Quality of life

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Quality_of_life

Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns".

Standard indicators of the quality of life include wealth, employment, the environment, physical and mental health, education, recreation and leisure time, social belonging, religious beliefs, safety, security and freedom. QOL has a wide range of contexts, including the fields of international development, healthcare, politics and employment. Health related QOL (HRQOL) is an evaluation of QOL and its relationship with health.

Engaged theory

One approach, called the engaged theory, outlined in the journal of Applied Research in the Quality of Life, posits four domains in assessing quality of life: ecology, economics, politics and culture. In the domain of culture, for example, it includes the following subdomains of quality of life:

• Beliefs and ideas?
• Creativity and recreation
• Enquiry and learning
• Gender and generations
• Identity and engagement
• Memory and projection
• Well-being and health

Under this conception, other frequently related concepts include freedom, human rights, and happiness. However, since happiness is subjective and difficult to measure, other measures are generally given priority. It has also been shown that happiness, as much as it can be measured, does not necessarily increase correspondingly with the comfort that results from increasing income. As a result, the standard of living should not be taken to be a measure of happiness. Also, sometimes considered related is the concept of human security, though the latter may be considered at a more basic level and for all people.

Quantitative measurement

Unlike per capita GDP or standard of living, both of which can be measured in financial terms, it is harder to make objective or long-term measurements of the quality of life experienced by nations or other groups of people. Researchers have begun in recent times to distinguish two aspects of personal well-being: Emotional well-being, in which respondents are asked about the quality of their everyday emotional experiences – the frequency and intensity of their experiences of, for example, joy, stress, sadness, anger and affection – and life evaluation, in which respondents are asked to think about their life in general and evaluate it against a scale. Such and other systems and scales of measurement have been in use for some time. Research has attempted to examine the relationship between quality of life and productivity.

There are many different methods of measuring quality of life in terms of health care, wealth, and materialistic goods. However, it is much more difficult to measure meaningful expression of one's desires. One way to do so is to evaluate the extent to which individuals have fulfilled their own ideals. Quality of life can simply mean happiness, which is the subjective state of mind. By using that mentality, citizens of a developing country appreciate more since they are content with the basic necessities of health care, education and child protection.

According to ecological economist Robert Costanza:

While Quality of Life (QOL) has long been an explicit or implicit policy goal, adequate definition and measurement have been elusive. Diverse "objective" and "subjective" indicators across a range of disciplines and scales, and recent work on subjective well-being (SWB) surveys and the psychology of happiness have spurred renewed interest.

Human Development Index

Main article: Human Development Index

Perhaps the most commonly used international measure of development is the Human Development Index (HDI), which combines measures of life expectancy, education, and standard of living, in an attempt to quantify the options available to individuals within a given society. The HDI is used by the United Nations Development Programme in their Human Development Report. However, since 2010, The Human Development Report introduced an Inequality-adjusted Human Development Index (IHDI). While the original HDI remains useful, it stated that "the IHDI is the actual level of human development (accounting for inequality), while the original HDI can be viewed as an index of 'potential' human development (or the maximum level of HDI) that could be achieved if there was no inequality."

World Happiness Report

Main article: World Happiness Report

Map showing happiness of countries by their score according to the 2023 World Happiness Report

The World Happiness Report is a landmark survey on the state of global happiness. It ranks 156 countries by their happiness levels, reflecting growing global interest in using happiness and substantial well-being as an indicator of the quality of human development. Its growing purpose has allowed governments, communities and organizations to use appropriate data to record happiness in order to enable policies to provide better lives. The reports review the state of happiness in the world today and show how the science of happiness explains personal and national variations in happiness.

Developed once again by the United Nations and published recently, along with the HDI, this report combines both objective and subjective measures to rank countries by happiness, which is deemed the ultimate outcome of a high quality of life. It uses surveys from Gallup, real GDP per capita, healthy life expectancy, having someone to count on, perceived freedom to make life choices, freedom from corruption, and generosity to derive the final score. Happiness is already recognized as an important concept in global public policy. The World Happiness Report indicates that some regions have, in recent years, been experiencing progressive inequality of happiness.

Other measures

The Physical Quality of Life Index (PQLI) is a measure developed by sociologist M. D. Morris in the 1970s, based on basic literacy, infant mortality, and life expectancy. Although not as complex as other measures, and now essentially replaced by the Human Development Index, the PQLI is notable for Morris's attempt to show a "less fatalistic pessimistic picture" by focusing on three areas where global quality of life was generally improving at the time, while ignoring gross national product and other possible indicators that were not improving.

The Happy Planet Index, introduced in 2006, is unique among quality of life measures in that, in addition to standard determinants of well-being, it uses each country's ecological footprint as an indicator. As a result, European and North American nations do not dominate this measure. The 2012 list is instead topped by Costa Rica, Vietnam and Colombia.

In 2010, Gallup researchers trying to find the world's happiest countries found Denmark to be at the top of the list. For the period 2014–2016, Norway surpasses Denmark to be at the top of the list.

A 2010 study by two Princeton University professors looked at 1,000 randomly selected U.S. residents over an extended period. It concludes that their life evaluations – that is, their considered evaluations of their life against a stated scale of one to ten – rise steadily with income. On the other hand, their reported quality of emotional daily experiences (their reported experiences of joy, affection, stress, sadness, or anger) levels off after a certain income level (approximately $75,000 per year in 2010); income above $75,000 does not lead to more experiences of happiness nor to further relief of unhappiness or stress. Below this income level, respondents reported decreasing happiness and increasing sadness and stress, implying the pain of life's misfortunes, including disease, divorce, and being alone, is exacerbated by poverty.

