Wednesday, April 7, 2010

Does the type of wine matter?

Questions that seem to come up frequently when I am lecturing about wines include “Does it have to be red in order to get the health benefits?” and “Which types of wine have the highest amount of the healthful polyphenols?” To answer the first, red wines do have much higher levels of resveratrol and other beneficial compounds for several reasons. Since these compounds come from the skins and seeds, the whole grape (berry) must be fermented together in order for optimal extraction. White wines are made by pressing out the juice and then fermenting it without contact of the skins and seeds. So yes, it has to be red for the full dose, and it has to be wine not grape juice.

The second question is a bit trickier. There are natural variations among the different varietals of grapes that wine is made from, but the terroir (local conditions) and methods of viticulture probably have more to do with it. To understand why this is the case, consider why grapes make resveratrol and other polyphenols in the skins in the first place: it is for protection against environmental stress. That is of course the reason why they are such potent antioxidants and anti-microbial agents.

One grape that seems to struggle mightily is pinot noir, so pinots are known to have high levels. One Oregon producer of pinot noir wines has petitioned for permission to state resveratrol content in the wines, which the government has resisted because people might start thinking that wine is actually a healthy beverage (it is.) But other reds have healthy polyphenol content too, and there are several studies now comparing the amount of resveratrol in similar wines from different parts of the world and with different traditions of winemaking.

In the end it may not be all that important, since the evidence that resveratrol explains all of the benefits of wine is pretty scant; for one thing, even wines with high resveratrol levels still don’t have much compared to the amounts used in laboratory studies. Other studies point to the combination of all of the compounds in wine working together as the key, including alcohol. So the answer is drink whatever kind of red wine you enjoy, and if you don’t like red maybe you should continue looking for one that you can at least suffer through.

Thursday, April 1, 2010

More good news about chocolate and wine

Just in time for your Easter egg hunt, more news that chocolate is good for you. A report out just this week from the German Institute of Human Nutrition in Potsdam confirmed that people consuming chocolate on a regular basis had lower rates of heart attack and stroke. The study was impressive in scope, monitoring nearly twenty thousand subjects over a ten-year period, after a dietary assessment at the beginning. It was part of a large project called the European Investigation into Cancer and Nutrition. Those in the top chocolate consumption group had 40% fewer heart attacks and strokes over the course of the study as compared to the low chocolate consumers. A reduction in blood pressure was identified as the reason.

It has been known for some time that compounds called polyphenols, found in both chocolate and wine, are able to relax blood vessels and thereby lower blood pressure. A study from the Institute of Food Safety in the Netherlands (why are the Europeans having all the fun with wine and chocolate studies?) identified exactly how this occurs. A molecule called Nitric Oxide, or NO, is the chemical signal for blood vessels to relax, and certain compounds from wine and chocolate have the specific ability to stimulate NO release. Among these are resveratrol (from wine) and compounds in a family of molecules called catechins, from both wine and chocolate.

These molecules are in much higher quantities in dark chocolate and red wine, so the chocolate eggs in your Easter basket might not be the best way to get the health benefits. Go for something dark and leave the milk chocolate goodies for the kids. And my recommendation for the wine with your ham (a problem match because of the saltiness) is Grenache.