Auburn, Feb. 27---Do fruits and vegetables play a role in preventing breast cancer?

Although some experts aren’t convinced, at least one nutritionist strongly believes they do play a role, if only indirectly.

A recent study involving more than 350,000 women concluded diets rich in fruits and vegetables probably do not play a role in preventing breast cancer.

The study, which was published recently in the Journal of the American Medical Association, revealed women with the highest consumption of fruits and vegetables – between 4.5 and 10 servings a day – had about a 7 percent lower risk of breast cancer. However, this was not considered statistically significant.

Scientists are reasonably sure fruit- and vegetable-rich diets play a significant role in safeguarding against other forms of cancer, such as colon or lung cancer. However, breast cancer, which is linked with high levels of estrogen production in the body, works differently from other forms of cancer.

On the other hand, researchers have uncovered strong evidence to indicate high-caloric and high-fat diets as well as high levels of body fat may contribute to a higher breast cancer risk. For this reason alone, women would find high-fruit and -vegetable diets beneficial, says Dr. Robert Keith, an Alabama Cooperative Extension System nutritionist.

"Scientists suspect there is a link between calorie intake, fat intake and body fat and breast cancer," Keith says, "It appears, for example, that women with higher proportions of body fat produce more estrogen, which may increase breast-cancer risk."

"For example, studies have shown women in Asian countries who consume low-fat diets and have a much lower level of body fat as compared with Westerners have a very low incidence of breast cancer."

Despite this intriguing evidence, Keith says the findings are still inconclusive. Soy, which is a staple in many Asian diets, also has been linked to lower rates of breast cancer. Could it be that soy plays a bigger role than fruits and vegetables? As far as Keith is concerned, the jury is still out on this question.

"Soy contains some compounds that appear to be estrogenlike and that bind to the receptors in breast tissue in a way that prevents estrogen binding, thereby possibly decreasing a woman’s chances of getting breast cancer," he says. "Still, this is only conjectural."

Even so, Keith says women have every incentive to follow low-fat, fruit- and vegetable-rich diets, because they have been proven time after time to be vital safeguards against other forms of cancer.

"There appears to be a strong link between colon cancer and diet and exercise," Keith says. "The incidence of this type cancer goes way down among people who eat lots of fruits and vegetables and exercise regularly."

Also noteworthy is the link between diet and exercise and lung cancer, another major cancer killer, which is almost entirely caused from smoking.

Although Keith’s first recommendation for preventing lung cancer is not to start or to quit smoking, he says fruit and vegetable diets and exercise appear to provide some degree of protection among people who smoke.

The advice to eat more fruits and vegetables are as valid for men as they are women, Keith says, partly because in addition to providing a safeguard against colon and lung cancer, diet and exercise appear to be major factors in reducing prostate cancer risk among men.

For example, studies have shown lycopene, a carotenoid associated with redness in tomatoes and widely believed to play a role in safeguarding against prostate cancer, actually accumulates in the prostate gland.

Like breast cancer, prostate cancer is a hormonal type cancer associated with high productions of sex hormones – in this case, testosterone. For this reason, fitness may also play a major role, because generally high levels of aerobic exercise may lower circulating levels of testosterone. In addition, exercise may reduce prostate cancer by working in other ways that are presently not yet clear to researchers.

Robert Keith, Alabama Cooperative Extension System nutritionist, 334-844-3273.