HealthDay News — Men who ate a moderate amount of chocolate on a regular basis had a lower risk for stroke, Swedish researchers found.
Those who ate a median 62.9 g of chocolate per week had a 17% lower risk for any type of stroke compared with those who at 0 g (relative risk=0.83; 95% CI:0.70-0.99), Susanna C. Larsson, PhD, of the Karolinska Institute in Stockholm, and colleagues reported in Neurology.
“The beneficial effect of chocolate consumption on stroke may be related to the flavonoids in chocolate,” Larsson said in a statement. “Flavonoids appear to be protective against cardiovascular disease through antioxidant, anti-clotting and anti-inflammatory properties.”
She added that the compounds may play a role in decreasing LDL blood concentrations and oxidation, as well as in improving endothelial function.
Larsson and colleagues analyzed the association between chocolate consumption and stroke risk in a prospective cohort study involving 37,103 men, aged 45 to 79 years, during a mean study period of 10.2 years. Additionally, the authors conducted a meta-analysis of five studies, including the current study, comparing men and women with the highest chocolate consumption with the group with the lowest consumption.
In the prospective study, the researchers collected information about participant education, weight, height, smoking, physical activity, aspirin use, history of hypertension, family history of myocardial infarction before age 60, alcohol consumption and diet at baseline. They assessed weekly chocolate consumption using a food frequency questionnaire at baseline and quartiles of <12 g/week, 12 to 19.5 g/week, 19.6 to 51.5 g/week, and ≥51.6 g/week based on age-adjusted frequency values.
During the follow-up period 1,511 cerebral infarctions, 321 hemorrhagic strokes and 163 unspecified strokes were reported.
The researchers found that men who had the highest chocolate consumption (median 62.9 g/week) had a 17% lower risk for stroke (relative risk, 0.83; 95% CI: 0.70-0.99) compared with those who did not eat any chocolate, with no difference noted based on type of stroke. This amounted to 12 fewer strokes per 100,000 person-years.
An inverse relationship between chocolate consumption and stroke was observed in men without a history of hypertension (RR=0.76; 95% CI: 0.62-0.93; P=0.006), but not in those with hypertension (RR=1.04; 95% CI: 0.77-1.41).
In the five study meta-analysis that involved 4,260 stroke cases, the researchers observed a similar 19% risk reduction in stroke among those who consumed the most chocolate vs. those who consumed the least (RR=0.81; 95% CI: 0.76-0.90. The follow-up range in all studies was 8 to 16 years and a total of 4,260 strokes were recorded.
Participants who ate the most chocolate were younger, had a university education, and were less likely to be current smokers, have a history of hypertension or atrial fibrillation. They were also leaner and more likely to consume more alcohol, red meat, fruits and vegetables.
Limitations of the prospective study included the single, self-reported nature of chocolate consumption at baseline, lack of differentiation between milk and dark chocolates and the potential for residual confounding factors.