When it comes to the moderate consumption of alcohol, be it wine, beer or spirits, any type will do in reducing the risk of thyroid cancer, a new set of research finds. In searching for a possible link between alcohol consumption and the risk of thyroid cancer, a team of scientists at the National Cancer Institute in Rockville, Maryland, reported that alcoholic beverages actually confer a protective effect for the neck gland.
The thyroid uses iodine to produce hormones vital to the regulation of cell metabolism. In the study, published in the October issue of the British Journal of Cancer, the authors noted that rates of thyroid cancer, though relatively low, are on the rise in the United States. And while the increase in cancer incidence is likely due to "certain environmental exposures" and the fact that technological advances are making diagnosis of cancer more accurate, it "remains unclear whether an association between alcohol and thyroid cancers exists independently of smoking."
Earlier research yielded inconclusive evidence. Seeing the need for a larger study on the topic, the team, lead by cancer epidemiologist Cari Meinhold, pulled data on 490,000 participants, more than half of them male, from the larger National Institutes of Health-AARP study. That study, which ran from 1995 to 1996, looked at 50- to 71-year-old Americans from several states and metropolitan areas. Participants in the NIH-AARP study filled out extensive lifestyle questionnaires, which included queries on alcohol consumption. For the study, one drink equals 13 to 14 grams of ethanol, or roughly 12 ounces of beer, 5 ounces of wine or 1.5 ounces of spirits. After an average of seven and a half years, the study followed up on subjects.
In the data pulled for the current NCI study, 200 women and 170 men developed thyroid cancer. By measuring their habits, based against those who did not suffer from the ailment, Meinhold and her team found that alcohol consumption appears to protect against the disease.
"We observed that the risk of thyroid cancer decreased with increasing alcohol consumption, by approximately 6 percent per 10 grams consumed daily," Meinhold said.
"Although this cohort included nearly half a million men and women," she continued, "thyroid cancer was a relatively rare outcome in this group and, therefore, we were unable to estimate precisely whether risk of thyroid cancer continued to decrease with heavier alcohol consumption beyond two drinks per day." The protective effect was somewhat greater among beer-drinking men, but Meinhold again cautions that the data set was too small to draw conclusions on the effectiveness of different beverages.
The scientists don't have evidence on why alcohol decreases risk of thyroid cancer, but they speculate that alcohol may protect the thyroid by helping it regulate the rate at which it releases hormones into the body, thus preventing any buildup in the gland.
Meinhold cautions that thyroid cancer is relatively rare compared to other diseases, and therefore self-prescribing daily alcohol consumption is not recommended. "There is convincing evidence linking alcohol consumption with a greater risk of other diseases," she said. "We did not evaluate the overall balance of the risks and benefits of alcohol consumption."