Recent studies confirm that dietary methionine restriction increases both mean and maximal lifespan in rats and mice, achieving "aging retardant" effects very similar to those of caloric restriction, including a suppression of mitochondrial superoxide generation. Although voluntary caloric restriction is never likely to gain much popularity as a pro-longevity strategy for humans, it may be more feasible to achieve moderate methionine restriction, in light of the fact that vegan diets tend to be relatively low in this amino acid.
Recent studies of vegetarian diets and their effects on morbidity and mortality are reviewed. Vegetarian diets are heterogeneous as are their effects on nutritional status, health, and longevity. Mortality rates are similar or lower for vegetarians than for nonvegetarians. Risks of dietary deficiency disease are increased on vegan but not on all vegetarian diets. Evidence for decreased risks for certain chronic degenerative diseases varies. Both vegetarian dietary and lifestyle practices are involved.
A cohort of 1,904 vegetarians and persons leading a health-conscious life-style in the Federal Republic of Germany was identified in 1978. After a follow-up of 11 years, mortality from all causes was reduced by one-half compared with the general population [the standardized mortality ratio (SMR) was 0.44 for men, 0.53 for women]. Among the 858 men, 111 deaths were observed, with 255 expected; among the 1,046 women, 114 deaths were observed, with 215 expected.
European journal of cancer prevention: the official journal of the European Cancer Prevention Organisation (ECP)
Chronic deficiency of various vitamins can influence the occurrence of some chronic degenerative diseases such as cancer, cardiovascular pathology, cataract, arthritis, disorders of the nervous system and photosensitivity. Similarly, vitamin intake can influence various disorders in infants and elderly people, in burns and in subjects following unbalanced diets or undergoing strenuous physical exercise. Among vitamins, beta-carotene, vitamin E and vitamin C have received most attention, particularly in the prevention of oxidative damage from free radicals.
Perhaps one of the most unexpected and novel findings in nutritional epidemiology in the past 5 y has been that nut consumption seems to protect against ischemic heart disease (IHD). Frequency and quantity of nut consumption have been documented to be higher in vegetarian than in nonvegetarian populations. Nuts also constitute an important part of other plant-based diets, such as Mediterranean and Asian diets.