Preliminary evaluation of a differential effect of an α-linolenate-rich supplement on ketogenesis and plasma ω-3 fatty acids in young and older adults.
OBJECTIVE
The aim of the present study was to compare the effects of an α-linolenic acid-rich supplement (ALA-RS) on the ketogenic response and plasma long-chain ω-3 polyunsaturated fatty acid in healthy young adults and older individuals.


METHODS
Ten young (25 ± 0.9 y) and 10 older adults (73.1 ± 2.2 y) consumed a flaxseed oil supplement providing 2 g/d of ALA for 4 wk. Plasma ketones, nonesterified fatty acids (NEFA), triacylglycerols, glucose, and insulin were measured over 6 h, before and after supplementation. Total body fat mass was assessed before and after the ALA-RS.


RESULTS
The ALA-RS did not significantly modify fasting ketones but postprandial production of β-hydroxybutyrate was increased by 26% (P = 0.037) only in the young adult group. Fasting plasma ketones were positively correlated to fasting plasma NEFA (P < 0.01) in both groups. However, the relation was shifted to the right in the older group, suggesting that older adults needed higher plasma NEFA levels to achieve the same ketone amounts as young adults. At baseline, the older group had 47% higher total plasma fatty acids than the young group (P = 0.007). After the ALA-RS, plasma ALA doubled in both groups (P < 0.01), an effect that was associated in the older group with a 40% higher eicosapentaenoic acid (EPA; P = 0.004), but no difference in docosahexaenoic acid. The postsupplementation increase in plasma ALA correlated positively with percent total body fat, especially in the older group (r(2) = 0.77; P = 0.0016).


CONCLUSIONS
In young adults, ALA-RS mildly stimulated postprandial ketogenesis, whereas in the older group, it favored increased plasma ALA and EPA.
Research Center on Aging, Sherbrooke, QC, Canada. Electronic address: Marie.hennebelle@usherbrooke.ca.
Marie
M
Hennebelle
Research Center on Aging, Sherbrooke, QC, Canada; Department of Pharmacology & Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada.
Alexandre
A
Courchesne-Loyer
Research Center on Aging, Sherbrooke, QC, Canada; Department of Pharmacology & Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada.
Valérie
V
St-Pierre
Research Center on Aging, Sherbrooke, QC, Canada; Department of Pharmacology & Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada.
Camille
C
Vandenberghe
Research Center on Aging, Sherbrooke, QC, Canada.
Christian-Alexandre
CA
Castellano
Research Center on Aging, Sherbrooke, QC, Canada.
Mélanie
M
Fortier
Research Center on Aging, Sherbrooke, QC, Canada; Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada.
Daniel
D
Tessier
Research Center on Aging, Sherbrooke, QC, Canada; Department of Pharmacology & Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada; Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada.
Stephen C
SC
Cunnane
D000273:Adipose Tissue / Q000033:anatomy & histology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D001786:Blood Glucose / Q000378:metabolism; D019587:Dietary Supplements; D005215:Fasting / Q000097:blood / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007659:Ketones / Q000097:blood / Q000378:metabolism*; D008043:Linseed Oil / Q000008:administration & dosage; D008055:Lipids / Q000097:blood; D008297:Male; D019518:Postprandial Period; D055815:Young Adult; D017962:alpha-Linolenic Acid / Q000008:administration & dosage* / Q000097:blood
D001786:Blood Glucose; D015525:Fatty Acids, Omega-3; D007328:Insulin; D007659:Ketones; D008055:Lipids; D017962:alpha-Linolenic Acid; D008043:Linseed Oil
Acetoacetate; Aging; Flaxseed; Ketogenesis; α-linolenic acid; β-hydroxybutyrate; ω-3 fatty acids