Search This Blog

Sunday, May 19, 2019

Bariatric surgery

From Wikipedia, the free encyclopedia

Bariatric surgery (or weight loss surgery) includes a variety of procedures performed on people who have obesity. Weight loss is achieved by reducing the size of the stomach with a gastric band or through removal of a portion of the stomach (sleeve gastrectomy or biliopancreatic diversion with duodenal switch) or by resecting and re-routing the small intestine to a small stomach pouch (gastric bypass surgery).

Long-term studies show the procedures cause significant long-term loss of weight, recovery from diabetes, improvement in cardiovascular risk factors, and a mortality reduction from 40% to 23%. The U.S. National Institutes of Health recommends bariatric surgery for obese people with a body mass index (BMI) of at least 40, and for people with BMI of at least 35 and serious coexisting medical conditions such as diabetes. However, research is emerging that suggests bariatric surgery could be appropriate for those with a BMI of 35 to 40 with no comorbidities or a BMI of 30 to 35 with significant comorbidities. The most recent American Society for Metabolic & Bariatric Surgery guidelines suggest the position statement on consensus for BMI as an indication for bariatric surgery. The recent guidelines suggest that any patient with a BMI of more than 30 with comorbidities is a candidate for bariatric surgery.

A National Institute of Health symposium held in 2013 that summarized available evidence found a 29% mortality reduction, a 10-year remission rate of Type 2 Diabetes of 36%, fewer cardiovascular events, and a lower rate of diabetes-related complications in a long-term, non-randomized, matched intervention 15-20 year follow-up study, the Swedish Obese Subjects Study. The symposium also found similar results from a Utah study using more modern gastric bypass techniques, though the follow-up periods of the Utah studies are only up to 7 years. While randomized controlled trials of bariatric surgery exist, they are limited by short follow-up periods.

Medical uses

Biliopancreatic Diversion.
 
  • "Surgery should be considered as a treatment option for patients with a BMI of 40 kg/m2 or greater who instituted but failed an adequate exercise and diet program (with or without adjunctive drug therapy) and who present with obesity-related comorbid conditions, such as hypertension, impaired glucose tolerance, diabetes mellitus, hyperlipidemia, and obstructive sleep apnea. A doctor–patient discussion of surgical options should include the long-term side effects, such as a possible need for reoperation, gallbladder disease, and malabsorption."
  • "Patients should be referred to high-volume centers with surgeons experienced in bariatric surgery."
The surgery is contraindicated in patients who have end stage disease and also in patients not committed to make lifestyle changes considered ideal for the surgery. 

In 2011, the International Diabetes Federation issued a position statement suggesting "Under some circumstances, people with a BMI 30–35 should be eligible for surgery." When determining eligibility for bariatric surgery for extremely obese patients, psychiatric screening is critical; it is also critical for determining postoperative success. Patients with a body-mass index of 40 kg/m2 or greater have a 5-fold risk of depression, and half of bariatric surgery candidates are depressed.

Weight loss

In general, the malabsorptive procedures lead to more weight loss than the restrictive procedures; however, they have a higher risk profile. A meta-analysis from University of California, Los Angeles, reports the following weight loss at 36 months:
  • Biliopancreatic diversion — 117 Lbs / 53 kg
  • Roux-en-Y gastric bypass (RYGB) — 90 Lbs / 41 kg
    • Open — 95 Lbs/ 43 kg
    • Laparoscopic — 84 Lbs / 38 kg
  • Vertical banded gastroplasty — 71 Lbs / 32 kg
A 2017 meta-analysis showed bariatric surgery to be effective for weight loss in adolescents, as assessed 36 months after the intervention. The same meta-analysis noted that additional data is needed to determine whether it is also effective for long-term weight loss in adolescents. According to the Canadian Agency for Drugs and Technologies in Health, the comparative evidence base for bariatric surgery in adolescents and young adults is "...limited to a few studies that were narrow in scope and with relatively small sample sizes."

Another 2017 meta-analysis reported that it was effective at reducing weight among morbidly obese adults in China.

Reduced mortality and morbidity

In the short term, weight loss from bariatric surgeries is associated with reductions in some comorbidities of obesity, such as diabetes, metabolic syndrome and sleep apnea, but the benefit for hypertension is uncertain. It is uncertain whether any given bariatric procedure is more effective than another in controlling comorbidities. There is no high quality evidence concerning longer-term effects compared with conventional treatment on comorbidities.

Bariatric surgery in older patients has also been a topic of debate, centered on concerns for safety in this population; the relative benefits and risks in this population is not known.

Given the remarkable rate of diabetes remission with bariatric surgery, there is considerable interest in offering this intervention to people with type 2 diabetes who have a lower BMI than is generally required for bariatric surgery, but high quality evidence is lacking and optimal timing of the procedure is uncertain.

Laparoscopic bariatric surgery requires a hospital stay of only one or two days. Short-term complications from laparoscopic adjustable gastric banding are reported to be lower than laparoscopic Roux-en-Y surgery, and complications from laparoscopic Roux-en-Y surgery are lower than conventional (open) Roux-en-Y surgery.

Fertility and pregnancy

The position of the American Society for Metabolic and Bariatric Surgery as of 2017 was that it was not clearly understood whether medical weight-loss treatments or bariatric surgery had an effect responsiveness to subsequent treatments for infertility in both men and women. Bariatric surgery reduces the risk of gestational diabetes and hypertensive disorders of pregnancy in women who later become pregnant but increases the risk of preterm birth.

Psychiatric/Psychological

Some studies have suggested that psychological health can improve after bariatric surgery.

Adverse effects

Weight loss surgery in adults is associated with relatively large risks and complications, compared to other treatments for obesity.

The likelihood of major complications from weight-loss surgery is 4%. “Sleeve gastrectomy had the lowest complication and reoperation rates of the three (main weight-loss surgery) procedures.....The percentage of procedures requiring reoperations due to complications was 15.3 percent for the gastric band, 7.7 percent for gastric bypass and 1.5 percent for sleeve gastrectomy” - American Society for Metabolic and Bariatric Surgery.

