Producers of tomatoes, tomato sauce and dietary supplements containing lycopene — the substance that makes tomatoes red — will not be allowed to advertise claims that they reduce the risk of many forms of cancer.

The Food and Drug Administration announced Wednesday that it will allow only a few limited health claims to appear on packages of tomatoes and tomato sauce. It also rejected proposals to advertise lycopene as having cancer-related benefits.

The rulings were in response to petitions from American Longevity, which makes health products, and the Lycopene Health Claim Coalition, a group that includes ketchup manufacturer H.J. Heinz Co.

The groups contend the lycopene within tomatoes reduces the risk of a number of cancers, including prostate, colon and breast cancer. They offered a number of published studies that they said supported their assertion.

But in its response to American Longevity's petition, the FDA questioned many of the studies, saying they were not conclusive.

American Longevity contends it has a free-speech right to make the statements, which are governed under two-year-old regulations allowing qualified health claims on some products where the science is less than universally accepted.

"The FDA decision greatly misleads the American consumer," said Steve Wallach, general manager of American Longevity, in a statement. "The American public is entitled to the whole truth and we will do all we can to prevent the FDA from keeping this scientific information from the American people."

Still, the agency authorized four tomato-related claims to be used on product labels, saying there was "very limited credible evidence" they provide a health benefit. The authorized claims must be heavily qualified:

—Prostate cancer: "Very limited and preliminary scientific research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate cancer. FDA concludes that there is little scientific evidence supporting the claim."

—Gastric cancer: "Four studies did not show that tomato intake reduces the risk of gastric cancer, but three studies suggest that tomato intake may reduce this risk. Based on these studies, FDA concludes that it is unlikely that tomatoes reduce the risk of gastric cancer."

—Ovarian cancer: "One study suggests that consumption of tomato sauce 2 times per week may reduce the risk of ovarian cancer; while this same study shows that consumption of tomatoes or tomato juice had no effect on ovarian cancer risk. FDA concludes that it is highly uncertain that tomato sauce reduces the risk of ovarian cancer."

—Pancreatic cancer: "One study suggests that consuming tomatoes does not reduce the risk of pancreatic cancer, but one weaker, more limited study suggests that consuming tomatoes may reduce this risk. Based on these studies, FDA concludes that it is highly unlikely that tomatoes reduce the risk of pancreatic cancer."