Gross national happiness and other subjective measures of happiness are being used by the governments of Bhutan and the United Kingdom. The World Happiness report, issued by Columbia University is a meta-analysis of happiness globally and provides an overview of countries and grassroots activists using GNH. The OECD issued a guide for the use of subjective well-being metrics in 2013. In the U.S., cities and communities are using a GNH metric at a grassroots level.

The Social Progress Index measures the extent to which countries provide for the social and environmental needs of their citizens. Fifty-two indicators in the areas of basic human needs, foundations of wellbeing, and opportunity show the relative performance of nations. The index uses outcome measures when there is sufficient data available or the closest possible proxies.

Day-Reconstruction Method was another way of measuring happiness, in which researchers asked their subjects to recall various things they did on the previous day and describe their mood during each activity. Being simple and approachable, this method required memory and the experiments have confirmed that the answers that people give are similar to those who repeatedly recalled each subject. The method eventually declined as it called for more effort and thoughtful responses, which often included interpretations and outcomes that do not occur to people who are asked to record every action in their daily lives.

The Digital Quality of Life Index - a yearly study on digital well-being across 121 countries created by Surfshark. It indexes each country according to five pillars that impact a population's digital quality of life: internet affordability, internet quality, electronic infrastructure, electronic security, and electronic government.

Livability

Main article: Livability

The Economist Intelligence Unit awarded Vienna the most livable city in 2019 Global Liveability Ranking.

The term quality of life is also used by politicians and economists to measure the livability of a given city or nation. Two widely known measures of livability are the Economist Intelligence Unit's Where-to-be-born Index and Mercer's Quality of Living Reports. These two measures calculate the livability of countries and cities around the world, respectively, through a combination of subjective life-satisfaction surveys and objective determinants of quality of life such as divorce rates, safety, and infrastructure. Such measures relate more broadly to the population of a city, state, or country, not to individual quality of life. Livability has a long history and tradition in urban design, and neighborhoods design standards such as LEED-ND are often used in an attempt to influence livability.

Crimes

Some crimes against property (e.g., graffiti and vandalism) and some "victimless crimes" have been referred to as "quality-of-life crimes". American sociologist James Q. Wilson encapsulated this argument as the broken windows theory, which asserts that relatively minor problems left unattended (such as litter, graffiti, or public urination by homeless individuals) send a subliminal message that disorder, in general, is being tolerated, and as a result, more serious crimes will end up being committed (the analogy being that a broken window left broken shows an image of general dilapidation).

Wilson's theories have been used to justify the implementation of zero tolerance policies by many prominent American mayors, most notably Oscar Goodman in Las Vegas, Richard Riordan in Los Angeles, Rudolph Giuliani in New York City and Gavin Newsom in San Francisco. Such policies refuse to tolerate even minor crimes; proponents argue that this will improve the quality of life of local residents. However, critics of zero tolerance policies believe that such policies neglect investigation on a case-by-case basis and may lead to unreasonably harsh penalties for crimes.

In healthcare

Main article: Quality of life (healthcare)

Within the field of healthcare, quality of life is often regarded in terms of how a certain ailment affects a patient on an individual level. This may be a debilitating weakness that is not life-threatening; life-threatening illness that is not terminal; terminal illness; the predictable, natural decline in the health of an elder; an unforeseen mental/physical decline of a loved one; or chronic, end-stage disease processes. Researchers at the University of Toronto's Quality of Life Research Unit define quality of life as "The degree to which a person enjoys the important possibilities of his or her life" (UofT). Their Quality of Life Model is based on the categories "being", "belonging", and "becoming"; respectively who one is, how one is connected to one's environment, and whether one achieves one's personal goals, hopes, and aspirations.

Experience sampling studies show substantial between-person variability in within-person associations between somatic symptoms and quality of life. Hecht and Shiel measure quality of life as "the patient's ability to enjoy normal life activities" since life quality is strongly related to wellbeing without suffering from sickness and treatment.

In international development

Quality of life has been deemed an important concept in the field of international development because it allows development to be analyzed on a measure that is generally accepted as more comprehensive than standard of living. Within development theory, however, there are varying ideas concerning what constitutes desirable change for a particular society. The different ways that quality of life is defined by institutions, therefore, shape how these organizations work for its improvement as a whole.

Organisations such as the World Bank, for example, declare a goal of "working for a world free of poverty", with poverty defined as a lack of basic human needs, such as food, water, shelter, freedom, access to education, healthcare, or employment. In other words, poverty is defined as a low quality of life. Using this definition, the World Bank works towards improving quality of life through the stated goal of lowering poverty and helping people afford a better quality of life.

Other organizations, however, may also work towards improved global quality of life using a slightly different definition and substantially different methods. Many NGOs do not focus at all on reducing poverty on a national or international scale, but rather attempt to improve the quality of life for individuals or communities. One example would be sponsorship programs that provide material aid for specific individuals. Although many organizations of this type may still talk about fighting poverty, the methods are significantly different.

Improving quality of life involves action not only by NGOs but also by governments. Global health has the potential to achieve greater political presence if governments were to incorporate aspects of human security into foreign policy. Stressing individuals' basic rights to health, food, shelter, and freedom addresses prominent inter-sectoral problems negatively impacting today's society, and may lead to greater action and resources. Integration of global health concerns into foreign policy may be hampered by approaches that are shaped by the overarching roles of defense and diplomacy.