As the rate of complications appears to be reduced when the procedure is performed by an experienced surgeon, guidelines recommend that surgery be performed in dedicated or experienced units. It has been observed that the rate of leaks was greater in low volume centres whereas high volume centres showed a lesser leak rate. Leak rates have now globally decreased to a mean of 1-5%.
Metabolic bone disease manifesting as osteopenia and secondary hyperparathyroidism have been reported after Roux-en-Y gastric bypass surgery due to reduced calcium absorption. The highest concentration of calcium transporters is in the duodenum. Since the ingested food will not pass through the duodenum after a bypass procedure, calcium levels in the blood may decrease, causing secondary hyperparathyroidism, increase in bone turnover, and a decrease in bone mass. Increased risk of fracture has also been linked to bariatric surgery.

Rapid weight loss after obesity surgery can contribute to the development of gallstones as well by increasing the lithogenicity of bile. Adverse effects on the kidneys have been studied. Hyperoxaluria that can potentially lead to oxalate nephropathy and irreversible renal failure is the most significant abnormality seen on urine chemistry studies. Rhabdomyolysis leading to acute kidney injury, and impaired renal handling of acid and base has been reported after bypass surgery.

Nutritional derangements due to deficiencies of micronutrients like iron, vitamin B12, fat soluble vitamins, thiamine, and folate are especially common after malabsorptive bariatric procedures. Seizures due to hyperinsulinemic hypoglycemia have been reported. Inappropriate insulin secretion secondary to islet cell hyperplasia, called pancreatic nesidioblastosis, might explain this syndrome.

Self-harm behaviors and suicide appear to be increased in people with mental health issues in the five years after bariatric surgery had been done.

Types

Diagram of a biliopancreatic diversion.
 
Procedures can be grouped in three main categories: blocking, restricting, and mixed. Standard of care in the United States and most of the industrialized world in 2009 is for laparoscopic as opposed to open procedures. Future trends are attempting to achieve similar or better results via endoscopic procedures.

Blocking procedures

Some procedures block absorption of food, although they also reduce stomach size.

Biliopancreatic diversion

This operation is termed biliopancreatic diversion (BPD) or the Scopinaro procedure. The original form of this procedure is now rarely performed because of problems with. It has been replaced with a modification known as duodenal switch (BPD/DS). Part of the stomach is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum

In around 2% of patients there is severe malabsorption and nutritional deficiency that requires restoration of the normal absorption. The malabsorptive effect of BPD is so potent that, as in most restrictive procedures, those who undergo the procedure must take vitamin and dietary minerals above and beyond that of the normal population. Without these supplements, there is risk of serious deficiency diseases such as anemia and osteoporosis.

Because gallstones are a common complication of the rapid weight loss following any type of bariatric surgery, some surgeons remove the gallbladder as a preventive measure during BPD. Others prefer to prescribe medications to reduce the risk of post-operative gallstones.

Diagram of a vertical banded gastroplasty.
 
Far fewer surgeons perform BPD compared to other weight loss surgeries, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients.

Jejunoileal bypass

This procedure is no longer performed. It was a surgical weight-loss procedure performed for the relief of morbid obesity from the 1950s through the 1970s in which all but 30 cm (12 in) to 45 cm (18 in) of the small bowel was detached and set to the side.

Endoluminal sleeve

A study on humans was done in Chile using the same technique  however the results were not conclusive and the device had issues with migration and slipping. A study recently done in the Netherlands found a decrease of 5.5 BMI points in 3 months with an endoluminal sleeve

Restrictive procedures

Procedures that are restrictive shrink the size of the stomach or take up space inside the stomach, making people feel more full when they eat less.

Diagram of an adjustable gastric banding.

Vertical banded gastroplasty

In the vertical banded gastroplasty, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach.

Adjustable gastric band

The restriction of the stomach also can be created using a silicone band, which can be adjusted by addition or removal of saline through a port placed just under the skin. This operation can be performed laparoscopically, and is commonly referred to as a "lap band". Weight loss is predominantly due to the restriction of nutrient intake that is created by the small gastric pouch and the narrow outlet. It is considered one of the safest procedures performed today with a mortality rate of 0.05%. 

Sleeve gastrectomy

Sleeve Gastrectomy.
 
Sleeve gastrectomy, or gastric sleeve, is a surgical weight-loss procedure in which the stomach is reduced to about 15% of its original size, by surgical removal of a large portion of the stomach, following the major curve. The open edges are then attached together (typically with surgical staples, sutures, or both) to leave the stomach shaped more like a tube, or a sleeve, with a banana shape. The procedure permanently reduces the size of the stomach. The procedure is performed laparoscopically and is not reversible. It has been found to be comparable in effectiveness to Roux-en-Y gastric bypass.

Intragastric balloon

Intragastric balloon involves placing a deflated balloon into the stomach, and then filling it to decrease the amount of gastric space. The balloon can be left in the stomach for a maximum of 6 months and results in an average weight loss of 5–9 BMI over half a year. The intragastric balloon is approved in Australia, Canada, Mexico, India, United States (received FDA approval in 2015) and several European and South American countries. The intragastric balloon may be used prior to another bariatric surgery in order to assist the patient to reach a weight which is suitable for surgery, further it can also be used on several occasions if necessary.

There are three cost categories for the intragastric balloon: pre-operative (e.g. professional fees, lab work and testing), the procedure itself (e.g. surgeon, surgical assistant, anesthesia and hospital fees) and post-operative (e.g. follow-up physician office visits, vitamins and supplements). 

Quoted costs for the intragastric balloon are surgeon-specific and vary by region. Average quoted costs by region are as follows (provided in United States Dollars for comparison): Australia: $4,178 USD; Canada: $8,250 USD; Mexico: $5,800 USD; United Kingdom: $6,195 USD; United States: $8,150 USD).

