White matter hyperintensities (WMHs) visible on brain magnetic resonance imaging (MRI) are markers of chronic small vessel damage, according to background information in the article. “Although diet may be an important predictor of vascular disease, little is known about the possible association between dietary habits and WMHs,” said Clinton Wright, M.D., M.S, the report’s senior author who is associate professor of neurology and scientific director of the Evelyn F. McKnight Brain Institute at the Miller School. “Studies have suggested that consumption of a MeDi (Mediterranean Diet) is associated with a reduced risk of the metabolic syndrome, coronary heart disease, stroke and cognitive disorders, but no studies to date, to our knowledge, have found an association between a MeDi and WMH volume (WMHV).”
Lead author Hannah Gardener, Sc.D., epidemiologist in the Miller School’s Department of Neurology and a co-investigator in the Evelyn F. McKnight Brain Institute, and colleagues evaluated data from 966 participants in the Northern Manhattan Study to examine the association between a MeDi and WMHV. Participants were given a food frequency questionnaire to assess dietary patterns during the previous year, and answers were used to determine a MeDi compliance score. The WMHV was measured by quantitative brain MRI.
Results of the survey showed that 11.6 percent of participants scored 0 to 2 on the MeDi scale, 15.8 percent scored 3, 23 percent scored 4, 23.5 percent scored 5, and 26.1 percent scored 6 to 9. Women had lower MeDi scores than men and participants who reported moderate to heavy levels of physical activity were more likely to report greater consumption of a MeDi. Participants with MeDi scores of 6 or higher also had lower BMI.
These results suggest a lower burden of WMHV among participants with a greater consumption of a MeDi. This association was independent of sociodemographic and vascular risk factors including physical activity, smoking, blood lipid levels, hypertension, diabetes, history of cardiac disease and BMI. Additionally, after adjustment, the only component of the MeDi score that was independently associated with WMHV was the ratio of monounsaturated to saturated fat.
“In summary, the current study suggests a possible protective association between increased consumption of a MeDi and small vessel damage,” Wright concluded. “The associations with WMHV may be driven by the favorable ratio of monounsaturated fat consumption over saturated fat. However, the results of the analysis of the individual MeDi scale components suggest that the overall dietary pattern, rather than any of the individual components, may be more etiologically relevant in relation to WMHV.”
The research was supported by grants from the National Institute of Neurological Disorders and Stroke, the American Heart Association, and the Evelyn F. McKnight Brain Institute.