Wednesday, September 21, 2016
Raw foodism
Raw foodism (or following a raw food diet) is the dietary practice of eating only uncooked, unprocessed foods. Depending on the philosophy, or type of lifestyle and results desired, raw food diets may include a selection of fruits, vegetables, nuts, seeds, eggs, fish, meat and dairy products. It may also include simply processed foods such as various types of sprouted seeds, cheese, and fermented foods such as yogurts, kefir, kombucha or sauerkraut, but generally not foods that have been pasteurized, homogenized, or produced with the use of synthetic pesticides, chemical fertilizers, industrial solvents or chemical food additives.
Varieties: Raw food diets are diets composed entirely of food that is uncooked or which is cooked at low temperatures.
Raw veganism: A raw vegan diet consists of unprocessed, raw plant foods, that have not been heated above 40–49 °C (104–120 °F). Raw vegans such as Brian Clement, Gabriel Cousens, Thierry Browers a.k.a. "Superlight", and Douglas Graham believe that foods cooked above this temperature have lost much of their nutritional value and are less healthy or even harmful to the body. Advocates argue that raw or living foods have natural enzymes, which are critical in building proteins and rebuilding the body, and that heating these foods destroys the natural enzymes and can leave toxic materials behind. However, critics point out that enzymes, as with other proteins consumed in the diet, are denatured and eventually lysed by the digestive process, rendering them non-functional. Typical foods included in raw food diets are fruits, vegetables, nuts, seeds, and sprouted grains and legumes. Among raw vegans there are some subgroups such as fruitarians, juicearians, or sproutarians. Fruitarians eat primarily or exclusively fruits, berries, seeds, and nuts. Juicearians process their raw plant foods into juice. Sproutarians adhere to a diet consisting mainly of sprouted seeds.
Raw vegetarianism: Vegetarianism is a diet that excludes meat (including game and byproducts like gelatin), fish (including shellfish and other sea animals) and poultry, but allows dairy and/or eggs. Common foods include fruit, vegetables, sprouts, nuts, seeds, grains, legumes, dairy, eggs and honey. There are several variants of this diet.
Raw animal food diets: Included in raw animal food diets are any food that can be eaten raw, such as uncooked, unprocessed raw muscle-meats/organ-meats/eggs, raw dairy, and aged, raw animal foods such as century eggs, fermented meat/fish/shellfish/kefir, as well as vegetables/fruits/nuts/sprouts/honey, but in general not raw grains, raw beans, and raw soy. Raw foods included on such diets have not been heated above 40 °C (104 °F). Raw animal foodists believe that foods cooked above this temperature have lost a lot of their nutritional value and are less bioavailable. Examples of raw animal food diets include the Primal Diet, Anopsology (otherwise known as "Instinctive Eating" or "Instincto"), and the Raw Paleolithic diet (otherwise known as the "Raw Meat Diet"). The Primal Diet consists of fatty meats, organ meats, dairy, honey, minimal fruit and vegetable juices, and coconut products, all raw. The "Raw Meat Diet", otherwise known as the "Raw, Paleolithic Diet", is a raw version of the (cooked) Paleolithic Diet, incorporating large amounts of raw animal foods such as meats/organ-meats, seafood, eggs, and some raw plant-foods, but usually avoiding non-Paleo foods such as raw dairy, grains, and legumes. A number of traditional aboriginal diets consisted of large quantities of raw meats, organ meats, and berries, including the traditional diet of the Nenets tribe of Siberia and the Inuit people.
History: In the 1830s, Presbyterian minister Sylvester Graham promoted dietary principles similar to the raw food diet as a proposed cure for the then-current cholera epidemic threatening to strike the United States. Graham, most noted for the famous graham cracker, claimed chronic disease in general and cholera in particular could be prevented by drinking pure water and eating simple fresh food not complicated or compounded by culinary practices. Graham saw such simple fare as a method to cure lust; for Graham, an unhealthy diet stimulated excessive sexual desire which irritated the body and caused disease. Raw food as a dietary health treatment was first developed in Switzerland by medical doctor Maximilian Bircher-Benner, inventor of muesli. After recovering from jaundice while eating raw apples, he conducted experiments into the effects on human health of raw vegetables. In November 1897, he opened a sanatorium in Zurich called "Vital Force," named after a "key term from the German lifestyle reform movement, which states that people should pattern their lives after the logic determined by nature". Weston A. Price, in a 1939 work titled Nutrition and Physical Degeneration, observed dental degeneration in the first generation abandoning traditional nutrient-dense foods, which included unprocessed raw milk. Price claimed that the parents of such first-generation children had excellent jaw development and dental health, while their children had malocclusion and tooth decay and attributed this to their new modern diet insufficient in nutrients. Price also noted, in his book, that the healthiest tribes he visited all incorporated some raw animal foods in their diets. Other notable proponents from the early part of this century include Ann Wigmore, Norman W. Walker (inventor of the Norwalk Juicing Press), and Herbert Shelton. Shelton was arrested, jailed, and fined numerous times for practicing medicine without a license during his career as an advocate of rawism and other alternative health and diet philosophies. Shelton's legacy, as popularized by books like Fit for Life by Harvey and Marilyn Diamond, has been deemed "pseudonutrition" by the National Council Against Health Fraud. Leslie Kenton's book Raw Energy - Eat Your Way to Radiant Health, published in 1984, popularized food such as sprouts, seeds, and fresh vegetable juices. The book brought together research into raw foodism and its support of health. It cites examples such as the sprouted-seed-enriched diets of the long-lived Hunza people and Gerson therapy, an unhealthy, dangerous and potentially very harmful raw juice-based diet and detoxification regime claimed to treat cancer. The book advocates a diet of 75% raw food which it claims will prevent degenerative diseases, slow the effects of aging, provide enhanced energy, and boost emotional balance.
