High protein intake makes you cleverer

Researchers from LIFE – The Faculty of Life Sciences, University of Copenhagen have just published a study showing that a high protein intake markedly strengthens certain signal substances in the brain. The purpose of the research project is to create a better basis for making dietary recommendations concerning protein intake for healthy people.

 

The test subjects who, for a period of three weeks, ate a particularly protein-rich diet showed significantly faster perception and reaction times and made fewer mistakes in a number of cognitive exercises than the test subjects eating an average diet.

 

Twenty-three young men aged 19-31 years were divided into two groups, of which one group had to stick to their normal protein intake, whereas the other group took in twice as much protein (approx. 3 g per kg of body weight per day), the primary sources being milk and meat. Both groups were kept on their respective diets for three weeks.

 

The purpose of the study was to establish whether cognitive and muscle functions are influenced by an increased protein intake. The physical functions of the subjects were not affected, but their cognitive functions, which were measured in various ways, were. A computer-based test showed that the number of mistakes fell and the speed at which the correct answers were given improved in the subjects eating a high-protein diet. Also, the young men eating a lot of protein performed better in an orientation test.

 

The improvement in cognitive function in the subjects eating a lot of protein is due to an increase in the level of certain amino acids in the blood which increased in step with the increased protein intake. These amino acids are believed to increase the level of certain signal substances in the brain, leading to faster reaction times.

 

- Earlier studies looking at the same topic have been based on one-day trials, so our study shows for the first time the lasting effects of a continuous high intake of protein, says Lene Holm Jakobsen, PhD at LIFE – The Faculty of Life Sciences and the Clinical Nutritional Unit at Rigshospitalet, Copenhagen.

 

Tailored dietary recommendations in future

The purpose of the trial was to create a better basis for making protein recommendations for healthy people.

 

- Most public dietary recommendations on the intake of fat, carbohydrates and protein focus on preventing obesity and cardiovascular diseases in middle-aged people. Our trial shows that there may be a need to adjust the dietary recommendations so that lean, physically active young people are advised to eat differently. Hopefully, our study can encourage such a development, says Professor Jens Kondrup from LIFE - The Faculty of Life Sciences and Head of the Clinical Nutritional Unit at Rigshospitalet.

 

The study has been published in Clinical Nutrition (DOI Information: 10.1016/j.clnu.2010.12.010). The study was partly funded by the Danish Meat Association (now the Danish Agriculture & Food Council).

 

Contact

Professor Jens Kondrup
Department of Human Nutrition, The Faculty of Life Sciences, University of Copenhagen
Senior Physician, Clinical Nutritional Unit, Rigshospitalet, Copenhagen
Mobile: +45 40 41 03 93

 

Lene Holm Jakobsen
Clinical Dietician, MSc in Clinical Nutrition, PhD, Clinical Nutritional Unit, Rigshospitalet, Copenhagen
Mobile: +45 61 69 95 11