A meta-analysis of a number of cohorts studies published in the International Journal of Cardiology (2009;137:216-25) demonstrates that habitual coffee consumption may be associated with a lower risk of coronary heart disease (CHD) in women. Analysis of data from 21 cohort studies showed that moderate coffee consumption (of up to four cups of coffee per day) were associated with a 18% reduction in risk of CHD in women. The investigators note that such an effect was unlikely to be caused by chance.

Further benefits have been shown from a meta-analysis published in the Archives of Internal Medicine (2009;169:2044) demonstrating that coffee consumption may be associated with a reduction in the risk of type 2 diabetes. Analysis of data from a cohort of 457,992 showed an inverse relationship between coffee consumption and subsequent risk of diabetes, such that every additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes relative risk, after adjustment for potential confounders.

Two cups of coffee a day may benefit cardiovascular health

Moderate consumption of coffee by hypertensive elderly individuals can lead to improvements in aortic distensibility, a measure of the elasticity of arteries which is recognised as an indicator of atherosclerosis and a predictor of future cardiovascular events.

For the study, a team from the University of Athens conducted a health and nutrition survey using a target group of 343 men and 330 women aged between 65 and 100 – all of whom were long-term residents of the Aegean island of Ikaria. The island was selected because of its population’s high life expectancy, with an above-average proportion of residents over 90 years of age.

Coffee consumption was particularly measured during the initial phase of the study because it is a deeply embedded social tradition within the Greek population, and also because of conflicting evidence of its impact on cardiovascular health.

Lead researcher, Dr Christina Chrysohoou, explained that the blood pressure raising effect of caffeine seems to be more pronounced in hypertensive or hypertension-prone subjects than in normotensive ones. Therefore, they focused on a sub-group of 235 hypertensive subjects, in whom they measured the impact of daily coffee consumption using echocardiographic indices of aortic distensibility.

Results showed that moderate coffee consumption (between one and two cups per day) is associated with higher values of aortic distensibility. Adjustments were made for various factors such as age, gender, physical activity status, creatinine levels, BMI and diabetes mellitus. There was also evidence that moderate coffee consumption leads to reduced cardiovascular disease, lower prevalence of diabetes and hyperlipidaemia, lower body mass index, better renal functions and higher creatinine clearance levels. There was no evidence, however, that increasing coffee consumption to three to five cups per day would lead to further improvements in aortic distensibility.

The researchers attribute these beneficial effects to the polyphenolic compounds found in coffee, especially traditional Greek blends, and other micronutrients, including flavonoids, magnesium, potassium, niacin and vitamin E.