A study published in the September 1996 American Journal of Epidemiology supports Kennedy's theory. The study examined 747 elderly people (age 60+) for nine to 12 years, focusing on food intake and vitamin C, vitamin E and beta-carotene levels in the blood. Those with daily intakes of vitamin C of 400 mg and higher had a lower incidence of death from heart disease than the other study participants. Another study, published in the British Medical Journal in 1995, determined that of 730 study participants, those with high intakes of vitamin C had a much reduced incidence of death from stroke than those participants with lower vitamin C intake levels.
vitamin C and cancer prevention
In terms of cancer prevention, vitamin C has been widely studied. A review article published in the 1991 American Journal of
Clinical Nutrition (54:13105-13145) stated that of 90 epidemiologic studies examining the role of vitamin C in cancer prevention, "the vast majority have found statistically significant protective effects:" However, several studies demonstrate that vitamin C has no effect on cancer. For example, one study described in the 1996 Journal of the National Cancer Institute (88:340-348) stated that there was no association between breast cancer risk and intake of vitamin C. Another study published in the same journal in 1993 (85:1483-1492) stated that vitamin C consumption had no significant effect on mortality rates from stomach and esophagus cancers.
vitamin C and stress relief?
Researchers are also reviewing vitamin C's relation to stress. There are only four species of mammals that cannot produce ascorbate in the body - fruit bats, gorillas, guinea pigs and humans. During times of stress, it has been noted that animal species produce higher amounts of their natural ascorbate to ward off disease, infection or emotional stress, according to Kennedy. A study conducted by P Samuel Campbell of the University of Alabama-Huntsville, which was presented at the 1999 American Chemical Society conference, demonstrated that with vitamin C supplementation, stress hormone secretion and other signs of stress in rats were reduced. The study also concluded that rats, and perhaps people, under emotional stress might benefit from higher doses of vitamin C to protect immune function.