Stomach folding

Basically, the procedure can best be understood as a version of the more popular gastric sleeve or gastrectomy surgery where a sleeve is created by suturing rather than removing stomach tissue thus preserving its natural nutrient absorption capabilities. Gastric plication significantly reduces the volume of the patient's stomach, so smaller amounts of food provide a feeling of satiety.[citation needed] The procedure is producing some significant results that were published in a recent study in Bariatric Times and are based on post-operative outcomes for 66 patients (44 female) who had the gastric sleeve plication procedure between January 2007 and March 2010. Mean patient age was 34, with a mean BMI of 35. Follow-up visits for the assessment of safety and weight loss were scheduled at regular intervals in the postoperative period. No major complications were reported among the 66 patients. Weight loss outcomes are comparable to gastric bypass

The study describes gastric sleeve plication (also referred to as gastric imbrication or laparoscopic greater curvature plication) as a restrictive technique that eliminates the complications associated with adjustable gastric banding and vertical sleeve gastrectomy—it does this by creating restriction without the use of implants and without gastric resection (cutting) and staples.

Mixed procedures

Roux-en-Y gastric bypass.

Gastric bypass surgery

A common form of gastric bypass surgery is the Roux-en-Y gastric bypass, designed to reduce the amount of food a person is able to eat by cutting away a part of the stomach. Gastric bypass is a permanent procedure that helps patients by changing how the stomach and small intestine handle the food that is eaten to achieve and maintain weight loss goals. After the surgery, the stomach will be smaller. A patient will feel full with less food. 

The gastric bypass had been the most commonly performed operation for weight loss in the United States, and approximately 140,000 gastric bypass procedures were performed in 2005. Its market share has decreased since then and by 2011, the frequency of gastric bypass was thought to be less than 50% of the weight loss surgery market. 

A factor in the success of any bariatric surgery is strict post-surgical adherence to a healthy pattern of eating. 

There are certain patients who cannot tolerate the malabsorption and dumping syndrome associated with gastric bypass. In such patients, although earlier considered to be an irreversible procedure, there are instances where gastric bypass procedure can be partially reversed.

Diagram of a sleeve gastrectomy with duodenal switch.

Sleeve gastrectomy with duodenal switch

A variation of the biliopancreatic diversion includes a duodenal switch. The part of the stomach along its greater curve is resected. The stomach is "tubulized" with a residual volume of about 150 ml. This volume reduction provides the food intake restriction component of this operation. This type of gastric resection is anatomically and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine. The duodenum and the upper part of the small intestine are reattached to the rest at about 75–100 cm from the colon.

Implantable gastric stimulation

This procedure where a device similar to a heart pacemaker that is implanted by a surgeon, with the electrical leads stimulating the external surface of the stomach, is being studied in the USA. Electrical stimulation is thought to modify the activity of the enteric nervous system of the stomach, which is interpreted by the brain to give a sense of satiety, or fullness. Early evidence suggests that it is less effective than other forms of bariatric surgery.

Subsequent procedures

After a person successfully loses weight following bariatric surgery, they are usually left with excess skin. These are addressed in a series of plastic surgery procedures sometimes called body contouring in which the skin flaps are removed. Targeted areas include the arms, buttocks and thighs, abdomen, and breasts. These procedures are taken slowly, step by step, and from beginning to end often takes three years. A single body lifting operation can require seven to 10 hours under general anesthesia, blood transfusions and often, another surgeon to assist. Possible risks include infections and reactions and complications due to being under anesthesia for longer than six hours. The person may also experience seroma, a buildup of fluid; dehiscence (wound separation) and deep vein thrombosis (blood clots forming in the legs.) Rare complications include lymphatic injury and major wound dehiscence. The hospital stay for the procedure can require from one to four days while recovery can require about a month.

Eating after bariatric surgery

Immediately after bariatric surgery, the patient is restricted to a clear liquid diet, which includes foods such as clear broth, diluted fruit juices or sugar-free drinks and gelatin desserts. This diet is continued until the gastrointestinal tract has recovered somewhat from the surgery. The next stage provides a blended or pureed sugar-free diet for at least two weeks. This may consist of high protein, liquid or soft foods such as protein shakes, soft meats, and dairy products. Foods high in carbohydrates are usually avoided when possible during the initial weight loss period. 

Post-surgery, overeating is curbed because exceeding the capacity of the stomach causes nausea and vomiting. Diet restrictions after recovery from surgery depend in part on the type of surgery. Many patients will need to take a daily multivitamin pill for life to compensate for reduced absorption of essential nutrients. Because patients cannot eat a large quantity of food, physicians typically recommend a diet that is relatively high in protein and low in fats and alcohol.

Fluid recommendations

It is very common, within the first month post-surgery, for a patient to undergo volume depletion and dehydration. Patients have difficulty drinking the appropriate amount of fluids as they adapt to their new gastric volume. Limitations on oral fluid intake, reduced calorie intake, and a higher incidence of vomiting and diarrhea are all factors that have a significant contribution to dehydration. In order to prevent fluid volume depletion and dehydration, a minimum of 48–64 fl oz (1.4-1.9 L) should be consumed by repetitive small sips all day.

Costs

The costs of bariatric surgery depend on the type of procedure performed and method of payment along with location-specific factors including geographical region, surgical practice and the hospital in which the surgery is performed. 

The four established procedure types (Roux-en-Y gastric bypass, gastric banding, vertical sleeve gastrectomy (gastric sleeve) and duodenal switch) carry an average cost in the United States of $24,000, $15,000, $19,000 and $27,000 respectively. However, costs can vary significantly by location. Quoted costs generally include fees for the hospital, surgeon, surgical assistant, anesthesia and implanted devices (if applicable). Depending on the surgical practice, costs may include or omit pre-op, post-op or longer-term follow-up office visits.

Youth

As childhood obesity has more than doubled over recent years and more than tripled in adolescents (according to the CDC), bariatric surgery for youth has become increasingly common. Some worry that a decline in life expectancy might occur from the increasing levels of obesity, so providing youth with proper care may help prevent the serious medical complications caused by obesity and its related diseases. Difficulties and ethical issues arise when making decisions related to obesity treatments for those that are too young or otherwise unable to give consent without adult guidance.

Children and adolescents are still developing, both physically and mentally. This makes it difficult for them to make an informed decision and give consent to move forward with a treatment. These patients may also be experiencing severe depression or other psychological disorders related to their obesity that make understanding the information very difficult.

