This may result in the underreporting of poor mental health among non-Western populations.
Another issue in research on immigrants is the grouping of highly diverse ethnic groups together in monolithic racial categories, namely the pan-ethnic "Asian" and "Latino" categories. Much of the research on Latinos and the immigrant paradox has been conducted with Mexican American populations, ignoring the fact that there are 32 other countries that fall under the Latin American label. Similarly, much research on Asian Americans has been conducted with East Asian populations, ignoring the differential treatment and experiences of South and Southeast Asians, and the different refugee status of individuals across Asia (examples include Lhotshampa refugees, who are of South Asian heritage, and Cambodian refugees, who are of Southeast Asian heritage). Such groupings are problematic in that they erase the large diversity in socioeconomic status, educational background, and historical trauma of each of these ethnic groups – factors which all contribute to the consequent positive or negative outcomes of immigrants.
Future directions in immigrant research
Carola Suárez-Orozco, Ph.D. calls for increased research on the psychology of immigrants paying attention to differences in refugee status, documentation status, gender, and ethnic group (in lieu of using pan-ethnic groupings). Research must also consider seasonal migrants, the differential racialization of ethnic groups, and the role of English proficiency on educational and health outcomes.
It is estimated that up to 90% of CVD may be preventable. Prevention of CVD involves improving risk factors through: healthy eating, exercise, avoidance of tobacco smoke and limiting alcohol intake. Treating risk factors, such as high blood pressure, blood lipids and diabetes is also beneficial. Treating people who have strep throat with antibiotics can decrease the risk of rheumatic heart disease. The use of aspirin in people who are otherwise healthy is of unclear benefit.
Cardiovascular diseases are the leading cause of death worldwide except Africa. Together CVD resulted in 17.9 million deaths (32.1%) in 2015, up from 12.3 million (25.8%) in 1990. Deaths, at a given age, from CVD are more common and have been increasing in much of the developing world, while rates have declined in most of the developed world since the 1970s. Coronary artery disease and stroke account for 80% of CVD deaths in males and 75% of CVD deaths in females. Most cardiovascular disease affects older adults. In high income countries, the mean age at first cardiovascular disease diagnosis lies around 70 years (73 years in women, 68 years in men). The average age of death from coronary artery disease in the developed world is around 80, while it is around 68 in the developing world. At the same age, men are about 50% more likely to develop CVD and are typically diagnosed seven to ten years earlier than women.
Types
There are many cardiovascular diseases involving the blood vessels. They are known as vascular diseases.
Heart failure – a clinical syndrome caused by the inability of the heart to supply sufficient blood to the tissues to meet their metabolic requirements
Myocarditis – inflammation of the myocardium, the muscular part of the heart, caused most often by viral infection and less often by bacterial infections, certain medications, toxins, and autoimmune disorders. It is characterized in part by infiltration of the heart by lymphocyte and monocyte types of white blood cells.
Eosinophilic myocarditis – inflammation of the myocardium caused by pathologically activated eosinophilic white blood cells. This disorder differs from myocarditis in its causes and treatments.
There are many risk factors for heart diseases: age, sex, tobacco use, physical inactivity, non-alcoholic fatty liver disease, excessive alcohol consumption, obesity, unhealthy diet, genetic predisposition and family history of cardiovascular disease, raised blood pressure (hypertension), raised blood sugar (diabetes mellitus), raised blood cholesterol (hyperlipidemia), undiagnosed celiac disease, psychosocial factors, poverty and low educational status, poor sleep, and air pollution.While the individual contribution of each risk factor varies between different communities or ethnic groups, the overall contribution of these risk factors is very consistent. Some of these risk factors, such as age, sex or family history/genetic predisposition, are immutable; however, many important cardiovascular risk factors are modifiable by lifestyle change, social change, drug treatment (for example prevention of hypertension, hyperlipidemia, and diabetes). People with obesity are at increased risk of atherosclerosis of the coronary arteries.
Genetics
Cardiovascular disease in a person's parents increases their risk by ~3 fold, and genetics is an important risk factor for cardiovascular diseases. Genetic cardiovascular disease can occur either as
a consequence of single variant (Mendelian) or polygenic influences. There are more than 40 inherited cardiovascular disease that can be traced to a single disease-causing DNA variant, although these conditions are rare. Most common cardiovascular diseases are non-Mendelian and are thought to be due to hundreds or thousands of genetic variants (known as single-nucleotide polymorphisms), each associated with a small effect.
