Clinical Summary

Sex-Specific Association Between Dietary Iron Intake and Dementia Risk in Older Adults

Vinod Rane, BS Pharm | Disclosures

Takeaway

Excessive iron intake (≥17.57 mg/day) was associated with an increased risk of all-cause dementia in men aged ≥60 years, and a history of smoking further increased this risk.
Deficient iron intake (<10.93 mg/day) was associated with a higher risk of all-cause dementia in women without a history of hypertension.

Previous studies demonstrated the association between dietary iron intake and Parkinson’s disease dementia or cognitive function, but none of these studies evaluated its association with all-cause dementia, Alzheimer’s disease (AD), or vascular dementia (VD).

This longitudinal study included 41,213 men and 48,892 women (age ≥60 years) using data from the UK Biobank (2006-2010).
Funding: Fundamental Research Funds of the State Key Laboratory of Ophthalmology and others.

During a median follow-up of 11.8 years, 560 men were diagnosed with all-cause dementia (247 with incident AD and 117 with incident VD) and 492 women were diagnosed with all-cause dementia (228 with incident AD and 77 with incident VD).
The incidence rates of dementia were lower in:
- men in the fourth quintile of iron intake (≥15.73 to <17.57 mg/day); and
- women in third quintile of iron intake (≥12.4 to <13.71 mg/day).
In men aged ≥60 years, deficient iron intake (first vs fourth quintile: adjusted HR [aHR] 1.37; 95% CI 1.01 to 1.86; P=0.042) and excessive iron intake (fifth vs fourth quintile: aHR 1.49; 95% CI 1.14 to 1.96; P=0.003) were associated with a higher risk of all-cause dementia.
In women without hypertension, deficient iron intake was linked to a higher risk of all-cause dementia (first vs fourth quintile: aHR 1.47; 95% CI 1.01 to 2.15; P=0.044).
Smoking status modified the association between dietary iron intake and incident dementia in men (P_trend=0.017).