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One Major Side Effect of Drinking "Several Cups" of Coffee a Day, Says Study

New research says there's at least one potential health benefit to drinking coffee by the pot.

According to the latest U.S. Dietary Guidelines, you shouldn't consume in excess of 400mg of caffeine every day. In coffee terms, that comes to roughly four cups. If you're regularly drinking more than that, say the leading health experts from the Mayo Clinic, you're putting yourself at greater risk of side effects that include headaches, a faster heartbeat, muscle tremors, insomnia, and prolonged nervousness. But if you're an adult man who is concerned about developing prostate cancer down the road, a new study says that there is at least one major upside of drinking "several cups" of coffee every day that you probably didn't see coming: Each additional cup of coffee you drink every day is linked to a reduced risk of developing prostate cancer.

For the study, which was published last month in BMJ Open, a team of researchers analyzed 16 different coffee-related studies that were conducted across three continents. All told, they analyzed coffee consumption habits and health markers for more than 1 million men, "of whom 57,732 developed prostate cancer." Ultimately, they found that "each additional cup" of coffee was associated with a "reduction in risk of nearly 1%."

"The highest level of consumption ranged from 2 to 9 or more cups per day," the study says. "The lowest level ranged from none to fewer than 2 cups a day."

Unlike the men who drank little or no coffee, the men who drank the most coffee experienced a 9% reduced risk of prostate cancer and a 12 to 16% "lower risk for advanced and fatal prostate cancer."

"This study suggests that increased coffee consumption may be associated with a reduced risk of prostate cancer," the study concludes. "Further research is still warranted to explore the underlying mechanisms and active compounds in coffee. If the association is further proved to be a causal effect, men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer."

If you do up your coffee intake, don't forget the inherent risks of exceeding the U.S. Dietary Guidelines. And, regardless of how much you're drinking, make sure you're not making any of the following coffee-drinking mistakes that could potentially harm your health. And for more news on your favorite pick-me-up, make sure you're aware of the The Single Worst Time of Day to Drink Coffee, According to Experts.

You're drinking from a paper cup.

Tim Wright/Unsplash

If you prefer to grab your daily cup of coffee on-the-go, a new study recently published in The Journal of Hazardous Materials may convince you to start brewing your own morning cup from your own kitchen. The findings suggest that drinking coffee, tea, and other piping hot beverages out of paper cups with linings that contain plastic film may be flooding your body with hazardous microplastic particles that can potentially have harmful consequences for your health.

"We never want to be alarmist, but it is concerning that these non-biodegradable materials that are present everywhere [may] enter and accumulate in human tissues, and we don't know the possible health effects," Varun Kelkar, a researcher and Ph.D student at ASU, told The Guardian.

The folks at Consumer Reports don't mince their words when they explain the dangers: "These chemicals have been linked to a variety of health problems, including reproductive harm and obesity, plus issues such as organ problems and developmental delays in children."

You're drinking from a French Press.

french press

It's one of the most elegant and environmentally responsible ways to prepare your morning cup of coffee, but if you're regularly using a French press, you could be doing serious damage to your body in the long run, according to a study published in The European Journal of Preventive Cardiology.

"Unfiltered coffee contains substances which increase blood cholesterol," explains study author Dag Thelle, a senior professor in the public health and community medicine department of the University of Gothenburg, Sweden. "Using a filter removes these and makes heart attacks and premature death less likely."

You're drinking coffee right when you wake up.

Woman drinking tea and water in bed in the morning

According to a new study published in The British Journal of Nutrition, if you have your morning dose of caffeine before you eat your breakfast, you could be negatively impacting your blood sugar levels and ultimately raising your risk of developing heart disease and diabetes down the road.

You're adding cream or sugar (or both!).

decaf coffee

Health experts warn that drinking too much Joe can affect your waistline. "Unless you drink it black, consuming several cups of coffee with milk, cream, or sugar per day can add up calorie-wise," Kelli McGrane, RD, a registered dietitian who works for the calorie counting app Lose It!, recently told us. "Overtime, those extra calories can lead to increases on the scale." For more on your favorite morning pick-me-up, make sure you're aware of Everything That Happens to Your Body When You Drink Coffee, According to Science.

William Mayle
William Mayle is a UK-based writer who specializes in science, health, fitness, and other lifestyle topics. Read more about William
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