History

Open weight loss surgery began slowly in the 1950s with the intestinal bypass. It involved anastomosis of the upper and lower intestine, which bypasses a large amount of the absorptive circuit, which caused weight loss purely by the malabsorption of food. Later Drs. J. Howard Payne, Lorent T. DeWind and Robert R. Commons developed in 1963 the Jejuno-colic Shunt, which connected the upper small intestine to the colon. The laboratory research leading to gastric bypass did not begin until 1965 when Dr. Edward E. Mason (b.1920) and Dr. Chikashi Ito (1930–2013) at the University of Iowa developed the original gastric bypass for weight reduction which led to fewer complications than the intestinal bypass and for this reason Mason is known as the "father of obesity surgery". 

Biodynamic agriculture

From Wikipedia, the free encyclopedia

Biodynamic agriculture is a form of alternative agriculture very similar to organic farming, but it includes various esoteric concepts drawn from the ideas of Rudolf Steiner (1861–1925). Initially developed in 1924, it was the first of the organic agriculture movements. It treats soil fertility, plant growth, and livestock care as ecologically interrelated tasks, emphasizing spiritual and mystical perspectives. 

Biodynamics has much in common with other organic approaches – it emphasizes the use of manures and composts and excludes the use of artificial chemicals on soil and plants. Methods unique to the biodynamic approach include its treatment of animals, crops, and soil as a single system, an emphasis from its beginnings on local production and distribution systems, its use of traditional and development of new local breeds and varieties. Some methods use an astrological sowing and planting calendar. Biodynamic agriculture uses various herbal and mineral additives for compost additives and field sprays; these are prepared using methods that are more akin to sympathetic magic than agronomy, such as burying ground quartz stuffed into the horn of a cow, which are said to harvest "cosmic forces in the soil."

No difference in beneficial outcomes has been scientifically established between certified biodynamic agricultural techniques and similar organic and integrated farming practices. Biodynamic agriculture lacks strong scientific evidence for its efficacy and has been labeled a pseudoscience because of its overreliance upon esoteric knowledge and mystical beliefs.

As of 2019, biodynamic techniques were used on 187.549 hectares in 55 countries. Germany accounts for 45% of the global total; the remainder average 1750 ha per country. Biodynamic methods of cultivating grapevines have been taken up by several notable vineyards. There are certification agencies for biodynamic products, most of which are members of the international biodynamics standards group Demeter International.

History

Origin of a theory

Rudolf Steiner, occultist philosopher and founder of "anthroposophic agriculture", later known as "biodynamic".
 
Biodynamics was the first modern organic agriculture. Its development began in 1924 with a series of eight lectures on agriculture given by philosopher Rudolf Steiner at Schloss Koberwitz in Silesia, Germany (now Kobierzyce in Poland). These lectures, the first known presentation of organic agriculture, were held in response to a request by farmers who noticed degraded soil conditions and a deterioration in the health and quality of crops and livestock resulting from the use of chemical fertilizers. The 111 attendees, less than half of whom were farmers, came from six countries, primarily Germany and Poland. The lectures were published in November 1924; the first English translation appeared in 1928 as The Agriculture Course.

Steiner emphasized that the methods he proposed should be tested experimentally. For this purpose, Steiner established a research group, the "Agricultural Experimental Circle of Anthroposophical Farmers and Gardeners of the General Anthroposophical Society". Between 1924 and 1939, this research group attracted about 800 members from around the world, including Europe, the Americas and Australasia. Another group, the "Association for Research in Anthroposophical Agriculture" (Versuchsring anthroposophischer Landwirte), directed by the German agronomist Erhard Bartsch, was formed to test the effects of biodynamic methods on the life and health of soil, plants and animals; the group published a monthly journal, Demeter. Bartsch was also instrumental in developing a sales organisation for biodynamic products, Demeter, which still exists today. The Research Association was renamed the Imperial Association for Biodynamic Agriculture (Reichsverband für biologisch-dynamische Wirtschaftsweise) in 1933. It was dissolved by the National Socialist regime in 1941. In 1931 the association had 250 members in Germany, 109 in Switzerland, 104 in other European countries and 24 outside Europe. The oldest biodynamic farms are the Wurzerhof in Austria and Marienhöhe in Germany.

In 1938, Ehrenfried Pfeiffer's text, Bio-Dynamic Farming and Gardening, was published in five languages – English, Dutch, Italian, French, and German; this became the standard work in the field for several decades. In July 1939, at the invitation of Walter James, 4th Baron Northbourne, Pfeiffer travelled to the UK and presented the Betteshanger Summer School and Conference on Biodynamic Farming at Northbourne's farm in Kent. The conference has been described as the 'missing link' between biodynamic agriculture and organic farming because, in the year after Betteshanger, Northbourne published his manifesto of organic farming, Look to the Land, in which he coined the term 'organic farming' and praised the methods of Rudolf Steiner. In the 1950s, Hans Mueller was encouraged by Steiner's work to create the organic-biological farming method in Switzerland; this later developed to become the largest certifier of organic products in Europe, Bioland.

Geographic developments

Today biodynamics is practiced in more than 50 countries worldwide and in a variety of circumstances, ranging from temperate arable farming, viticulture in France, cotton production in Egypt, to silkworm breeding in China. Demeter International is the primary certification agency for farms and gardens using the methods.
  • In Australia, the first biodynamic farmer was Ernesto Genoni who in 1928 joined the Experimental Circle of Anthroposophical Farmers and Gardeners, followed soon after by his brother Emilio Genoni. Ileen Macpherson and Ernesto Genoni founded Demeter Biological Farm at Dandenong, Victoria, in 1934 and it was farmed using biodynamic principles for over two decades. Bob Williams presented the first public lecture in Australia on biodynamic agriculture on 26 June 1938 at the home of the architects Walter Burley Griffin and Marion Mahony Griffin at Castlecrag, Sydney. Since the 1950s research work has continued at the Biodynamic Research Institute (BDRI) in Powelltown, near Melbourne under the direction of Alex Podolinsky. In 1989 Biodynamic Agriculture Australia was established, as a not for profit association.
  • In 1928 the Anthroposophical Agricultural Foundation was founded in England; this is now called the Biodynamic Agriculture Association. In 1939, Britain's first biodynamic agriculture conference, the Betteshanger Summer School and Conference on Biodynamic Agriculture, was held at Lord Northbourne's farm in Kent; Ehrenfried Pfeiffer was the lead presenter.
  • In the United States, the Biodynamic Farming & Gardening Association was founded in 1938 as a New York state corporation.
  • In France the International Federation of Organic Agriculture Movements (IFOAM) was formed in 1972 with five founding members, one of which was the Swedish Biodynamic Association.
  • The University of Kassel had a Department of Biodynamic Agriculture from 2006 to March 2011.

