The results were clear: "Our study found that coffee drinking was associated with a lower risk of total mortality," says Dr. Ming Ding, a doctoral student at Harvard University and author of the study — as well as lower incidents of death due to Parkinson's, heart disease, and suicide.
And just how much should you drink? Three to five 8-ounce cups a day. Researchers came to this number by looking at health data from three different studies and assessing coffee drinking among male and female participants every four years during a 30-year period. Taking into account health factors such as smoking, body mass index, physical activity, and alcohol consumption, they concluded that participants who reported drinking three to five 8-ounce cups of coffee a day were less likely to die from cardiovascular and neurological diseases, type 2 diabetes, and even had lower suicide rates.
If there's a magic protective ingredient in coffee, it doesn't appear to be caffeine — decaf drinkers showed the same benefits. Researchers aren't sure why coffee appears to be associated with diminished risk of premature death from some common diseases, but Ding says that the chlorogenic acid, lignans, quinides, trigonelline, and magnesium in coffee reduce insulin resistance and systematic inflammation and therefore might be responsible for the effect.
All this still doesn't mean you should start up a habit right now. "As our study was observational, we don't know if the inverse association is causal," Ding says. In other words, if you drink coffee already, keep doing it — and feel free to roll your eyes at the next person who announces he is "giving up coffee" for no discernible reason.
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