Beer for Your Prostate? Pistachios Against Cancer? Studies We Wish Were True
Experts explain how to read the studies we wish were true.
Dec. 11, 2009— -- It is another study with broad appeal but not a lot of science behind it yet. It says -- at least in headline form -- that drinking beer may help men ward off prostate cancer.
There are some studies people just want to believe. Even if they're disproven by later ones.
Beer is hardly the first popular food to get headlines because of a study that suggests it may be good for you. At the same Houston conference as the beer study, other researchers presented a small study suggesting that pistachio nuts may help prevent lung cancer.
Coffee is also a popular subject for studies that draw headlines, although its potential benefits have been better studied. But in recent years, any number of foods have gotten headlines for possible health benefits, whether it be boosting the immune system or preventing cancer.
(The cynical might note that we are learning about all these presumed superfoods at a time when we know people are eating more of everything -- including things that are good for you.)
"Small studies are better than no studies at all, but usually small studies require more studies, and I wouldn't recommend someone change their decisions or change their diet based on a small study," said Keith-Thomas Ayoob, director of the nutrition clinic at the Albert Einstein College of Medicine.
Neither the beer study nor the pistachio study quite say there are long-term benefits in humans. The beer study showed an ingredient in hops that might be beneficial, while the pistachio study showed that people absorbed vitamin E when they ate them. The authors noted that vitamin E has been shown to help prevent lung cancer. Of course, with a finding from a small study, other findings can easily knock them down.
"Basically, we've got a series of weak links here," said Dr. David L. Katz, director of the Yale Prevention Research Center. "Interventional studies (studies where vitamins are given to subjects) of vitamin E have shown an increased cancer risk."
He noted that the increased cancer risk was a variant of the form looked at by researchers in the current study, but the bottom line, he said, is that people cannot smoke and expect a pistachio-heavy diet to protect them.
"Do not make this your insurance policy against lung cancer," said Katz.