Biodynamic method of farming

In common with other forms of organic agriculture, biodynamic agriculture uses management practices that are intended to "restore, maintain and enhance ecological harmony." Central features include crop diversification, the avoidance of chemical soil treatments and off-farm inputs generally, decentralized production and distribution, and the consideration of celestial and terrestrial influences on biological organisms. The Demeter Association recommends that "(a) minimum of ten percent of the total farm acreage be set aside as a biodiversity preserve. That may include but is not limited to forests, wetlands, riparian corridors, and intentionally planted insectaries. Diversity in crop rotation and perennial planting is required: no annual crop can be planted in the same field for more than two years in succession. Bare tillage year round is prohibited so land needs to maintain adequate green cover."

The Demeter Association also recommends that the individual design of the land "by the farmer, as determined by site conditions, is one of the basic tenets of biodynamic agriculture. This principle emphasizes that humans have a responsibility for the development of their ecological and social environment which goes beyond economic aims and the principles of descriptive ecology." Crops, livestock, and farmer, and "the entire socioeconomic environment" form a unique interaction, which biodynamic farming tries to "actively shape ...through a variety of management practices. The prime objective is always to encourage healthy conditions for life": soil fertility, plant and animal health, and product quality. "The farmer seeks to enhance and support the forces of nature that lead to healthy crops, and rejects farm management practices that damage the environment, soil plant, animal or human health....the farm is conceived of as an organism, a self-contained entity with its own individuality," holistically conceived and self-sustaining. "Disease and insect control are addressed through botanical species diversity, predator habitat, balanced crop nutrition, and attention to light penetration and airflow. Weed control emphasizes prevention, including timing of planting, mulching, and identifying and avoiding the spread of invasive weed species."

Biodynamic agriculture differs from many forms of organic agriculture in its spiritual, mystical, and astrological orientation. It shares a spiritual focus, as well as its view toward improving humanity, with the "nature farming" movement in Japan. Important features include the use of livestock manures to sustain plant growth (recycling of nutrients), maintenance and improvement of soil quality, and the health and well being of crops and animals. Cover crops, green manures and crop rotations are used extensively and the farms to foster the diversity of plant and animal life, and to enhance the biological cycles and the biological activity of the soil.

Biodynamic farms often have a cultural component and encourage local community, both through developing local sales and through on-farm community building activities. Some biodynamic farms use the Community Supported Agriculture model, which has connections with social threefolding

Compared to non-organic agriculture, BD farming practices have been found to be more resilient to environmental challenges, to foster a diverse biosphere, and to be more energy efficient, factors Eric Lichtfouse describes being of increasing importance in the face of climate change, energy scarcity and population growth.

Biodynamic preparations

In his "agricultural course" Steiner prescribed nine different preparations to aid fertilization, and described how these were to be prepared. Steiner believed that these preparations mediated terrestrial and cosmic forces into the soil. The prepared substances are numbered 500 through 508, where the first two are used for preparing fields, and the other seven are used for making compost. A long term trial (DOK experiment) evaluating the biodynamic farming system in comparison with organic and conventional farming systems, found that both organic farming and biodynamic farming resulted in enhanced soil properties, but had lower yields than conventional farming. Regarding compost development beyond accelerating the initial phase of composting, some positive effects have been noted:
  • The field sprays contain substances that stimulate plant growth including cytokinins.
  • Some improvement in nutrient content of compost is evident from the ingredients included, but not necessarily as a result of the practices and exact preparations as Steiner described them.
Although the preparations have direct nutrient values, modern biodynamic practitioners believe their benefit is to support the self-regulating capacities of the biota already present in the soil and compost. Critics of the practice have pointed out that no evidence or logic underlies the practices themselves, which instead are dependent on magical thinking and debunked theories of Steiner himself. There is no evidence that biodynamic practices have any benefit beyond the direct nutrients they add as fertilizer, which may itself be of smaller benefit than other traditionally organic or commercial fertilizers.

Field preparations

Field preparations, for stimulating humus formation:
  • 500: A humus mixture prepared by filling a cow's horn with cow manure and burying it in the ground (40–60 cm below the surface) in the autumn. It is left to decompose during the winter and recovered for use as fertilizer the following spring.
  • 501: Crushed powdered quartz stuffed into a cow's horn and buried in the ground in springtime and taken out in autumn. It can be mixed with 500 but is usually prepared on its own. The mixture is sprayed under very low pressure over the crop during the wet season, as a supposed antifungal.

Compost preparations

The compost preparations Steiner recommended employ herbs which are frequently used in alternative medical remedies. Many of the same herbs Steiner referenced are used in organic practices to make foliar fertilizers, green manure, or in composting. The preparations Steiner discussed were:
  • 502: Yarrow blossoms (Achillea millefolium) stuffed into the urinary bladders from red deer (Cervus elaphus), placed in the sun during summer, buried in the ground during winter, and retrieved in the spring.
  • 503: Chamomile blossoms (Matricaria recutita) stuffed into the small intestines of cattle, buried in humus-rich earth in the autumn, and retrieved in the spring.
  • 504: Stinging nettle (Urtica dioica) plants in full bloom stuffed together underground surrounded on all sides by peat for a year.
  • 505: Oak bark (Quercus robur) chopped in small pieces, placed inside the skull of a domesticated animal, surrounded by peat, and buried in the ground in a place near rain runoff.
  • 506: Dandelion flowers (Taraxacum officinale) stuffed into the mesentery of a cow, buried in the ground during winter, and retrieved in the spring.
  • 507: Valerian flowers (Valeriana officinalis) extracted into water.
  • 508: Horsetail (Equisetum).

