Insulin Sensitivity in Vegans: Unraveling the Relationship with Mitochondrial Density

The Link Between Vegetarian Diet, Insulin Sensitivity, and Muscle Mitochondria

Summary of research by J Gojda, J Patková, M Jaček, J Potočková, J Trnka, P Kraml & M Anděl

This 2013 study analyzed whether the higher insulin sensitivity seen in vegetarians relates to aspects of muscle cell metabolism compared to non-vegetarians. Insulin sensitivity refers to how well the hormone insulin can signal cells to take up glucose from the bloodstream.

The researchers enrolled 11 vegetarians and 10 comparable non-vegetarians matched for body mass index, age, sex and other factors. They measured:

- Insulin sensitivity using a specialized test

- Muscle cell mitochondrial content and activity

- Fat stored inside muscle cells

The key findings were:

- As expected, the vegetarian group did have higher insulin sensitivity. Their cells took up glucose better when exposed to insulin.

- However, the vegetarians showed no significant difference in markers of mitochondrial function in muscle cells. This was surprising given the link between mitochondria and metabolic health.

- There was also no significant difference in fat content inside the muscle cells between groups.

In summary, this small but well-controlled study found that vegetarians had better insulin sensitivity without alterations in muscle mitochondrial traits or fat storage. This suggests the vegetarian diet boosts insulin sensitivity via mechanisms not driven by muscle mitochondria density or intracellular fat content.

Gojda, J., Patková, J., Jaček, M., Potočková, J., Trnka, J., Kraml, P., & Anděl, M. (2013). "Higher insulin sensitivity in vegans is not associated with higher mitochondrial density." European Journal of Clinical Nutrition, 67(12), 1310–1315. Available at: https://www.nature.com/articles/ejcn2013202#citeas