L-Carnitine has been filling up our Tik Tok and other social media feeds a lot lately. You’re seeing it light up the fitness industry with strong claims about its ability to increase muscle mass and promote weight loss. While the evidence around L-carnitine and weight loss is not strong (yet), the research around depression is promising.
L-Carnitine is a substance that occurs naturally. The majority of it can be found in the diet and the body produces some as well. You can find L-carnitine in red meat like beef or lamb. If you’re not a fan of red meat, it’s also in white meat and fish like chicken, turkey and tuna. It’s also found in dairy products like yogurt and milk but to a lesser extent.
The body can convert L-carnitine into something called acetyl-L-carnitine (ALC) which has many different roles in our bodies–including acting as an anti-oxidant and preserving nervous system health and function. It’s important to note that ALC crosses the blood brain barrier which means it has access to the brain and can influence brain activity.
Research has shown that people with depression have lower levels of ALC than those without. This pattern was also observed in patients with treatment-resistant depression which sheds light on a very frustrating and frightening problem. It’s also interesting that lower levels of this chemical have been found in women with a history of childhood trauma and childhood trauma is a well known risk factor for the development of depression.
Low ALC may not be related to all cases of depression but there may be some subtypes of depression that are related to low L-carnitine or ALC levels. It’s an interesting observation but does this mean that treating with ALC can actually help with depression symptoms?
Studies have been giving us some answers to this question. Reliable research has shown that ALC supplementation can improve symptoms of depression.
A meta-analysis of 9 studies (over 400 patients) examined the effect of ALC on depression and found that it significantly improved depression symptoms. ALC was also found to be just as helpful as anti-depressants with fewer side effects. It’s still not clear what doses are optimal for depression management but, in general, doses of this supplement typically range from 500-2000 mg daily.
I have not often used ALC in my practice but this year I’ve been recommending it a bit more and I plan to start discussing it more with patients. As always, interactions and risks are possible with any supplement, so speak to a naturopathic doctor or other regulated healthcare provider before starting any new supplements.