Planting calendar

The approach considers that there are lunar and astrological influences on soil and plant development—for example, choosing to plant, cultivate or harvest various crops based on both the phase of the moon and the zodiacal constellation the moon is passing through, and also depending on whether the crop is the root, leaf, flower, or fruit of the plant. This aspect of biodynamics has been termed "astrological" and "pseudoscientific" in nature.

Seed production

Biodynamic agriculture has focused on the open pollination of seeds (with farmers thereby generally growing their own seed) and the development of locally adapted varieties.

Biodynamic certification

The Demeter biodynamic certification system established in 1924 was the first certification and labelling system for organic production. As of 2018, to receive certification as biodynamic, the farm must meet the following standards: agronomic guidelines, greenhouse management, structural components, livestock guidelines, and post-harvest handling and processing procedures.

The term Biodynamic is a trademark held by the Demeter association of biodynamic farmers for the purpose of maintaining production standards used both in farming and processing foodstuffs. The trademark is intended to protect both the consumer and the producers of biodynamic produce. Demeter International an organization of member countries; each country has its own Demeter organization which is required to meet international production standards (but can also exceed them). The original Demeter organization was founded in 1928; the U.S. Demeter Association was formed in the 1980s and certified its first farm in 1982. In France, Biodivin certifies biodynamic wine. In Egypt, SEKEM has created the Egyptian Biodynamic Association (EBDA), an association that provides training for farmers to become certified. As of 2006, more than 200 wineries worldwide were certified as biodynamic; numerous other wineries employ biodynamic methods to a greater or lesser extent.

Effectiveness

Research into biodynamic farming has been complicated by the difficulty of isolating the distinctively biodynamic aspects when conducting comparative trials. Consequently, there is no strong body of material that provides evidence of any specific effect.

Since biodynamic farming is a form of organic farming, it can be generally assumed to share its characteristics, including "less stressed soils and thus diverse and highly interrelated soil communities".

A 2009/2011 review found that biodynamically cultivated fields:
  • Had lower absolute yields than conventional farms, but achieved better efficiency of Production relative to the amount of energy used;
  • Had greater earthworm populations and biomass than conventional farms.
Both factors were similar to the result in organically cultivated fields.

Reception

In a 2002 newspaper editorial, Peter Treue, agricultural researcher at the University of Kiel, characterized biodynamics as pseudoscience and argued that similar or equal results can be obtained using standard organic farming principles. He wrote that some biodynamic preparations more resemble alchemy or magic akin to geomancy.

In a 1994 analysis, Holger Kirchmann, a soil researcher with the Swedish University of Agricultural Sciences, concluded that Steiner's instructions were occult and dogmatic, and cannot contribute to the development of alternative or sustainable agriculture. According to Kirchmann, many of Steiner's statements are not provable because scientifically clear hypotheses cannot be made from his descriptions. Kirchmann asserted that when methods of biodynamic agriculture were tested scientifically, the results were unconvincing. Further, in a 2004 overview of biodynamic agriculture, Linda Chalker-Scott, a researcher at Washington State University, characterized biodynamics as pseudoscience, writing that Steiner did not use scientific methods to formulate his theory of biodynamics, and that the later addition of valid organic farming techniques has "muddled the discussion" of Steiner's original idea. Based on the scant scientific testing of biodynamics, Chalker-Scott concluded "no evidence exists" that homeopathic preparations improve the soil.

In Michael Shermer's The Skeptic Encyclopedia of Pseudoscience, Dan Dugan says that the way biodynamic preparations are supposed to be implemented are formulated solely on the basis of Steiner's "own insight". Skeptic Brian Dunning writes "the best way to think of 'biodynamic agriculture' would be as a magic spell cast over an entire farm. Biodynamics sees an entire farm as a single organism, with something that they call a life force."

Florian Leiber, Nikolai Fuchs and Hartmut Spieß, researchers at the Goetheanum, have defended the principles of biodynamics and suggested that critiques of biodynamic agriculture which deny it scientific credibility are "not in keeping with the facts...as they take no notice of large areas of biodynamic management and research." Biodynamic farmers are "charged with developing a continuous dialogue between biodynamic science and the natural sciences sensu stricto," despite important differences in paradigms, world views, and value systems.

Philosopher of science Michael Ruse has written that followers of biodynamic agriculture rather enjoy the scientific marginalisation that comes from its pseudoscientific basis, revelling both in its esoteric aspects and the impression that they were in the vanguard of the wider anti-science sentiment that has grown in opposition to modern methods such as genetic modification.

Steiners theory was similar to those of the agricultural scientist Richard Krzymowski, who was teaching in Breslau since 1922. The environmental scientist Frank M. Rauch mentioned in 1995, concerning the reprint of a book from Raoul Heinrich Francé, another source probably used by Steiner.

Copper deficiency

From Wikipedia, the free encyclopedia

Copper deficiency is defined either as insufficient copper to meet the needs of the body, or as a serum copper level below the normal range. The neurodegenerative syndrome of copper deficiency has been recognized for some time in ruminant animals, in which it is commonly known as "swayback". Copper deficiency can manifest in parallel with vitamin B12 and other nutritional deficiencies.

Overview

The most common cause of copper deficiency is a remote gastrointestinal surgery, such as gastric bypass surgery, due to malabsorption of copper, or zinc toxicity. On the other hand, Menkes disease is a genetic disorder of copper deficiency involving a wide variety of symptoms that is often fatal.

Copper is required for the functioning of many enzymes, such as cytochrome c oxidase, which is complex IV in the mitochondrial electron transport chain, ceruloplasmin, Cu/Zn superoxide dismutase, and in amine oxidases. These enzyme catalyze reactions for oxidative phosphorylation, iron transportation, antioxidant and free radical scavenging and neutralization, and neurotransmitter synthesis, respectively. Diets vary in the amount of copper they contain, but may provide about 5 mg/day, of which only 20-50% is absorbed. The diet of the elderly may have a lower copper content than the recommended daily intake. Dietary copper can be found in whole grain cereals, legumes, oysters, organ meats (particularly liver), cherries, dark chocolate, fruits, leafy green vegetables, nuts, poultry, prunes, and soybeans products like tofu.

