A pilot, short-term dietary manipulation of branched chain amino acids has modest influence on
fasting levels of branched chain amino acids
Sammanfattning
Background: Elevated fasting levels of branched chain amino acids (BCAAs: valine, isoleucine,
leucine) in venous blood are associated with a variety of metabolic impairments, including increased
risk of type 2 diabetes (T2D). Fasting BCAA levels are influenced by non-dietary factors. However, it
is unknown whether fasting BCAAs can be altered through manipulation of dietary intake alone.
Objective: To test whether a specific dietary intervention, using differences in BCAA intake, alters
fasting BCAA levels independent of other factors.
Design: Five healthy male volunteers underwent 4 days of a low and 4 days of a high BCAA content
dietary intervention (ClinicalTrials.gov [NCT02110602]). All food and supplements were provided.
Fasting BCAAs were measured from venous blood samples by mass spectrometry at baseline and
after each intervention.
Results: Diets were isocaloric; contained equal percentages of calories from carbohydrate, fats, and
protein; and differed from each other in BCAA content (1.5±0.1 vs. 14.0±0.6 g for valine; 4.5±0.9 g vs.
13.8±0.5 g for isoleucine; 2.1±0.2 g vs. 27.1±1.0 g for leucine; p<0.0001 for all). Fasting valine was
significantly lower (p=0.02) and fasting isoleucine and leucine were numerically lower following the
low BCAA content vs. the high BCAA content diet levels. The inter-individual response to the dietary
interventions was variable and not explained by adherence.
Conclusion: Short-term dietary manipulation of BCAA intake led to modest changes in fasting levels of
BCAAs. The approach from our pilot study can be expanded to test the metabolic implications of
dietary BCAA manipulation.