Age
Calcified heart of an older woman with cardiomegaly
Age is the most important risk factor in developing cardiovascular or heart diseases, with approximately a tripling of risk with each decade of life. Coronary fatty streaks can begin to form in adolescence. It is estimated that 82 percent of people who die of coronary heart disease are 65 and older. Simultaneously, the risk of stroke doubles every decade after age 55.
Multiple explanations are proposed to explain why age increases the risk of cardiovascular/heart diseases. One of them relates to cholesterol level in serum. In most populations, the serum total cholesterol level increases as age increases. In men, this increase levels off around age 45 to 50 years. In women, the increase continues sharply until age 60 to 65 years.
At the same age, men are about 50% more likely to develop CVD and are typically diagnosed seven to ten years earlier than women. A notable exception are thromboembolic diseases which are similarly common in men and women. It has been argued that the excess risk of CVD observed in men compared to women only applied to the pre-menopausal period, but more recent data from the WHO and UN disputes this. If a female has diabetes, she is more likely to develop heart disease than a male with diabetes. Women who have high blood pressure and had complications in their pregnancy have three times the risk of developing cardiovascular disease compared to women with normal blood pressure who had no complications in pregnancy.
Coronary heart diseases are 2 to 5 times more common among middle-aged men than women. In a study done by the World Health Organization, sex contributes to approximately 40% of the variation in sex ratios of coronary heart disease mortality. Another study reports similar results finding that sex differences explains nearly half the risk associated with cardiovascular diseases One of the proposed explanations for sex differences in cardiovascular diseases is hormonal difference. Among women, estrogen is the predominant sex hormone. Estrogen may have protective effects on glucose metabolism and hemostatic system, and may have direct effect in improving endothelial cell function. The production of estrogen decreases after menopause, and this may change the female lipid metabolism toward a more atherogenic form by decreasing the HDL cholesterol level while increasing LDL and total cholesterol levels.
Cigarettes are the major form of smoked tobacco. Risks to health from tobacco use result not only from direct consumption of tobacco, but also from exposure to second-hand smoke. Approximately 10% of cardiovascular disease is attributed to smoking; however, people who quit smoking by age 30 have almost as low a risk of death as never smokers.
Insufficient physical activity (defined as less than 5 × 30 minutes of moderate activity per week, or less than 3 × 20 minutes of vigorous activity per week) is currently the fourth leading risk factor for mortality worldwide. In 2008, 31.3% of adults aged 15 or older (28.2% men and 34.4% women) were insufficiently physically active. The risk of ischemic heart disease and diabetes mellitus is reduced by almost a third in adults who participate in 150 minutes of moderate physical activity each week (or equivalent). In addition, physical activity assists weight loss and improves blood glucose control, blood pressure, lipid profile and insulin sensitivity. These effects may, at least in part, explain its cardiovascular benefits.
High dietary intakes of saturated fat, trans-fats and salt, and low intake of fruits, vegetables and fish are linked to cardiovascular risk, although whether all these associations indicate causes is disputed. The World Health Organization attributes approximately 1.7 million deaths worldwide to low fruit and vegetable consumption. Frequent consumption of high-energy foods, such as processed foods that are high in fats and sugars, promotes obesity and may increase cardiovascular risk. The amount of dietary salt consumed may also be an important determinant of blood pressure levels and overall cardiovascular risk. There is moderate quality evidence that reducing saturated fat intake for at least two years reduces the risk of cardiovascular disease. High trans fat intake has adverse effects on blood lipids and circulating inflammatory markers, and elimination of trans-fat from diets has been widely advocated. In 2018 the World Health Organization estimated that trans fats were the cause of more than half a million deaths per year. There is evidence that higher consumption of sugar is associated with higher blood pressure and unfavorable blood lipids, and sugar intake also increases the risk of diabetes mellitus. High consumption of processed meats is associated with an increased risk of cardiovascular disease, possibly in part due to increased dietary salt intake.
The relationship between alcohol consumption and cardiovascular disease is complex, and may depend on the amount of alcohol consumed. There is a direct relationship between high levels of drinking alcohol and cardiovascular disease. Drinking at low levels without episodes of heavy drinking may be associated with a reduced risk of cardiovascular disease, but there is evidence that associations between moderate alcohol consumption and protection from stroke are non-causal. Moderate drinking is defined as one drink per day for women or two drinks a day for men. At the population level, the health risks of drinking alcohol exceed any potential benefits. Exercising regularly can provide the same benefits as potentially consuming small amounts of alcohol and is a much safer alternative. Consuming too much alcohol can cause a high blood pressure, heart failure, and cardiomyopathy. Drinking alcohol can also cause obesity, which can contribute to cardiovascular issues as well.
