Positive news about caffeine and coffee is on the rise! Annia Galano, a Cuban chemist, recently published a paper suggesting that coffee is one of the richest sources of healthful antioxidants in the average person’s diet. It scavenges free radicals that can have damaging effects on the body. Here is a summary of recent research.
Cognitive decline: A study by French neuropsychologist Karen Ritchie found that women over age 65 who drank over three cups of coffee a day showed less cognitive decline over 4 years than those drinking one cup or less. No such relationship was found for men in this study. A study in mice at the University of South Florida found that caffeinated coffee increases a growth factor called GCSF (granulocyte colony stimulating factor) . GCSF improves memory performance in Alzheimer’s mice, acting to remove harmful beta-amyloid protein that initiates the disease. GCSF also creates new brain connections and increases the birth of new neurons. Decaf coffee and caffeine alone did not give this protection.
Heart disease: While coffee may increase blood pressure in certain people, it can also increase blood vessel elasticity. If your blood pressure is high, it is important to assess the effects of coffee with a home blood pressure cuff and a talk with your doctor. Researchers in the Netherlands found that people drinking 2-4 ups of coffee daily had a 20% lower risk of heart disease, and a slightly reduced risk of death from heart disease and all other causes.
Reduced stroke risk: A study from Sweden’s Karolinska Institute found that women who drank one or more cups of coffee a day had a 22% lower risk of stroke – both the kind from arterial blockage and from bleeding in the brain. Men were not included in this study, as the population of 35,000 women were in a mammography study.
Breast cancer risk: Another Swedish study showed that drinking coffee specifically reduces the risk of estrogen-receptor negative breast cancer. There has been speculation that the boiled coffee used by Swedes has more beneficial compounds against cancer than the filtered coffee preferred in this country, but this remains an unproven question. Boiled coffee can increase cholesterol levels.
Prostate cancer risk: A recent study from Harvard School of Public Health of 48,000 male health professionals showed that men who drink coffee (regular or decaf) had a lower risk of developing a lethal form of prostate cancer. Men consuming 6 or more cups daily had a 20% lower risk of developing any form of prostate cancer. They had a 60% lower risk of developing lethal prostate cancer. Drinking 1-3 cups daily was associated with a 30% lower risk of lethal prostate cancer. Additional studies of the mechanisms involved are underway.
Diabetes risk: Past studies have suggested that regular coffee drinking may reduce the risk of type 2 diabetes. At the University of Nagoya in Japan, lab mice commonly used to study diabetes were fed either water or coffee. Coffee consumption prevented the development of high blood sugar and improved insulin sensitivity. There were also beneficial changes in inflammation and fatty liver. Caffeine was felt to be the anti-diabetic compound. However, another recent study from Duke University found that in humans, caffeine can increase insulin resistance in people without diabetes , and produce an exaggerated blood glucose spike in diabetics after they eat carbohydrates. More research needed here.
Gout: A Harvard study of male health professionals looked at 46,000 men over age 40 with no history of gout. After controlling for risk factors for gout, they found that men who drank 4-5 cups of coffee daily had a 40% lower risk of gout, and those drinking 6 or more cups had a 59% lower risk. Decaf coffee showed a more modest lower risk. Tea drinking had no effect on gout, and factors other than caffeine were believed responsible for the benefit.
Coffee makes most users feel energetic, and for many people it is a great pleasure. However, the caffeine in coffee can be a big problem for people with irregular heart rhythms, insomniacs and children. These recent studies should help to clarify what to do with this amazing beverage. Consult your body and your medical history; use it wisely.
Sadja Greenwood, MD, MPH back issues on this blog