One in three Americans has hypertension, or high blood pressure, and another 25 percent of the population have pre-hypertension. Hypertension leads to the number-one and number-three killers in the United States, heart disease and cancer, respectively. The trickiest thing about high blood pressure is that the condition is "silent," meaning it has no symptoms. According to the Centers for Disease Control and Prevention, it is preventable.
Resveratrol
In the early 1990s, researchers found resveratrol in red wine. Red wine was being studied because the French drink more red wine but have less heart disease than Americans. Finding resveratrol in wine led researchers to believe it is this component that helps decrease heart risks. Resveratrol is scientifically referred to as a stilbene and is found in plants such as grapes, peanuts, blueberries, bilberries and cranberries. The resveratrol in grapes is present only in the skins, which accounts for its content in red and white wines and in grape juice. Red wine has higher concentrations than white wine since it is fermented in the presence of the grape skins for longer time periods. The highest concentrations of resveratrol have been found in Spanish red wines and red grapes, according to the Linus Pauling Institute at Oregon State University.
Hypertension
There seems to be no primary cause for hypertension other than it may gradually rise over the years. Diseases such as atherosclerosis, a buildup of fatty deposits along the artery walls, and arteriosclerosis, or hardening of the arteries, can contribute to high blood pressure by making the blood vessels narrower and less flexible, respectively. High cholesterol can contribute to both of these problems, since excess low-density lipoprotein build up in the arteries and damages the vessel walls. Exercising and eating a healthy diet low in sodium and saturated fats and high in fruits and vegetables can help to lower both cholesterol and blood pressure levels.
Resveratrol and Pulmonary Hypertension
Different arteries can be affected by various disease processes leading to specific areas of hypertension in the body, or small areas of the blood vessels where blood pressure is higher than everywhere else. Pulmonary hypertension is one of these types of hypertension and can be worrisome because it puts extra pressure on the blood going into the lungs. A 2009 article in "Hypertension" reported evidence that doses of 25 mg/kg of resveratrol in rats helped with pulmonary hypertension. Resveratrol resulted in decreased inflammatory markers and a higher availability of NO, or nitrous oxide, which is used as a medication for chest pain. While this model worked in rats, there is uncertainty about its effects in humans because the body absorbs resveratrol rapidly; moreover, it may work better in females than in males as it binds to estrogen receptors in the body. Additionally, the doses used in the study were higher than one or two glasses of wine a day would provide.
Malignant Hypertension
Malignant hypertension is the sudden and rapid development of high blood pressure. Researchers reporting in the "Journal of Hypertension" in June of 2010 studied rats with spontaneous hypertension and the effects of chronic resveratrol doses. The group that received resveratrol showed reduced mean arterial pressure and aortal blood flow, along with an increase in anti-inflammatory activity. While the results were positive, this was a only a four-week study, and the results on effectiveness cannot be extrapolated to humans.
Safety
Even in high doses, no ill or toxic effects of resveratrol have been reported in rats or humans. The studies on humans have been limited, so data are not sufficient to show resveratrol is truly safe. Studies using high doses have not lasted longer than four weeks, so no long-term effects have been reported. No studies have been done on lactating or pregnant women, so no safe values have been established for these populations. Since resveratrol binds to estrogen receptors, supplementation is not recommended for women with a history of estrogen-related breast, uterine and ovarian cancers.
References
- Centers for Disease Control and Prevention; High Blood Pressure Facts; March 21, 2011
- Oregon State University, Linus Pauling Institute: Micronutrient Information Center: Resveratrol 2005-2011
- "Hypertension"; Is Resvertatrol the Magic Bullet for Pulmonary Hypertension?; L.G. Chicoine et al.; 2009
- "Journal of Hypertension"; Resveratrol Reduces Blood Pressure, Changes of Antioxidant Enzyme Activity and Histological Parameters in Experimental Model of Malignant Hypertension; G. Milanovic et al.; June 2010
- "Clinical and Experimental Pharmacology and Physiology"; Effects of Trans-Resveratrol on Hypertension-Induced Cardiac Hypertrophy Using the Partially Nephrectomized Rat Model; Z. Liu et al.; January 24, 2006
- Centers for Disease Control and Prevention; Pulmonary Hypertension Fact Sheet; December 20, 2010