Proposition

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Proposition

A proposition is a statement that can be either true or false. It is a central concept in the philosophy of language, semantics, logic, and related fields. Propositions are the objects denoted by declarative sentences; for example, "The sky is blue" expresses the proposition that the sky is blue. Unlike sentences, propositions are not linguistic expressions, so the English sentence "Snow is white" and the German "Schnee ist weiß" denote the same proposition. Propositions also serve as the objects of belief and other propositional attitudes, such as when someone believes that the sky is blue.

Formally, propositions are often modeled as functions which map a possible world to a truth value. For instance, the proposition that the sky is blue can be modeled as a function which would return the truth value ${\displaystyle T}$ if given the actual world as input, but would return ${\displaystyle F}$ if given some alternate world where the sky is green. However, a number of alternative formalizations have been proposed, notably the structured propositions view.

Propositions have played a large role throughout the history of logic, linguistics, philosophy of language, and related disciplines. Some researchers have doubted whether a consistent definition of propositionhood is possible, David Lewis even remarking that "the conception we associate with the word ‘proposition’ may be something of a jumble of conflicting desiderata". The term is often used broadly and has been used to refer to various related concepts.

Relation to the mind

In relation to the mind, propositions are discussed primarily as they fit into propositional attitudes. Propositional attitudes are simply attitudes characteristic of folk psychology (belief, desire, etc.) that one can take toward a proposition (e.g. 'it is raining,' 'snow is white,' etc.). In English, propositions usually follow folk psychological attitudes by a "that clause" (e.g. "Jane believes that it is raining"). In philosophy of mind and psychology, mental states are often taken to primarily consist in propositional attitudes. The propositions are usually said to be the "mental content" of the attitude. For example, if Jane has a mental state of believing that it is raining, her mental content is the proposition 'it is raining.' Furthermore, since such mental states are about something (namely, propositions), they are said to be intentional mental states.

Explaining the relation of propositions to the mind is especially difficult for non-mentalist views of propositions, such as those of the logical positivists and Russell described above, and Gottlob Frege's view that propositions are Platonist entities, that is, existing in an abstract, non-physical realm. So some recent views of propositions have taken them to be mental. Although propositions cannot be particular thoughts since those are not shareable, they could be types of cognitive events or properties of thoughts (which could be the same across different thinkers).

Philosophical debates surrounding propositions as they relate to propositional attitudes have also recently centered on whether they are internal or external to the agent, or whether they are mind-dependent or mind-independent entities. For more, see the entry on internalism and externalism in philosophy of mind.

In modern logic

In modern logic, propositions are standardly understood semantically as indicator functions that take a possible world and return a truth value. For example, the proposition that the sky is blue could be represented as a function ${\displaystyle f}$ such that ${\displaystyle f(w)=T}$ for every world ${\displaystyle w,}$ if any, where the sky is blue, and ${\displaystyle f(v)=F}$ for every world ${\displaystyle v,}$ if any, where it is not. A proposition can be modeled equivalently with the inverse image of ${\displaystyle T}$ under the indicator function, which is sometimes called the characteristic set of the proposition. For instance, if ${\displaystyle w}$ and ${\displaystyle w^{\prime }}$ are the only worlds in which the sky is blue, the proposition that the sky is blue could be modeled as the set ${\displaystyle \{w,w^{\prime }\}}$.

Numerous refinements and alternative notions of proposition-hood have been proposed including inquisitive propositions and structured propositions. Propositions are called structured propositions if they have constituents, in some broad sense. Assuming a structured view of propositions, one can distinguish between singular propositions (also Russellian propositions, named after Bertrand Russell) which are about a particular individual, general propositions, which are not about any particular individual, and particularized propositions, which are about a particular individual but do not contain that individual as a constituent.

Objections to propositions

Attempts to provide a workable definition of proposition include the following:

Two meaningful declarative sentences express the same proposition, if and only if they mean the same thing.

which defines proposition in terms of synonymity. For example, "Snow is white" (in English) and "Schnee ist weiß" (in German) are different sentences, but they say the same thing, so they express the same proposition. Another definition of proposition is:

Two meaningful declarative sentence-tokens express the same proposition, if and only if they mean the same thing.

The above definitions can result in two identical sentences/sentence-tokens appearing to have the same meaning, and thus expressing the same proposition and yet having different truth-values, as in "I am Spartacus" said by Spartacus and said by John Smith, and "It is Wednesday" said on a Wednesday and on a Thursday. These examples reflect the problem of ambiguity in common language, resulting in a mistaken equivalence of the statements. "I am Spartacus" spoken by Spartacus is the declaration that the individual speaking is called Spartacus and it is true. When spoken by John Smith, it is a declaration about a different speaker and it is false. The term "I" means different things, so "I am Spartacus" means different things.

A related problem is when identical sentences have the same truth-value, yet express different propositions. The sentence "I am a philosopher" could have been spoken by both Socrates and Plato. In both instances, the statement is true, but means something different.

These problems are addressed in predicate logic by using a variable for the problematic term, so that "X is a philosopher" can have Socrates or Plato substituted for X, illustrating that "Socrates is a philosopher" and "Plato is a philosopher" are different propositions. Similarly, "I am Spartacus" becomes "X is Spartacus", where X is replaced with terms representing the individuals Spartacus and John Smith.

In other words, the example problems can be averted if sentences are formulated with precision such that their terms have unambiguous meanings.

A number of philosophers and linguists claim that all definitions of a proposition are too vague to be useful. For them, it is just a misleading concept that should be removed from philosophy and semantics. W. V. Quine, who granted the existence of sets in mathematics, maintained that the indeterminacy of translation prevented any meaningful discussion of propositions, and that they should be discarded in favor of sentences.

