Lycopene From Tomato Can't Protect Against Prostate Cancer, New Study

The majority of previous studies have suggested that tomatoes and tomato-based products offer some measure of protection against prostate cancer.

22/06/07 Diet-cancer experts at the American Institute for Cancer Research (AICR) weighed in on a new study which suggests that tomatoes and other foods containing a well-known phytochemical called lycopene offered no protection against prostate cancer in a group of 28,000 men.

The new study, published in the journal Cancer Epidemiology Biomarkers and Prevention, is the latest in a long line of research into the effects of lycopene-containing foods. The majority of previous studies have suggested that tomatoes and tomato-based products offer some measure of protection against prostate cancer.

"This new study is a major contribution to the research, and it will be considered alongside all of the work that has come before," said AICR Nutrition Advisor Karen Collins, RD.

"It's long been clear that loading up on any one food, or food supplement, is not supported by the research," Collins said. "The strongest evidence shows that diets high in a variety of different fruits, vegetables, whole grains and beans are associated with lower risk of developing cancer, including prostate cancer."

New Findings Compared to Previous Evidence

In the coming weeks and months, researchers will continue to examine the new study and place it in context with compelling evidence from previous scientific investigations.

In the laboratory, tomato components have stopped the proliferation of several cancer cells types, including breast, lung, and endometrium. Tomatoes have attracted particular attention from prostate cancer researchers because lycopene and its related compounds tend to concentrate in tissues of the prostate. In animal models, consumption of tomato compounds has been linked to large decreases in prostate cancer risk.

In fact, studies that compare the diets and disease rates of different populations have repeatedly associated diets high in tomatoes with lower prostate cancer risk, as well as lower risk of stomach and pancreatic cancers.

One notable study that tracked the diets of more than 47,000 men for six years found that those who ate the most tomato products (cooked tomatoes, tomato sauce, pizza and tomato juice) had a 35% lower risk of early prostate cancer and a 53% lower risk of advanced prostate cancer than men who ate the least of these foods.

"This new study doesn't close the book on tomatoes and lycopene, it just starts a new chapter," Collins said.

No Magic Bullets

AICR experts repeatedly caution that no single food or food substance should be seen as a magic bullet of protection. All fruits, vegetables, whole grains and beans contain natural phytochemicals, and many of these compounds have shown the potential to protect against cancer development in a variety of ways.

Because many of these substances seem to work in combination, the key is to eat a diet that's high in a variety of the foods that contain them. Loading up on any one food, or a supplement that contains high doses of isolated food components, is not recommended.

Expert Report Will Help Dispel Confusion

On November 1st of this year, AICR and its international affiliate organizations will publish the most comprehensive assessment of the scientific literature on diet, physical activity and cancer risk ever undertaken.

That report, Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective, will synthesize data from thousands of studies and provide guidelines for the public, and for the scientific/medical community. It will provide answers to questions about nutrition and cancer - including the role of lycopene - that are based on a thorough review of the available science.