Vegetarians generally have a lower incidence of cancer than other populations, but the reasons for this are not yet fully understood.
It is also not clear to what extent the nutrient contributes to the reduction in disease among vegetarians. When factors other than diet are approximately the same, the difference in cancer rates among vegetarians and non-vegetarians decreases, although differences in rates for some cancers remain significant.
An analysis of the indicators of some groups of vegetarians with the same age, sex, attitude to smoking did not find a difference in the percentage of cancer of the lungs, breast, uterus, and stomach, but found huge differences in other cancers.
Thus, in vegetarians, the percentage of prostate cancer is 54% less than in non-vegetarians, and cancer of the proctology organs (including the intestines) is 88% less than in non-vegetarians.
Other studies have also shown reduced rates of neoplasms in the gut in vegetarians compared to non-vegetarians, and reduced blood levels in vegans of type I proinsulin growth factors, which scientists believe are involved in the development of some cancers, compared even with vegetarians and vegetables. -lacto-vegetarians.
Both red and white meat have been shown to increase the risk of bowel cancer. Observations have found an association between increased intake of dairy products and calcium and an increased risk of prostate cancer, although this observation is not supported by all researchers. A pooled analysis of 8 observations found no association between meat consumption and breast cancer.
Research suggests certain factors in a vegetarian diet may be associated with a reduced risk of cancer. The vegan diet is very close in composition to the diet prescribed by the National Institute for Cancer Research.than a non-vegetarian diet, especially regarding fat and bio-fiber intake. While data on fruit and vegetable intake by vegetarians is limited, recent studies have shown that it is much higher among vegans than among non-vegetarians.
The increased amount of estrogen (female hormones) that accumulates in the body throughout life also leads to an increased risk of breast cancer. Some studies show reduced levels of estrogen in the blood and urine and in vegetarians. There is also evidence that vegetarian girls start menstruating later in life, which may also reduce the chance of developing breast cancer, due to a reduced accumulation of estrogen throughout life.
Increased fiber intake is a factor in reducing the risk of bowel cancer, although not all studies support this claim. The gut flora of vegetarians is fundamentally different from that of non-vegetarians. Vegetarians have significantly lower levels of potentially carcinogenic bile acids and intestinal bacteria that convert primary bile acids into carcinogenic secondary bile acids. More frequent excretion and increased levels of certain enzymes in the gut increase the elimination of carcinogens from the gut.
Most studies show that vegetarians have significantly reduced levels of faecal mutogens (substances that cause mutations). Vegetarians practically do not consume heme iron, which, according to studies, leads to the formation of highly cytotoxic substances in the intestine and leads to the formation of colon cancer. Finally, vegetarians have an increased intake of phytochemicals, many of which have anti-cancer activity.
Soy products have been shown in studies to have anti-cancer effects, especially in relation to breast and prostate cancer, although not all studies support this view.