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The lowdown on wine, tea, coffee, energy drinks and heart health

European conference hears the latest research on matters cardiovascular

Red wine good, tea OK, energy drinks bad, right? Well, as is so often the case, the answer isn't always quite as black and white as we might think, as a series of new studies reminds us. The studies, along with many others, were presented at the European Society of Cardiology in Barcelona, Spain over the weekend.

Red wine

Here's the good news abouy red wine: it protects against cariovascular disease. But here's the rest of the story: it only works that way for people who exercise, according to results from the In Vino Veritas (IVV) study presented at ESC Congress by Professor Milos Taborsky from the Czech Republic.

Evidence suggesting that mild to moderate consumption of wine protects against cardiovascular disease has been accumulating since the early 1990s. In particular, retrospective studies have found that wine increases levels of HDL, the "good" cholesterol. But until now there has been no long-term, prospective, randomized study comparing the effects of red and white wine on HDL cholesterol and other markers of atherosclerosis.

That's what Prof. Taborsky and associates set out to test. The results: "We found that moderate wine drinking was only protective in people who exercised. Red and white wine produced the same results."

The study included 146 people with mild to moderate risk of cardiovascular disease according to the HeartScore. Participants were randomized to one year of moderate consumption of red wine (Pinot Noir) or white wine (Chardonnay-Pinot) from the same year and wine region of the Czech Republic.

"The only positive and continuous result was in the subgroup of patients who took more exercise, which means regular exercise at least twice a week, plus the wine consumption. ... There may be some synergy between the low dose of ethyl alcohol in wine and exercise which is protective against CVD."

Spot of tea then?

So how about tea versus coffee? Drinking tea reduces non-cardiovascular mortality by 24%, reveals a study of 131,000 people presented by Professor Nicolas Danchin from France.

"If you have to choose between tea or coffee it's probably better to drink tea," Danchin. "Coffee and tea are important components of our way of life. Their effects on cardiovascular health have been investigated in the past with sometimes divergent results. We investigated the effects of coffee and tea on CV mortality and non-CV mortality in a large French population at low risk of cardiovascular diseases."

Tea had a more marked effect on blood pressure than coffee, with a 4-5 mmHg decrease in SBP and 3 mmHg decrease in DBP in the heavy tea drinkers, compared to non-drinkers, when adjusted for age.

Coffee showed a trend for increasing CV mortality in the heavy compared to non-drinkers but the effect was not significant. Coffee significantly increased non-CV mortality but the increased risk disappeared when the effect was adjusted for smoking. Danchin said: "The trend for higher mortality in coffee drinkers is probably largely explained by the fact that there are more smokers in the group who drink a lot of coffee."

He concluded: "Tea has antioxidants which may provide survival benefits. Tea drinkers also have healthier lifestyles so does tea drinking reflect a particular person profile or is it tea, per se, that improves outcomes -- for me that remains an open question. Pending the answer to that question, I think that you could fairly honestly recommend tea drinking rather than coffee drinking and even rather than not drinking anything at all."

Skip the energy drinks

But while the wine, tea and coffee crowd can find both encouraging and discouraging aspects in the latest research, that's not the case with energy drinks, which French Professor Milou-Daniel Drici characterized as dangerous for most consumers.

"So-called 'energy drinks' are popular in dance clubs and during physical exercise, with people sometimes consuming a number of drinks one after the other. This situation can lead to a number of adverse conditions including angina, cardiac arrhythmia (irregular heartbeat) and even sudden death," Drici said.

"Around 96% of these drinks contain caffeine, with a typical 0.25 litre can holding 2 espressos worth of caffeine. Caffeine is one of the most potent agonists of the ryanodine receptors and leads to a massive release of calcium within cardiac cells," he said, presenting the results of a study which found 95 cases of cardiovascular problems linked to energy drinks over a two-year period in France.

"We found that 'caffeine syndrome' was the most common problem, occurring in 60 people. It is characterised by a fast heart rate (called tachycardia), tremor, anxiety and headache," Drici said. "Rare but severe adverse events were also associated with these drinks, such as sudden or unexplained death, arrhythmia and heart attack (myocardial infarction). Our literature search confirmed that these conditions can be related to consumption of energy drinks."

Drici added: "The general public need to know that so-called 'energy drinks' have absolutely no place during or after physical exercise, as compared with other drinks designed for that purpose. When used in long alcoholic cocktails, the caffeine in 'energy drinks' enables young people in dance clubs or elsewhere to overcome the unwanted effects of alcohol, leading to an even greater intake of caffeine."

The European Society of Cardiology (ESC) represents more than 80 000 cardiology professionals across Europe and the Mediterranean. Its mission is to reduce the burden of cardiovascular disease in Europe.

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