Impact of fish consumption on all-cause mortality in older people with and without dementia: a community-based cohort study

Fish consumption and omega-3 polyunsaturated fatty acids from diet are positively associated with cognitive function in older adults even in the presence of exposure to lead, cadmium, selenium, and methylmercury: a cross-sectional study using NHANES 2011-2014 data

BACKGROUND

Long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are reported to be beneficial for cognition, but limited consumption of some fish is recommended due to high concentrations of heavy metals and persistent organics.

OBJECTIVE

We aimed to determine whether dietary ω-3 PUFAs from fish consumption are associated with higher cognitive scores in older adults and explored the associations of mixtures of ω-3 PUFAs and blood concentrations of lead, cadmium, selenium, and methylmercury on cognitive performance.

METHODS

We conducted a cross-sectional study with data from the NHANES 2011-2014, assessing cognitive scores of immediate recall, delayed recall, and executive function in adults ≥60 y (n = 3123). We performed multivariate linear regressions and mixture models utilizing the quantile-based g-computation method to identify associations between monthly fish consumption or dietary ω-3 PUFAs with blood concentrations of lead, cadmium, methyl mercury, and selenium on cognitive scores.

RESULTS

Fish consumption had significant positive associations with all 3 cognitive scores, whereas dietary ω-3 PUFAs were only significantly associated with the Digit Symbol Substitution Test (DSST) scores. Mixture analysis showed significant positive associations with DSST scores for fish consumption (β: 0.88; 95% CI: 0.48, 1.29) and dietary ω-3 PUFAs (β: 0.41; 95% CI: 0.03, 0.78) with positive component weights for fish consumption, dietary ω-3 PUFAs, and blood selenium and negative component weight for blood cadmium concentrations.

CONCLUSIONS

Our findings support dietary recommendations for older adults to consume fish to maintain cognitive function, likely due to biomolecular actions of ω-3 PUFAs that increase neuronal membrane fluidity, have antioxidation activity, and restore cell damage. The combination of selenium and fish consumption or ω-3 PUFAs was associated with reduced decline in cognitive scores and less negative associations from exposures to lead, cadmium, and mercury compounds.

Living Alone: Associations with Diet and Health in the Spanish Young Adult Population

Eating together as a family has important health benefits, as the diet is more balanced and of a higher quality. Eating together is also a factor in the prevention of diet-related diseases. The promotion of family and shared meals is currently a public health strategy. The aim of this research was to study the eating habits of the Spanish young adult population and their impact on health. An observational, descriptive, cross-sectional study was carried out using surveys. A questionnaire was designed and validated to explore a set of variables related to food and health. The dissemination was carried out through social networks by means of an online form, using non-probabilistic snowball sampling to obtain a sample of 17,969 subjects aged between 18 and 45 years. We found statistically significant differences between people living in a family home compared to people living outside a family home in the healthy eating index for the Spanish population, fish consumption, and fried food consumption. This suggests that the nutrition of people living in a family home is healthier, although their BMI is higher. People living together have a statistically higher healthy eating index value than people living alone; consume fast food, fried food, and ultra-processed food less frequently; and eat fish more often. On the other hand, people who live in a family home or are accompanied are more likely to have a sedentary lifestyle and are less physically active. It was concluded that people living alone have a worse healthy eating index than those living with company, which seems to indicate that nutritional interventions should pay attention to people living alone as a variable to be taken into account in future analyses.