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Add protection against cataracts and healthy heart to the laundry list of health benefits of moderate beer drinking. Cancer protection, relief from kidney stones, prevention of osteoporosis — the list gets longer and longer — although cardiologists and endocrinologists have been careful to caution against patients adding beer to their health regimens just yet. Several epidemiological studies have demonstrated health benefits, particularly cardioprotection, from moderate beer consumption.
Now Canadian and American researchers are reporting the results of laboratory and animal studies conducted in an effort to discover the reasons behind the benefits. The bottom line: Beer, especially the darker lagers and stouts, may reduce the incidence of atherosclerosis by as much as 67% and cataracts by as much as 50%. Darker beers have more antioxidants than the lighter pilsner beers.
In a paper presented at the American Chemical Society meeting in Honolulu in December, Canadian researcher John Threvithick, PhD, found potential benefits to diabetic patients. He is professor of biochemistry at the University of Western Ontario in London. Threvithick says he found that antioxidants in beer protect the lenses in the eyes of rats and cows exposed to high glucose levels as might be found in diabetes.
Will the animal experiments translate to humans? "The question is: After someone takes a drink, how much of the antioxidants actually get into the blood stream and to the lens of the eye?" says Threvithick. "The answer is: We don’t know.’"
Threvithick and his team worked with alcohol to dissolve amino acids and found that alcohol itself has a fairly notable amount of antioxidant activity. However, as other researchers have noted, the benefits of beer and other types of alcohol diminish and dramatically tip the scales to the negative with overconsumption.
"Several studies have shown a 50% risk reduction for heart disease with the consistent consumption of one beer a day. For those who drink two beers a day, there was a 10% risk reduction, and for those who drink more, there was a higher risk," says Threvithick. "Obviously there’s a trend here. The optimum health benefits seem to be with one to two beers a day."1,2,3
"It’s a U-shaped curve. There are good benefits with low consumption and great harm with high consumption," says Joe Vinson, PhD, professor of chemistry at the University of Scranton in Pennsylvania, author of a soon-to-be published paper on atherosclerosis and beer consumption.
The 50% risk reduction for cataracts in beer drinkers, Threvithick found, is equivalent to the antioxidant benefits of 400 IU of vitamin E daily, but he argues that beer seems to have some other properties that may make it a more valuable protectant against free radicals than vitamin E. "We were surprised to see almost the same kind of risk reduction for cataracts as for heart disease, especially since it can’t be a factor of cholesterol, since cholesterol doesn’t come into contact with the lens of the eye," he says.
People with diabetes have twice the normal risk of cataracts because of recurring episodes of hyperglycemia, which destroys the mitochondria in lens cells. Therefore, the means of addressing oxidative damage to the lens of the eye are important. "What often happens with diabetes is that people don’t get diagnosed until they’ve had one or two episodes of really high blood glucose for a period of time, like a day or two," Threvithick says. "That may be enough to damage the lens."
Threvithick says the anti-cataract effect is most likely due to a mixture of polyphenols, which strengthen cell walls. "They polymerize the cell walls much the same way the polymer bonds to the plastic fibers when fiberglass boats are made. In the case of the lens, the lignan small molecules are polymerized by this mixture of several polyphenols," he says.
Threvithick’s daughter, Colleen Threvithick, PhD candidate in chemistry and biochemistry at the University of California in Los Angeles, is analyzing the brewing process, trying to discover the stage at which the antioxidants are produced. Threvithick expects to publish his results soon.
Alcohol itself seems to have some antioxidant properties, but alcohol alone is not the cause of beer’s cardioprotective effects, says Vinson. He contends his is the first study to specifically show that antioxidants in beer can add to the already established alcohol benefit. "We don’t really have a smoking gun, but we think the best candidate for this protective effect is ferrulic acid, a catechin in the polyphenol category."
It will take more research to determine the exact effect, but Vinson theorizes the ferrulic acid works with the antioxidants already present in alcoholic beverages. He also credits ferrulic acid and other catechins and polyphenols with reducing platelet aggregation, thereby reducing the amount of plaque in arteries. Darker beers have more antioxidants than lighter beers, says Vinson, although phytochemicals in the darker beers may not be as well absorbed.
His 10-week study involved giving hamsters water, beer 50% diluted with water, or beer diluted tenfold by water. The high-dose hamsters received a human equivalent of two beers a day. "Hamsters have a lipid profile similar to that of humans. They love the taste of beer, but they don’t get drunk," says Vinson. The half-diluted beer resulted in a 67% cardioprotective effect, and the low-dose beer resulted in a 21% protective effect.
Vinson also presented results of other studies that showed antioxidants in tea and grape juice also reduced atherosclerosis. "We have a definite beneficial effect," he says. "The low-dose is probably more relevant to you and I, since if you extrapolate it to the whole body, it would be equivalent to two beers a day for humans."
The current animal studies are related to the 1976 study that defined what has been called the French paradox — showing lower morbidity and mortality among the French population despite a high-fat diet and sedentary lifestyle. Much of the heart protective benefit the French enjoy is ascribed to the custom of drinking wine, particularly red wine, with meals.
Vinson says beer isn’t any more effective than wine in diminishing the risk for atherosclerosis. In fact, beer drinkers may have a somewhat lower protection because wine drinkers generally have a healthier lifestyle than beer drinkers, he says. In an interesting aside, Vinson notes that wine contains five to six times more antioxidants than beer, although the protective effects of beer and wines are similar.
Vinson is careful to say his study should not in any way be considered definitive for humans, nor should it be considered a green light for nondrinking patients to start drinking for heart health. "We think beer drinking over the course of many years might be preventive for heart disease," he says. "I think the research is well-established that moderate alcohol drinking is good for you."
Yet, he says, there are many cautions in light of the negative effects of alcohol consumption, among them high caloric content (150 calories in a 12-ounce beer and about 75 calories in a 3.5-ounce glass of wine), not to speak of the potential for alcoholism and even death. Earlier studies have shown other benefits of beer drinking:
What should health care professionals tell patients who ask about the benefits of drinking beer? "I’d say tell them what we’ve been saying all along — drinking one or two beers a day is fine. But that should be coupled with the caution that more is not better," says Vinson.
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2. Bobak MJ, Skodova S, Marmot M. Effect of beer drinking on risk of myocardial infarction: Population-based case-control study. BMJ 2000; 320:1,378-1,379.
3. Gronbaek M, Becker U, Johansen D, et al. Type of alcohol consumed and mortality from all causes, coronary heart disease and cancer. Ann Intern Med 2000; 133:411-419.
4. Truelsen T, Gronbek M, Schnohr P, et al. Intake of beer, wine, and spirits and the risk of stroke: The Copenhagen City Heart Study. Stroke 1998; 29:2,467-2,472.
5. Miranda CL, Stevens JF, Helmrich A, et al. Antiproli-ferative and cytotoxic effects of prenylated flavonoids from hops (humulus lupulus) in human cancer cell lines. Food Chem Toxicol 1999; 37:271-285.
6. Curhan GC, Willett WC, Speizer FE et al. Beverage use and risk for kidney stones in women. Ann Intern Med 1998; 128:534-540.
7. Hoidrup S, Gronbaek M, Gopttschau A, et al. Alcohol intake, beverage preference, and risk of hip fracture in men and women. Copenhagen Centre for Prospective Population Studies. Am J Epidemiol 1999; 149:993-1,001.