The prescription pad, cont.

While no-one who doesn't work for the grocery manufacturing and meat and potato frying industries any longer disputes that eating your veggies and whole grains is a good way to avoid heart disease and diabetes, the picture got murky for a while on cancer. Epidemiological studies seemed to point to protective effects against cancer of what was also a heart-healthy diet, but when they tried prospective trials using supplements of anti-oxidant vitamins -- the ingredients in veggies thought to be protective against cancer -- they didn't work.

But maybe it wasn't the vitamins after all. A case control study by Matthew Schabath and colleagues in the Sept. 28 JAMA, in which lung cancer patients were matched with controls (mostly smokers, obviously), assumes that it's not the vitamins after all but chemicals called phytoestrogens that do the protecting. These are compounds in plants that resemble the hormone estrogen, but their biological effects are complex. Some may act like a weak version of estrogen, others may block estrogen receptors and reduce the activity of estrogen in some cells. They effect different estrogen receptors in different ways. So we don't have a straightforward explanation of why they might protect against certain cancers.

Nevertheless, the results of this study were quite dramatic. They were more powerful in men than in women (not surprisingly, it would seem, as women have higher estrogen levels than men to begin with). People with the highest levels of phytoestrogen consumption appear to have reduced risk of lung cancer of something like 1/3 to almost 1/2 -- even if they smoke.

The most important sources of these compounds are peas and beans, soybeans and soy products (not a whole lot in tofu, though), and some kinds are also found in leafy vegetables, cruciferous vegetables (eat your broccoli George), fruits, vegetable oils, tea and coffee, although the compounds in tea and coffee don't seem to be as protective.

Anyway, don't sweat the details. Eat legumes for protein, whole grains, vegetables and fruits, and you can't go wrong. Drink tea if you want, it sure won't hurt anything.

Caution: This study design cannot prove that it is actually these foods and these compounds that are protective. It could be other plant compounds that are found along with these, or something else that the people who eat these foods tend to do. But what the hell, it's one more reason to do what you already know is right.

Oh yeah, weren't those hippie wackos saying all this 30 years ago?