Coffee drinkers live longer, according to two large-scale studies released Monday that add to extensive research indicating coffee consumption is associated with better health.
The studies examined the health histories of hundreds of thousands of people who were tracked over many years. They found that coffee-drinking reduced the risk of various diseases among people from several ethnicities, and this effect was seen in drinkers of regular or decaffeinated coffee. And the more coffee consumed, the greater the benefit.
These are observational studies, not controlled clinical trials. So while they demonstrate an association, they don't prove cause and effect. But at the least, researchers said the latest evidence reinforces a large body of previous reports indicating there's no harm from coffee — and that it might very well benefit people's health.
Both of the new studies were published in the Annals of Internal Medicine. They asked participants about whether they drank coffee, and if so, how much. Participants were also asked about habits that influence health, such as smoking, exercise and heart disease.
One study was led by Veronica Setiawan of the University of Southern California. Funded by the National Cancer Institute, it examined coffee-drinking habits among more than 180,000 whites, blacks, Latinos, Japanese-Americans and Native Hawaiians. They were followed for an average of 16 years.
The other was performed by European scientists from Imperial College London and the International Agency for Research on Cancer. It examined coffee-drinking among more than 520,000 adults from 10 European countries.
Setiawan's study found those drinking one cup of coffee daily had a 12 percent lower risk of death from heart disease, cancer, stroke, diabetes, respiratory and kidney disease. For three-a-day drinkers, the risk reduction rose to 18 percent.
In previous studies, the great majority of those examined were white, meaning that environmental and lifestyle differences among ethnicities could have confounded the results. But her study found these benefits to occur regardless of the ethnicity studied.