Lower Vitamin C Means Higher Cancer Risk for Men
July 18, 2000 -- Guys, here's another reason to drink your orange juice: A new study has found that men with low blood levels of vitamin C may have an increased risk of dying of cancer. Women who were low in vitamin C seemed to be spared this risk.
These findings echo those of earlier studies showing "that low vitamin C levels put people at risk," lead researcher Catherine M. Loria, PhD, tells WebMD. In those studies, however, the risk is shared by both sexes. Loria isn't certain why these data singled out men.
Loria, an epidemiologist at the National Heart, Lung, and Blood Institute, and her colleagues analyzed data gathered between 1976 and 1980 for the National Health and Nutrition Examination Survey II, a snapshot of the nutritional status of the U.S. population.
In all, more than 9,000 men and women aged 30 to 75 participated. In 1992, the authors followed up with those subjects, looking at their weight, intake of vitamins A and E, blood pressure, diabetes status, and patterns of smoking and alcohol consumption, as well as their levels of vitamin C. More than 7,000 of the original subjects were available for the follow-up study.
During the 12- to 16-year follow-up period, approximately 800 men and 600 women died. The investigators found that men with the lowest blood levels of vitamin C had a 57% higher risk of dying of cancer than did men whose vitamin C was highest. In women, on the other hand, there was no relationship between vitamin C levels and the risk of death from either cancer or heart disease.
"I'm not sure why we didn't see [an increased cancer mortality risk] in women," Loria says. One possible explanation is that women tend to have higher vitamin C levels than men. Also, she says, vitamin C seems to confer its greatest protection against cancers like lung cancer, which, unlike breast or prostate cancer, are not related to hormone levels. Since men were more likely to develop non-hormone-related cancers, they also would be more likely to suffer the consequences of having too little vitamin C.