Largest Study to Date Links Chocolate to Lower BP and CV Risk
Lisa Nainggolan, Charles P. Vega, MD
Lisa Nainggolan, Charles P. Vega, MD
April 8, 2010 The largest observational study so far to examine the association between chocolate consumption and risk of cardiovascular disease has found that those who ate the most chocolate--around 7.5 g per day--had a 39% lower risk of myocardial infarction (MI) and stroke than individuals who ate almost no chocolate (1.7 g per day).
Lead author Dr Brian Buijsse (German Institute of Human Nutrition, Nuthetal, Germany) told heartwire : "This shows that habitual consumption of chocolate is related to a lower risk of heart disease and stroke that is partly explained by bloodpressure reduction. The risk reduction is stronger for stroke than for MI, which is logical because it appears that chocolate and cocoa have a pronounced effect on BP [blood pressure], and BP is a higher risk factor for stroke than for MI." Buijsse and colleagues report their findings online March 31, 2010 in the European Heart Journal.
However, Buijsse cautions that only small amounts of chocolate were associated with the benefits and it is too early to give recommendations on chocolate consumption: "Maybe it's a boring message, but it's a little too early to come up with recommendations, because chocolate contains so many calories and sugar, and obesity is already an epidemic. We have to be careful." However, he added, that if people did want to treat themselves, they would be better off choosing small amounts of chocolate, preferably dark chocolate, over other sweet snacks. "We know it is the cocoa content in chocolate that is important, so the higher the cocoa content, the better."
Dr Steffen Desch (University of Leipzig, Heart Center, Germany), who wasnot involved with this study but who has performed research on the effects of chocolate on blood pressure, told heartwire : "This is an interesting study that adds to the growing body of evidence that flavanol-rich chocolate might be associated with health benefits. Several epidemiological studies (including the Zuphten Elderly Study, by the same first author) and even more physiological trials have been published before."
"What is missing now is a large-scale randomized trial of flavanol-rich chocolate versus control. The most reasonable end point would probably be the change in blood pressure between groups." However, Desch added, "the major problems in designing such a study are the lack of funding and finding an appropriate control substance. To the best of my knowledge, there is no commercially available flavanol-free chocolate that offers the distinct bitter taste and dark color inherent to cocoa-rich chocolate."
Biggest Chocolate Consumers Had Lowest Blood Pressure
Buijsse and colleagues followed 19 357 people, aged between 35 and 65, who were participants in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC). They received medical checks, including blood pressure and height and weight measurements at the start of the study (19941998), and they also answered questions about their diet, lifestyle, and health, including how frequently they ate 50-g bars of chocolate.
The research was conducted before the health benefits of chocolate and cocoa were recognized, so no differentiation was made between milk, dark, and white chocolate in the study. But in a subset analysis of 1568 participants later asked to recall their chocolate intake over a 24-hour period, 57% ate milk chocolate, 24% dark chocolate, and 2% white chocolate.
Participants were divided into quartiles according to their level of chocolate consumption. Those in the top quartile, eating around 7.5 g of chocolate a day, had blood pressure that was about 1 mm Hg (systolic) and 0.9 mm Hg (diastolic) lower than those in the bottom quartile. In follow-up questionnaires, sent out every two or three years until December 2006, the participants were asked whether they had had a heart attack or stroke, information that was subsequently verified by medical records from general physicians or hospitals. Death certificates from those who had died were also used to identify MIs and strokes.
"Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke, explained Buijsse.
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Lead author Dr Brian Buijsse (German Institute of Human Nutrition, Nuthetal, Germany) told heartwire : "This shows that habitual consumption of chocolate is related to a lower risk of heart disease and stroke that is partly explained by bloodpressure reduction. The risk reduction is stronger for stroke than for MI, which is logical because it appears that chocolate and cocoa have a pronounced effect on BP [blood pressure], and BP is a higher risk factor for stroke than for MI." Buijsse and colleagues report their findings online March 31, 2010 in the European Heart Journal.
However, Buijsse cautions that only small amounts of chocolate were associated with the benefits and it is too early to give recommendations on chocolate consumption: "Maybe it's a boring message, but it's a little too early to come up with recommendations, because chocolate contains so many calories and sugar, and obesity is already an epidemic. We have to be careful." However, he added, that if people did want to treat themselves, they would be better off choosing small amounts of chocolate, preferably dark chocolate, over other sweet snacks. "We know it is the cocoa content in chocolate that is important, so the higher the cocoa content, the better."
Dr Steffen Desch (University of Leipzig, Heart Center, Germany), who wasnot involved with this study but who has performed research on the effects of chocolate on blood pressure, told heartwire : "This is an interesting study that adds to the growing body of evidence that flavanol-rich chocolate might be associated with health benefits. Several epidemiological studies (including the Zuphten Elderly Study, by the same first author) and even more physiological trials have been published before."
"What is missing now is a large-scale randomized trial of flavanol-rich chocolate versus control. The most reasonable end point would probably be the change in blood pressure between groups." However, Desch added, "the major problems in designing such a study are the lack of funding and finding an appropriate control substance. To the best of my knowledge, there is no commercially available flavanol-free chocolate that offers the distinct bitter taste and dark color inherent to cocoa-rich chocolate."
Biggest Chocolate Consumers Had Lowest Blood Pressure
Buijsse and colleagues followed 19 357 people, aged between 35 and 65, who were participants in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC). They received medical checks, including blood pressure and height and weight measurements at the start of the study (19941998), and they also answered questions about their diet, lifestyle, and health, including how frequently they ate 50-g bars of chocolate.
The research was conducted before the health benefits of chocolate and cocoa were recognized, so no differentiation was made between milk, dark, and white chocolate in the study. But in a subset analysis of 1568 participants later asked to recall their chocolate intake over a 24-hour period, 57% ate milk chocolate, 24% dark chocolate, and 2% white chocolate.
Participants were divided into quartiles according to their level of chocolate consumption. Those in the top quartile, eating around 7.5 g of chocolate a day, had blood pressure that was about 1 mm Hg (systolic) and 0.9 mm Hg (diastolic) lower than those in the bottom quartile. In follow-up questionnaires, sent out every two or three years until December 2006, the participants were asked whether they had had a heart attack or stroke, information that was subsequently verified by medical records from general physicians or hospitals. Death certificates from those who had died were also used to identify MIs and strokes.
"Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke, explained Buijsse.
DOWNLOAD COMPLETE PDF HERE.
The researchers searched Cochrane CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Relief Database for studies through March 10, 2010. The 13 selected studies, including 4222 participants, were randomized, double-blind, placebo-controlled, or active-controlled; evaluated the use of aspirin to treat a single migraine headache episode; and included at least 10 participants per treatment group. In addition, studies compared aspirin 900 mg or 1000 mg (alone or in combination) and metoclopramide 10 mg vs placebo or other active comparators (typically sumatriptan 50 mg or 100 mg).