We read with interest the recent report by Smyth et al. concerning the influence of diet on risk of cognitive decline with aging. [1] Data from three international trials with over 27,800 subjects showed higher levels of diet quality are associated with lower risk of cognitive decline, without relationship to baseline cognition. Several other investigations also documented an association of diet quality and preserved cognitive function with aging. [2] Numerous mechanisms of influence have been proposed, including influences of food on inflammation, oxidative toxicity, stroke risk, lipid metabolism, obesity, as well as the health of the heart and other organs.
Recent studies have shown another important avenue by which diet may influence cognitive function with aging. All humans are home to a complex population of organisms, referred to as the microbiota, which reside in the gut, on body surfaces, and elsewhere. [2-5] Human microbiota play important roles in health and disease with aging, and a relationship between gut microbiota composition, cognition, depression, and inflammation has been described. [5] These commensal partners evolved with their human host and are dependent upon dietary ingredients for their energy supply. Dietary alterations as short as 2 weeks can alter the gut microbial population with important implications for metabolism, inflammation, oxidative stress, toxin production, atherogenesis, and DNA damage. [2-4]
It would be valuable for similar, future studies to consider the potential influence of diet on microbiota.
1. Smyth A, Dehghan M, O'Donnell M, et al. Healthy eating and reduced risk of cognitive decline: A cohort from 40 countries. Neurology 2015;84:2258-2265.
2. Tangney CC, Li H, Wang Y, et al. Relation of DASH- and Mediterranean-like dietary patterns to cognitive decline in older persons. Neurology 2014;83:1410-1416.
3. David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature 2014;505:559-563.
4. O'Keefe SJ, Li JV, Lahti L, et al. Fat, fibre and cancer risk in African Americans and rural Africans. Nat Commun 2015;6:6342.
5. Claesson MJ, Jeffery IB, Conde S, et al. Gut microbiota composition correlates with diet and health in the elderly. Nature 2012;488:178-184.
For disclosures, please contact the editorial office at journal@neurology.org.
We read with interest the recent report by Smyth et al. concerning the influence of diet on risk of cognitive decline with aging. [1] Data from three international trials with over 27,800 subjects showed higher levels of diet quality are associated with lower risk of cognitive decline, without relationship to baseline cognition. Several other investigations also documented an association of diet quality and preserved cognitive function with aging. [2] Numerous mechanisms of influence have been proposed, including influences of food on inflammation, oxidative toxicity, stroke risk, lipid metabolism, obesity, as well as the health of the heart and other organs.
Recent studies have shown another important avenue by which diet may influence cognitive function with aging. All humans are home to a complex population of organisms, referred to as the microbiota, which reside in the gut, on body surfaces, and elsewhere. [2-5] Human microbiota play important roles in health and disease with aging, and a relationship between gut microbiota composition, cognition, depression, and inflammation has been described. [5] These commensal partners evolved with their human host and are dependent upon dietary ingredients for their energy supply. Dietary alterations as short as 2 weeks can alter the gut microbial population with important implications for metabolism, inflammation, oxidative stress, toxin production, atherogenesis, and DNA damage. [2-4]
It would be valuable for similar, future studies to consider the potential influence of diet on microbiota.
1. Smyth A, Dehghan M, O'Donnell M, et al. Healthy eating and reduced risk of cognitive decline: A cohort from 40 countries. Neurology 2015;84:2258-2265.
2. Tangney CC, Li H, Wang Y, et al. Relation of DASH- and Mediterranean-like dietary patterns to cognitive decline in older persons. Neurology 2014;83:1410-1416.
3. David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature 2014;505:559-563.
4. O'Keefe SJ, Li JV, Lahti L, et al. Fat, fibre and cancer risk in African Americans and rural Africans. Nat Commun 2015;6:6342.
5. Claesson MJ, Jeffery IB, Conde S, et al. Gut microbiota composition correlates with diet and health in the elderly. Nature 2012;488:178-184.
For disclosures, please contact the editorial office at journal@neurology.org.