Do you consume more than four cups of coffee every day? Then pay heed to the findings of this latest study.
Using coffee to maintain your energy level regularly may have an unintended consequence: According to a new study published in the Clinical Journal of the American Society of Nephrology, it could be hard on your kidneys.
Researchers looked at 372 blood metabolites in around 3,800 people who took part in health research that gathered data on lifestyle factors that potentially increase the risk of heart failure. Metabolites are created when the body breaks down food, drugs, and even tissue, such as muscles or fat. Examining which metabolites are present in the blood can provide insight into how they contribute to individual variances in organ function.
The researchers discovered 41 metabolites linked to coffee use in the trial, and greater levels of three of them were linked to a significantly higher risk of chronic kidney disease.
Is this to say you should give up coffee entirely? The researchers advise against it unless you already have kidney problems.
They point out that drinking a reasonable amount of coffee has been beneficial in various studies. (In fact, according to recent studies from The Kidney Foundation, one cup of coffee each day can cut the incidence of kidney stones by 40%.)
That doesn't just mean getting your caffeine fix—coffee has its own set of benefits as a beverage, according to Andrea Dunn, RD, a dietitian in Cleveland Clinic's gastrointestinal, hepatology, and nutrition department.
"Coffee has over a thousand different plant chemicals, and it's the single best source of antioxidants in the American diet," she says, noting that it's also high in potassium, B vitamins, and riboflavin. According to Dunn, research has connected the chemicals in coffee to a reduced risk of diseases such as type 2 diabetes, liver disease, and some types of cancer.
In terms of what constitutes "moderate," one study that examined data from over 350,000 participants found that up to four cups of coffee per day are protective, but that one to two cups per day seemed to be the sweet spot.
Dunn says this is in line with earlier studies, especially if you don't use a lot of extras like flavoured syrups, sugar, and whipped cream. Caffeine intake should be limited to fewer than 400 mg per day across all beverages. Coffee has roughly 80 to 100 mg in an 8-ounce cup, so as long as you don't drink more than four cups, you'll be fine.