showed that enzymes in uncooked foods are released in the mouth when vegetables are chewed. It is believed that these enzymes interact with other substances, notably the enzymes produced by the body itself, to aid the digestion process
Leslie Kenton's book, The New Raw Energy, in 1984 popularized food such as sprouts, seeds, and fresh vegetable juices, which have become staples in many different food cultures. The book brought together research into raw foodism and its support of health, citing examples such as the sprouted seed enriched diets of the long lived Himalayan Hunza people, as well as Max Gerson's claim of a raw juice-based cancer cure. The book advocates a diet of 75% raw food in order to prevent degenerative diseases, slow the effects of aging, provide enhanced energy, and boost emotional balance.
Freezing food is acceptable; some raw foodists choose to preserve nuts and seeds in a freezer. Although freezing decreases enzyme activity, the food is still raw.
The benefits of a raw food diet are said to include: a stable body mass index, clear skin, more energy, and minimising a range of common illnesses, from the flu to obesity-related illnesses.
Anthropologist Peter Lucas of George Washington University in Washington, DC, US, was reported in New Scientist magazine in 2005 as having the theory that man being the only mammal with chronic poor dentition, and the only mammal to significantly process and cook his food, are causally linked. He believes that the adoption of food processing and cooking reduced the size of our jaw through evolutionary processes, but not the size of our teeth.
A study by the University of Toronto and another published in the Journal of the National Cancer Institute suggest that ingesting cooked or pasteurized dairy products may increase risk of colon cancer. The increased risk is due to the effect of heating casein, a phosphoprotein found in dairy products.
Although research that provides a correlation between the health of an animal and the diet's proximity to vegan and raw food is essentially what is needed in order to show evidence of its impact, a large portion of the revenue brought in by a nation like the U.S. is from dairy and meat products, so the funding for this type of research may not meet the interests of today's money makers.
Some raw foodists claim that ingesting enzymes aids digestion in the mouth, stomach, and intestines. The claim about stomach digestion, however, goes against well established knowledge regarding the biochemistry of enzymes. Enzymes are very sensitive to pH and their activity will be nullified outside a specific pH range. The digestive enzymes produced by the stomach are active in the low pH (2-4) of the stomach, whereas enzymes found in most foods will be most active at cellular pH (approximately 7).However, some dietary enzymes such as bromelain and a protected form of SOD have been shown to be absorbed through the intestines and into the bloodstream. Also, enzymes found in acidic plant foods, including many fruits, are active at low pH similar to that of the human stomach
A 2005 study has shown that a raw food vegetarian diet is associated with a lower bone density. This may not be a problem however, as new research appears to indicate that high bone density early in life is associated with osteoporosis, regardless of genetic variation
amenorrhea may be a normal condition of fertile women, and that indeed menstruation as most women experience is neither natural nor healthy, but a consequence of intoxication due to unnatural cooked diets