Research looks into positive health effects from eating chocolate
Following a widely reported collaborative study that found eating chocolate improves cognitive function, researchers at the University of Maine, University of South Australia and Luxembourg Institute of Health have published additional research to determine potential causes.
The initial research involved 968 participants ages 23–98 from the Maine-Syracuse Longitudinal Study. Participants who ate chocolate at least once per week had better scores on tests of cognitive abilities as compared to those who never or rarely ate chocolate. The study controlled for many possible confounds such as diet, cardiovascular disease, lifestyle factors, age, education, sex and race.
While a popular finding, questions remain as to the biological mechanisms behind the results, according to the researchers.
It is well-known that polyphenol gives chocolate its favorable influence on metabolic function and that better metabolic function is associated with improved cognitive functioning. Meaning improved metabolic function may be a reason chocolate is associated with cognitive ability.
Two recently published papers, which include UMaine investigators, may provide further explanations for why chocolate is positively related to cognitive ability.
In an article published in the British Journal of Nutrition, the researchers examined the association of chocolate consumption with insulin resistance and serum liver enzymes in adults. They found eating a small amount of chocolate daily was associated with less diabetes and decreased insulin resistance.
Data from 1,153 people, aged 18–69 years who were part of the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX), study were analyzed. It was found that those who ate 100 grams of chocolate per day — equivalent to a bar — had reduced insulin resistance and improved liver enzymes. Insulin resistance plays a major role in diabetes mellitus and has been associated with lowered cognitive functioning in many previous studies, the researchers says.
In a paper published in Pulse, the Maine-Syracuse Longitudinal Study group reports findings using the same study protocol as the chocolate and cognition study, but with arterial stiffness as the outcome measure.
Five-hundred MSLS participants were used in the analysis. Habitual chocolate intakes were related to pulse wave velocity (PWV) — a noninvasive measure of arterial stiffness, or the rate at which pressure waves move down the vessel — measured five years after the assessment of chocolate consumption.
Chocolate intake was significantly associated with PWV in a nonlinear fashion with the highest levels of PWV in those who never or rarely ate chocolate and lowest levels in those who consumed chocolate once a week.
The results remained and were not attenuated after multivariate adjustment for diabetes, cardiovascular risk factors and nonchocolate dietary patterns, and demographic factors. Other studies are planned to determine whether lower PWV and better insulin resistance mediate between modest levels of chocolate consumption and cognitive ability.
While translation of the cognition, diabetes and insulin, and arterial stiffness studies to dietary practice encourages individuals to consume chocolate in moderate amounts for better health and cognition, the study teams emphasize the importance to differentiate between the natural product cocoa and the processed product chocolate, which is an energy-dense food. Therefore, physical activity, diet and other lifestyle factors must be carefully balanced to avoid weight gain over time.
The interrelated studies on chocolate have resulted from a no-cost collaborative agreement for data sharing between UMaine, the Luxembourg Institute of Health and the University of South Australia. Merrill “Pete” Elias, a UMaine psychologist and epidemiologist and professor in the Graduate School of Biomedical Sciences and Engineering; Georgina Crichton, a University of South Australia nutritionist and psychologist; and cardiovascular researcher Dr. Ala’a Alkerwi of the Luxembourg Institute of Health are principal investigators.
Michael Robbins, a UMaine psychology professor, is among many participating investigators. The interdisciplinary team represents epidemiology, neuropsychology, nutrition and cardiology.
Contact: Margaret Nagle, 207.581.3745