In 2020, the National Heart Foundation of New Zealand Expert Nutrition Policy (ENP) issued a position statement that concluded that high consumption of red meat increases risk of heart disease and stroke by 16%.
The American Medical Association (AMA) recommends that people replace full-fat dairy products with nonfat and low-fat dairy products. In 2017, the AMA stated that there is no high-quality clinical evidence that cheese consumption lowers the risk of cardiovascular disease. In 2021, they stated that "taken together, replacing full-fat dairy products with nonfat and low-fat dairy products and other sources of unsaturated fat shifts the composition of dietary patterns toward higher unsaturated to saturated fat ratios that are associated with better cardiovascular health".
In 2017, the National Heart Foundation of New Zealand published an umbrella review which found an "overall neutral effect of dairy on cardiovascular risk for the general population". Their position paper stated that "the evidence overall suggests dairy products can be included in a heart-healthy eating pattern and choosing reduced-fat dairy over full-fat dairy reduces risk for some, but not all, cardiovascular risk factors".
In 2019 the National Heart Foundation of Australia published a position statement on full fat dairy products, "Based on current evidence, there is not enough evidence to recommend full fat over reduced fat products or reduced fat over full fat products for the general population. For people with elevated cholesterol and those with existing coronary heart disease, reduced fat products are recommended." The position statement also noted that the "evidence for milk, yoghurt and cheese does not extend to butter, cream, ice-cream and dairy-based desserts; these products should be avoided in a heart healthy eating pattern".
Recent reviews of randomized controlled trials have found that dairy intake from cheese, milk and yogurt does not have detrimental effects on markers of cardiometabolic health.A 2025 global analysis found that that total dairy consumption is associated with a 3.7% reduced risk of cardiovascular disease and a 6% reduced risk of stroke.
Eggs
One systematic review and meta-analysis of egg consumption found that higher consumption of eggs (more than 1 egg/day) was associated with a significant reduction in risk of coronary artery disease. Another systematic review and meta-analysis of dietary cholesterol and egg consumption found that egg consumption was associated with an increased all-cause mortality and CVD mortality. These contrary results may be due to somewhat different methods of study selection and the use primarily of observational studies, where confounding factors are not controlled.
A 2018 meta-analysis of randomized clinical trials found that consumption of eggs increases total cholesterol (TC), LDL-C and HDL-C compared to no egg-consumption, but not to low-egg control diets. In 2020, two meta-analyses found that moderate egg consumption (up to one egg a day) is not associated with an increased cardiovascular disease risk. A 2020 umbrella review concluded that increased egg consumption is not associated with cardiovascular disease risk in the general population. Another umbrella review found no association between egg consumption and cardiovascular disorders.
A 2013 meta-analysis found no association between egg consumption and heart disease or stroke. A 2013 systematic review and meta-analysis found no association between egg consumption and cardiovascular disease or cardiovascular disease mortality, but did find egg consumption of more than once daily increased cardiovascular disease risk 1.69-fold in those with type 2 diabetes mellitus when compared to type 2 diabetics who ate less than one egg per week. Another 2013 meta-analysis found that eating four eggs per week increased the risk of cardiovascular disease by six percent.
Eggs are one of the largest sources of phosphatidylcholine (lecithin) in the human diet. A study published in the scientific journal, Nature, showed that dietary phosphatidylcholine is digested by bacteria in the gut and eventually converted into the compound TMAO, a compound linked with increased heart disease.Another study found that type 2 diabetes mellitus and kidney disease also increase TMAO levels and that evidence for a link between TMAO and cardiovascular diseases may be due to confounding or reverse causality.
Celiac disease
Untreated celiac disease can cause the development of many types of cardiovascular diseases, most of which improve or resolve with a gluten-free diet and intestinal healing. However, delays in recognition and diagnosis of celiac disease can cause irreversible heart damage.
Sleep
A lack of good sleep, in amount or quality, is documented as increasing cardiovascular risk in both adults and teens. Recommendations suggest that infants typically need 12 or more hours of sleep per day, adolescents at least eight or nine hours, and adults seven or eight. About one-third of adult Americans get less than the recommended seven hours of sleep per night, and in a study of teenagers, just 2.2 percent of those studied got enough sleep, many of whom did not get good quality sleep. Studies have shown that short sleepers getting less than seven hours sleep per night have a 10 percent to 30 percent higher risk of cardiovascular disease.
