“The research linking alcohol to breast cancer is deadly solid. There’s no controversy here. Alcohol, regardless of whether it’s in Everclear or a vintage Bordeaux, is carcinogenic. More than 100 studies over several decades have reaffirmed the link with consistent results. The National Cancer Institute says alcohol raises breast cancer risk even at low levels.
Researchers estimate that alcohol accounts for 15 percent of US breast cancer cases and deaths—about 35,000 and 6,600 a year, respectively. That’s about three times more than the number of breast cancer cases caused by a mutation of the BRCA genes, which prompted Angelina Jolie, who carries one of the abnormal genes, to have both her healthy breasts removed in 2013. The breast cancer risk from alcohol isn’t nearly as high as the lung cancer risk from smoking. But alcohol-related breast cancer kills more than twice as many American women as drunk drivers do. And alcohol is one of the few breast cancer risk factors women can control. Others, like starting menstrual periods before the age of 12 and entering menopause after 55, are baked in.
Scientists have long known that heavy drinking causes high blood pressure, strokes, and heart attacks. That’s why early studies investigating drinking and heart disease started with the logical supposition that people who abstain from alcohol should have low rates of heart disease compared with moderate or heavy drinkers. As it turned out, they didn’t. When plotted on a curve, drinkers fell into a J-shaped pattern: Abstainers in the studies had rates of cardiovascular disease similar to those of heavy drinkers.
But this J-curve is deceptive. Not all the nondrinkers in these studies were teetotalers like the ones I grew up with in Utah. The British epidemiologist A. Gerald Shaper began a wide-ranging men’s heart health study in the late 1970s, and when he examined the data, he found that 71 percent of nondrinkers in the study were actually former drinkers who had quit. Some of these ex-drinking men were as likely to smoke as heavy drinkers. They had the highest rate of heart disease of any group and elevated rates of high blood pressure, peptic ulcers, diabetes, gallbladder disease, and even bronchitis. Shaper concluded that ex-drinkers were often sicker than heavy drinkers who hadn’t quit, making them a poor control group.
Yet for decades, researchers continued to include them and consequently found an implausible number of health benefits to moderate drinking, including lower rates of deafness and liver cirrhosis. The industry has helped promote these studies to doctors.
That’s one reason why, until recently, alcohol’s heart health benefits have been treated as incontrovertible science. But in the mid-2000s, Kaye Middleton Fillmore, a researcher at the University of California-San Francisco, decided to study Shaper’s ex-drinkers. When no one in the United States would fund her work, she persuaded Tim Stockwell, then the director of Australia’s National Drug Research Institute, to help her secure Australian government funding.
Stockwell and Fillmore analyzed decades’ worth of studies on alcohol and heart disease. Once they excluded studies with ex-drinkers—which was most of them—the heart benefits of alcohol largely disappeared. Since then, a host of other studies have found that drinking does not provide any heart benefits. (Some studies have found that drinking small amounts of alcohol—sometimes less than one drink per day—can be beneficial for certain people at risk of heart disease.) Robert Brewer, who runs an alcohol program at the Centers for Disease Control and Prevention, says, “Studies do not support that there are benefits of moderate drinking.” The Agriculture Department removed language suggesting that alcohol may lower the risk of heart disease in the most recent US Dietary Guidelines.”
Image: Edmon De Haro