It’s been a big week for anybody watching the news on alcohol and health. Late on Tuesday, a much-anticipated report on alcohol was released that confirmed that moderate drinkers have lower all-cause mortality than non-drinkers.
In other words, drinking a small amount of alcohol is better for your health than not drinking at all.
The significance of that report by the National Academies of Science, Engineering and Medicine (NASEM) is that it was written by one of the teams tasked with evaluating the alcohol evidence as part of the overhaul of the US Dietary Guidelines for Americans (DGAs). The results are informed by the best possible science.
There was so much noise about that report that it dampened the news of another important study—one that shows that drinking a moderate amount of wine lowers the risk of serious heart disease in those at high risk, provided they’re following a Mediterranean diet.
What’s new about the study
There are plenty of observational studies have already shown that people who drink moderate amounts of wine have lower all-cause mortality than people who don’t, but the studies have relied on what people say about their alcohol consumption. Of course, this is a topic about which people tend to lie. While researchers have attempted to correct for this failing, it’s led to plenty of disputes around the results, some of them acrimonious.
This new study—”Urinary tartaric acid as a biomarker of wine consumption and cardiovascular risk: the PREDIMED trial”—did something different.
Led by Professor Ramon Estruch from the University of Barcelona and the Hospital Clinic Barcelona, Spain, the research is part of an ongoing study into the Mediterranean diet; an earlier study, as reported by Meininger’s, already concluded that wine is an important part of the diet.
What the team did for this latest round was to take a group of 1,232 people who either had diabetes Type 2, or who were at high risk of cardiovascular disease, and put them on the Mediterranean diet. They were followed for between four and five years.
At the start of the study, participants gave a urine sample, and then did the same a year later. The researchers were looking for tartaric acid, a byproduct of wine production. In other words, the researchers could tell if someone had consumed wine.
“By measuring tartaric acid in the urine, alongside food and drink questionnaires, we have been able to make a more accurate measurement of wine consumption,” said Prof. Estruch in a press statement.
The results
By the end of the study, there were 685 cases of cardiovascular disease, including heart attacks and strokes. The researchers concluded that light-to-moderate drinking “reduces the risk of developing a cardiovascular event by 50% in this group of people at high risk of cardiovascular disease who were following a Mediterranean diet”.
Prof Estruch said the results demonstrated “a much greater protective effect of wine than that observed in other studies. A reduction in risk of 50% is much higher than can be achieved with some drugs, such as statins.”
He went on, “Until now, we believed that 20% of the effects of the Mediterranean diet could be attributed to moderate wine consumption; however, in light of these results, the effect may be even greater.”
Not surprisingly, the release of the report generated plenty of media buzz. The Mirror, a British tabloid, cheerfully recommended a bottle of wine a week to its readers.
CNN, however, took a dimmer view. They lined up experts to slam the findings and warn that even if moderate drinking has benefits, it's too difficult to measure a moderate amount of alcohol and, by the way, heavy drinking is really, really bad for your health.
Here’s the catch
While the report is good news for moderate drinkers, the problem for most people is that the study defined "moderate" as half to one glass of wine a day—and the effects disappeared at higher levels.
That is well below the amount that many people drink, and it would take two people several days to get through one bottle of wine if they were drinking at that level. By the time they got to their final glass, the wine would be oxidised. (Though this could represent an opportunity for producers working with smaller packaging sizes or bag-in-box.)
It does not, of course, mean that drinking to the level of the official guidelines is unhealthy, just that it has no apparent health benefits.
Another report is on the way
Earlier this week, the much-awaited report from (NASEM) was released. A carefully worded, thorough document, it affirmed that moderate drinkers have lower all-cause mortality than non-drinkers.
Despite the positive findings, it may actually lead to a lowering of the drinking guidelines, at least for women, as it found there was moderate certainty that moderate drinking raises the risk of breast cancer.
There is a second report on its way, which will also be used to inform the DGAs. This one is by the US Interagency Coordinating Committee on the Prevention of Underage Drinking (ICCPUD), and there are good reasons to predict that it may contradict the NASEM report.
The stakes are extremely high. If the US were to lower its drinking guidelines from two drinks a day for men and one for women, it would send a strong message that drinking even small amounts of alcohol is dangerous—a message likely to inform the thinking of other governments. Regardless of what the data on the Mediterranean diet says.
