Ketogenic diet increases mitochondria volume in the liver and skeletal muscle without altering oxidative stress markers in rats

Abstract

Ketogenic diets (KD) consist of high fat, moderate protein and low carbohydrates. Studies have suggested that KD may influence oxidative stress by affecting mitochondrial quantity and/or quality, and perhaps lengthen lifespan. Therefore, we determined the effects of KD on multi-organ mitochondria volume and oxidative stress markers in rats. Ten month-old male Fisher 344 rats (n = 8 per group) were provided with one of two isocaloric diets: standard chow (SC) or KD. Rats were euthanized if: a) vitality scores exceeded a score of 16, b) rapid weight loss, or c) veterinarian deemed euthanasia necessary. The median lifespan of rats was higher in KD (762 days) compared to SC (624 days). Citrate synthase activity (i.e. estimate of mitochondria volume) was higher in the liver (p = 0.034) and gastrocnemius (p = 0.041) of KD compared to SC. Liver superoxide dismutase 1 and catalase antioxidant protein levels were higher in KD, albeit not significant (p = 0.094 and p = 0.062, respectively). No significant differences in protein levels of other antioxidants or markers of lipid and protein oxidative damage were observed in either the gastrocnemius, liver, or brain. In summary, KD increased mitochondria volume in liver and gastrocnemius and median lifespan in rats. Additionally, our data show that the increase in mitochondrial volume occurred without changes in oxidative damage or antioxidant protein levels in the gastrocnemius, liver, or brain.

Ketogenic diet feeding improves aerobic metabolism property in extensor digitorum longus muscle of sedentary male rats

“…Therefore, the relative muscle mass was higher in KD animals. This finding is consistent with earlier reports describing four-week ketogenic diet feeding [ 6 , 24 , 25 ]. Consequently, application of a ketogenic diet for four weeks is not harmful to muscle quantity.…”

“…Then the EDL muscle was removed, weighed, and frozen for subsequent analyses. For this study, EDL muscle was selected because it is a fast-twitch fiber muscle similar to the gastrocnemius and quadriceps femoris muscles, which have been used often in earlier ketogenic diet studies [ 22 , 24 – 26 ]. Also, EDL muscle is suitable to isolate with tendon-to-tendon manner for performing muscle contraction experiments.…”

Ketogenic Diets and Exercise Performance

“…In addition to variable reports in exercise performance, some potential negative side effects, including increased adipose tissue mass [78,80], decreased muscle glycogen content [79], increased serum triglycerides [80], and decreased cardiac function [80], were noted. However, KDs may decrease mortality [81,82], improve memory [81], and increase muscle citrate synthase [82] in aged mice. Perhaps additional studies in animal models are necessary to help derive definitive conclusions.…”

Ketogenic Diet and Sport Performance

“…This might be a limitation of the human study, and a well-designed in vivo or in vitro experiment may validate this result. It was reported that in an experiment that lasted for 762 days, muscle mitochondrial volume was increased by KD (Parry et al, 2018). Other authors show that a 12-week KD combined with daily treadmill exercise induced higher gene expression in markers of fatty acid oxidation, as compared with the control diet combined with exercise (Shimizu et al, 2018).…”