There’s good news and bad news for those of you looking for an excuse to enjoy your favorite red wine or green tea. The health benefits of these beverages have been touted for years, but the scientific evidence to back up these claims is inconclusive. Cam McDonald-Hyman, senior biology major, investigates.
Cam’s comps talk last Monday was titled “The use of naturally occurring polyphenols in modern medicine: where we are and where we're going.” What gets people so excited about red wine and green tea, as well as other fruits and vegetables, is the polyphenols they contain. Polyphenols are a class of chemical compounds that, as the name might suggest, contain multiple phenol groups in their chemical structure. Plants produce these compounds to defend themselves against fungal and bacterial infection. If we animals ingest these plants, we might be able to take advantage of the polyphenols’ healthy properties for ourselves.
Cam brought up the results of some in vitro studies that suggest that the resveratrol in red wine and EGCG in green tea may help to prevent the metastasis of cancer. Metastasis occurs by three steps: first, a tumor recruits blood vessels to grow towards it, then cancerous cells slough off of the tumor. Finally, the cancer cells pass through the bloodstream and lodge in other parts of the body. Polyphenols appear to hinder all three of these steps by altering gene expression and the regulation of intracellular signaling cascades.
But, he says, don’t reach for that bottle just yet. “You’d have to crush a whole lot of grapes to get enough to make a medicine.” Polyphenols are hard for the body to absorb and are excreted quickly, so in order to consume enough resveratrol to have a medicinal effect, you’d have to consume eight grams of resveratrol a day. That’s about how much resveratrol there is in a liter of wine. (If you are consuming a liter of wine a day, you will have other health problems.)
Also, many of the studies on polyphenols have been conducted in vitro, in isolated animal cells in a petri dish. Resveratrol and EGCG might have a different effect inside an actual living body.
“Resveratrol and EGCG have a lot of potential,” Cam says. One potential avenue of research for the future is to develop synthetic analogs that are harder to metabolize so they stay in the body longer. In the meanwhile, we don’t know if green tea or red wine really help, but they’re delicious regardless. There’s no harm in enjoying them in moderation.
