Lifelong diet including common unsaturated fatty acids extends the lifespan and affects oxidation in Caenorhabditis elegans consistently with hormesis model

Abstract

Diets abundant in unsaturated fatty acids (UFAs) help to support a longer and healthier life. We evaluated effects of dietary oleic acid (OA), linoleic acid (LnA), and linolenic acid (ALA) on lifespan and physical activities of Caenorhabditis elegans (C. elegans). Supplementation at doses per plate of 0.5 mg OA, 0.1 mg LnA, or 0.5 mg ALA extended the lifespan of C. elegans by 10.49, 14.17, or 8.47%, respectively (p < 0.05). At these doses, LnA and ALA significantly inhibited growth, pharyngeal pumping, reproduction, and respiration (p < 0.05), while OA did not influence these physiological activities (p > 0.05). Furthermore, OA significantly increased superoxide dismutase, catalase, and glutathione peroxidase activities. Based on results obtained with wild‐type N2, eat‐2, and sod‐2‐mutated C. elegans, OA extended C. elegans lifespan through a hormesis mechanism by activating antioxidant enzymes. In contrast, LnA and ALA acted via a caloric restriction mechanism. Consistent with calorie restriction being a type of stress, however, lifespan was shortened as LnA and ALA doses were further increased. Therefore, the effects of all three fatty acids might be regarded as being consistent with a classic hormesis effect.Practical applications: Oleic acid, linoleic acid, and linolenic acid are the three most common unsaturated fatty acids in vegetable oils. The beneficial effects of oleic acid, linoleic acid, and linolenic acid supplementation on lifespan, normal physiological activities, and oxidation in our study support consumers choosing vegetable oils in their diets.Supplementation with 0.5 mg OA, 0.1 mg LnA or 0.5 mg ALA extended the lifespan of C. elegans by 10.49%, 14.17% or 8.47%, respectively (p < 0.05). At these doses, LnA and ALA significantly inhibited growth, pharyngeal pumping, reproduction and respiration, while OA did not influence these physiological activities and significantly increased superoxide dismutase, catalase and glutathione peroxidase activities. Using the eat‐2, and sod‐2 mutated strains, the anti‐aging mechanism of OA was hormesis, while LnA and ALA acted via caloric restriction.