Cognitive impairment and dementia are significant conditions affecting women as they age, with a reported two-thirds of instances of age-related cognitive impairment and dementia seen in women. Previous research has found associations between diet and cognitive function, however large, well-designed studies have been significantly lacking.
Given the relative ease of dietary interventions, this might be a significant prevention strategy. Researchers from the United States set out to determine whether a low-fat diet has any long-term effects on cognitive function in women.
The researchers conducted a randomized, controlled clinical study, examining the possible benefits of a low-fat diet on cognitive function. All participants were postmenopausal women who were enrolled in The Women’s Health Initiative (WHI) Dietary Modification (DM) trial, as well as the Women’s Health Initiative Memory Study (WHIMS). WHIMS consisted of 1,606 participants, a subgroup of the 48,835 participants enrolled in the WHI DM. Participants were either placed in an intervention or a comparison group. All participants reduced their fat intake to 20% of energy. They consumed more fruits, vegetables, and grains.
Cognitive function assessments were completed on each participant at the start of the WHIMS study. Any participant who scored low on the first assessment was considered to possibly be at risk of cognitive impairment and therefore, was further evaluated. These participants were eventually categorized as “no cognitive impairment”, “mild cognitive impairment”, or “probable dementia”. All participants, no matter their original assessment outcome, were assessed annually.
The researchers found that women who were in the dietary intervention group had a significant reduction in their risk of cognitive impairment. The study also reported that during the follow-up period, the number of deaths in this group was lower, however, this result was not statistically significant.
The results of this study contribute to current evidence that dietary changes can significantly impact on cognitive health, specifically, that reducing fat consumption can improve cognitive health in aging women.
According to the researchers, “our current findings provide prospective, randomized clinical trial evidence that adoption of a low-fat dietary pattern, representing dietary moderation, significantly reduced risk of possible cognitive impairment in postmenopausal women.”
Written by Laura Laroche, HBASc, Medical Writer
Chlebowski, Rowan T. et al. “Low-fat dietary pattern and global cognitive function: Exploratory analyses of the Women’s Health Initiative (WHI) randomized Dietary Modification Trial”. EClinicalMedicine – The Lancet. Vol. 18. January 1st, 2020. Online.
Mild Cognitive Impairment. 2020, https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild-cognitive-impairment, accessed February 6th, 2020.
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