Friday, May 10, 2013

Alcohol and blood pressure: Hypertension is caused by and worsened by drinking

May is Blood Pressure Education Month, emphasizing the causes and prevention of hypertension.  While many assume alcohol (especially red wine) is heart healthy, several studies in this article indicate the opposite may be the case. 

A third of adults have hypertension, or high blood pressure, but as many as one in four of them don't even know it. And it kills. High blood pressure contributes to nearly a thousand deaths every day.

May is National Blood Pressure Education Month, putting a spotlight on awareness of the $47.5 billion health condition. The statistics, from the U.S. Centers for Disease Control and Prevention (CDC), favor those who are being treated, but half of Americans with high blood pressure do not have it under a doctor's plan of care.

Hypertension makes a heart work harder, increases the stress on the heart muscle and arteries and leads to a thickened heart muscle. High blood pressure can also lead to plaque build-up in the arteries, upping the risk for a heart attack or stroke. (See the article on “Stroke Awareness Month, which also is May.)

Some with high blood pressure rely on observational studies that claim alcohol – red wine, specifically – reduces hypertension. This notion is based on observation and is not evidence-based, meaning that patients on the wine-is-good-for-the-heart plan may be getting sicker rather than better. (See related “Wishful Thinking” article.) According to the CDC, “Patients can achieve greater hypertension control by taking their medications as directed, measuring their own blood pressure, and eating a lower-sodium diet.”

Part of the challenge with the “healthy” wine reports is many people aren't mindful of the other health consequences of drinking. In an American Heart Association survey, 67 percent of those surveyed agreed with the statement that wine can be good for your heart, yet only 30 percent knew the association's recommended limits for daily wine consumption. “This survey shows that we need to do a better job of educating people about the heart-health risks of overconsumption of wine, especially its possible role in increasing blood pressure,” said Gerald Fletcher, M.D., American Heart Association spokesperson.

If a person drinks at all, the association recommends no more than two drinks per day for men and one drink per day for women. 

Having more than three glasses of wine in one sitting temporarily increases blood pressure, but repeated binge drinking can lead to long-term hypertension. Heavy or daily use of any type of alcohol can dramatically increase blood pressure or cause heart failure and irregular heartbeats. The consequences go beyond blood pressure and the heart. There's also an increased risk of alcohol use disorders including the disease of alcoholism, suicide and accidents. And cancer: In a 2013 study, Boston University researchers concluded, “When it comes to cancer, no amount of alcohol is safe.”

Even modest alcohol consumption can cause blood pressure to increase, according to two studies conducted in Japan. Noriyuki Nakanishi, M.D., Osaka University Graduate School of Medicine in Japan and lead author of one of the studies, concluded that even very low alcohol consumption can be a health risk, especially older adults. Nakanishi and his research team observed that systolic blood pressure (the top number in a blood pressure reading) went up 1.4 points in those between the ages of 25 and 35, but increased 5.4 points for men between the ages of 48 and 59, for just 12g-22g of alcohol per day. A glass of wine contains about 20g alcohol on average.

In the second of the two studies, researchers from Kyushu University followed more than 1,100 people over age 40 for 10 years. One hundred men and 106 women developed hypertension, with the risk of developing hypertension higher for drinkers, even those who drank less than 23 grams daily. Both Japanese studies were published in the journal Alcohol: Clinical Experience and Research.

Quitting drinking has the expected benefit of reducing blood pressure. In one study reported in the journal Hypertension, researchers concluded that a reduction in alcohol intake among drinkers significantly reduced their blood pressure. They found that when alcohol consumption fell by 16 to 100 percent, there were significant drops in systolic blood pressure. Diastolic blood pressure (the bottom number) also dropped significantly in eight clinical trials. The greatest drop in blood pressure was seen in patients with the highest blood pressure before treatment and those who cut back on alcohol the most. However, the Mayo Clinic warns, “Heavy drinkers who want to lower blood pressure should slowly reduce how much they drink over one to two weeks. Heavy drinkers who stop suddenly risk developing severe high blood pressure for several days.”

Like all alcoholic drinks, wine contains calories and may contribute to unwanted weight gain — another risk factor for high blood pressure. For the wine drinker, dry wine contains fewer calories than sweet: 106 calories for five ounces of dry wine and champagnes… double it for five ounces of sweeter wines. A glass of wine before dinner, another glass with dinner and a sweet wine for dessert, that’s more than 400 calories in addition to the meal.

Another problem arising from drinking with hypertension: Alcohol can interfere with the effectiveness, or increase the side effects, of some blood pressure medications.
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The media portrayal of drinking being good for the heart might not consider all the other health consequences of drinking... and the portrayal isn't widely encouraged by the medical community.  The key to the debate over alcohol and its purported heart benefit stems from the 1976-1992 Copenhagen City Heart Study, in which 13,285 men and women were observed. The results from this study suggested that patients who drank wine had half the risk of dying from coronary heart disease or stroke as those who never drank wine. Other research since the Danish study failed to show a beneficial effect for drinking alcohol, wine included.  The more recent reports suggest the lifestyle profile of the wine drinker's OTHER activities -- being more prone to exercise regularly and eat healthier than beer drinkers, for example -- has more to do with their longevity than the wine.

Scroll down to listen to the replay of the Feb. 10, 2014 interview about Every Silver Lining Has a Cloud.