Half Baked: The Raw Foodism Movement
In Chapter One: the Quest for Raw-Foodist, Wrangham explores the Giessen Raw Foods Diet. He investigates the reasons for and implications of abstaining from cooked food. Participants in raw-food diets report “a sense of well-being, better physical functioning, less bodily pain, more vitality…improved emotional and social performance…reductions in rheumatoid arthritis and fibromyalgia symptoms, less dental erosion, and improved antioxidant intake” (Wrangham, 2009). However, the qualitative results may be more along the lines of vitamins deficiencies (especially of B12), decreased levels on HDL (the good cholesterol) and low amounts of homocysteine (lack of which may lead to heart disease) (Wrangham, 2009). Raw food diets (in nature as well as in the “1st world”) are especially tough on women, and lead to severe weight loss, amenorrhea, loss of menstrual cycle and decreased fertility (Wrangham, 2009).
A former vegetarian myself (who returned to meat after chronic anemia) I decided to investigate deeper into the nutritional validity of raw foods. “Raw-foodists, it is clear, do not fare well,” asserts Wrangham (2009) at the conclusion of the chapter. This implies cooking is superior (if it was so bad for us, wouldn’t we have stopped several hundreds of thousands of years ago?). But, let’s explore the nutritional science a bit more thoroughly.
According to Food Writer Scott Kustes, the central claim of the Raw Foods Movement is that “that cooking denatures or destroys essential enzymes in the food, that all food has a kind of 'life force' that is killed off by cooking.” (Kustes, 2012). Raw foodists claim that these “natural enzymes” are essential for proper digestion (Better Nutrition, 2004). They also believe cooked food is the cause of many of the chronic diseases and obesity that effect industrialized nations (Biali, 2006). Therefore, digesting raw food is better for you (more natural, more energy efficient etc.) than cooked food, considering our evolutionary ancestors and great ape cousins ate or eat mostly raw plant matter.
However, cooking has obvious nutritional benefits, are here are the most well-known. Cooking tough fibrous foods makes them 2-12 times more digestible as compared to their raw forms, especially for foods of high nutritional values like legumes, grains and seeds (Kustes, 2012). Some vegetables actually release more nutrients when heated and consumed (such as garlic and diallyl, which lowers blood pressure). Also, according to Kustes (2012) cooking helps break down some anti-nutrients (the plant’s evolved chemical defenses). Kustes (2012) gives the example of soy, whose trypsin inhibitors and lectins (cytotoxins) are neutralized by heating.
As Wrangham states, the negative effects of a raw the diet may very well surpass the aforementioned “benefits.” Weight loss may be the most obvious consequence. According to a study done by Koebnick et al. (1999), in long term raw food diets (3.7 years), men loose approximately 9.9kg and women loose about 12 kg. For 30% of the women in the same study, this caused partial to complete amenorrhea. The study concluded that because “the consumption of a raw food diet is associated with a high loss of body weight. Since many raw food dieters exhibited underweight and amenorrhea, a very strict raw food diet cannot be recommended on a long term basis” (Koebnick et al, 1999). Besides malnourishment and amenorrhea, the deficiencies in raw food diets can cause loss of bone mineral density and rotten teeth (Biali, 2006). Ironically, because raw foodists often ingest a high proportion of citrus fruits, they have significantly MORE dental erosion (Ganss C. et al., 1999). Looks like even a purposed benefit of the raw food diet is a detriment.
Against the basic benefits of cooking food, and the numerous deficiencies and negative effects of consuming only raw foods, straight nutritional science has me erring on the side of “well-done.”
References:
Anonymous. 2004. Are raw foods a raw deal? Better nutrition. 66:19.
Biali, S. 2006. The raw foods diet: a raw deal? Med Post. 42: 25.
Ganss, C, Schlechtriemen M, Klimek J. (1999). Dental erosions in subjects living on a raw foot diet. Caries Research. 33: 74-80.
Koebnick C, Strassner C, Hoffmann I, and Leitzmann C. (1999). Consequences of a long-term raw food diet on body weight and menstruation: results of a questionnaire survey. Ann Nutr Metab. 43: 69-79.
Wrangham, R. 2009. Catching fire: how cooking made us human. New York: Basics Books.
Kustes S. 2012. Are Raw Vegetables Healthier Than Cooked Vegetables?. In Real Food University. Retrieved March 7, 2012, from http://www.realfooduniversity.com/
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