Author: Winston Craig, MPH, PhD, RD.
Why are so many people switching off their stoves and turning to raw foods and discovering the art of non-cooking? There is a growing belief among some that a raw food diet comprised of uncooked foods is the healthiest diet and that it most closely resembles the original diet. Some even believe that raw foods have curative and health-promoting properties not afforded by a diet containing cooked foods.
Raw Foods Claims
Those who eat the raw food diet claim that it gives them more energy, enhances mental acuity, and purifies the body of toxins. Followers of the raw food diet have a real gift of persuasion, so that adherents of the diet are steadily growing. Normally there are 3 pieces of equipment that are deemed essential for eating a raw food diet: a Vita-Mix blender, a Green Life juicer, and a food dehydrator.
The main health benefits attributed to raw foods are:
- stress reduction
- improved mental outlook
- strengthened immune system
- lowered blood pressure levels
- increased bone mineralization with a decreased risk of osteoporosis in the elderly
- lowered risk of heart disease, with increased HDL cholesterol levels
- improved control of diabetes improved weight management
One of the main reasons given as to why we should be consuming our food uncooked is that raw food contains “live” enzymes which are suggested to help the body with its task of digestion. Proponents of the raw food diet argue that heating food above 118 degrees F destroys the enzymes, and hence destroys the vitality of food and lessens its nutritional value. In reality, enzymes are denatured (inactivated) by the very acidic environment of the stomach so that the enzymes in raw food never really make it past the stomach.
Raw food diets are not anything new. Popular health concepts often re-cycle in history and re-appear in a different era as a “new” idea. Sylvester Graham promoted raw food diets in 1839. He condemned cooking and claimed that illness could be prevented by eating only raw foods. Ellen White, however, recommended the use of both raw and cooked foods. She emphasized that some foods needed to be thoroughly cooked. Her writings make it abundantly clear that in her household they baked or boiled the potatoes and beans, cooked their grains and baked their bread thoroughly.
Cooking or baking legumes, grains, potatoes and other starchy foods is important for improved digestibility, since raw protein and starch are very difficult to digest. Cooking is also necessary to preserve food and have it available during seasons when fresh food is scarce or otherwise unavailable. When properly administered, cooking and baking causes minimal losses of most vitamins and minerals.
Proponents of raw food diets claim that cooking turns minerals from an organic form into a non-readily usable inorganic form. The truth of the matter is that heat does not deteriorate or destroy minerals in any way. However, they can be leached from vegetables if cooked in a large volume of water that is subsequently discarded.
Testing the Waters
Regarding the notion that a raw food diet is the best diet, I would say that there are certain claims made by proponents of raw foods which are not scientifically sound. In fact, they are quite erroneous (see Table 1).
TABLE 1: What Happens When You Cook Your Food?
|False Claims About Cooked Foods||Discussion About Those Claims|
|Cooked, baked and processed foods have little nutritional value.||Cooking and baking may cause some loss of a few heat-sensitive vitamins such as vitamin C. Heavily milled and refined grains will lose considerable amounts of minerals and vitamins.|
|Cooking destroys all the enzymes. The body then has to use energy to make new digestive enzymes.||The very acidic environment of the stomach (pH of 2-3) will inactivate enzymes before they get to the small intestines. Hence, the enzymes in raw food never get past the stomach.|
|The soaking of grains and nuts leaches out detrimental enzyme inhibitors making the grains and nuts safe to eat.||Soaking grains and nuts does not effectively leach out the enzyme inhibitors. Rather normal household cooking will destroy much of these compounds.|
|Heating or cooking an oil turns its fat into toxic trans fatty acids.||This process is only achieved with an industrial catalyst. Heating an oil in an open skillet can cause oxidation and deterioration of the oil but trans fatty acids cannot be produced by normal household cooking.|
Are Raw Foods Really Better?
There are actually some advantages to using cooked foods. Research data reveals that cooking unleashes more of the lycopene and other carotenoids (the pigments in bright yellow-orange, and red colored fruits and vegetables as well as the green, leafy vegetables) for the body to absorb. In some cases, the difference in availability is several fold greater for the cooked foods. The carotenoids are known to enhance the immune system as well as lowering the risk of heart disease and cancer.
Baking bread with yeast activates the enzyme phytase, which breaks down phytic acid and thus increases the absorption of zinc and calcium. The availability of these minerals from flat breads or uncooked grains is quite low.
The cooking/heating process causes protein to be denatured and starch to be gelatinized which enhances digestibility. Cooking beans destroys growth inhibitors and helps to diminish the problem of flatulence (gas production). The oligosaccharides in legumes which cause the flatulence problem are partially removed with usual cooking procedures.
Cooking is a preventive measure against lethal and harmful bacteria. A number of major food poisonings have been caused by raw or improperly cooked foods contaminated with Salmonella and E. coli 07:H157. Sufficient heat is required to destroy these dangerous organisms.
It appears that a totally raw food diet may actually have some disadvantages. While eating some raw fruit and vegetables is a good plan, a totally raw diet may not be the best.