Flabby minds

High fat diets can impair memory

source: Alison Motluk
New Scientist March 3 2001 p10

High fat diets can impair memory, according to researchers from Baycrest Centre for Geriatric Care, Toronto. They fed rats a high-fat diet, from the ages of one to four months, with 40% of the diet accounted for by fat, either vegetable or animal. These rats were compared to rats on a diet with 10% fat. All the rats were given a task to obtain food. They could obtain food by pressing a lever, but were only rewarded only every second time they were shown the lever. There was a delay of up to 80 seconds between when the lever appeared and its previous appearance. Rats on high fat diets, whether vegetable or animal fat, showed a poor performance in this task, compared with rats on the 10% fat diet, which learnt more quickly that they did not need to press the lever each time they saw it.

Fat could interfere with how insulin works, and how the brain uses glucose, the researchers argue. This research may be relevant to other animals, including humans. There is concern that a high fat diet could prevent young animals’ neural pathways from developing properly. This research is dealt with in detail in ‘Neurobiology of learning and memory’, vol 75 p179.