In addition, sleep research displays differences in race and class. Short sleep and poor sleep tend to be more frequently reported in ethnic minorities than in whites. African-Americans report experiencing short durations of sleep five times more often than whites, possibly as a result of social and environmental factors. Black children and children living in disadvantaged neighborhoods have much higher rates of sleep apnea.
One study found that of adults who are 45 and older, subjects that fell asleep at different times each night and slept inconsistent numbers of hours each night were more likely to develop atherosclerosis. Poor sleep habits, such as too little sleep, too much sleep, or fragmented sleep, were associated with cardiovascular disease, obesity, and high blood pressure. Another study noted that participants whose sleep duration varied by more than two hours within the course of a week were 1.4 times more likely to have elevated levels of coronary artery calcium, a predictor of cardiovascular events.
Socioeconomic disadvantage
Cardiovascular disease has a greater impact on low- and middle-income countries compared to those with higher income. Although data on the social patterns of cardiovascular disease in low- and middle-income countries is limited, reports from high-income countries consistently demonstrate that low education, income, and socioeconomic status are associated with a greater risk of cardiovascular disease. Policies that have resulted in increased socio-economic inequalities have been associated with greater subsequent socio-economic differences in cardiovascular disease. Psychosocial factors, environmental exposures, health behaviours, and health-care access and quality contribute to socio-economic differentials in cardiovascular disease. The Commission on Social Determinants of Health recommended that more equal distributions of power, wealth, education, housing, environmental factors, nutrition, and health care were needed to address inequalities in cardiovascular disease and non-communicable diseases.
Air pollution
Particulate matter has been studied for its short- and long-term exposure effects on cardiovascular disease. Currently, airborne particles under 2.5 micrometers in diameter (PM2.5) are the major focus, in which gradients are used to determine CVD risk. Overall, long-term PM exposure increased rate of atherosclerosis and inflammation. In regards to short-term exposure (2 hours), every 25μg/m3 of PM2.5 resulted in a 48% increase of CVD mortality risk. In addition, after only 5 days of exposure, a rise in systolic (2.8 mmHg) and diastolic (2.7 mmHg) blood pressure occurred for every 10.5μg/m3 of PM2.5. Other research has implicated PM2.5 in irregular heart rhythm, reduced heart rate variability (decreased vagal tone), and most notably heart failure. PM2.5 is also linked to carotid artery thickening and increased risk of acute myocardial infarction.
Cardiovascular risk assessment
Existing cardiovascular disease or a previous cardiovascular event, such as a heart attack or stroke, is the strongest predictor of a future cardiovascular event. Age, sex, smoking, blood pressure, blood lipids and diabetes are important predictors of future cardiovascular disease in people who are not known to have cardiovascular disease. These measures, and sometimes others, may be combined into composite risk scores to estimate an individual's future risk of cardiovascular disease. Numerous risk scores exist although their respective merits are debated. Other diagnostic tests and biomarkers remain under evaluation but currently these lack clear-cut evidence to support their routine use. They include family history, coronary artery calcification score, high sensitivity C-reactive protein (hs-CRP), ankle–brachial pressure index, lipoprotein subclasses and particle concentration, lipoprotein(a), apolipoproteins A-I and B, fibrinogen, white blood cell count, homocysteine, N-terminal pro B-type natriuretic peptide (NT-proBNP), and markers of kidney function. High blood phosphorus is also linked to an increased risk.
Psychological stress
There is evidence that mental health problems, in particular depression and traumatic stress, is linked to cardiovascular diseases. Whereas mental health problems are known to be associated with risk factors for cardiovascular diseases such as smoking, poor diet, and a sedentary lifestyle, these factors alone do not explain the increased risk of cardiovascular diseases seen in depression, stress, and anxiety. Moreover, posttraumatic stress disorder is independently associated with increased risk for incident coronary heart disease, even after adjusting for depression and other covariates.
Many studies recognize depression and anxiety as two important disorders that can cause an increase in the risk of developing cardiovascular disease. Only half of the instances of cardiovascular disease are explained by factors such as age and gender that cannot be changed. The other half of instances are due to other sources, including psychological stress. Studies have shown that the prevalence of depression in patients with heart failure is higher than 20%.
Another study assessed the link between men and women who had been divorced and instance of cardiovascular disease. The study found that women who had gone through at least two divorces were just as likely to experience cardiovascular disease as a smoker or diabetic. Men, on the other hand, also had a higher risk of cardiovascular disease, however, their health improved upon remarriage while women did not.