Statements

In logic and semantics, the term statement is variously understood to mean either:

1. A meaningful declarative sentence that is true or false, or
2. a proposition. Which is the assertion that is made by (i.e., the meaning of) a true or false declarative sentence.

In the latter case, a (declarative) sentence is just one way of expressing an underlying statement. A statement is what a sentence means, it is the notion or idea that a sentence expresses, i.e., what it represents. For example, it could be said that "2 + 2 = 4" and "two plus two equals four" are two different sentences expressing the same statement. As another example, consider that the Arabic numeral '7', the Roman numeral 'VII', and the English word 'seven' are all distinct from the underlying number.

Philosopher of language Peter Strawson (1919–2006) advocated the use of the term "statement" in sense (2) in preference to proposition. Strawson used the term "statement" to make the point that two declarative sentences can make the same statement if they say the same thing in different ways. Thus, in the usage advocated by Strawson, "All men are mortal." and "Every man is mortal." are two different sentences that make the same statement.

In either case, a statement is viewed as a truth bearer.

Examples of sentences that are (or make) true statements:

• "Socrates is a man."
• "A triangle has three sides."
• "Madrid is the capital of Spain."

Examples of sentences that are also statements, even though they aren't true:

• "All toasters are made of solid gold."
• "Two plus two equals five."

Examples of sentences that are not (or do not make) statements:

1. "Who are you?"
2. "Run!"
3. "Greenness perambulates."
4. "I had one grunch but the eggplant over there."
5. "King Charles III is wise."
6. "Broccoli tastes good."
7. "Pegasus exists."

The first two examples are not declarative sentences and therefore are not (or do not make) statements. The third and fourth are declarative sentences but, lacking meaning, are neither true nor false and therefore are not (or do not make) statements. The fifth and sixth examples are meaningful declarative sentences, but are not statements but rather matters of opinion or taste. Whether or not the sentence "Pegasus exists." is a statement is a subject of debate among philosophers. Bertrand Russell held that it is a (false) statement. Strawson held it is not a statement at all.

As an abstract entity

In some treatments, "statement" is introduced in order to distinguish a sentence from its informational content. A statement is regarded as the information content of an information-bearing sentence. Thus, a sentence is related to the statement it bears like a numeral to the number it refers to. Statements are abstract logical entities, while sentences are grammatical entities.

Historical usage

By Aristotle

In Aristotelian logic a proposition was defined as a particular kind of sentence (a declarative sentence) that affirms or denies a predicate of a subject, optionally with the help of a copula. Aristotelian propositions take forms like "All men are mortal" and "Socrates is a man."

Aristotelian logic identifies a categorical proposition as a sentence which affirms or denies a predicate of a subject, optionally with the help of a copula. An Aristotelian proposition may take the form of "All men are mortal" or "Socrates is a man." In the first example, the subject is "men", predicate is "mortal" and copula is "are", while in the second example, the subject is "Socrates", the predicate is "a man" and copula is "is".

By the logical positivists

Often, propositions are related to closed formulae (or logical sentence) to distinguish them from what is expressed by an open formula. In this sense, propositions are "statements" that are truth-bearers. This conception of a proposition was supported by the philosophical school of logical positivism.

Some philosophers argue that some (or all) kinds of speech or actions besides the declarative ones also have propositional content. For example, yes–no questions present propositions, being inquiries into the truth value of them. On the other hand, some signs can be declarative assertions of propositions, without forming a sentence nor even being linguistic (e.g. traffic signs convey definite meaning which is either true or false).

Propositions are also spoken of as the content of beliefs and similar intentional attitudes, such as desires, preferences, and hopes. For example, "I desire that I have a new car", or "I wonder whether it will snow" (or, whether it is the case that "it will snow"). Desire, belief, doubt, and so on, are thus called propositional attitudes when they take this sort of content.

By Russell

Bertrand Russell held that propositions were structured entities with objects and properties as constituents. One important difference between Ludwig Wittgenstein's view (according to which a proposition is the set of possible worlds/states of affairs in which it is true) is that on the Russellian account, two propositions that are true in all the same states of affairs can still be differentiated. For instance, the proposition "two plus two equals four" is distinct on a Russellian account from the proposition "three plus three equals six". If propositions are sets of possible worlds, however, then all mathematical truths (and all other necessary truths) are the same set (the set of all possible worlds).

Protein (nutrient)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Protein_(nutrient)

Amino acids are the building blocks of protein.

Amino acids are necessary nutrients. Present in every cell, they are also precursors to nucleic acids, co-enzymes, hormones, immune response, repair and other molecules essential for life.

Proteins are essential nutrients for the human body. They are one of the constituents of body tissue and also serve as a fuel source. As fuel, proteins have the same energy density as carbohydrates: 17 kJ (4 kcal) per gram. The defining characteristic of protein from a nutritional standpoint is its amino acid composition.

Proteins are polymer chains made of amino acids linked by peptide bonds. During human digestion, proteins are broken down in the stomach into smaller polypeptide chains via hydrochloric acid and protease actions. This is crucial for the absorption of the essential amino acids that cannot be biosynthesized by the body.

There are nine essential amino acids that humans must obtain from their diet to prevent protein-energy malnutrition and resulting death. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. There has been debate as to whether there are eight or nine essential amino acids. The consensus seems to lean toward nine since histidine is not synthesized in adults. There are five amino acids that the human body can synthesize: alanine, aspartic acid, asparagine, glutamic acid and serine. There are six conditionally essential amino acids whose synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress: arginine, cysteine, glycine, glutamine, proline and tyrosine. Dietary sources of protein include grains, legumes, nuts, seeds, meats, dairy products, fish, and eggs.

