Scientists from the European Nutrigenomics Organisation have profiled the changes in our bodies’ molecules caused by prolonged fasting. This ‘fasting metabolome’ may make it possible to characterise different people according to their metabolic reaction to nutritional stress, as a step towards personalised nutrition for maintaining an individual’s health and wellbeing.
Of 377 products analysed, 44 per cent of them were shown to change after prolonged fasting of 36 hours compared with overnight fasting of 12 hours. They include a large number of metabolites as well as hormones, enzymes and other signalling molecules.
While some of the molecules that were seen to change are known “fasting markers”, many metabolites and hormones that were altered were not previously known to be associated with fasting.
During prolonged fasting, the body’s fuel management system changes completely and molecules from the liver, muscle and fat are broken down to provide energy. In the new study, 36 entities in blood and urine samples had changed in all the volunteers by a similar extent, but other products changed by different amounts in each volunteer.
“We now have a clear fasting signature,” said Professor Hannelore Daniel from the ZIEL Research Centre for Nutrition and Food Sciences in Germany.
Particularly high variability between individuals was shown for 33 entities. In blood they include leptin, the satiety hormone, which decreased significantly but to varying degrees. Higher levels of plasma leptin are associated with increased body mass and the highest levels are found in obesity. In urine, ketone bodies rose by varying degrees though in blood they rose by a similar amount in all volunteers. The presence of plasma ketone bodies indicates tissue fat being broken down.
“This study shows how it is possible to use metabolomics to characterise the different responses of individuals to nutritional or physiological stress.” said Professor Ian Johnson from the Institute of Food Research.
“By using the same approach applied to a large number of volunteers, we hope in the future to be able to divide the population into metabolic “types”, an important step towards personalised nutrition.”
The Human Nutrition Unit at the University of Aberdeen Rowett Institute of Nutrition and Health recruited three male volunteers and seven females. On four different days of the week the volunteers fasted overnight and provided blood, saliva and urine samples. For the last sampling day fasting was extended to 36 hours.
This study was funded by the EU through the European Nutrigenomics Organisation, NuGO. NuGO brings together researchers from across Europe to share facilities and expertise in nutrigenomics, the study of how the food we eat affects our bodies, our genes and our metabolism. A long-term goal of this area of research is to improve health by modifying dietary intake according to an individual’s genetic make-up.
Notes to editors
- Full reference: Metabolomics of prolonged fasting in humans reveals new catabolic markers, Metabolomics, DOI: 10.1007/s11306-010-0255-2
- The mission of the Institute of Food Research (www.ifr.ac.uk) is to undertake international quality scientific research relevant to food and human health and to work in partnership with others to provide underpinning science for consumers, policy makers, the food industry and academia. It is a company limited by guarantee, with charitable status, grant aided by the Biotechnology and Biological Sciences Research Council (www.bbsrc.ac.uk).
- NuGO (www.nugo.org) is an Association of Universities and Research Institutes focusing on jointly developing the exiting research area of nutrigenomics and nutritional systems biology. NuGO evolved from a EU Sixth Framework Network of Excellence and is now expanding to global dimensions.
NuGO has two major objectives:
- Stimulating developments in nutrigenomics, nutrigenetics and nutritional systems biology, and incorporating these aspects in nutrition and health research, by joint research projects, conferences, workshops and training.
- Shaping the nutrition bioinformatics infrastructure by initiating, coordinating, facilitating projects in this area and by hosting and disseminating all data, results and information in this area.