A recent paper, published in the British Medical Journal (BMJ), looked at over 200 studies on coffee drinking and health outcomes. The work was done at the University of Southampton (England) and the University of Edinburgh. Researchers reviewed over 200 observational studies across many countries. Drinking coffee was consistently associated with a lower risk of death from all causes and from heart disease, with the largest reductions at 3 cups a day, compared with non-coffee drinkers. Drinking more than 3 cups daily was not associated with harm, but the beneficial effect was less pronounced. There was less evidence for the positive aspects of decaf coffee, but it had similar benefits for a number of outcomes. Some but not all of the studies corrected for factors that may be associated with coffee drinking, such as smoking, that may influence health outcomes.
Coffee was also associated with a lower risk of several cancers, including prostate, endometrial (uterine), skin and liver cancer, as well as type 2 Diabetes, gallstones, gout and cirrhosis of the liver. Finally, there seemed to be beneficial associations between coffee use and Parkinson’s disease, depression and Alzheimer’s.
The authors concluded that coffee drinking seems safe within usual patterns of use, except during pregnancy and in women with increased risk of fracture. They also wrote that there is substantial uncertainty about the effects of higher levels of intake. It may be a trigger for rapid or irregular heartbeat in some people. Additionally – coffee is often consumed with sugars and unhealthy fats which may not be beneficial.
The warnings about coffee during pregnancy are based on an English and Swedish study showing that caffeine use may be associated with lower birth weight babies and an increased risk of miscarriage. Caffeine from coffee, tea, chocolate , soft drinks and some medicines should be counted. The authors suggest limiting caffeine use - a cup of coffee contains about 100 mg of caffeine, while tea may have half that amount. It may be prudent not to exceed one cup a day in pregnancy. Avoid colas, whether sweetened with sugars or chemicals. In addition do not smoke during pregnancy and limit alcohol use to one small glass of wine once a week. It is best to avoid alcohol completely, since studies on minimal amounts have not been done. Binge drinking is associated with serious harm to the fetus.
Warnings against caffeine use in post-menopausal women come from a few studies looking at osteoporotic fractures and diet. A 2001 study from Creighton University showed that a caffeine intake of more than 300 mg daily was associated with decreased bone density of the spine in women with a particular genotype influencing vitamin D receptors. There is currently no test for this problematic vitamin D receptor. The authors suggest that postmenopausal women at risk of osteoporosis decrease caffeine intake (no more than 3 cups daily) and use vitamin D supplements.
Ways to Avoid Overeating during the Holidays!
*Include lean protein sources at every meal – such as chicken (minimal skin), beans and fish. Protein triggers a hormone that signals the brain to slow down emptying of the stomach. This hormone also acts to decrease the hunger promoting hormone called ghrelin.
*Choose minimally processed, high fiber carbohydrates, such as whole grains and vegetables. You will feel full more quickly, and help your microbiome!
*Chew your food thoroughly, don’t gulp! Eating more slowly allows you to know when you’ve had enough.
*Get enough sleep. Inadequate sleep is associated with increased levels of hunger and weight gain.
Sadja Greenwood, MD, MPH