The authors of a related editorial note that studies evaluating the relationship between specific dietary supplements and cognitive decline have had consistently negative findings. Although severe nutritional deficiencies (e.g. vitamin B12 deficiency) are known to contribute to cognitive impairment in older adults, RCTs have failed to demonstrate benefits from nutritional supplementation on cognition or the prevention of dementia. Epidemiological evidence has however suggested possible benefits from adherence to a Mediterranean diet. Long-term adherence to a balanced, healthy diet may therefore have more benefit than a more narrow focus on supplementing specific micronutrients, with improvements on a wider variety of health outcomes.