Can dietary interventions improve the cognition of Alzheimer patients?

Alzheimer is a devastating condition. Despite much research, we are still far from being able to effectively prevent or treat it. Some claim that relatively simple dietary interventions might work. What does the evidence tell us?

The aim of this systematic review was to evaluate the effect of dietary interventions on the cognitive performance of individuals with Alzheimer’s disease (AD).  Thirty-two RCT could be included.

The findings show that a wide range of supplements have been submitted to testing in RCTs. Most of the supplements seem to be less than useful. However, some seem to show some promise:

• Omega-3 fatty acid has positive effects at different doses.
• ‘Fortasyn Connect’ (a multi-nutrient mixture) seems to be effective in the early stages of the disease.
• Probiotic, Ginseng, Inositol and specialized nutritional formulas seem to have a positive effect on cognition.

Most of the primary studies had poor methodological quality, included patients with mild AD, small samples, and did not obtain significative results for all the cognitive outcomes.

The authors concluded that the effect of most dietary interventions on cognition in AD patients remains inconclusive, however, several nutrients, isolated or not, show potential to improve cognitive function in AD, especially in its early stages.

I am relieved that the authors of this thoroughly-researched review phrased their conclusions as cautiously as they did. The thing is, most of the primary trials are truly not worth writing home about. Some are just 4 weeks long, others include merely 30 odd patients. Many look more like marketing excercises than science.

The authors also stated that better quality studies are urgently needed to confirm the therapeutic potential of the diet so that a dietary recommendation in AD that contributes to the quality of life of patients and relatives can be established. This has become almost a standard sentence for ending a scientific paper. In this instance, however, it seems very true.