Two studies released this week link specific forms of cancer with the consumption of certain meats, but ACSH is skeptical. In one study, published in the American Journal of Clinical Nutrition, researchers found that women who ate a lot of processed meat had an 18 percent greater risk of ovarian cancer than those who ate little or none, while the other study suggests frequent eaters of well-done meat increased their risk of bladder cancer.
ACSH's Dr. Gilbert Ross says the Clinical Nutrition study has its problems. It was a retrospective dietary recall study that asked participants to try to remember what they had eaten over five years, he says. Also, rather than being a randomized, double-blind study, it was a case control study that matched participants by age and sex. Given those limitations, he says an increased risk of just 18 percent is simply not meaningful.
"This is an example of a study that really shows absolutely nothing," Dr. Ross says.
The other study, presented Monday at the annual meeting of the American Association for Cancer Research, showed participants who ate the most red meat had a 50 percent greater chance of developing bladder cancer than those who ate the least. The study looked at 884 patients with bladder cancer and 878 without it.
"This is a whole new one on us," says Dr. Whelan of the study. "It's out of the mainstream, and has not yet been peer-reviewed."
Dr. Ross says while the 50 percent correlation in the bladder-cancer study is more meaningful than the 18 percent link in the Clinical Nutrition study of ovarian cancer, more research is needed -- such as a prospective study that looks at what people eat over five years.
Dr Ross added: "While this should generate further research, there's no reason for anyone to change their dietary habits because of this one study."