This study also found that during a World Cup soccer event in Germany, heart attacks more than doubled during the days when the nation's team was playing. Researchers assume this link is due to the fact that stress can increase inflammation in the body, which can cause high blood pressure and low HDL cholesterol. Chronic stress can also affect sleep, exercise, and food choices.
Recent meta-analyses indicate that meditation and mindfulness practices, including Mindfulness-Based Stress Reduction (MBSR) programs, can significantly reduce blood pressure and improve cardiovascular biomarkers by reducing sympathetic nervous system activity, regulating cortisol, and decreasing inflammation.
Anxiety
Patients who suffer from generalized anxiety disorder are more likely to develop some form of cardiovascular disease. It is hypothesized that anxiety makes one more likely to develop cardiovascular disease due to the fact that it can change the body's stress response through hormonal and physiological reactions. People with anxiety often experience high blood pressure, arrhythmias, and heart attacks. The stress response caused by anxiety can increase inflammation in the body. It was also discovered that patients with anxiety had lower levels of omega-3-fatty acids which is linked to an increased risk of developing cardiovascular disease.
Little is known about the relationship between work and cardiovascular disease, but links have been established between certain toxins, extreme heat and cold, exposure to tobacco smoke, and mental health concerns such as stress and depression.
Non-chemical risk factors
A 2015 SBU-report looking at non-chemical factors found an association for those:
with mentally stressful work with a lack of control over their working situation — with an effort-reward imbalance
who experience low social support at work; who experience injustice or experience insufficient opportunities for personal development; or those who experience job insecurity
those who work night schedules; or have long working weeks
those who are exposed to noise
Specifically the risk of stroke was also increased by exposure to ionizing radiation. Hypertension develops more often in those who experience job strain and who have shift-work. Differences between women and men in risk are small, however men risk having and dying of heart attacks or stroke twice as often as women during working life.
Workplace exposure to silica dust or asbestos is also associated with pulmonary heart disease. There is evidence that workplace exposure to lead, carbon disulphide, phenoxyacids containing TCDD, as well as working in an environment where aluminum is being electrolytically produced, is associated with stroke.
Somatic mutations
As of 2017, evidence suggests that certain leukemia-associated mutations in blood cells may also lead to increased risk of cardiovascular disease. Several large-scale research projects looking at human genetic data have found a robust link between the presence of these mutations, a condition known as clonal hematopoiesis, and cardiovascular disease-related incidents and mortality.
Radiation therapy
Radiation treatments (RT) for cancer can increase the risk of heart disease and death, as observed in breast cancer therapy. Therapeutic radiation increases the risk of a subsequent heart attack or stroke by 1.5 to 4 times; the increase depends on the dose strength, volume, and location. Use of concomitant chemotherapy, e.g. anthracyclines, is an aggravating risk factor. The occurrence rate of RT induced cardiovascular disease is estimated between 10% and 30%.
Density-Dependent Colour Scanning Electron Micrograph SEM (DDC-SEM) of cardiovascular calcification, showing in orange calcium phosphate spherical particles (denser material) and, in green, the extracellular matrix (less dense material)
Population-based studies show that atherosclerosis, the major precursor of cardiovascular disease, begins in childhood. The Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study demonstrated that intimal lesions appear in all the aortas and more than half of the right coronary arteries of youths aged 7–9 years.
Obesity and diabetes mellitus are linked to cardiovascular disease, as are a history of chronic kidney disease and hypercholesterolaemia. In fact, cardiovascular disease is the most life-threatening of the diabetic complications and diabetics are two- to four-fold more likely to die of cardiovascular-related causes than nondiabetics.
Screening
Screening ECGs (either at rest or with exercise) are not recommended in those without symptoms who are at low risk. This includes those who are young without risk factors. In those at higher risk the evidence for screening with ECGs is inconclusive. Additionally echocardiography, myocardial perfusion imaging, and cardiac stress testing is not recommended in those at low risk who do not have symptoms. Some biomarkers may add to conventional cardiovascular risk factors in predicting the risk of future cardiovascular disease; however, the value of some biomarkers is questionable.Ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP), and coronary artery calcium, are also of unclear benefit in those without symptoms as of 2018.
The National Institutes of Health (NIH) recommends lipid testing in children beginning at the age of 2 if there is a family history of heart disease or lipid problems. It is hoped that early testing will improve lifestyle factors in those at risk such as diet and exercise.
