BOSTON, MASSACHUSETTS. Numerous studies done over the past 30 years have found a strong association between the consumption of fruits and vegetables and a reduced risk of cancer. Two studies just released by the Harvard Medical School now question the validity of this association. The two studies involved 80,000 female nurses and 47,000 male health professionals who were enrolled in 1980 and 1986 respectively. By 1996 the researchers had documented 519 cases of lung cancer in the women and 274 cases among the men. In addition there were a total of 937 cases of colon cancer in the two groups combined. The study participants had completed food frequency questionnaires in 1984 or 1986 in order to determine their intake of fruits and vegetables.
An analysis of the collected data showed that the women who consumed seven or more servings of fruits and vegetables daily had a 21 per cent lower risk of lung cancer than the women who consumed two or less servings a day. There was no correlation between fruit and vegetable intake and lung cancer risk in the men. Apples, pears, oranges, and cauliflower seemed to offer the most protection. The researchers found no association between a high intake of fruits and vegetables and a reduced risk of colon cancer. They do point out that the use of multivitamin supplementation and supplementation with folic acid in particular has been found to protect against colon cancer.
Cancer researchers were clearly disappointed by the results of the new studies, but says Dr. Regina Ziegler, MD of the National Institutes of Health "No one study can discount a lot of other studies" and "A lot of good studies have shown a protective effect for fruits and vegetables and we can't discount that."
Editor's note: It is amazing that the researchers involved did not
consider the possibility that commercial (as opposed to organic) fruits and
vegetables may have deteriorated dramatically in nutritional value in the 30
years since the original studies were done.