Determination of the safety of leucine supplementation in healthy elderly men

  title={Determination of the safety of leucine supplementation in healthy elderly men},
  author={Betina F Rasmussen and Erin Gilbert and Abrar Turki and Kenneth Michael Madden and Rajavel Elango},
  journal={Amino Acids},
Leucine, a branched-chain amino acid (BCAA), has been shown to stimulate muscle protein synthesis, and thus has been proposed to prevent age-related muscle atrophy (sarcopenia). Therefore, leucine supplementation may have potential benefits in elderly populations to preserve muscle mass. The tolerable upper intake level (UL) for leucine intake in young men has recently been determined to be 500 mg kg−1 day−1, and increases in blood ammonia concentrations were seen at intake levels above 500 mg… 
Safety and Tolerability of Leucine Supplementation in Elderly Men.
2 current studies to determine the Tolerable Upper Intake Level (UL) for leucine in young and elderly men are described and the conceptual model of determining the maximum oxidative capacity of an amino acid to be an ideal marker for identifying the UL is tested.
Tolerance to increased supplemented dietary intakes of methionine in healthy older adults.
On the basis of plasma homocysteine, the NOAEL of supplemented Met intake is 46.3 and the LOAEL is 91 mg · kg body weight-1 · d-1 in healthy older adults, both of which are not associated with meaningful effects on health and wellbeing.
Safety and tolerability of 6-month supplementation with a vitamin D, calcium and leucine-enriched whey protein medical nutrition drink in sarcopenic older adults
A 6 months intervention with up to 2 servings of WP-MND did neither result in kidney function deterioration nor symptoms of vitamin D or calcium toxicity, and the product was overall well tolerated.
Food supplements-High intake of isolated branched-chain amino acids can lead to health impairments-BfR Opinion No. 052/2019 of 20 December 2019
  • 2020
Leucine, isoleucine and valine form the group of branched-chain amino acids (BCAAs2). As protein building blocks, they are natural components of foods containing protein such as meat, fish or
Dietary Aromatic Amino Acid Requirements During Early and Late Gestation in Healthy Pregnant Women.
The results suggest that the current estimated average requirement for TAA during pregnancy of 36 mg·kg-1·d-1 for TAAs is underestimated and has potential implications for creating gestation stage-specific TAA recommendations.
Dietary phenylalanine requirements during early and late gestation in healthy pregnant women.
The results suggest a higher requirement (40%) for phenylalanine during late pregnancy than during early pregnancy, and the early pregnancy requirements are higher than the previous adult male requirement (9.1 mg · kg-1 · d-1; 95% CI: 4.6, 13.6 mg ·kg-1· d- 1), although the 95% CIs overlap.
Branched‐chain amino acids differently modulate catabolic and anabolic states in mammals: a pharmacological point of view
An overview of the current literature on the different effects of BCAAs in health and disease is presented and the results showing the most promising therapeutic effects of dietary BCAA supplementation are highlighted.
Safety assessment of l-lysine oral intake: a systematic review
The observed adverse events were mainly subjective symptoms related to the gastrointestinal tract such as nausea, stomachache, and diarrhea, and the provisional no-observed-adverse-effect level obtained based on these gastrointestinal symptoms was 6000 mg/ person/day.
BCAA Metabolism and Insulin Sensitivity - Dysregulated by Metabolic Status?
A working hypothesis of the mechanism(s) by which lipids may contribute to altered BCAA catabolism, which often accompanies metabolic disease, is provided.


Determination of the tolerable upper intake level of leucine in acute dietary studies in young men.
On the basis of plasma and urinary variables, the tolerable upper intake level (UL) for leucine in healthy adult men can be suggested at 500 mg · kg¹ · d⁻¹ or ~35 g/d as a cautious estimate under acute dietary conditions.
Long-term effects of leucine supplementation on body composition
There is no evidence that chronic leucine supplementation is efficient in promoting muscle mass or preventing protein loss during catabolic states, andLeucine-rich amino acid mixture or proteins appeared more efficient than leucINE alone to improve muscle mass and performance, suggesting the efficacy of leucines depends nevertheless on the presence of other amino acids.
A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly.
It is concluded that increasing the proportion of leucine in a mixture of EAA can reverse an attenuated response of muscleprotein synthesis in elderly but does not result in further stimulation of muscle protein synthesis in young subjects.
Amino acid ingestion improves muscle protein synthesis in the young and elderly.
Despite differences in the time course of plasma phenylalanine kinetics and a greater residual IC phenylAlanine concentration, amino acid supplementation acutely stimulated muscle protein synthesis in both young and elderly individuals.
Co-ingestion of protein and leucine stimulates muscle protein synthesis rates to the same extent in young and elderly lean men.
Co-ingestion of protein and leucine with carbohydrate after activities of daily living improves whole-body protein balance, and the increase in muscle protein synthesis rates is not significantly different between lean young and elderly men.
Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults.
Essential amino acids are primarily responsible for the amino acid-induced stimulation of muscle protein anabolism in the elderly.
Leucine as a pharmaconutrient to prevent and treat sarcopenia and type 2 diabetes.
Although short-term studies suggest that leucine supplementation can stimulate muscle mass accretion in the elderly, there are no long-term nutritional intervention studies to confirm this or the other proposed benefits ofLeucine as a pharmaconutrient.
Amino acid and vitamin supplementation improved health conditions in elderly participants
It is suggested that a mixture of arginine, glutamine, leucine, and vitamins is useful to support innate immunity in unhealthy older people, even if their diseases, symptoms, and prescribed medicines are different.
Protein and amino acid supplementation in older humans
This review focuses on recent studies examining the use of specific AA or mixtures as supplements in the elderly and whether/how AA may assist in the maintenance of health and independence.