While red wine in moderation has a number of health benefits such as increasing "good" cholesterol and protecting against artery damage, lowering blood pressure is not one unless it's dealcoholized, new research suggests.
In a study, published in the journal Circulation Research, investigators found two glasses of red wine a day can help reduce blood pressure, only if the alcohol has been removed.
The study included 67 men with numerous cardiovascular risk factors or diabetes. Researchers instructed participants to consume non-alcoholic red wine, red wine or gin with their meals. Each man spent three stages for a total of four weeks consuming one of each beverage, switching to a different beverage at the end of every cycle.
Study author Gemma Chiva-Blanch, from the Department of Internal Medicine at the Hospital Clinic of Barcelona, found that after participants consumed red wine with alcohol or gin there was no significant change in blood pressure but after consuming dealcoholized red wine participants blood pressure levels decreased. Systolic blood pressure levels were reduced by approximately 6 mmhg, and diastolic blood pressure levels decreased by 2 mmhg.This equates to a 14 percent decrease in the risk for coronary heart disease and a 20 percent decrease in the risk for strokes.
Researchers theorize removing alcohol increases nitric oxide in the blood stream, which is in turn relaxes blood vessels.
However, according to Mayo Clinic cardiologist Dr. Sharonne Hayes, the research is too small of a study and needs more investigation. The study contained no control group and the two week "wash out" period prior to the study may have influenced the results. Additionally, participants did not do a "wash out" period before switching beverages, in turn not giving their blood pressures an opportunity to reset their baseline.
Chiva-Blanch did state the study only observed effects on blood pressure, and not other cardiovascular risk factors.