Cardiovascular health
Coffee consumption and cardiovascular disease risk factors
Coffee consumption and blood pressure
The precise nature of the relationship between coffee and blood pressure is still unclear; most evidence would suggest that regular intake of caffeinated coffee does not increase the risk of hypertension.
A large 2008 review10 of the effect of habitual coffee consumption on blood pressure showed that some studies found a protective effect of coffee whereas others found a small elevation in blood pressure (1-2 mmHg) with a coffee intake of about 5 cups a day compared with abstinence or consumption of decaffeinated coffee.
Coffee consumption and cholesterol – effect of brewing method
The overall evidence would indicate that coffee’s effect on cholesterol levels is largely dependent on the method of brewing. The coffee component cafestol, and to a lesser extent kahweol, raise the serum levels of both total and LDL-cholesterol11. However, these components only pass into the brew in so-called ‘boiled’ coffee, but are retained in the filter paper in ‘filtered’ coffee.
A 2001 meta-analysis12 concluded that trials using filtered coffee demonstrated very little increase in serum cholesterol levels. Interestingly, a more recent study comparing the effects of no coffee versus 4 cups of filtered, and 8 cups of filtered, coffee per day found that filtered coffee raised both total and HDL-cholesterol levels somewhat13. Further studies are required to definitively establish coffee’s effects on cholesterol.
Coffee consumption and blood flow
So far only small, short-term experiments have been carried out looking at the effects of coffee on flow-mediated dilation in the brachial artery14,15. These observed a 22% reduction in flow-mediated dilation after consumption of a cup of caffeinated espresso. Larger studies are required before any implications of this short-term vasoconstrictor effect can be assessed.
Coffee consumption and blood homocysteine
There is some evidence from intervention studies that high levels of coffee consumption (6 to 10 cups of coffee per day) increase blood homocysteine levels16,17. However, it is still unclear whether reducing high homocysteine levels will lead to a lower risk of cardiovascular disease. In addition, no causal relationship has been established between high blood homocysteine levels and cardiovascular disease18.
