The uncertainty surrounding high intakes of folic acid and associations with cognitive decline in older adults with low vitamin B12 status has been an obstacle to mandatory folic acid fortification for many years. We estimated the prevalence of combinations of low/normal/high vitamin B12 and folate status and compared associations with global cognitive function using two approaches, of individuals in a population-based study of those aged ≥50 years in the Republic of Ireland. Cross-sectional data from 3781 men and women from Wave 1 of The Irish Longitudinal Study on Ageing were analysed. Global cognitive function was assessed by the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Prevalence estimates for combinations of vitamin B12 (plasma vitamin B12 < or ≥258 pmol/l) and folate (plasma folate ≤ or >45·3 nmol/l) concentrations were generated. Negative binomial regression models were used to investigate the associations of vitamin B12 and folate status with global cognitive function. Of the participants, 1·5 % (n 51) had low vitamin B12 (<258 pmol/l) and high folate (>45·3 nmol/l) status. Global cognitive performance was not significantly reduced in these individuals when compared with those with normal status for both B-vitamins (n 2433). Those with normal vitamin B12/high folate status (7·6 %) had better cognitive performance (MMSE: incidence rate ratio (IRR) 0·82, 95 % CI 0·68, 0·99; P = 0·043, MoCA: IRR 0·89, 95 % CI 0·80, 0·99; P = 0·025). We demonstrated that high folate status was not associated with lower cognitive scores in older adults with low vitamin B12 status. These findings provide important safety information that could guide fortification policy recommendations in Europe.

The risk of undernutrition in older community-dwelling adults increases when they are no longer able to shop or cook themselves. Home-delivered products could then possibly prevent them from becoming undernourished. This single-blind randomised trial tested the effectiveness of home-delivered protein-rich ready-made meals and dairy products in reaching the recommended intake of 1·2 g protein/kg body weight (BW) per d and ≥25 g of protein per meal. Community-dwelling older adults (n 98; mean age 80·4 (sd 6·8) years) switched from self-prepared to home-delivered hot meals and dairy products for 28 d. The intervention group received ready-made meals and dairy products high in protein; the control group received products lower in protein. Dietary intake was measured at baseline, after 2 weeks (T1), and after 4 weeks (T2). Multilevel analyses (providing one combined outcome for T1 and T2) and logistic regressions were performed. Average baseline protein intake was 1·09 (se 0·05) g protein/kg BW per d in the intervention group and 0·99 (se 0·05) g protein/kg BW per d in the control group. During the trial, protein intake of the intervention group was 1·12 (se 0·05) g protein/kg BW per d compared with 0·87 (se 0·03) g protein/kg BW per d in the control group (between-group differences P < 0·05). More participants of the intervention group reached the threshold of ≥25 g protein at dinner compared with the control group (intervention T1: 84·8 %, T2: 88·4 % v. control T1: 42·9 %, T2: 40·5 %; P < 0·05), but not at breakfast and lunch. Our findings suggest that switching from self-prepared meals to ready-made meals carries the risk of a decreasing protein intake, unless extra attention is given to protein-rich choices.

Diet has been investigated in relation to its ability to promote cognitive function. However, evidence is currently limited and has rarely been systematically reviewed, particularly in a mild cognitive impairment (MCI) population. This review examined the effect of diet on cognitive outcomes in MCI patients. A total of five databases were searched to find randomised controlled trial (RCT) studies, with diet as the main focus, in MCI participants. The primary outcome was incident dementia and/or Alzheimer's disease (AD) and secondary outcomes included cognitive function across different domains using validated neuropsychological tests. Sixteen studies met the inclusion criteria. There was a high degree of heterogeneity relating to the nature of the dietary intervention and cognitive outcomes measured, thus making study comparisons difficult. Supplementation with vitamin E (one study, n 516), ginkgo biloba (one study, n 482) or Fortasyn Connect (one study, n 311) had no significant effect on progression from MCI to dementia and/or AD. For cognitive function, the findings showed some improvements in performance, particularly in memory, with the most consistent results shown by B vitamins, including folic acid (one study, n 266), folic acid alone (one study, n 180), DHA and EPA (two studies, n 36 and n 86), DHA (one study, n 240) and flavonol supplementation (one study, n 90). The findings indicate that dietary factors may have a potential benefit for cognitive function in MCI patients. Further well-designed trials are needed, with standardised and robust measures of cognition to investigate the influence of diet on cognitive status.