Beta Carotene Found Not To Reduce Risk of Cancers of Heart Disease

Vitamin pills fail to give the same protection as fruits and vegetables

By William J. Cromie

Gazette Staff

It seemed too good to be true. Take a beta carotene pill every other day and reduce your chances of getting cancer and heart disease.

It is too good to be true, according to two reports in yesterday's New England Journal of Medicine. One describes how researchers at the Medical School and the School of Public Health gave 22,071 healthy male physicians a 50-milligram beta-carotene pill every other day for 12 years. From the results, they concluded that the supplements offer no protection against these major killers.

The conclusion "is the biggest disappointment of my career," admitted Charles Hennekens, Snow Professor of Medicine and lead author of the study.

In the other investigation, scientists at the Fred Hutchinson Cancer Research Center in Seattle gave beta carotene and vitamin A supplements to 18,318 smokers and others at high risk for lung cancer. After four years, they found no reduction in the incidence of lung cancer or risk of death from lung cancer or heart disease. In fact, they ended the study early when they found an increase in the risk of death from lung cancer among those who took the pills.

Virtually all experts believe that eating lots of fresh fruits and vegetables can protect people against a variety of cancers and heart disease. Beta carotene, a relative of vitamin A, is present in carrots, spinach, broccoli, and leafy, green vegetables. Therefore, it was natural to assume it offered protection against the two biggest killers of Americans. Not so, at least in pill form, according to these reports.

Beta carotene-rich foods contain many other nutrients. Therefore, protection from cancer and heart disease must be due to something else in the fruits and vegetables, or to the lifestyle of those who consume many portions of them.

"Even though beta carotene is ineffective in preventing cancer and cardiovascular disease, other nutrients may not be," Hennekens points out. "Vitamin E supplements still remain promising. They are currently being tested in a large-scale trial [the Women's Health Study] at Harvard as well as in several other studies."

The results of one such trial was reported in the same issue of The New England Journal of Medicine by researchers at the University of Minneapolis School of Public Health. A study of 34,000 postmenopausal women found lower death rates from heart disease among those who ate lots of foods rich in vitamin E. This nutrient is abundant in leafy, green vegetables, vegetable oils, nuts, cereal, wheat germ, meat, and egg yolks.

In contrast, the researchers concluded that vitamin E in pill form does not offer this protection. However, other studies, including one done at the School of Public Health, found reductions in heart disease of 40 to 50 percent among men and women who took vitamin E supplements daily.

The Minneapolis team also reported no reduction in heart disease as a result of taking vitamin A or C supplements. The Harvard vitamin E study also found no connection between vitamin C and a decreased risk of heart disease.

So what should a person do? In an editorial that comments on vitamin studies in general, E. Robert Greenberg and Michael Sporn of Dartmouth Medical School give this advice: "While we wait for a better understanding of [how vitamins and other nutrients work], consumption of more vegetables and fruits, like the use of mosquito nets and window screens, seems a prudent preventive strategy."