Functions

After water, proteins account for more mass in an organism than any other type of molecule. Protein is present in every cell, and it is a structural component of every body tissue and organ, including hair, skin, blood, and bone. Protein is especially abundant in muscle. Cellular messengers (hormones) and transport molecules are constructed from proteins, including enzymes and antibodies, as are cell membrane components, such as glycoproteins, G proteins, and ion channels. The types of amino acids and their sequence determine the unique 3-dimensional structure and function of a protein.

Amino acids obtained through protein catabolism also enable the biosynthesis of non-protein molecules that are essential for life, such as nucleotides, certain neurotransmitters, and heme.

Sources

Protein milkshakes, made from protein powder (center) and milk (left), are a common bodybuilding supplement

Protein occurs in a wide range of food. On a worldwide basis, plant protein foods contribute over 60% of the per capita supply of protein. In North America, animal-derived foods contribute about 70% of protein sources. Insects are a source of protein in many parts of the world. In parts of Africa, up to 50% of dietary protein derives from insects. It is estimated that more than 2 billion people eat insects daily.

Protein powders—such as casein, whey, egg, rice, soy and cricket flour—are processed and manufactured sources of protein. People eating a balanced diet do not need protein supplements.

The table below presents food groups as protein sources.

Food source	Lysine	Threonine	Tryptophan	Sulfur-containing amino acids
Legumes	64	38	12	25
Cereals and whole grains	31	32	12	37
Nuts and seeds	45	36	17	46
Fruits	45	29	11	27
Animal	85	44	12	38

Colour key:

  Protein source with highest density of respective amino acid.

  Protein source with lowest density of respective amino acid.

Animal-based protein

Nutritional value and environmental impact of animal products,
compared to agriculture overall

Categories	Contribution of farmed animal product [%]
Calories	18
Proteins	37
Land use	83
Greenhouse gases	58
Water pollution	57
Air pollution	56
Freshwater withdrawals	33

Some sources of animal-based protein

 

Seafood

 

Eggs

 

Cheese

Meat, dairy, eggs, soybeans, fish, whole grains, and cereals are sources of protein. Examples of food staples and cereal sources of protein, each with a concentration greater than 7%, are (in no particular order) buckwheat, oats, rye, millet, maize (corn), rice, wheat, sorghum, amaranth, and quinoa. Game meat is an affordable protein source in some countries.

Non-animal-based protein

Plant sources of protein.

Plant sources of proteins include legumes, nuts, seeds, grains, and some vegetables and fruits. Plant foods with protein concentrations greater than 7% include (but are not limited to) soybeans, lentils, kidney beans, white beans, mung beans, chickpeas, cowpeas, lima beans, pigeon peas, lupines, wing beans, almonds, Brazil nuts, cashews, pecans, walnuts, cotton seeds, pumpkin seeds, hemp seeds, sesame seeds, and sunflower seeds.

Photovoltaic-driven microbial protein production uses electricity from solar panels and carbon dioxide from the air to create fuel for microbes, which are grown in bioreactor vats and then processed into dry protein powders. The process makes highly efficient use of land, water and fertiliser.

Testing in foods

Nitrogen-based crude protein

The classic assays for protein concentration in food are the Kjeldahl method and the Dumas method. These tests determine the total nitrogen in a sample. The only major component of most food which contains nitrogen is protein (fat, carbohydrate and dietary fiber do not contain nitrogen). If the amount of nitrogen is multiplied by a factor depending on the kinds of protein expected in the food the total protein can be determined. This value is known as the "crude protein" content. The use of correct conversion factors is heavily debated, specifically with the introduction of more plant-derived protein products. However, on food labels the protein is calculated as the amount of nitrogen multiplied by 6.25, because the average nitrogen content of proteins is about 16%. The Kjeldahl test is typically used, because it is the method the AOAC International has adopted and is therefore used by many food standards agencies around the world, though the Dumas method is also approved by some standards organizations.

Nitrogen-based protein measurement cannot distinguish between true protein and non-protein nitrogen (NPN). NPN occurs in significant amounts in milk, edible insects, and fish. In addition, accidental contamination and intentional adulteration of protein meals with NPN sources that inflate crude protein content measurements have been known to occur in the food industry for decades. To ensure food quality, purchasers of protein meals routinely conduct quality control tests designed to detect the most common non-protein nitrogen contaminants, such as urea and ammonium nitrate.

The limitations of the Kjeldahl method were at the heart of the Chinese protein export contamination in 2007 and the 2008 China milk scandal in which the industrial chemical melamine was added to the milk or glutens to increase the measured "protein".

True protein

In at least one segment of the food industry, the dairy industry, some countries (at least the U.S., Australia, France and Hungary) have adopted "true protein" measurement, as opposed to crude protein measurement, as the standard for payment and testing: "True protein is a measure of only the proteins in milk, whereas crude protein is a measure of all sources of nitrogen and includes nonprotein nitrogen, such as urea, which has no food value to humans. ... Current milk-testing equipment measures peptide bonds, a direct measure of true protein." Measuring peptide bonds in grains has also been put into practice in several countries including Canada, the UK, Australia, Russia and Argentina where near-infrared reflectance (NIR) technology, a type of infrared spectroscopy is used.