Copper deficiency can have many hematological consequences, such as myelodysplasia, anemia, low white blood cell count, and low count of neutrophils(a type of white blood cell that is often called "the first line of defense" of the immune system). Copper deficiency has long been known for as a cause of myelodysplasia (when a blood profile has indicators of possible future leukemia development), but it was not until 2001 that copper deficiency was associated with neurological manifestations like sensory ataxia (irregular coordination due to proprioceptive loss), spasticity, muscle weakness, and more rarely visual loss due to damage in the peripheral nerves, myelopathy (disease of the spinal cord), and rarely optic neuropathy.

Signs and symptoms

Blood symptoms

Ring Sideroblast smear 2010-01-13
 
The characteristic hematological (blood) effects of copper deficiency are anemia (which may be microcytic, normocytic or macrocytic) and neutropenia. Thrombocytopenia (low blood platelets) is unusual.

The peripheral blood and bone marrow aspirate findings in copper deficiency can mimic myelodysplastic syndrome. Bone marrow aspirate in both conditions may show dysplasia of blood cell precursors and the presence of ring sideroblasts (erythroblasts containing multiple iron granules around the nucleus). Unlike most cases of myelodysplastic syndrome, the bone marrow aspirate in copper deficiency characteristically shows cytoplasmic vacuoles within red and white cell precursors, and karyotyping in cases of copper deficiency does not reveal cytogenetic features characteristic of myelodysplastic syndrome.

Anemia and neutropenia typically resolve within six weeks of copper replacement.

Neurological symptoms

Copper deficiency can cause a wide variety of neurological problems including myelopathy, peripheral neuropathy, and optic neuropathy.

Myelopathy

Copper deficiency myelopathy in humans was discovered and first described by Schleper and Stuerenburg in 2001. They described a patient with a history of gastrectomy and partial colonic resection who presented with severe tetraparesis and painful paraesthesias and who was found on imaging to have dorsomedial cervical cord T2 hyperintensity. Upon further analysis, it was found that the patient had decreased levels of serum coeruloplasmin, serum copper, and CSF copper. The patient was treated with parenteral copper and the patient`s paraesthesias did resolve. Since this discovery, there has been heightened and increasing awareness of copper-deficiency myelopathy and its treatment, and this disorder has been reviewed by Kumar. Sufferers typically present difficulty walking (gait difficulty) caused by sensory ataxia (irregular muscle coordination) due to dorsal column dysfunction or degeneration of the spinal cord (myelopathy). Patients with ataxic gait have problems balancing and display an unstable wide walk. They often feel tremors in their torso, causing side way jerks and lunges.

In brain MRI, there is often an increased T2 signalling at the posterior columns of the spinal cord in patients with myelopathy caused by copper deficiency. T2 signalling is often an indicator of some kind of neurodegeneration. There are some changes in the spinal cord MRI involving the thoracic cord, the cervical cord or sometimes both. Copper deficiency myelopathy is often compared to subacute combined degeneration (SCD). Subacute combined degeneration is also a degeneration of the spinal cord, but instead vitamin B12 deficiency is the cause of the spinal degeneration. SCD also has the same high T2 signalling intensities in the posterior column as copper deficient patient in MRI imaging.

Peripheral neuropathy

Another common symptom of copper deficiency is peripheral neuropathy, which is numbness or tingling that can start in the extremities and can sometimes progress radially inward towards the torso. In an Advances in Clinical Neuroscience & Rehabilitation (ACNR) published case report, a 69-year-old patient had progressively worsened neurological symptoms. These symptoms included diminished upper limb reflexes with abnormal lower limb reflexes, sensation to light touch and pin prick was diminished above the waist, vibration sensation was lost in the sternum, and markedly reduced proprioception or sensation about the self’s orientation. Many people suffering from the neurological effects of copper deficiency complain about very similar or identical symptoms as the patient. This numbness and tingling poses danger for the elderly because it increases their risk of falling and injuring themselves. Peripheral neuropathy can become very disabling leaving some patients dependent on wheel chairs or walking canes for mobility if there is lack of correct diagnosis. Rarely can copper deficiency cause major disabling symptoms. The deficiency will have to be present for an extensive amount of time until such disabling conditions manifest.

Optic neuropathy

Some patients suffering from copper deficiency have shown signs of vision and color loss. The vision is usually lost in the peripheral views of the eye. The bilateral vision loss is usually very gradual. An optical coherence tomography (OCT) shows some nerve fiber layer loss in most patients, suggesting the vision loss and color vision loss was secondary to optic neuropathy or neurodegeneration.

Causes

Surgery

Bariatric surgery is a common cause of copper deficiency. Bariatric surgery, such as gastric bypass surgery, is often used for weight control of the morbidly obese. The disruption of the intestines and stomach from the surgery can cause absorption difficulties not only as regards copper, but also for iron and vitamin B12 and many other nutrients. The symptoms of copper deficiency myelopathy may take a long time to develop, sometimes decades before the myelopathy symptoms manifest.

Zinc toxicity

Increased consumption of zinc is another cause of copper deficiency. Zinc is often used for the prevention or treatment of common colds and sinusitis (inflammation of sinuses due to an infection), ulcers, sickle cell disease, celiac disease, memory impairment, and acne. Zinc is found in many common vitamin supplements and is also found in denture creams. Recently, several cases of copper deficiency myeloneuropathy were found to be caused by prolonged use of denture creams containing high quantities of zinc.

Metallic zinc is the core of all United States currency coins, including copper coated pennies. People who ingest a large number of coins will have elevated zinc levels, leading to zinc-toxicity-induced copper deficiency and the associated neurological symptoms. This was the case for a 57-year-old woman diagnosed with schizophrenia. The woman consumed over 600 coins, and started to show neurological symptoms such as unsteady gait and mild ataxia.

