"Our findings do not support the idea that potential cardiovascular benefits of red wine consumption result from blood pressure lowering by polyphenols," says researcher Dr. Ilse Botden, MD, a PhD scholar at Erasmus Medical Center in Rotterdam, Netherlands.
In the double-blind, placebo-controlled study, which she presented in Orlando on Friday at the American Heart Association High Blood Pressure Research 2011 Scientific Sessions, she said that 61 men and women with an average age of 61 years, having mild hypertension (145./86) were given three types of doses-containing placebo, 280 mg of red wine polyphenols, or 560 mg of the same, daily for four weeks. She said that the higher dose of polyphenols was the equivalent to two to four glasses of red wine, minus the alcohol.
The researchers measured blood pressures after each four-week study period. Blood pressures were taken in the office and using 24-hour measurements while the people went through their day wearing a monitor.
Although 24-hour BP slightly decreased after administration of 560 mg of the polyphenols, the reduction was found not to be significant, and there was no effect of the 280-mg dose on 24-hour BP. The team also split the patients into two groups-those with the 'highest' high BP and the lowest. Even then no significant effect of the polyphenols was seen in reduction of BP in either group.
However, D. Botden says that the same polyphenols she tested in people, when tested in animals, did produce a blood pressure decrease. In other studies done in people, polyphenols from red wine seem to work by improving the health of the cells lining the blood vessels, in turn improving blood flow and heart health. One possibility, she says, is that perhaps more severe problems in the health of the blood vessel linings may be needed before the red wine polyphenols affect the blood pressure, according to WebMD.
The findings don't suggest red wine isn't heart-healthy, admits Botden. ‘It just doesn't seem to work by lowering blood pressure, she claims. The benefit of red wine and heart health, she says, ''apparently occurs in a blood pressure-independent manner." However, it may be that people with more severe hypertension might benefit, she suggests.