The more traditional approach to true protein analysis is amino acid analysis. Data from such analysis has additional nutritional meaning, as humans and other animals have specific requirements for essential amino acids. The Food and Agriculture Organization of the United Nations (FAO) recommends that only amino acid analysis be used to determine protein in, inter alia, foods used as the sole source of nourishment, such as infant formula, but also provides: "When data on amino acids analyses are not available, determination of protein based on total N content by Kjeldahl (AOAC, 2000) or similar method ... is considered acceptable." Using standard methods for amino acid analysis, the true protein content can be reported as the sum of the anhydrous masses of all 18 amino acids analyzed. AA analysis can be performed using standard methods including ISO 13903 (2005) and AOAC 988.15.

In the context of dairy products, NPN can also be calculated by precipitating away all protein and measuring the nitrogen content in the remaining fraction.

Ruminant metabolizable protein

The testing method for protein in beef cattle feed has grown into a science over the post-war years. The standard text in the United States, Nutrient Requirements of Beef Cattle, has been through eight editions over at least seventy years. The 1996 sixth edition substituted for the fifth edition's crude protein the concept of "metabolizeable protein", which was defined around the year 2000 as "the true protein absorbed by the intestine, supplied by microbial protein and undegraded intake protein". (This refers specifically to ruminant nutrition, where microbes living in the rumen can convert NPNs to proteins. Such conversion does not happen in non-ruminants such as humans.)

Protein quality

Further information: Protein quality and Amino acid score

The most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition. There are multiple systems which rate proteins by their usefulness to an organism based on their relative percentage of amino acids and, in some systems, the digestibility of the protein source. They include biological value, net protein utilization, and PDCAAS (Protein Digestibility Corrected Amino Acids Score) which was developed by the FDA as a modification of the Protein efficiency ratio (PER) method. The PDCAAS rating was adopted by the US Food and Drug Administration (FDA) and the Food and Agricultural Organization of the United Nations/World Health Organization (FAO/WHO) in 1993 as "the preferred 'best'" method to determine protein quality. These organizations have suggested that other methods for evaluating the quality of protein are inferior.

In 2013 FAO proposed changing to Digestible Indispensable Amino Acid Score.

Digestion

Most proteins are decomposed to single amino acids by digestion in the gastro-intestinal tract.

Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the small intestine. Before the absorption in the small intestine, most proteins are already reduced to single amino acid or peptides of several amino acids. Most peptides longer than four amino acids are not absorbed. Absorption into the intestinal absorptive cells is not the end. There, most of the peptides are broken into single amino acids.

Absorption of the amino acids and their derivatives into which dietary protein is degraded is done by the gastrointestinal tract. The absorption rates of individual amino acids are highly dependent on the protein source; for example, the digestibilities of many amino acids in humans, the difference between soy and milk proteins and between individual milk proteins, beta-lactoglobulin and casein. For milk proteins, about 50% of the ingested protein is absorbed between the stomach and the jejunum and 90% is absorbed by the time the digested food reaches the ileum. Biological value (BV) is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism's body.

Newborn

Newborns of mammals are exceptional in protein digestion and assimilation in that they can absorb intact proteins at the small intestine. This enables passive immunity, i.e., transfer of immunoglobulins from the mother to the newborn, via milk.

Dietary requirements

An education campaign launched by the United States Department of Agriculture in 1917, on cottage cheese as a lower-cost protein substitute for meat.

Average protein supply by region and origin

Considerable debate has taken place regarding protein intake requirements. The amount of protein required in a person's diet is determined in large part by overall energy intake, the body's need for nitrogen and essential amino acids, body weight and composition, rate of growth in the individual, physical activity level, the individual's energy and carbohydrate intake, and the presence of illness or injury. Physical activity and exertion as well as enhanced muscular mass increase the need for protein. Requirements are also greater during childhood for growth and development, during pregnancy, or when breastfeeding in order to nourish a baby or when the body needs to recover from malnutrition or trauma or after an operation.

Dietary recommendations

According to US & Canadian Dietary Reference Intake guidelines, women ages 19–70 need to consume 46 grams of protein per day while men ages 19–70 need to consume 56 grams of protein per day to minimize risk of deficiencies. These Recommended Dietary Allowances (RDAs) were calculated based on 0.8 grams protein per kilogram body weight and average body weights of 57 kg (126 pounds) and 70 kg (154 pounds), respectively. However, this recommendation is based on structural requirements but disregards use of protein for energy metabolism. This requirement is for a normal sedentary person. In the United States, average protein consumption is higher than the RDA. According to results of the National Health and Nutrition Examination Survey (NHANES 2013–2014), average protein consumption for women ages 20 and older was 69.8 grams and for men 98.3 grams/day. According to research from Harvard University, the National Academy of Medicine suggests that adults should consume at least 0.8 grams of protein per kilogram of body weight daily, which is roughly equivalent to a little more than 7 grams for every 20 pounds of body weight. This recommendation is widely accepted by health professionals as a guideline for maintaining muscle mass, supporting metabolic functions, and promoting overall health.

Active people

Several studies have concluded that active people and athletes may require elevated protein intake (compared to 0.8 g/kg) due to increase in muscle mass and sweat losses, as well as need for body repair and energy source. Indeed, it has been shown that protein contribute around 3% of the total energy expenditure during exercise. Suggested amounts vary from 1.2 to 1.4 g/kg for those doing endurance exercise to as much as 1.6-1.8 g/kg for strength exercise and up to 2.0 g/kg/day for older people, while a proposed maximum daily protein intake would be approximately 25% of energy requirements i.e. approximately 2 to 2.5 g/kg. However, many questions still remain to be resolved.

