The researchers did note an uptick in lung cancer among coffee drinkers. But the authors point out that some studies did not account for participants’ smoking habits. No higher risk was seen in nonsmokers. The review also revealed a higher risk of low birth weight and pregnancy loss among heavy coffee drinkers, who were also more likely to give birth prematurely.
Other studies that have come out in the past 2 years or so have only added to what we know about coffee’s potential positives, says preventive medicine specialist Michael Roizen, MD.
“For example, we now have more data supporting the point of view that there’s a 20% to 30% reduction in risk of type 2 diabetes if you drink three cups of coffee a day,” says Roizen, chief wellness officer at the Cleveland Clinic.
He says much of what we know about coffee’s effect on human health comes from observational studies. Such studies can only show associations; they can’t find cause and effect. In other words, researchers may see that fewer coffee drinkers get certain cancers. But they can’t say with certainty that it’s the coffee itself that protects against cancer.
But it does appear that the major potential benefits of coffee apply to a wide range of people. In a study published last August, researchers report that African-Americans, Latinos, native Hawaiians, and Japanese Americans had a 12% lower chance of an early death if they drank a single cup of coffee each day. Two to four cups lowered the chance of dying prematurely by 18%. They were also less likely to die from heart disease, cancer, diabetes, kidney disease, and chronic lower respiratory disease.
Source : https://www.webmd.com/food-recipes/news/20180416/dont-ditch-the-coffee-over-cancer-risk-news286