Reference
Pedrera-Zamorano JD, Lavado-Garcia JM, Roncero-Martin R, Calderon-Garcia JF, Rodriguez-Dominguez T, Canal-Macias ML. Effect of beer drinking on ultrasound bone mass in women. Nutrition. 2009;25(10):1057-1063.
Design
Cross-sectional study of healthy women recruited in a clinical convenience sample.
Participants
1,697 healthy women of whom 710 were premenopausal, 176 were perimenopausal, and 811 were postmenopausal.
Study Design
The recruited women completed a questionnaire on current cigarette, alcohol, caffeine, and nutrient consumption. Subjects were classified as moderate drinkers, light drinkers, and nondrinkers and also to type of alcohol consumed: wine or beer. Quantitative bone ultrasound values were measured in the participants, and the amplitude-dependent speed of sound was used as a dependent variable and compared to age, body mass index (BMI), gonadal status, intake of beer and wine, and number of cigarettes per day as independent variables.
Key Findings
Age, BMI, and menopause were associated with significant decreases in sound transmission, but beer intake was associated with a significant increase in speed of sound transmission, suggesting an association with increased bone density.
Age, BMI, and menopause were associated with significant decreases in sound transmission, but beer intake was associated with a significant increase in speed of sound transmission, suggesting an association with increased bone density.
Practice Implications
The authors of this study suggest that, “The greater bone density found in women beer drinkers might be a result of the phytoestrogen content of this alcoholic drink…” This is not the first study to link beer drinking with increased bone density, although earlier studies suggest the high silicon content of beer may be responsible for the effect.
Tucker et al. also reported a positive effect from beer drinking on bone density in their April 2009 article that analyzed data from the population-based Framingham Offspring cohort, which comprised 1,182 men, 1,289 postmenopausal, and 248 premenopausal women. Moderate beer drinking of 1–2 beers a day was associated with increased bone density in men and women. Women who drank more than 2 beers a day had significantly greater (5%–8.3%) bone density, but in men who drank more than 2 beers a day, density decreased.1
Mukamal et al. reported a similar U-shaped curve for alcohol consumption in their 2007 paper. They analyzed data from the Cardiovascular Health Study that included 5,865 participants and reported their use of beer, wine, and liquor yearly. There was a significant U-shaped relationship between alcohol intake and risk of hip fracture. Risk of hip fracture decreased to 0.78 (95% confidence interval [CI], 0.61–1.00) among those who consumed up to 14 drinks per week compared to abstainers. Those who consumed more than 14 drinks per week had increased risk of fracture.2
The beneficial effects of alcohol consumption on bone are attributed to several factors including the direct ethanol effect at inhibiting bone resorption, the high silicon content of beer, and the effects of various phytochemicals contained in the beverages.3
A 2008 double-blind, placebo-controlled human clinical trial using silicon in the form of orthosilicic acid (OSA) in postmenopausal women compared moderate doses of silicon (3, 6 and 12 mg Si) against placebo in combination with vitamin D and calcium. Results suggested that this “treatment is of potential use in osteoporosis.”4
Beer is an excellent source of bioavailable silicon. For example 64% of the silicon found in alcohol-free beer is absorbed, while only 4% of the silicon in bananas is.5
In a February 2010 paper, Bamforth and Casey reported that an analysis of 100 commercial beers found silicon content ranged from 6.4 mg/L to 56.5 mg/L, with an average of 30 mg/L.6
Chemicals in beer may act as phytoestrogens. A 2006 paper found the phytoestrogen, 8-prenylnaringenin, isolated from hops useful in preventing hotflash-like symptoms in animals with surgically induced menopause.7 A prospective, randomized, double-blind, placebo-controlled study using a hop extract to alleviate menopausal symptoms in women was published in May of the same year.8
The chemicals found in hops may also lower risk of breast cancer. Some appear to act as aromatase inhibitors lowering levels of estrogens. Prenylflavonoids isolated from hops and from various beers have been shown to possess significant effect at inhibiting aromatase.9 Xanthohumol is the most abundant prenylated chalcone in hops extract. However, during beer brewing and during digestion, the xanthohumol breaks down into different metabolites, including isoxanthohumol and 8-prenylnaringenin. When these 3 chemicals, xanthohumol, isoxanthohumol, and 8-prenylnaringenin, were tested on breast cancer cells, all inhibited aromatase activity and thus estrogen formation. Additionally, the 3 compounds decreased breast cancer cell line proliferation and induced apoptosis. Adding estrogen to the cells neutralized the antiproliferative effect of these compounds, suggesting that their mechanism of action involved estrogen depletion.10
Still, as a clear increase in breast cancer risk remains associated with any alcohol consumption, including beer, we cannot encourage our female patients to drink beer.11 Having weak bones still seems preferable to having breast cancer. The exception of course is if they are saying ‘cheers’ with alcohol-free products.
In the meantime, it is encouraging to read that this often-debated therapy, which is in such high demand by patients, may actually be of benefit.
