5 January 2012
The role of coffee in heart disease, hypertension and diabetes.
HOW does coffee affect our health? This question has prompted researchers from all over the world to study coffee in search of answers.
In a previous article, we looked at what is known so far of the effects of coffee on Alzheimer’s disease, Parkinson’s disease and certain cancers.
This time, let’s look at the available scientific findings on coronary heart disease, blood pressure and type 2 diabetes.
Coffee and your heart
Some people believe that coffee may not be good for the heart.
However, in 2006, a meta-analysis of 21 studies concluded that there is no evidence that coffee increases the long-term risk of coronary heart disease.
In fact, coffee may actually have some beneficial effects against coronary heart disease, as a study published in the International Journal of Cardiology in 2009 suggested that coffee is associated with a lower risk of coronary heart disease in women.
However, excessive consumption of coffee is not recommended as there are studies that suggest that excessive drinking of coffee (eight cups or more a day) may cause an increase in cholesterol level, possibly leading to an increased risk of coronary heart disease.
Easy on blood pressure?
Regular caffeine intake has been known to temporarily increase our blood pressure. However, a meta-analysis in the Journal of Hypertension in 2005 showed that the blood pressure effect is small when caffeine is ingested through coffee.
People with hypertension may be worried about the effects of coffee on their health.
A systematic review and meta-analysis published in the American Journal of Clinical Nutrition this year however, showed that there is currently no evidence to support an association between long-term coffee consumption and increased risk of high blood pressure or cardiovascular disease in people with hypertension.
Coffee and type 2 diabetes
Type 2 diabetes is the most common form of diabetes.
It causes high levels of sugar to build up in our blood, eventually leading to conditions such as eye problems, damaged nerves, kidney damage, heart attack and stroke.
Family history, a sedentary lifestyle, unhealthy diet and excessive fat around the waist are some of the factors that increase the risk of diabetes.
Can coffee reduce our risk of type 2 diabetes?
A review, published in the American Journal of Clinical Nutrition in 2006, examined epidemiologic and laboratory studies, and suggested that long-term coffee consumption may have minor positive effects on weight loss, which in turn may help reduce the risk of diabetes.
A large prospective study in Singapore, which analysed data from 36,908 Chinese participants from 1993 to 1998, suggested that regular consumption of coffee is associated with a lower risk of type 2 diabetes in Singaporean men and women.
More studies are still needed to support current findings on the possible beneficial effects of coffee consumption on the risks for coronary heart disease, blood pressure and type 2 diabetes.
Nevertheless, it has been established that drinking a moderate amount of coffee (three to five cups a day) is safe for adults.
Therefore, as we wait for more conclusive evidence, let’s enjoy our coffee in moderation.
References:
1. Wu JN, Ho SC, Chun Zhou, Ling WH, Chen WQ, Wang CL, Chen YM. 2009. Coffee consumption and risk of coronary heart diseases: a meta-analysis of 21 prospective cohort studies. Int J Cardiol. 137(3):216-225.
2. Verhoef P., Pasman W.J., Vliet T.V., Urgert R., and Katan M.B. 2002. Contribution of caffeine to the homocysteine-raising effect of coffee: A randomized controlled trial in humans. Am. J. Clin. Nutr. 76:1244–1248.
3. Tverdal, A., Stensvold, I., Solvoll, K., Foss, O. P., Lund-Larsen, P.G., and Bjartveit, K. 1990. Coffee consumption and death from coronary heart disease in middle aged Norwegian men and women. BMJ. 300:566–569.
4. Noordzija M, Uiterwaalb Cuno S.P.M, Lidia R. Arendsc, Frans J. Koka, Diederick E. Grobbeeb and Johanna M. Geleijnsea. 2005. Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of
randomized controlled trials. J Hypertens. 23(5):921-928
5. Mesas AE, Leon-Muñoz LM, Rodriguez-Artalejo F, Lopez-Garcia E. 2011. The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. Am J Clin Nutr;
94:1113–1126.
6. MedLine Plus, National Institute of Health, US. Type 2 Diabetes. Retrieved November 25, 2011 from http://www.ncbi.nlm.nih.gov/medlineplus/ency/article/00313.htm
7. Greenberg JA, Boozer CN, and Geliebter A. 2006. Coffee, diabetes, and weight control. Am J Clin Nutr.84:682–693.
8. Odegaard AO, Pereira MA, Koh WP, Kazuko A, Lee HP, and Yu Mimi C. 2008. Coffee, tea, and incident type 2 diabetes: the Singapore Chinese Health Study. Am J Clin Nutr. 88:979–985.
9. Higdon JV & Frei B. 2006. Coffee and Health: A Review of Recent Human Research. Critical Reviews in Food Science and Nutrition. 46(2):101-123.
This article was published in www.thestar.com.my on 18 December 2011.