Abstract
BackgroundObservational studies have frequently reported an association between cognitive function and nutrition in later life but randomised trials of B vitamins and antioxidant supplements have mostly found no beneficial effect. We examined the effect of daily supplementation with 11 vitamins and 5 minerals on cognitive function in older adults to assess the possibility that this could help to prevent cognitive decline.MethodsThe study was carried out as part of a randomised double blind placebo controlled trial of micronutrient supplementation based in six primary care health centres in North East Scotland. 910 men and women aged 65 years and over living in the community were recruited and randomised: 456 to active treatment and 454 to placebo. The active treatment consisted of a single tablet containing eleven vitamins and five minerals in amounts ranging from 50–210 % of the UK Reference Nutrient Intake or matching placebo tablet taken daily for 12 months. Digit span forward and verbal fluency tests, which assess immediate memory and executive functioning respectively, were conducted at the start and end of the intervention period. Risk of micronutrient deficiency at baseline was assessed by a simple risk questionnaire.ResultsFor digit span forward there was no evidence of an effect of supplements in all participants or in sub-groups defined by age or risk of deficiency. For verbal fluency there was no evidence of a beneficial effect in the whole study population but there was weak evidence for a beneficial effect of supplementation in the two pre-specified subgroups: in those aged 75 years and over (n 290; mean difference between supplemented and placebo groups 2.8 (95% CI -0.6, 6.2) units) and in those at increased risk of micronutrient deficiency assessed by the risk questionnaire (n 260; mean difference between supplemented and placebo groups 2.5 (95% CI -1.0, 6.1) units).ConclusionThe results provide no evidence for a beneficial effect of daily multivitamin and multimineral supplements on these domains of cognitive function in community-living people over 65 years. However, the possibility of beneficial effects in older people and those at greater risk of nutritional deficiency deserves further attention.
Highlights
Observational studies have frequently reported an association between cognitive function and nutrition in later life but randomised trials of B vitamins and antioxidant supplements have mostly found no beneficial effect
Intervention studies with antioxidant vitamins [2,3,4,5] or B vitamins [6,7,8] given for 24 weeks or more in community-living older people have found no evidence for a beneficial effect of supplements, though a recent study of subjects with raised homocysteine levels found a significant benefit of folic acid supplementation for 3 years on global cognitive function and two of the five component cognitive domains [9]
Two randomised trials which used multivitamins for 24 weeks or more found no evidence of a beneficial effect [10,11] but a small trial of frail elderly people in residential care found a beneficial effect of multivitamin and multimineral supplementation in two of the five tests of cognitive function after six months [12]
Summary
Observational studies have frequently reported an association between cognitive function and nutrition in later life but randomised trials of B vitamins and antioxidant supplements have mostly found no beneficial effect. Two randomised trials which used multivitamins for 24 weeks or more found no evidence of a beneficial effect [10,11] but a small trial of frail elderly people in residential care found a beneficial effect of multivitamin and multimineral supplementation in two of the five tests of cognitive function after six months [12] Another trial of a multivitamin and multimineral supplement in healthy elderly subjects reported beneficial effects after one year in six of seven tests [13], though these findings have recently been retracted in the light of concerns about the veracity of the data and possible conflicting commercial interest [14]. We did not collect information on the educational status of participants but this age group would all have attended formal education for at least seven years
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
