Effect of an Alpha-linolenic Acid-rich Supplement on Ketogenesis and Plasma Fatty Acids

Effect of an Alpha-linolenic Acid-rich Supplement on Ketogenesis and Plasma n-3 Polyunsaturated Fatty Acids in Young Compared to Older Adults

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 humans.

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 supplementation.

Hypothesis: ALA-rich supplement for 4 weeks will increase ketone production in both groups.

Inclusion Criteria:

• aged between 18 and 30 or 65 years and more

Exclusion Criteria:

• non smoker
• pregnancy or breastfeeding
• diabetes or insulin resistance
• uncontrolled thyroid disease, hepatic or renal disease
• uncontrolled high blood pressure
• medical treatment influencing lipid or glucide metabolism
• ongoing or past severe drug or alcohol abuse
• dementia or psychiatric difficulties or depression
• chronic immune condition or inflammation