Ultra-processed food consumption and risk of dementia and Alzheimer's disease: The Framingham Heart Study.
Level 3 - non-randomized controlled study
Prospective cohort follow-up study
PubMed 39863327 · doi:10.1016/j.tjpad.2024.100042
What was done
This prospective cohort study analyzed 1,375 participants (mean age 68 ± 6 years, 54% female) free of dementia and stroke from the Framingham Heart Study Offspring cohort who attended examination cycles 5 (1991–1995) and 7 (1998–2001) at age ≥60 years. Dietary intake was gathered via food frequency questionnaires and categorized into ultra-processed foods using the NOVA classification system. Participants were followed for incident all-cause dementia and Alzheimer's disease over a mean of 12.7 ± 6.0 years. Hazard ratios were estimated using Cox proportional hazards regression adjusting for age, sex, education, total energy, metabolic factors, and diet quality, stratified by median baseline age (68 years) due to age-interaction effects.
What was found
Over follow-up, 224 individuals developed all-cause dementia and 172 developed Alzheimer's disease. Ultra-processed food consumption interacted significantly with age for dementia (p = 0.02) and Alzheimer's disease (p = 0.007). In participants <68 years of age at baseline, each additional serving per day was associated with a 13% increased risk of Alzheimer's disease (HR = 1.13, 95% CI: 1.03–1.25), and consuming ≥10 servings/day versus <10 servings/day was associated with a 2.7-fold increased risk (HR = 2.71, 95% CI: 1.18–6.24). Associations with all-cause dementia were less robust, and no significant associations were observed in participants aged ≥68 years at baseline.
Why it matters
These findings suggest that higher intake of ultra-processed foods in middle to early-late adulthood is linked to elevated Alzheimer's disease risk, highlighting a potentially modifiable dietary target.
Limits
Diet was self-reported using food frequency questionnaires, introducing measurement error and recall bias. As an observational study, residual confounding cannot be ruled out. The positive association was confined to subgroup analyses (<68 years) with no effect seen in older participants. The sample was drawn from a single-site, community-based cohort with limited demographic diversity.
Cited by
- context A prospective study following 1,111 individuals over 12.7 years found that consuming an average of one serving of ultra-processed food per day was associated with a 13% increased risk of Alzheimer's disease.
- supports In the same prospective study, consuming 10 or more servings of ultra-processed foods per day was associated with a 270% increased risk of Alzheimer's disease.