Screening and selection for primary prevention interventions has traditionally been done through absolute risk using a variety of scores (ex. Framingham or Reynolds risk scores). This stratification has separated people who receive the lifestyle interventions (generally lower and intermediate risk) from the medication (higher risk). The number and variety of risk scores available for use has multiplied, but their efficacy according to a 2016 review was unclear due to lack of external validation or impact analysis. Risk stratification models often lack sensitivity for population groups and do not account for the large number of negative events among the intermediate and low risk groups. As a result, future preventative screening appears to shift toward applying prevention according to randomized trial results of each intervention rather than large-scale risk assessment.
Prevention
Up to 90% of cardiovascular disease may be preventable if established risk factors are avoided.Currently practised measures to prevent cardiovascular disease include:
Replacing saturated fat with healthier choices: a 2017 American Heart Association presidential advisory found that, across pooled randomized controlled trials, replacing saturated fat with polyunsaturated vegetable oil was associated with an approximately 30% reduction in cardiovascular events; prospective observational studies similarly link lower saturated-fat and higher unsaturated-fat intake with lower rates of CVD.
Decrease body fat if overweight or obese. The effect of weight loss is often difficult to distinguish from dietary change, and evidence on weight reducing diets is limited. In observational studies of people with severe obesity, weight loss following bariatric surgery is associated with a 46% reduction in cardiovascular risk.
Limit alcohol consumption to the recommended daily limits. People who moderately consume alcoholic drinks have a 25–30% lower risk of cardiovascular disease. However, people who are genetically predisposed to consume less alcohol have lower rates of cardiovascular disease suggesting that alcohol itself may not be protective. Excessive alcohol intake increases the risk of cardiovascular disease and consumption of alcohol is associated with increased risk of a cardiovascular event in the day following consumption.
Decrease non-HDL cholesterol. Statin treatment reduces cardiovascular mortality by about 31%.
Stopping smoking and avoidance of second-hand smoke. Stopping smoking reduces risk by about 35%.
At least 150 minutes (2 hours and 30 minutes) of moderate exercise per week.
Lower blood pressure, if elevated. A 10mmHg reduction in blood pressure reduces risk by about 20%. Lowering blood pressure appears to be effective even at normal blood pressure ranges.
Not enough sleep also raises the risk of high blood pressure. Adults need about 7–9 hours of sleep. Sleep apnea is also a major risk as it causes breathing to stop briefly, which can put stress on the body which can raise the risk of heart disease.
In 2023, the American Heart Association developed PREVENT (Predicting Risk of cardiovascular disease EVENTs), a trademarked tool that measures potential risks of cardiovascular disease, heart failure and atherosclerotic cardiovascular disease.
Most guidelines recommend combining preventive strategies. There is some evidence that interventions aiming to reduce more than one cardiovascular risk factor may have beneficial effects on blood pressure, body mass index and waist circumference; however, evidence was limited and the authors were unable to draw firm conclusions on the effects on cardiovascular events and mortality.
There is additional evidence to suggest that providing people with a cardiovascular disease risk score may reduce risk factors by a small amount compared to usual care. However, there was some uncertainty as to whether providing these scores had any effect on cardiovascular disease events. It is unclear whether or not dental care in those with periodontitis affects their risk of cardiovascular disease. According to a 2021 WHO study, working 55+ hours a week raises the risk of stroke by 35% and the risk of dying from heart conditions by 17%, when compared to a 35–40 hours week.
Psychological prevention
Decrease psychosocial stress. This measure may be complicated by imprecise definitions of what constitute psychosocial interventions. Mental stress–induced myocardial ischemia is associated with an increased risk of heart problems in those with previous heart disease. Severe emotional and physical stress leads to a form of heart dysfunction known as Takotsubo syndrome in some people. Specific relaxation therapies are of unclear benefit. Decreasing psychological stress can be accomplished by receiving access to services and support, recognizing signs and symptoms of mental health disorders, awareness of family history, and understanding which mental health disorders increase the risk of cardiovascular disease. Psychosocial intervention programs have been shown to improve risk of developing cardiovascular disease in the high-risk population.
A diet high in fruits and vegetables decreases the risk of cardiovascular disease and death.
A 2021 review found that plant-based diets can provide a risk reduction for CVD if a healthy plant-based diet is consumed. Unhealthy plant-based diets do not provide benefits over diets including meat. A similar meta-analysis and systematic review also looked into dietary patterns and found "that diets lower in animal foods and unhealthy plant foods, and higher in healthy plant foods are beneficial for CVD prevention". A 2018 meta-analysis of observational studies concluded that "In most countries, a vegan diet is associated with a more favourable cardio-metabolic profile compared to an omnivorous diet."