In addition, some have suggested that athletes using restricted-calorie diets for weight loss should further increase their protein consumption, possibly to 1.8–2.0 g/kg, in order to avoid loss of lean muscle mass.

Aerobic exercise protein needs

Endurance athletes differ from strength-building athletes in that endurance athletes do not build as much muscle mass from training as strength-building athletes do. Research suggests that individuals performing endurance activity require more protein intake than sedentary individuals so that muscles broken down during endurance workouts can be repaired. Although the protein requirement for athletes still remains controversial (for instance see Lamont, Nutrition Research Reviews, pages 142 - 149, 2012), research does show that endurance athletes can benefit from increasing protein intake because the type of exercise endurance athletes participate in still alters the protein metabolism pathway. The overall protein requirement increases because of amino acid oxidation in endurance-trained athletes. Endurance athletes who exercise over a long period (2–5 hours per training session) use protein as a source of 5–10% of their total energy expended. Therefore, a slight increase in protein intake may be beneficial to endurance athletes by replacing the protein lost in energy expenditure and protein lost in repairing muscles. One review concluded that endurance athletes may increase daily protein intake to a maximum of 1.2–1.4 g per kg body weight.

Anaerobic exercise protein needs

Research also indicates that individuals performing strength training activity require more protein than sedentary individuals. Strength-training athletes may increase their daily protein intake to a maximum of 1.4–1.8 g per kg body weight to enhance muscle protein synthesis, or to make up for the loss of amino acid oxidation during exercise. Many athletes maintain a high-protein diet as part of their training. In fact, some athletes who specialize in anaerobic sports (e.g., weightlifting) believe a very high level of protein intake is necessary, and so consume high protein meals and also protein supplements.

Special populations

Protein allergies

Main article: Food allergy

A food allergy is an abnormal immune response to proteins in food. The signs and symptoms may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. These symptoms typically occurs within minutes to one hour after exposure. When the symptoms are severe, it is known as anaphylaxis. The following eight foods are responsible for about 90% of allergic reactions: cow's milk, eggs, wheat, shellfish, fish, peanuts, tree nuts and soy.

Chronic kidney disease

While there is no conclusive evidence that a high protein diet can cause chronic kidney disease, there is a consensus that people with this disease should decrease consumption of protein. According to one 2009 review updated in 2018, people with chronic kidney disease who reduce protein consumption have less likelihood of progressing to end stage kidney disease. Moreover, people with this disease while using a low protein diet (0.6 g/kg/d - 0.8 g/kg/d) may develop metabolic compensations that preserve kidney function, although in some people, malnutrition may occur.

Phenylketonuria

Individuals with phenylketonuria (PKU) must keep their intake of phenylalanine – an essential amino acid – extremely low to prevent a mental disability and other metabolic complications. Phenylalanine is a component of the artificial sweetener aspartame, so people with PKU need to avoid low calorie beverages and foods with this ingredient.

Excess consumption

See also: Protein poisoning

The U.S. and Canadian Dietary Reference Intake review for protein concluded that there was not sufficient evidence to establish a Tolerable upper intake level, i.e., an upper limit for how much protein can be safely consumed.

When amino acids are in excess of needs, the liver takes up the amino acids and deaminates them, a process converting the nitrogen from the amino acids into ammonia, further processed in the liver into urea via the urea cycle. Excretion of urea occurs via the kidneys. Other parts of the amino acid molecules can be converted into glucose and used for fuel. When food protein intake is periodically high or low, the body tries to keep protein levels at an equilibrium by using the "labile protein reserve" to compensate for daily variations in protein intake. However, unlike body fat as a reserve for future caloric needs, there is no protein storage for future needs.

Excessive protein intake may increase calcium excretion in urine, occurring to compensate for the pH imbalance from oxidation of sulfur amino acids. This may lead to a higher risk of kidney stone formation from calcium in the renal circulatory system. One meta-analysis reported no adverse effects of higher protein intakes on bone density. Another meta-analysis reported a small decrease in systolic and diastolic blood pressure with diets higher in protein, with no differences between animal and plant protein.

High protein diets have been shown to lead to an additional 1.21 kg of weight loss over a period of 3 months versus a baseline protein diet in a meta-analysis. Benefits of decreased body mass index as well as HDL cholesterol were more strongly observed in studies with only a slight increase in protein intake rather where high protein intake was classified as 45% of total energy intake. Detrimental effects to cardiovascular activity were not observed in short-term diets of 6 months or less. There is little consensus on the potentially detrimental effects to healthy individuals of a long-term high protein diet, leading to caution advisories about using high protein intake as a form of weight loss.

The 2015–2020 Dietary Guidelines for Americans (DGA) recommends that men and teenage boys increase their consumption of fruits, vegetables and other under-consumed foods, and that a means of accomplishing this would be to reduce overall intake of protein foods. The 2015–2020 DGA report does not set a recommended limit for the intake of red and processed meat. While the report acknowledges research showing that lower intake of red and processed meat is correlated with reduced risk of cardiovascular diseases in adults, it also notes the value of nutrients provided from these meats. The recommendation is not to limit intake of meats or protein, but rather to monitor and keep within daily limits the sodium (< 2300 mg), saturated fats (less than 10% of total calories per day), and added sugars (less than 10% of total calories per day) that may be increased as a result of consumption of certain meats and proteins. While the 2015 DGA report does advise for a reduced level of consumption of red and processed meats, the 2015–2020 DGA key recommendations recommend that a variety of protein foods be consumed, including both vegetarian and non-vegetarian sources of protein.

