Tuesday, March 31, 2009

Should wine labels make health claims?

Winemakers have been in a debate for some years now with the U.S. Department of Treasury's Alcohol, Tax and Trade Bureau (formerly the ATF, for Alcohol, Tobacco, and Firearms--yeah, that made a lot of sense) about ingredient listing for wines, particularly since the healthful properties of wine polyphenols such as resveratrol have been widely publicised. A couple of years back, an Oregon pinot noir producer gained approval for a fairly benign claim: "Pinot noir develops a natural defense against botrytis (mold) in our moist, cool climate - the antioxidant resveratrol." Since resveratrol is indeed produced in the skins of grapes subjected to certain environmental stresses such as mold, and Oregon's climate is certifiably moist, it seems a fairly harmless claim. However, the feds simultaneously disallowed placing the same wording on another vintage from the same producer, citing concern about making therapeutic claims on labels or creating "misleading" associations between the consumption of alcohol and health.
With more than 2500 scientific publications on the healthful effects of resveratrol, it may seem that the ATTB has some catching up to do. Wine is demostrably a health food when consumed in the right amounts and in the right pattern. But the problem that I have with expanded labeling is that it gives too much credit to the individual ingredients and not enough emphasis on healthy drinking and associated lifestyle choices. For all of resveratrol's impressive properties, clinical data about its effects in people is still lacking. We know that it does wonderful things in a petri dish or a lab rat, but frankly not much else.
So rather than making claims about how magical the components of wine are, the debate really should be about whether or not wine itself is good for you. How about this on the label: "When consumed in moderation, with meals, wine can be an important part of a healthy lifestyle."

Monday, March 23, 2009

drink with a friend

When I was growing up in California, there were periodic droughts that resulted in mandates to cut down on water use, and one of my favorite pieces of advice was to shower with one or more friends. Now it turns out that drinking with friends has measurable health benefits. It seems obvious that drinking alone is not necessarily a good thing, but a new study from Japan provides actual data that social drinking--in moderation--is healthful. (Whether it also leads to communal bathing remains a personal choice.)
The data comes from a large prospective public health study in Japan involving more than 19,000 subjects evaluated for the incidence of stroke and heart disease relative to drinking habits. As one would expect, light-to-moderate drinkers had fewer episodes (this has been reported in studies too numerous to list) and heavy drinkers had more. In epidemiology this is known as a J-shaped curve, about which more in my book. What was unique about this study was the use of a measure called the "social support score" which looks at patterns of social behavior. When this was applied as a filter (a tool known as stratification) the risk of stroke was significantly lower among social drinkers.
There are a number of ways this can be interpreted. The most likely one is that it is simply a "marker" for healthy behaviors and a healthful drinking habit. But from an anti-aging point of view, it is an important finding, as it reinforces the well-known phenomenon of people living longer when they are connected and engaged in their communities. This study provides a link between the two.
I say cheers to that. Join me for a glass of wine?

Tuesday, March 10, 2009

red, white, and breast cancer

The red vs white debate is enough to make me blue. Red wine, with very few exceptions, has much higher levels of the polyphenols to which many but not all of wine's benefits are attributed. In recent weeks, reports came out that it didn't matter whether it was even wine or any other alcoholic drink, breast cancer risk was apparently raised by as little as a glass a day. As I have pointed out in previous posts, there are too many problems with the way the data for these studies is gathered to say anything that definitive, but now a study from the Fred Hutchinson Cancer Research Center here in Seattle weighs in with the red vs white wine question. They were particularly interested because earlier studies from the Hutch (as we call it here) found that red wine drinking correlated to lowered odds of prostate cancer in men, and a large body of research suggests that wine polyphenols are effective at countering breast cancer.

The study, funded by the National Cancer Institute, was looking for reduced risk of breast cancer with red wine. What they found was that more than 14 drinks per week correlated to an increase of 24% in breast cancer incidence, regardless of type. The authors were careful it appears to not make the mistake that many others do in interpreting the data, however, which is to extrapolate backwards from 2 drinks per day equalling 24% risk to 1 drink implying a 10-12% risk. The reason it is a mistake is that there is no way of measuring self-reported behavioral data that accurately so the effects of a drink a day are essentially unknowable. This is especially true because there are so many other studies showing that moderate drinking is beneficial, in terms of cancer risk and many other health factors. And of course there are few people who really only drink one type of alcoholic beverage and in the same amounts every day.

The authors did recommend that women should limit drinking to one per day, which is probably sensible especially if you are in a higher than average cancer risk category. I'm still in the red wine camp, at least where healthy drinking is concerned.

Friday, March 6, 2009

Wine lowers risk of esophageal cancer

Last week the news was that wine is supposedly equal to any other type of alcoholic beverage in encouraging the development of cancer, particularly of the digestive tract, even when consumed in moderate amounts. This week it is the opposite, at least in terms of one especially nasty type of cancer involving the esophagus. Wine drinkers, it turns out, have a lower risk because they tend not to get as much reflux of stomach acid up into the lower esophagus, which causes inflammation. This condition is called Barrett's esophagus and is not only miserable but potentially deadly because it predisposes to cancer.
It reminds me of my days as a general surgery resident, when one of the most common conditions leading to surgery was stomach ulcers. (They are prone to bleeding and numerous other unfortunate consequences.) Standard advice regarding ulcers was to avoid spicy foods and alcohol, in the belief that these encouraged the stomach to produce more acid. It was some years later that we learned that the culprit in most cases was a type of bacteria, which as luck would have it is inactivated by wine polyphenols. So ironically we should have been encouraging these patients to have wine with dinner, contrary to all prevailing logic.
The real point here is that studies of this type, called population studies, require a healthy degree of skepticism in order to derive anything useful. For one thing, they rely on self-reporting of drinking habits, which is notoriously unreliable; for another, there are few populations with consistent drinking patterns anymore. The best information actually comes from studies done years ago when such populations did exist, for example in rural France. These studies consistently find health benefits to regular moderate consumption of wine. The final lesson here is that regular moderate wine drinking is linked to other healthy behaviors, so that it can't be reduced to a chemical formula and put into a pill. So when you see the ads for the newest supplement touting "all the benfits of wine without the alcohol" you know it just ain't so.