Should we be cooking our food?
Graham Butler, BSc, CNPA, RH
If you've followed nutrition trends, you've probably come across advocates of raw food diets. But what are the health benefits to this type of diet?
If you’ve followed nutrition trends over the last few decades, you’ve probably come across advocates of raw food diets. Raw fooders embrace the concept that all food is best served cold, uncooked, or at most sun-warmed to preserve its natural enzymes and vitamins.
It may not be a surprise to learn that raw food diets tend to thrive in warmer climates and are less popular in regions with shorter growing seasons and less sunshine. Most raw food diets are vegan, at least in their modern incarnation. The Inuit survived for thousands of years on a diet made up almost entirely of raw meat and fish–apparently they never read Fit for Life.
North Americans eat too much processed food, fat, and sugar; yet fresh, minimally prepared food is more nutritious. Fresh vegetables, fruits, nuts, seeds, and sprouted beans arelow in fat and high in phytonutrients and antioxidants.
Dr. Ann Wigmore, the well-known 20th century nutritionist and naturopath, and author of nearly a dozen books on raw food diets, demonstrated that raw sprouted grains and seeds are a valuable and economical source of B vitamins, minerals, and other nutrients. Wigmore is probably best known for popularizing wheat grass and wheat grass juice as a health tonic.
Dr. Max Gerson, one of Wigmore’s contemporaries, advocated a raw vegetable juice diet as part of his treatment centre’s program for cancer patients in the 1920s. Dr. Gerson’s therapy continues to be practised through the efforts of The Gerson Institute and its affiliated treatment centres and clinics.
A study published in the Journal of Nutrition (2005) found that a raw food diet lowered total cholesterol and triglyceride concentrations–two common risk factors for cardiovascular disease.
Heat: Help or Hindrance?
A more controversial claim than that suggested by the heart-health study is that enzymes found in raw plant foods play a role in human digestion and health. Enzymes are proteins that serve as catalysts for specific biochemical reactions. The heat of cooking, it is said, destroys these enzymes. But the role of plant enzymes in human nutrition is unclear. It’s possible that humans have evolved in such a way that we have developed a use for plant enzymes, but there is not a lot of research to support this reasoning. Nor is it clear whether plant enzymes survive human digestionin any case.
While it’s true that cooking can destroy nutrients such as vitamin C, carotenoids such as lycopene and the proteins in grains may be more easily absorbed and digested after they are heated. This is why proponents of macrobiotic diets and most nutritionists recommend a mix of some rawproducts with cooked foods in orderto take maximum advantage of all available nutrients.
If raw foods are so nutritious, why cook? Aside from freeing up some nutrients, cooking kills bacteria and parasites, both of which are common in both domestic and wild animals, making meats much safer to eat. It also neutralizes toxins, making otherwise dangerous foods safe for consumption. Cassava, a major source of food energy, albeit otherwise nutritionally deficient, is one example of a food that is toxic when raw, but once cooked, can be processed by the body and safely eaten.
What message should we take home from raw food diets? Fresh vegetables, nuts, seeds, and sprouts are good for us–and we should all be eating more of them.
A few claims made for raw food diets: