Background: As the main alternative fuel to glucose for the brain, increased plasma ketones
could potentially help compensate for brain glucose hypometabolism occurring during aging.
The precursor long-chain n-3 polyunsaturated fatty acid (PUFA), α-linolenic acid (ALA), is
normally mostly β-oxidized and so could potentially be used to stimulate ketogenesis in
Objective: To compare the impact of an ALA-rich supplement on the ketogenic response in young
and older healthy adults.
Design: Ten young and ten older adults will consume a flaxseed oil supplement providing 2 g/d
of ALA for 4 weeks. Plasma ketones, free fatty acids, triglycerides, glucose and insulin will
be measured over 6 h during two metabolic study days, one before and one at the end of the
Hypothesis: ALA-rich supplement for 4 weeks will increase ketone production in both groups.