Carnitine in the dairy chain

PhD research project

This promotional research focuses on carnitine metabolism in elderly people. Ageing is generally accompanied by loss of muscle mass, muscle weakness and fatigue (frailty syndrome), which negatively impacts the quality of life. In addition, ageing is associated with a reduction in the amount of carnitine in the muscles.

Carnitine is a metabolite that plays an important role in the energy supply; it transports fatty acids to the mitochondria. The fatty acids are broken down in the mitochondria and energy is generated. The tissues that mainly use fatty acids as fuel have a great deal of carnitine, for example muscles. The body itself makes carnitine, but we also ingest it via our nutrition. Meat and dairy products in particular are rich in carnitine.

In order to determine how carnitine metabolism originated during evolution, a phylogenetic analysis is carried out with the genes that are involved here. Well-conserved genes in the evolution are a sign that they play an important role in carnitine metabolism. These genes will be investigated further in a cross-sectional study; the Fitaal study.

In the Fitaal study, we will investigate the carnitine status in fit and vulnerable elderly people in comparison with healthy young adults.  Ageing causes the carnitine status in the muscle to decline, but it is not known whether this decline is associated with the physical state of elderly people and the mitochondrial function. In addition, we will also investigate the cognitive function of elderly people in relation to the carnitine status. In 2017, the Fitaal study was conducted among 30 fit elderly people, 25 vulnerable elderly people and 26 healthy young adults.


This research will provide more insight into the ageing process in relation to carnitine metabolism. It will generate data on the type of genes involved and whether the carnitine status has an impact on the physical well-being of elderly people and the mitochondrial function. Given we conduct the Fitaal study among both men and women, we also hope to generate data on gender differences in ageing. If it appears that carnitine indeed plays an important role in ageing and the physical state, a future study could be conducted into the effect of carnitine supplementation in ageing.

Would you like to know more about the Carnitine in the Dairy Chain project? Then contact



Start – 1 July 2014
End – 31 December 2018

Core team

  • Feike van der Leij
  • PhD student: Marjanne van der Hoek


  • Wageningen University & Research
  • Medisch Centrum Leeuwarden
  • Alfasigma
  • TNO