In a randomised Clinical Trial, researchers from Spain took 450 ‘seniors’ and assigned one of the following diets to them:
1. A colourful Mediterranean Diet plus a litre of extra virgin olive oil a week
2. A colourful Mediterranean diet plus 30 gms of fresh nuts a day
3. A low-fat diet.
The seniors may have been overweight, had high cholesterol or high cardiac risk.
The findings were very clear. The standard low-fat medical recommendation was worse than useless. The group using the diet had cognitive function and memory declines.
The group eating the nuts had improved memory, while the group eating the olive oil had increased cognitive function.
Ref: JAMA Intern Med. Published online May 11, 2015. doi:10.1001/jamainternmed.2015.1668