A diverse diet may help ward off hippocampal atrophy

Greater dietary diversity seems to preserve hippocampal volume and may help prevent atrophy, a recent Japan study has found.

The study included 1,683 participants (aged 40–89 years, 50.6 percent men), in whom dietary intake was assessed using 3-day dietary records and scored using the Quantitative Index for Dietary Diversity. T1-weighted brain magnetic resonance imaging was used to track longitudinal changes in hippocampal and total gray matter volumes.

Grouping participants into quintiles of dietary diversity scores, the researchers found that baseline gray matter volumes were comparable across categories, with values ranging from 574.72±1.73 to 578.04±1.76 cm³ (p_trend=0.265). The same was true for baseline hippocampal volume (range: 8.685±0.048 to 8.827±0.048 cm³; p_trend=0.333).

Dietary diversity at baseline correlated with the change in hippocampal volume over 2 years of follow-up. In the lowest quintile, for example, the percentage decrease from baseline was 1.32±0.12 percent. This decreased progressively with increasing diet diversity, such that at quintiles four and five, the percentage decrease values from baseline were 0.81±0.12 percent and 0.85±0.12 percent, respectively (p_trend=0.003).

“[E]ating a variety of foods may be a new effective nutritional strategy to prevent hippocampal atrophy among community dwellers,” the researchers said.

“It is possible that a 2-year longitudinal study might be insufficient not only to evaluate morphological changes but also to detect cognitive decline,” they added. “More longitudinal studies and studies including non-Asians are needed to confirm any association between dietary diversity and brain atrophy and cognitive function.”