Research, for example, has found that people who for years had followed a vegetarian, fiber-rich diet had lower blood levels of several hormones and other substances linked to certain cancers compared to people of the same average age (53) eating a Western-style diet full of high-fat, high-protein meat and dairy products and heavily processed foods like fast foods, potato chips, and candy.(1)
Another group that was studied, long-distance runners eating a largely Western-style diet, also had higher levels of most of these cancer-linked substances.
Lower levels of cancer-linked IFG-1
The vegetarians had a big edge over both runners and the Western diet group because they were the only group that had markedly lower levels of a body protein called IGF-1, or insulin-like growth factor. High IFG-1 levels are associated with “a greater risk of breast (premenopausal), prostate, and colon cancers,” explained lead author Luigi Fontana, MD, and colleagues from Washington University School of Medicine in St. Louis.
Several past studies of people attending the Pritikin Longevity Center have also demonstrated dramatic drops in IGF-1, and in just two to three weeks of adopting the Pritikin Program.(2,3,4)
What makes the results from the Washington University study noteworthy is their suggestion that the IGF-1-lowering effects of a healthy diet are long lasting. Not just for a few weeks but for years and years does a fiber-rich, whole foods diet keep IGF-1 levels low.
Moreover, the healthy eating plan in and of itself – irrespective of its effect on body weight – was the major force behind the vegetarians’ low levels of IGF-1. The runners were just as lean as the vegetarians, but only the vegetarians reaped low IGF-1 levels.
The vegetarians ate a wide variety of vegetables, fruit, nuts, seeds, whole grains and cereals “and strictly avoided processed and refined foods (eg, partially hydrogenated oils, refined flours, sweets, free sugars, and soft drinks) and foods of animal origin,” described Dr. Fontana and his team.
Superfoods and Fiber
The daily fiber intake of the vegetarians was much higher than that of the runners and Western diet group. The men in the vegetarian group tallied up an average 60 grams of fiber a day from the food they ate; the runners and Western diet group consumed just 34 and 25 grams, respectively.
And though they ate plenty of food, the men and women in the vegetarian group took in, on average, nearly 350 fewer calories each day compared to the Western diet group.
To the media and in medical conferences worldwide, Dr. Fontana advised people to eat more fruits and vegetables, fiber-rich whole grains, beans, and fish, and less red meat. “It’s the superfoods diet not just for your heart but also, as this new research suggests, for cancer protection as well,” sums up Pritikin’s Director of Nutrition, Kimberly Gomer.
1. American Journal of Clinical Nutrition, 2006; 84: 1456.
2. Nutrition and Cancer, 2006; 55: 28.
3. Prostate, 2003; 56: 201.
4. >Journal of Applied Physiology, 2004; 96: 450.