Nutrients
Meat Makes You Happy
Carnitine from meat plays a crucial role in depression – with fewer side effects than antidepressants. Discover why meat could make you happier.
Nutrients
Carnitine from meat plays a crucial role in depression – with fewer side effects than antidepressants. Discover why meat could make you happier.
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Admittedly, this statement might sound a bit exaggerated at first glance. But it's not the meat itself (although the taste of a good steak can certainly make you happy ;-), but rather a compound found exclusively in meat and animal products.
It belongs to the so-called meat-based bioactive compounds – (semi-)essential nutrients found only in meat – and some may know it as a fat burner.
Carnitine, more specifically the form Acetyl-L-carnitine produced from carnitine in the body, plays an incredibly important role in depression. Over 10 years ago, animal studies showed that administering Acetyl-L-carnitine had a "rapid, robust, and long-lasting antidepressant effect."1
Okay, happy mice are nice, but what about humans?
Acetyl-L-carnitine appears to be involved in a similar way. Multiple studies found that people with depression have significantly lower Acetyl-L-carnitine levels compared to healthy controls. That was remarkable.
Moreover, when patients were treated with antidepressants, those who responded to therapy showed elevated carnitine levels! In those who still suffered severely from depression despite medication, the reduced carnitine value didn't change.2,3
These results suggest that Acetyl-L-carnitine could be an excellent blood marker for depression. Or perhaps even a potential therapeutic agent.
A meta-analysis4 reviewed various clinical studies on this topic and reached the following conclusions:
Same effect with fewer side effects. We like that.
A very recent review by German researchers examines the effects of Acetyl-L-carnitine on the neuropsychiatric symptoms of long COVID.6
These include, among others, fatigue, cognitive impairment such as concentration and memory disorders, as well as depressive mood. Similar symptoms are found in other post-viral syndromes like ME/CFS.
Long COVID patients also show reduced plasma carnitine levels. Due to the significant symptom overlap and the positive effects of carnitine in depression and ME/CFS, the researchers conclude that carnitine could also help with long COVID. A promising approach!
But back to the question of where to get enough carnitine from meat. As briefly noted, animal products, especially meat, contain valuable carnitine. In omnivores, about three-quarters of requirements are met through diet, while the rest is provided through the body's own synthesis.
… but it needs the amino acids lysine and methionine, plus the cofactors vitamin C, vitamin B6, and iron.
Now it's clear why vegans and vegetarians have lower carnitine levels than omnivores.5 Both lysine and methionine are limiting amino acids in plant-based proteins. And bioavailable iron is found mainly in meat.
Furthermore, the body's own synthesis is very limited and amounts to only a low double-digit milligram range. For comparison: just 100g of beef provides about 100mg of highly bioavailable carnitine.
In short: those who rely only on plant-based food risk suboptimal carnitine supply. And in extreme cases, demonstrably jeopardize their mental health.
Those who eat little or no meat and animal products should absolutely ensure their carnitine supply through supplementation.
It's remarkable what such a small molecule as carnitine can have on the body and, in this case, on the psyche. And how simple it often is for us to counteract through proper nutrition and supplementation!
Nasca, C. et al. L-acetylcarnitine causes rapid antidepressant effects through the epigenetic induction of mGlu2 receptors. Proc. Natl. Acad. Sci. U. S. A. 110, 4804–4809 (2013).
Nasca, C. et al. Acetyl-l-carnitine deficiency in patients with major depressive disorder. Proc. Natl. Acad. Sci. 115, 8627–8632 (2018).
Nie, L.-J. et al. L-Carnitine and Acetyl-L-Carnitine: Potential Novel Biomarkers for Major Depressive Disorder. Front. Psychiatry 12, (2021).
Veronese, N. et al. Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis. Psychosom. Med. 80, 154–159 (2018).
Krajcovicová-Kudlácková, M., Simoncic, R., Béderová, A., Babinská, K. & Béder, I. Correlation of carnitine levels to methionine and lysine intake. Physiol. Res. 49, 399–402 (2000).
Helbing, D. L. et al. Conceptual foundations of acetylcarnitine supplementation in neuropsychiatric long COVID syndrome: a narrative review. Eur. Arch. Psychiatry Clin. Neurosci. (2024) doi:10.1007/s00406-023-01734-3.
