L-Carnitine helps centenarians build muscle mass

A daily dose of 2 g L-carnitine does wonders for body composition and vitality in people who’ve already celebrated their hundredth birthday. Italian gerontologists at the University of Catania discovered that this amino acid helps this part of the population to build muscle mass, reduce fat mass, and have more energy and stamina.


If you look at what textbooks say about L-carnitine, then it’s almost bound to work. This amino acid helps the mitochondria to convert more nutrients such as fatty acids into energy. More L-carnitine, more fat burning and probably also more muscle mass – that’s the reasoning used by the supplements industry.

When researchers started to examine the effects of L-carnitine in the nineties, however, the results were disappointing. This may be because the bodies of young adults produce copious quantities of this amino acid, and certainly in those who are physically active. Another possibility is that the body only absorbs L-carnitine if you consume the compound together with large amounts of carbohydrates. Cells only absorb L-carnitine if the blood has a high insulin level.

As ageing progresses L-carnitine production declines. Once people reach their seventies the concentration declines rapidly, but decline in production starts much earlier.

The over-seventies are therefore ideal subjects for L-carnitine experiments, the researchers reasoned. And even better than people in their seventies – are centenarians. So the Italians gave 32 centenarians a daily dose of 2 g L-carnitine for six months. They also gave 34 centenarians a placebo for the same period. By the way, the L-carnitine they used was produced by Sigma Tau.

The amino acid caused an average increase in muscle mass of just less than four kg, whereas the muscle mass in the placebo group increased by just under a kilogram. The fat mass in the L-carnitine group went down by just under two kilograms, while the fat mass in the placebo group increased by half a kilogram.

The condition of the subjects in the L-carnitine group improved: this was tested by getting the subjects to walk for six minutes and measuring the distance they covered. The carnitine group managed to walk four metres further. (Yes, we know, it’s not a lot. But the test subjects did not take regular exercise.)

The subjects in the L-carnitine group felt better and more energetic. And they also scored better on a mental test.


Three people in the L-carnitine group died. In the placebo group the figure was five. So maybe L-carnitine is a longevity supplement as well?

L-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial.


Centenarians are characterized by weakness, decreasing mental health, impaired mobility, and poor endurance. L-Carnitine is an important contributor to cellular energy metabolism.

This study evaluated the efficacy of L-carnitine on physical and mental fatigue and on cognitive functions of centenarians.

This was a placebo-controlled, randomized, double-blind, 2-phase study. Sixty-six centenarians with onset of fatigue after even slight physical activity were recruited to the study. The 2 groups received either 2 g levocarnitine once daily (n = 32) or placebo (n = 34). Efficacy measures included changes in total fat mass, total muscle mass, serum triacylglycerol, total cholesterol, HDL cholesterol, LDL cholesterol, Mini-Mental State Examination (MMSE), Activities of Daily Living, and a 6-min walking corridor test.

At the end of the study period, the levocarnitine-treated centenarians, compared with the placebo group, showed significant improvements in the following markers: total fat mass (-1.80 compared with 0.6 kg; P < 0.01), total muscle mass (3.80 compared with 0.8 kg; P < 0.01), plasma concentrations of total carnitine (12.60 compared with -1.70 mumol; P < 0.05), plasma long-chain acylcarnitine (1.50 compared with -0.1 micromol; P < 0.001), and plasma short-chain acylcarnitine (6.0 compared with -1.50 micromol; P < 0.001). Significant differences were also found in physical fatigue (-4.10 compared with -1.10; P < 0.01), mental fatigue (-2.70 compared with 0.30; P < 0.001), fatigue severity (-23.60 compared with 1.90; P < 0.001), and MMSE (4.1 compared with 0.6; P < 0.001). CONCLUSIONS: Our study indicates that oral administration of levocarnitine produces a reduction of total fat mass, increases total muscular mass, and facilitates an increased capacity for physical and cognitive activity by reducing fatigue and improving cognitive functions. PMID: 18065594 [PubMed - indexed for MEDLINE] Source: http://www.ncbi.nlm.nih.gov/pubmed/18065594