In ancient Greece, the physician Hippocrates first noted gastrointestinal upset in some people who consumed milk. While we don’t know what the good doctor’s diagnosis was or how he treated the problem, modern medical science tells us those people may have been suffering from lactose intolerance, a condition in which the body isn’t able to fully digest lactose, a type of natural sugar found in milk and dairy products. Common symptoms include nausea, cramps, bloating, gas, and diarrhea, which begin within thirty minutes to two hours after eating or drinking foods containing lactose. It is estimated that close to 50 million American adults have some degree of lactose intolerance, but a government panel says not enough research has been done to know exactly how many people have the condition or how it ultimately affects their health.The 14-member panel, composed of experts from across the medical spectrum and convened by the National Institutes of Health (NIH), spent nearly three days in Bethesda, Maryland assessing the available information on lactose intolerance and made their findings known on Wednesday in a draft report. They concluded that, of the nearly 60 relevant studies, none of them “evaluated a representative U.S. sample” and thus “cannot be used to estimate the prevalence” of the condition. “I think that there are huge gaps in knowledge,” said panel chairman Dr. Frederick J. Suchy, professor and chief of pediatric hepatology at Mount Sinai School of Medicine. “There is a huge amount of research that needs to be done.”