The Effect of Different Dietary Fats on the Longevity and Muscle Strength in Drosophila

Abstract

Fat is an essential source of energy and is important for human growth and development. A high fat diet, however, leads to pathological obesity and associated comorbidities, such as reduced lifespan and muscle strength in both humans and model organisms. In this study we analyzed the effects of four dietary fats on lifespan and overall health using a Drosophila model system, which shares the mechanisms of energy processing, storage, and utilization with humans. One day old wild type male Drosophila were collected and placed on a control diet or high fat diets containing 5%, 10% or 15% of coconut oil (medium chain‐saturated fat), vegetable oil, olive oil, or flax seed oil (all three contain unsaturated fats). Lifespan was determined for 100 flies on each diet. Skeletal muscle performance was evaluated by climbing and flying assays. Among all the groups, flies on a control diet had the greatest survival with a median lifespan of 30.5 days, while flies on a 5% coconut oil diet had the second longest survival time, yielding a median lifespan of 13 days. For all other diets, the median lifespan was 2 days. Flies on the control diet also performed significantly better (p<0.05) in the flying and climbing assays relative to flies on high fat diets. Flies on a 5% coconut oil diet had a significantly higher (p<0.05) muscle strength based on the flying assay compared to flies maintained on 5% diets with unsaturated fats. Interestingly, intestinal permeability measured using the Smurf assay revealed no difference between flies maintained on a control diet, 5% coconut oil diet, and 5% vegetable oil diet, suggesting that the adverse health effects of a high fat diet did not result from the compromised function of the intestine. Taken together, these data indicate that plant based medium chain saturated fats preserved longevity and muscle function better than plant‐based fats containing high amounts of polyunsaturated fatty acids.Support or Funding InformationFunding Source: University of Memphis SHS Faculty Grant