Monday December 14 2009
Could champagne have the same health benefits as previously found in red wine?
Champagne is good for the heart, according to The Daily Telegraph. It says that a study has “found that champagne has the same health benefits as previously found in red wine”, and may reduce strokes and heart disease.
This small study in 15 healthy volunteers compared the effects of champagne with a “dummy” drink containing similar amounts of alcohol, fruit sugars and acids. It found that champagne had some short-term effects on the blood vessels that were not seen with the dummy drink, and these effects may be due to the polyphenol chemicals it contains. However, these effects on blood vessels are very different to clinical outcomes such as heart disease. Therefore, this study cannot tell us whether moderate consumption of champagne would have an effect on cardiovascular risk.
While claims that champagne has health benefits may seem cause for celebration, this study does not prove these claims, so it’s probably best to leave the bubbly on ice for now.
Where did the story come from?
This research was conducted by Dr David Vauzour and colleagues from the University of Reading and research centres in the Champagne region of France. The study was funded by the Biotechnology and Biological Sciences Research Council in the UK. The study was published in the peer-reviewed British Journal of Nutrition.
The Daily Telegraph, Daily Mail and The Observer have reported on this study. The newspapers take a lighthearted approach to this story, and overall their coverage is probably more positive than this research merits. None of them pointed out that the effects on heart disease are not yet clear.
What kind of research was this?
This was a single-blind, randomised, crossover trial that looked at the effect that drinking champagne had on volunteers’ blood vessels. Previous studies have suggested that moderate red wine consumption may reduce the risk of heart disease. The researchers wanted to assess whether champagne might have the same effects on blood vessels and, therefore, heart disease. It's thought that the polyphenol chemicals in wine are responsible for the heart-protecting effects found by some studies.
This was a randomised controlled trial, which is an appropriate way to compare the effects of different exposures. However, this study only looked at “proxy” outcomes, in this case effects on blood vessels. Proxy outcomes are often used because they are quicker and easier to measure than clinical outcomes. Different proxy outcomes vary in their ability to indicate whether a clinical outcome might be affected by a treatment.
While proxy outcomes can be considered to be a small step towards looking at more important clinical outcomes, such as heart disease, they should not be taken as proof that a particular treatment will alter the risk of a clinical outcome.
What did the research involve?
The researchers enrolled 15 healthy adult volunteers from the Reading area (average age 39.5, average BMI 23.6kg/m2). The volunteers were asked not to consume wine and other foods containing large amounts of polyphenols for 48 hours before the start of the study, and for 32 hours after the study commenced.
Before the start of the study, the researchers took the volunteers’ body measurements, plus scans of their blood vessels and samples of their urine and blood. The volunteers were then asked to drink either 375ml of champagne (12% alcohol and made from Chardonnay, Pinot Noir and Pinot Meunier grapes) or a control drink containing the same amount of alcohol, fruit sugars and acids. The drink each volunteer received was randomly assigned.
The researchers then collected multiple blood samples and two urine samples over a period of 32 hours after the volunteers drank the champagne or control drink. The researchers tested the volunteers’ urine to see if it contained chemicals formed during the breakdown of polyphenols.
The volunteers also had the blood vessels in their arms scanned at intervals up to eight hours after the start of the experiment. The researchers did this to look at whether or not the blood vessels had dilated (got wider), allowing increased blood flow. Two different types of dilation were tested through applying chemicals to the skin. One test, using acetylcholine, identifies dilation caused by the cells that line the blood vessel walls. The other test, using sodium nitroprusside, identifies dilation that is not dependent on the cells lining the blood vessels.
After 28 days, the volunteers returned to the laboratory to repeat the experiment. This time they drank the drink they had not had in the first experiment, i.e. those who had the champagne in the first experiment had the control drink, and vice versa.
Although the study was reported as a single blind, it is not clear whether this blinding was of the volunteers drinking the drinks or of the researchers assessing the outcomes of the drinks. Although there was an attempt to create a drink of similar taste and appearance to champagne as a control, it is quite likely that the participants could tell the difference.
What were the basic results?
Both the champagne and the control alcoholic drink caused the type of blood vessel dilation that relied on the cells lining the vessels. This dilation peaked at four hours and returned to normal by eight hours after the drink. However, over the eight-hour period, the champagne caused more of the other type of blood vessel dilation, which did not depend on the cells lining the vessels.
Among other biochemical findings, the researchers found that when the volunteers drank champagne, their urine contained more of the chemicals formed in the breakdown of polyphenols than when they drank the control drink.
How did the researchers interpret the results?
The researchers concluded that their findings suggest that drinking champagne in moderate amounts “may help to improve cardiovascular risk” due to its effects on the blood vessels. They say this may be caused by the polyphenols in the champagne.
This small study suggests that champagne has some short-term effects on the blood vessels that are not solely caused by its alcohol content. These may be due to polyphenols. However, the “proxy” outcomes of blood vessel dilation tested are a long way from clinical outcomes, such as heart disease. Therefore, this study cannot tell us whether moderate consumption of champagne would have an effect on cardiovascular risk. To answer this question, there would need to be further studies that compared health outcomes in people who drink champagne and those who do not. However, it seems unlikely that enough people consume champagne frequently enough for this type of study to detect any benefits.
In this festive season, people may use this study as a reason to enjoy champagne in moderation. However, their optimism may be misplaced if they expect to reduce their heart disease risk by doing so.