A new study delving into the physiological effects of coffee has found that drinking a couple of extra cups of the beverage heightens the risk of stroke for infrequent coffee drinkers.
According to experts, light coffee drinkers, who are given to consuming the beverage no more than once or twice a day, double their risk of suffering a blood clot in the brain if they up their intake of coffee by an extra cup or two.
It was noted that increased stroke risk was the highest in the hour after drinking a cup of coffee, but it returned to baseline within a two-hour period, strengthening the possibility of it being a causal relationship.
Lead author of the study, Elizabeth Mostofsky, MPH, from Harvard Medical School in Boston, Massachusetts stated, "Consumption was linked with a risk of stroke in the subsequent hour twice as high as during the periods where there was no coffee consumption,"
Link between coffee consumption and stroke risk assessed
In a bid to assess the link between coffee consumption and stroke, the researchers conducted a study involving 400 stroke victims.
The focus of the study was to compare the coffee consumption of each person an hour before stroke symptoms to their usual intake of the beverage in the previous year.
Nearly 78 percent of the patients admitted to drinking coffee in the year gone by.
More than half had consumed the beverage within 24 hours of suffering the stroke while around 10 percent had consumed coffee within an hour of falling ill.
Findings of the study
The researchers noted that the risk of stroke was confined to only those who drank coffee and there was no apparent danger of the sickness in the hour after drinking caffeinated tea or cola.
The researchers found the risk of ischemic stroke in the hour after coffee consumption was only evident among those who drank the beverage infrequently and not for those who drank coffee more regularly.
Experts theorize that coffee lovers who drink several cups of coffee every day perhaps become ‘desensitized’ to the effects of caffeine which is known to elevate blood pressure, impact insulinsensitivity, stiffen arteries and rapidly increase epinephrine release, a stress hormone that accelerates the heart rate.
A Stroke Association spokesman stated, "Caffeine intake can contribute to increased blood pressure, the single biggest risk factor for stroke, but we have known for some time that antioxidants found in certain foods and drinks, including coffee, can help in the prevention of stroke."
The work appears in the journal 'Neurology.'
By Neharika Sabharwal - December 13, 2010