Some historical context will help put things into perspective. Most studies have concluded that breast cancer risk is increased by alcohol consumption, though the effect at moderate drinking levels is a very difficult thing to measure. On the other hand, it is well-documented that moderate regular consumption of wine is associated with longer life and lower rates of diseases such as cancer, diabetes, atherosclerosis, and Alzheimer’s. Though red wine contains a number of antioxidant molecules, resveratrol has emerged as one of the more interesting ones despite that fact that wine doesn’t actually have very much of it. Nevertheless, resveratrol is touted as the explanation for the French paradox and an anti-aging miracle. So more sober-minded scientists can be forgiven a bit of cynicism here.
Resveratrol does do some very interesting things though, at least in laboratory studies. One vein of research follows the observation that wine drinkers tend to have lower rates of osteoporosis. This it turns out is explained by resveratrol’s estrogen-like properties. Tied with an impressive array of specific anti-cancer effects (again, in lab studies not clinical trials) it seems that something must be going on with resveratrol and breast cancer. But since many breast cancers are “estrogen receptor positive” (ER+) meaning that too much estrogen could encourage cancer growth, it is important to know the details.
This recent study helps to sort that out, by looking specifically at ER+ cancer cells. What the researchers found was that resveratrol appeared to turn off the gene that makes estrogen receptors, reducing the number of receptors in the cells and ramping down cell growth. Combined with non-ER-related cancer fighting properties, resveratrol or its derivatives could very well be useful in fighting breast cancer. The road to effective cancer treatments is littered with false starts and dead ends, however, so the smart money will wait for clinical trial data.