Evidence suggests that the Mediterranean diet may improve cardiovascular outcomes. There is also evidence that a Mediterranean diet may be more effective than a low-fat diet in bringing about long-term changes to cardiovascular risk factors (e.g., lower cholesterol level and blood pressure).
The DASH diet (high in nuts, fish, fruits and vegetables, and low in sweets, red meat and fat) has been shown to reduce blood pressure, lower total and low density lipoprotein cholesterol and improve metabolic syndrome; but the long-term benefits have been questioned. A high-fiber diet is associated with lower risks of cardiovascular disease.
Worldwide, dietary guidelines recommend a reduction in saturated fat, and although the role of dietary fat in cardiovascular disease is complex and controversial there is a long-standing consensus that replacing saturated fat with unsaturated fat in the diet is sound medical advice. Total fat intake has not been found to be associated with cardiovascular risk.A 2020 systematic review found moderate quality evidence that reducing saturated fat intake for at least 2 years caused a reduction in cardiovascular events. A 2015 meta-analysis of observational studies however did not find a convincing association between saturated fat intake and cardiovascular disease. Variation in what is used as a substitute for saturated fat may explain some differences in findings. The benefit from replacement with polyunsaturated fats appears greatest, while replacement of saturated fats with carbohydrates does not appear to have a beneficial effect. A diet high in trans fatty acids is associated with higher rates of cardiovascular disease, and in 2015 the Food and Drug Administration (FDA) determined that there was 'no longer a consensus among qualified experts that partially hydrogenated oils (PHOs), which are the primary dietary source of industrially produced trans fatty acids (IP-TFA), are generally recognized as safe (GRAS) for any use in human food'. There is conflicting evidence concerning whether dietary supplements of omega-3 fatty acids (a type of polyunsaturated essential fatty acid) added to diet improve cardiovascular risk.
The benefits of recommending a low-salt diet in people with high or normal blood pressure are not clear. In those with heart failure, after one study was left out, the rest of the trials show a trend to benefit. Another review of dietary salt concluded that there is strong evidence that high dietary salt intake increases blood pressure and worsens hypertension, and that it increases the number of cardiovascular disease events; both as a result of the increased blood pressure and probably through other mechanisms. Moderate evidence was found that high salt intake increases cardiovascular mortality; and some evidence was found for an increase in overall mortality, strokes, and left ventricular hypertrophy.
Intermittent fasting
Overall, the current body of scientific evidence is uncertain on whether intermittent fasting could prevent cardiovascular disease. Intermittent fasting may help people lose more weight than regular eating patterns, but was not different from energy restriction diets.
Medication
Blood pressure medication reduces cardiovascular disease in people at risk, irrespective of age, the baseline level of cardiovascular risk, or baseline blood pressure. The commonly used drug regimens have similar efficacy in reducing the risk of all major cardiovascular events, although there may be differences between drugs in their ability to prevent specific outcomes. Larger reductions in blood pressure produce larger reductions in risk, and most people with high blood pressure require more than one drug to achieve adequate reduction in blood pressure. Adherence to medications is often poor, and while mobile phone text messaging has been tried to improve adherence, there is insufficient evidence that it alters secondary prevention of cardiovascular disease.
Statins are effective in preventing further cardiovascular disease in people with a history of cardiovascular disease. As the event rate is higher in men than in women, the decrease in events is more easily seen in men than women. In those at risk, but without a history of cardiovascular disease (primary prevention), statins decrease the risk of death and combined fatal and non-fatal cardiovascular disease. The benefit, however, is small. A United States guideline recommends statins in those who have a 12% or greater risk of cardiovascular disease over the next ten years. Niacin, fibrates and CETP Inhibitors, while they may increase HDL cholesterol do not affect the risk of cardiovascular disease in those who are already on statins. Fibrates lower the risk of cardiovascular and coronary events, but there is no evidence to suggest that they reduce all-cause mortality.
Anti-diabetic medication may reduce cardiovascular risk in people with Type 2 diabetes, although evidence is not conclusive. A meta-analysis in 2009 including 27,049 participants and 2,370 major vascular events showed a 15% relative risk reduction in cardiovascular disease with more-intensive glucose lowering over an average follow-up period of 4.4 years, but an increased risk of major hypoglycemia.
Aspirin has been found to be of only modest benefit in those at low risk of heart disease, as the risk of serious bleeding is almost equal to the protection against cardiovascular problems. In those at very low risk, including those over the age of 70, it is not recommended. The United States Preventive Services Task Force recommends against use of aspirin for prevention in women less than 55 and men less than 45 years old; however, it is recommended for some older people.