Claims: Claims held by raw food proponents include:
- That heating food above 104-118 °Fahrenheit (40-49 °C) starts to degrade and destroy the enzymes in raw food that aid digestion. A few raw food proponents such as Douglas Graham dispute the importance of enzymes in foods.
- That raw foods have higher nutrient values than foods that have been cooked.
- That wild foods followed by organic whole foods are more nutritious than conventionally domesticated foods or industrially produced foods.
- That cooked foods contain harmful toxins, which can cause chronic disease and other problems, Processing oils and fats can produce harmful trans fatty acids. Cooking foods produces advanced glycation end products ("glycotoxins", see also Maillard reaction).
- That raw foods such as fruits and vegetables are high in antioxidants, which raw-food proponents claim can help to stifle signs of aging. Dr. Joel Fuhrman, author of "Eat To Live", says that uncooked cruciferous vegetables have the most powerful anti-cancer effects of all foods. He also says that most of the phytonutrients function as antioxidants in the body, meaning they neutralize free radicals, rendering them harmless and reducing cancer risk. Raw food proponents claim that this property found in alkaline living foods or raw food, which neutralizes free radicals, makes green smoothies a powerful antioxidant drink.
Food preparation: Many foods in raw food diets are simple to prepare, such as fruits, salads, meat, and dairy. Other foods can require considerable advanced planning to prepare for eating. Rice and some other grains, for example, require sprouting or overnight soaking to become digestible. Raw food proponents claim it is best to soak nuts and seeds before eating them, to activate their enzymes, and deactivate enzyme inhibitors. Some claim Freezing food is acceptable, even though freezing lowers enzyme activity. Others claim freezing is harmful, though not as unhealthy as cooking.
Research: A study surveying people practicing raw vegan diets of varying intensities found that 30% of the women under age 45 had partial to complete amenorrhoea and that "subjects eating high amounts of raw food (> 90%) were affected more frequently than moderate raw food dieters". The study concluded that since many raw food dieters were underweight and exhibited amenorrhoea "a very strict raw vegan diet cannot be recommended on a long-term basis". A meta-analysis of scientific studies from 1994 to 2004 concluded there to be an inverse correlation between the risk of developing certain types of cancer and eating both raw and cooked vegetables. Consumption of raw vegetables tended to be associated with decreased cancer risks somewhat more often than consumption of cooked vegetables. The majority of studies included show an inverse association between both raw and cooked vegetables and cancer. On the other hand, certain studies have indicated detrimental health effects stemming from raw vegan diets. A 2005 study has shown that a raw vegan diet is associated with a lower bone density. One study of raw vegan diets shows amenorrhea and underweightness in women. Another one indicates an increased risk of dental erosion with a raw vegan diet.
