The raw-foods movement took hold in the mid-1970s with the publication of Survival into the 21st Century, a book that purported the diet could resolve physical ailments and extend lifespan. Its unlikely author: Viktoras Kulvinskas, a former computer consultant for MIT. Three decades later, the diet still thrives.
High-profile devotees, such as actors Demi Moore and Woody Harrelson and Chicago chef Charlie Trotter, shun animal products and heat-processed grains; they eat nuts, seeds, sprouted grains, fruits and vegetables—ones that haven’t been heated past 118°F.
The theory is that consuming uncooked foods boosts energy, aids in weight loss and prevents disease. Heat-processing destroys digestion-aiding enzymes and creates tissue-damaging toxins—two reasons why raw foods are healthier, say the diet’s advocates.
Supporting evidence for the “enzyme hypothesis” and reduced toxin loads are lacking, but limited studies do suggest some health benefits—and risks. A 2005 study in the Journal of Nutrition found that raw-foodists were far less likely than the general population to register high levels of “bad” LDL cholesterol. On the flip side, 38% of the study’s 201 subjects were deficient in vitamin B12, a nutrient that’s also important for heart health. A 2005 study in Archives of Internal Medicine reported that raw-foods-diet followers had significantly lower body-mass indices (a measure of body fat) than people consuming a typical American diet; they also had lower bone densities, a risk factor for osteoporosis.
Experts say: “There’s no doubt that plant-based diets have been linked with a lower risk of obesity and other chronic diseases, but because the raw-foods diet is so restrictive, its followers are at risk for deficiencies of vitamin B12 and omega-3 fatty acids if they don’t take supplements,” says Andrea N. Giancoli, M.P.H., R.D., a spokesperson for the American Dietetic Association in Los Angeles. “And the diet isn’t based on science: cooking destroys some nutrients, but it makes others (like the lycopene in tomatoes) more absorbable.”
Our bottom line: Our digestive systems have their own enzymes; we don’t need to get them from foods. The benefits of raw-foods diets—reduced cholesterol and weight control—can be achieved by eating more vegetables, fruits and whole grains, limiting foods high in saturated and trans fats, and using portion control.