The use of vasoactive agents for people with pulmonary hypertension with left heart disease or hypoxemic lung diseases may cause harm and unnecessary expense.
Antibiotics for secondary prevention of coronary heart disease
Antibiotics may help patients with coronary disease to reduce the risk of heart attacks and strokes. However, evidence in 2021 suggests that antibiotics for secondary prevention of coronary heart disease are harmful, with increased mortality and occurrence of stroke; the use of antibiotics is not supported for preventing secondary coronary heart disease.
Physical activity
Exercise-based cardiac rehabilitation following a heart attack reduces the risk of death from cardiovascular disease and leads to less hospitalizations. There have been few high-quality studies of the benefits of exercise training in people with increased cardiovascular risk but no history of cardiovascular disease.
A systematic review estimated that inactivity is responsible for 6% of the burden of disease from coronary heart disease worldwide. The authors estimated that 121,000 deaths from coronary heart disease could have been averted in Europe in 2008 if people had not been physically inactive. Low-quality evidence from a limited number of studies suggest that yoga has beneficial effects on blood pressure and cholesterol. Tentative evidence suggests that home-based exercise programs may be more efficient at improving exercise adherence.
Dietary supplements
While a healthy diet is beneficial, the effect of antioxidant supplementation (vitamin E, vitamin C, etc.) or vitamins has not been shown to protect against cardiovascular disease and in some cases may possibly result in harm. Mineral supplements have also not been found to be useful. Niacin, a type of vitamin B3, may be an exception with a modest decrease in the risk of cardiovascular events in those at high risk. Magnesium supplementation lowers high blood pressure in a dose-dependent manner. Magnesium therapy is recommended for people with ventricular arrhythmia associated with torsades de pointes who present with long QT syndrome, and for the treatment of people with digoxin intoxication-induced arrhythmias. There is no evidence that omega-3 fatty acid supplementation is beneficial. A 2022 review found that some dietary supplements, including micronutrients, may reduce risk factors for cardiovascular disease.
Management
Cardiovascular disease is treatable with initial treatment primarily focused on diet and lifestyle interventions. Influenza may make heart attacks and strokes more likely and therefore influenza vaccination may decrease the chance of cardiovascular events and death in people with heart disease.
Proper CVD management necessitates a focus on myocardial infarction (MI) and stroke cases due to their combined high mortality rate, keeping in mind the cost-effectiveness of any intervention, especially in developing countries with low or middle-income levels. Regarding MI, strategies using aspirin, atenolol, streptokinase or tissue plasminogen activator have been compared for quality-adjusted life-year (QALY) in regions of low and middle income. The costs for a single QALY for aspirin and atenolol were less than US$25, streptokinase was about $680, and t-PA was $16,000.[236] Aspirin, ACE inhibitors, beta-blockers, and statins used together for secondary CVD prevention in the same regions showed single QALY costs of $350.
There are also surgical or procedural interventions that can save someone's life or prolong it. For heart valve problems, a person could have surgery to replace the valve. For arrhythmias, a pacemaker can be put in place to help reduce abnormal heart rhythms and for a heart attack, there are multiple options two of these are a coronary angioplasty and a coronary artery bypass surgery.
There is probably no additional benefit in terms of mortality and serious adverse events when blood pressure targets were lowered to ≤ 135/85 mmHg from ≤ 140 to 160/90 to 100 mmHg.
Epidemiology
Deaths from cardiovascular disease
Cardiovascular diseases are the leading cause of death worldwide and in all regions except Africa. In 2008, 30% of all global deaths were attributed to cardiovascular diseases. Deaths caused by cardiovascular diseases are also higher in low- and middle-income countries, as over 80% of all global deaths caused by cardiovascular diseases occurred in those countries. It is also estimated that by 2030, over 23 million people will die from cardiovascular diseases each year.
According to the Indian Heart Association, an estimated 60% of the world's cardiovascular disease burden will occur in the South Asian subcontinent despite the region accounting for only 20% of the world's population. Organizations such as the Indian Heart Association are working with the World Heart Federation to raise awareness about this issue.
There is evidence that cardiovascular disease existed in pre-history, and research into cardiovascular disease dates from at least the 18th century. The causes, prevention, and/or treatment of all forms of cardiovascular disease remain active fields of biomedical research, with hundreds of scientific studies being published on a weekly basis.
Recent areas of research include the link between inflammation and atherosclerosis the potential for novel therapeutic interventions, and the genetics of coronary heart disease.
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