Older people who just follow a low-fat diet tend to have worse memory and thinking over time.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
A systematic review of longitudinal studies on cognitive decline in older adults on low-fat diets would provide a comprehensive picture of expected decline rates.
A systematic review of cohort studies and RCTs that observed cognitive changes in older adults on low-fat diets for at least 2 years, reporting change scores on standardized tests.
A larger RCT with a low-fat control group would more precisely estimate the rate of cognitive decline in this population, but it's not the primary focus.
An RCT comparing low-fat diet vs. Mediterranean diet with cognitive outcomes, including a control group followed for at least 5 years, with annual cognitive testing.
A prospective cohort study of older adults following low-fat diets could document cognitive change over time in real-world settings.
A prospective cohort of 5,000 adults aged 60+ who self-report a low-fat diet, with cognitive assessments every 2 years for 10 years.
A case-control study could compare the rate of prior cognitive decline in low-fat diet followers vs others, but this is less relevant.
A case-control study of older adults with defined cognitive decline, retrospectively assessing dietary pattern and changes over time.
A cross-sectional study could show if low-fat diet adherence is associated with worse cognitive performance, but it cannot show decline.
A cross-sectional study of older adults comparing cognitive test scores between those on low-fat diets and others, adjusting for confounders.