Potential harmful effects of cooking
Compounds created by cooking: Several studies published since 1990 indicate that cooking muscle meat creates heterocyclic amines (HCAs). High rates of HCA can cause cancer in other animals; whether such an exposure causes cancer in humans remains unclear. Researchers at the National Cancer Institute found that human subjects having eaten beef rare or medium-rare had less than one-third the risk of stomach cancer as those having eaten beef medium-well or well-done. While eating muscle meat raw may be the only way to avoid HCAs fully, the National Cancer Institute states that cooking meat below 212 °F (100 °C) creates "negligible amounts" of HCAs. Also, microwaving meat before cooking may substantially reduce HCAs. Although microwave cooking may lead to reduced HCA levels in cooked meat products, Raw Foodists do not consider it any more favorable than other forms of cooking. Microwaving has been shown to cause a great decrease in all studied antioxidants in broccoli, compared to other cooking methods. Microwaving has also been shown to reduce vitamin B12 levels in beef, pork, and milk by 30-40%. Breast milk is commonly stored cold, and reheated before use. Using the microwave for this purpose has been shown to significantly reduce the anti-infective factors in human milk. Nitrosamines, formed by cooking and preserving in salt and smoking, have been linked to colon cancer and stomach cancer. Cooking also creates certain heat-created toxic compounds, advanced glycation end products, otherwise known as AGEs. This reaction occurs both within the body and external to the body. Many cells in the body (for example endothelial cells, smooth muscle cells, and cells of the immune system) from tissue such as lung, liver, kidney, and peripheral blood bear the receptor for advanced glycation end-products (RAGE) that, when binding AGEs, contributes to age- and diabetes-related chronic inflammatory diseases, such as atherosclerosis, renal failure, arthritis, myocardial infarction, macular degeneration, cardiovascular disease, nephropathy, retinopathy, or neuropathy. Excretion of dietary AGEs is reduced in diabetics and lowering AGE intake may greatly reduce the impact of AGEs in diabetic patients and possibly improve prognosis. Also, toxic compounds called PAHs, or Polycyclic aromatic hydrocarbons, are formed by cooking. They are known to be carcinogenic and an industrial pollutant. Acrylamide in a substance found at high levels in certain cooked foods, such as potato chips (crisps) and bread when heated higher than 120 °C (248 °F)., and in black olives, prunes, dried pears, and coffee. According to the American Cancer Society it is not clear, as of 2013, whether acrylamide consumption affects people's risk of getting cancer. Acrylamide has known toxic effects on the nervous system and on fertility; however, the World Health Organization concluded in 2002 that the intake level required to observe neuropathy (0.5 mg/kg body weight/day) was 500 times higher than the average dietary intake, and 2,000 times higher for effects on fertility. The FDA has measured it in many foods. As of 2015, however, the UK Food Standards Agency has warned against acrylamide in cooked foods.
Effect of cooking on digestibility and allergy: Contrary to a belief frequently held by raw foodists (that "heating food above 104-120 °Fahrenheit (40-49 °C) degrades or destroys the enzymes in raw food that aid digestion) many enzymes central to digestion actually work optimally at temperatures exceeding this range (e.g. alpha amylase works best at 161-169 °F, beta amylase at 140-149 °F, and protease at 113 °F-122 °F). There are various scientific reports, such as one by the Nutrition Society, which describe in detail the loss of vitamins and minerals caused by cooking. Another study has shown that meat heated for 10 minutes at 130 °C (266 °F), showed a 1.5% decrease in protein digestibility. Similar heating of hake meat in the presence of potato starch, soy oil, and salt caused a 6% decrease in amino acid content. Frying chickpeas, oven-heating winged beans, or roasting cereals at 200–280 °C (392–536 °F) reduces protein digestibility. One study, comparing the effects of consuming either pasteurized, or homogenized/pasteurized, or unpasteurized milk, showed that pasteurized and homogenized/pasteurized milk might increase allergic reactions in patients allergic to milk.
Cooking and global warming: It has also been pointed out that cooking food, directly or indirectly, requires energy and may thus release gases associated with global warming. Raw diets mitigate the use of non-renewable resources, which results in raw diets being less environmentally deleterious than cooked food diets in this respect.
Nutritional deficiencies in raw vegan diets: Care is required in planning a raw vegan diet, especially for children. Dr. Joel Fuhrman, author of Disease-Proof Your Child, says there may not be enough vitamin B12, enough vitamin D, and enough calories for a growing child on a totally raw vegan diet. Fuhrman fed his own four children raw and cooked vegetables, fruits, nuts, grains, beans, and occasionally eggs.
Food poisoning: Food poisoning is a health risk for all people eating raw foods, and increased demand for raw foods is associated with greater incidence of foodborne illness, especially for raw meat, fish, and shellfish. Outbreaks of gastroenteritis among consumers of raw and undercooked animal products (including smoked, pickled or dried animal products) are well-documented, and include raw meat, raw organ meat, raw fish (whether ocean-going or freshwater), shellfish, raw milk and products made from raw milk, and raw eggs. In his book Health or Hoax, nutritionist Arnold E. Bender has written that "Many raw foods are toxic and only become safe after they have been cooked. Some raw foods contain substances that destroy vitamins, interfere with digestive enzymes or damage the walls of the intestine. Raw meat can be contaminated with bacteria which would be destroyed by cooking; raw fish can contain substances that interfere with vitamin B1 (anti-thiaminases)"
Controversies: Richard Wrangham, a primate researcher and professor of anthropology, has suggested that eating cooked food is more "natural" for the human digestive system, because the human digestive system may have evolved to deal with cooked foods. Wrangham thinks that cooking explains the increase in hominid brain sizes, smaller digestive tract, smaller teeth and jaws and decrease in sexual dimorphism that occurred roughly 1.8 million years ago. Most other anthropologists oppose Wrangham, stating that archaeological evidence suggests that cooking fires began in earnest only c.250,000 years ago, when ancient hearths, earth ovens, burnt animal bones, and flint appear across Europe and the Middle East. Two million years ago, the only sign of fire is burnt earth with human remains, which most other anthropologists consider to be mere coincidence rather than evidence of intentional fire. The mainstream view among anthropologists is that the increases in human brain-size occurred well before the advent of cooking, due to a shift away from the consumption of nuts and berries to the consumption of raw meat.
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