Hereditary disorders

Menkes disease showing symptoms of the sparse, steel colored "kinky hair" and paleness
 
Menkes disease is a congenital disease that is a cause of copper deficiency. Menkes disease is a hereditary condition caused by a defective gene involved with the metabolism of copper in the body. Menkes disease involves a wide variety of symptoms including floppy muscle tone, seizures, abnormally low temperatures, and a peculiar steel color hair that feels very rough. Menkes disease is usually a fatal disease with most children dying within the first ten years of life.

Other

It is rarely suggested that excess iron supplementation causes copper deficiency myelopathy. Another rarer cause of copper deficiency is Coeliac disease, probably due to malabsorption in the intestines. Still, a large percentage, around 20%, of cases have unknown causes.

Pathophysiology

Copper functions as a prosthetic group, which permits electron transfers in key enzymatic pathways like the electron transport chain. Copper is integrated in the enzymes cytochrome c oxidase, which is involved in cellular respiration and oxidative phosphorylation, Cu/Zn dismutase, which is involved in antioxidant defense, and many more listed in the table below.

Several Copper Dependent Enzymes and Their Function
Group Enzyme Function
Oxidases Flavin-containing amine oxidase Metabolism of neurotransmitters: noradrenaline, dopamine, serotonin and some dietary amines

Protein-lysine-6-oxidase (lysyl oxidase) Connective tissue synthesis- cross-linking of collagen and elastin

Copper-containing amine oxidase Metabolism of amines- histamines, putrescine, cadaverine

Cytochrome c oxidase Oxidative phosphorylation, electron transport in the mitochondrial membrane

Superoxide dismutase (Cu/Zn dismutase) Antioxidant and free radical scavenger, oxidizes dangerous superoxides to safer hydrogen peroxide

Ferroxidase I (ceruloplasmin) Iron transport-oxidation of Fe2+ to Fe3+, copper storage and transport, antioxidant and free radical neutralizer

Hephaestin (ferroxidase) Iron transport and oxidation of Fe2+ to Fe3+ in intestinal cells to enable iron uptake
Monooxygenases Dopamine beta-monooxygenase Conversion of dopamine to norepinephrine

Peptidylglycine monooxygenase Peptide hormone maturation- amidation of alpha-terminal carboxylic acid group of glycine

Monophenol monooxygenase (Tyrosinase) Melanin synthesis
Methylation Cycle Methionine synthase Transfer of methyl group from methyltetrahydrofolate to homocysteine to generate methionine for the methylation cycle and tetrahydrofolate for purine synthesis

Adenosylhomocysteinase (S-Adenosyl-L-homocysteine) Regeneration of homocysteine from adenosylhomocyesteine (S-Adenosyl-L-homocysteine) in the methylation cycle

Neurological

Cytochrome c Oxidase mechanism in mitochondrial membrane

Cytochrome c oxidase

There have been several hypotheses about the role of copper and some of its neurological manifestations. Some suggest that disruptions in cytochrome c oxidase, also known as Complex IV, of the electron transport chain is responsible for the spinal cord degeneration.

Methylation cycle

Myelinated neuron
 
Another hypothesis is that copper deficiency myelopathy is caused by disruptions in the methylation cycle. The methylation cycle causes a transfer of a methyl group (-CH3) from methyltetrahydrofolate to a range of macromolecules by the suspected copper dependent enzyme methionine synthase. This cycle is able to produce purines, which are a component of DNA nucleotide bases, and also myelin proteins. The spinal cord is surrounded by a layer of protective protein coating called myelin (see figure). When this methionine synthase enzyme is disrupted, the methylation decreases and myelination of the spinal cord is impaired. This cycle ultimately causes myelopathy.

Hematological cause

Iron transportation

The anemia caused by copper deficiency is thought to be caused by impaired iron transport. Hephaestin is a copper containing ferroxidase enzyme located in the duodenal muscosa that oxidizes iron and facilitates its transfer across the basolateral membrane into circulation. Another iron transporting enzyme is ceruloplasmin. This enzyme is required to mobilize iron from the reticuloendothelial cell to plasma. Ceruloplasmin also oxidizes iron from its ferrous state to the ferric form that is required for iron binding. Impairment in these copper dependent enzymes that transport iron may cause the secondary iron deficiency anemia. Another speculation for the cause of anemia is involving the mitochondrial enzyme cytochrome c oxidase (complex IV in the electron transport chain). Studies have shown that animal models with impaired cytochrome c oxidase failed to synthesize heme from ferric iron at the normal rate. The lower rate of the enzyme might also cause the excess iron to clump, giving the heme an unusual pattern. This unusual pattern is also known as ringed sideroblastic anemia cells.

Cell growth halt

The cause of neutropenia is still unclear; however, the arrest of maturing myelocytes, or neutrophil precursors, may cause the neutrophil deficiency.

Zinc intoxication

Zinc intoxication may cause anemia by blocking the absorption of copper from the stomach and duodenum. Zinc also upregulates the expression of chelator metallothionein in enterocytes, which are the majority of cells in the intestinal epithelium. Since copper has a higher affinity for metallothionein than zinc, the copper will remain bound inside the enterocyte, which will be later eliminated through the lumen. This mechanism is exploited therapeutically to achieve negative balance in Wilson’s disease, which involves an excess of copper.

Treatment

Copper deficiency is a very rare disease and is often misdiagnosed several times by physicians before concluding the deficiency of copper through differential diagnosis (copper serum test and bone marrow biopsy are usually conclusive in diagnosing copper deficiency). On average, patients are diagnosed with copper deficiency around 1.1 years after their first symptoms are reported to a physician. Copper deficiency can be treated with either oral copper supplementation or intravenous copper. If zinc intoxication is present, discontinuation of zinc may be sufficient to restore copper levels back to normal, but this usually is a very slow process. People who suffer from zinc intoxication will usually have to take copper supplements in addition to ceasing zinc consumption. Hematological manifestations are often quickly restored back to normal. The progression of the neurological symptoms will be stopped by appropriate treatment, but often with residual neurological disability.

Computer-aided software engineering

From Wikipedia, the free encyclopedia ...