Protein deficiency

A child in Nigeria during the Biafra War with kwashiorkor – one of the three protein energy malnutrition ailments affecting over 10 million children in developing countries.

Main article: Protein-energy malnutrition

Protein deficiency and malnutrition (PEM) can lead to a variety of ailments, including Intellectual disability and kwashiorkor. Symptoms of kwashiorkor include apathy, diarrhea, inactivity, failure to grow, flaky skin, fatty liver, and edema of the belly and legs. This edema is explained by the action of lipoxygenase on arachidonic acid to form leukotrienes and the normal functioning of proteins in fluid balance and lipoprotein transport.

PEM is fairly common worldwide in both children and adults and accounts for 6 million deaths annually. In the industrialized world, PEM is predominantly seen in hospitals, is associated with disease, or is often found in the elderly.

Royal jelly

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Royal_jelly

Developing queen larvae surrounded by royal jelly

Royal jelly is a honey bee secretion that is used in the nutrition of larvae and adult queens. It is secreted from the glands in the hypopharynx of nurse bees, and fed to all larvae in the colony, regardless of sex or caste.

Queen larva in a cell on a frame with bees

During the process of creating new queens, the workers construct special queen cells. The larvae in these cells are fed with copious amounts of royal jelly. This type of feeding in part triggers the development of queen morphology, including the fully developed ovaries needed to lay eggs. Note however that some newer research shows it is not solely the presence of royal jelly that develops the queen but rather the absence of certain other nutrients fed to worker bees.

Royal jelly is sometimes used in alternative medicine under the category apitherapy. It is often sold as a dietary supplement for humans, but the European Food Safety Authority concluded in 2011 that evidence does not support the claim that consuming royal jelly offers health benefits to humans. In the United States, the Food and Drug Administration has taken legal action against companies that have marketed royal jelly products using unfounded claims of health benefits.

Production

Royal jelly is secreted from the glands in the heads of worker bees and is fed to all bee larvae, whether they are destined to become drones (males), workers (sterile females), or queens (fertile females). After three days, the drone and worker larvae are no longer fed with royal jelly, but queen larvae continue to be fed this special substance throughout their development.

Composition

Royal jelly is 67% water, 12.5% protein, 11% simple sugars (monosaccharides), 6% fatty acids and 3.5% 10-hydroxy-2-decenoic acid (10-HDA). It also contains trace minerals, antibacterial and antibiotic components, pantothenic acid (vitamin B5), pyridoxine (vitamin B6) and trace amounts of vitamin C, but none of the fat-soluble vitamins: A, D, E or K.

Proteins

Main article: Major royal jelly protein

Major royal jelly proteins (MRJPs) are a family of proteins secreted by honey bees. The family consists of nine proteins, of which MRJP1 (also called royalactin), MRJP2, MRJP3, MRJP4, and MRJP5 are present in the royal jelly secreted by worker bees. MRJP1 is the most abundant, and largest in size. The five proteins constitute 83–90% of the total proteins in royal jelly. They are synthesised by a family of nine genes (mrjp genes), which are in turn members of the yellow family of genes such as in the fruitfly (Drosophila) and bacteria. They are involved in differential development of queen larvae and worker larvae, thus establishing division of labour in the bee colony.

Epigenetic effects

The honey bee queens and workers represent one of the most striking examples of environmentally controlled phenotypic polymorphism. Even if two larvae had identical DNA, one raised to be a worker, the other a queen, the two adults would be strongly differentiated across a wide range of characteristics including anatomical and physiological differences, longevity, and reproductive capacity. Queens constitute the female sexual caste and have large active ovaries, whereas female workers have only rudimentary, inactive ovaries and are functionally sterile. The queen–worker developmental divide is controlled epigenetically by differential feeding with royal jelly; this appears to be due specifically to the protein royalactin. A female larva destined to become a queen is fed large quantities of royal jelly; this triggers a cascade of molecular events resulting in development of a queen. It has been shown that this phenomenon is mediated by an epigenetic modification of DNA known as CpG methylation. Silencing the expression of an enzyme that methylates DNA in newly hatched larvae led to a royal jelly-like effect on the larval developmental trajectory; the majority of individuals with reduced DNA methylation levels emerged as queens with fully developed ovaries. This finding suggests that DNA methylation in honey bees allows the expression of epigenetic information to be differentially altered by nutritional input.

Use by humans

Cultivation

Royal jelly is harvested by stimulating colonies with movable frame hives to produce queen bees. Royal jelly is collected from each individual queen cell (honeycomb) when the queen larvae are about four days old. These are the only cells in which large amounts are deposited. This is because when royal jelly is fed to worker larvae, it is fed directly to them, and they consume it as it is produced, while the cells of queen larvae are "stocked" with royal jelly much faster than the larvae can consume it. Therefore, only in queen cells is the harvest of royal jelly practical.

A well-managed hive during a season of 5–6 months can produce approximately 500 g (18 oz) of royal jelly. Since the product is perishable, producers must have immediate access to proper cold storage (e.g., a household refrigerator or freezer) in which the royal jelly is stored until it is sold or conveyed to a collection center. Sometimes honey or beeswax is added to the royal jelly, which is thought to aid its preservation.

The Vegetarian Society considers royal jelly to be non-vegan.

Adverse effects

Royal jelly may cause allergic reactions in humans, ranging from hives or asthma (or both), to even fatal anaphylaxis. The incidence of allergic side effects in people who consume royal jelly is unknown. The risk of having an allergy to royal jelly is higher in people who have other allergies.