This is another one of my articles inspired yet again, by my travels through Thailand. I see products all over filled with one type of supplement or another and carnitine is common. You may have heard of this compound before. Do you take supplemental carnitine? What is it good for and do we need more than what is provided in a healthy diet?
Carnitine comes from an amino acid and is in almost all of the body’s cells. It was initially found in meat and you may have seen it written as L-Carnitine, propionyl-L-Carnitine, and acetyl-L-Carnitine. If you have ever seen it touted for its ability to burn calories or provide energy, that is true. It helps bring certain fats into the mitochondria (the powerhouses of the cell) so they can be burned, or in more scientific terms, oxidized to make energy. It also removes toxic compounds that are generated in the mitochondria by transporting them out. So, carnitine does help burn fat and prevent build up of toxic substances, but that doesn’t mean extra carnitine will lead to extra fat loss.
As far as recommended intakes are concerned, most people do not need supplemental carnitine because our bodies can make and store what we need. Most of it is concentrated in skeletal and cardiac muscles that can and do use fat from food as fuel. There are a few exceptions for needing supplemental carnitine, however they are very specific and related to genetic and medical issues. The liver and kidneys synthesize carnitine from the amino acids lysine and methionine and animal products are the best, naturally occurring sources of carnitine. It is found in meat, fish, poultry, and dairy products (primarily in whey), and then of course, there are products with added carnitine.
So what’s the scoop, or the goop?! The Food And Nutrition Board (FNB) has not set recommendations on intake amounts as they concluded it is not an essential nutrient after reviewing various studies. A good place to look is at the metabolism of supplements in question and see what happens when we have too much. Our bodies are able to regulate and maintain proper blood concentrations of many substances and compounds in the body, that whole homeostasis thing, and so our kidneys do that for us with carnitine. Even those who may not consume much carnitine, like vegetarians and vegans, are able to maintain proper blood levels. Furthermore, and according to the National Institute of Health, most (54-86%) of the carnitine that we do eat is easily absorbed in the small intestine and enters into the bloodstream. Guess what happens when we eat too much? The kidneys will excrete it in our urine, it helps maintain that stable blood concentration. So while we may want more of a good thing, something that helps us burn fat, extra amounts do not really help if its weight loss we are looking for.
With that, however, there may be some instances where additional carnitine, more specifically, acetyl-L-carnitine, is warranted. This form of L-carnitine is better absorbed in the small intestine and gets into brain tissue better (it can cross the blood brain barrier more easily). Regarding athletics, there has been inconsistent evidence showing that carnitine enhances performance, helps the body use more oxygen, improves metabolism during exercise, nor has it been shown to increase intra muscular levels of it. When it comes to aging, and some other instances, added carnitine maybe beneficial. It may play a positive role in improving mental function and lessen deterioration in adults with some cognitive impairments and Alzheimer’s disease. Supplemental carnitine may help manage cardiovascular and peripheral artery disease, fatigue caused by chemotherapy for cancer treatment, type 2 diabetes; and in HIV and AIDS, it may slow progression and reduce neuropathy associated with the disease. But, these benefits are very specific and if you are affected by any of them, speak to your doctor for more case specific treatment regarding supplemental carnitine, Furthermore, many studies yield mixed results, so more research is always needed.
In short, we excrete carnitine beyond what the body needs, so supplements to improve athletic performance or to speed weight loss are largely ineffective. In the case of products with added carnitine, you can eat or drink them if you like, but like all things, do so in moderation. I’m not going to lie, sometimes I like the cool, fruit flavored jelly pouches in Thailand that have various supplements in them, but I only eat them occasionally and do so mostly because they are tasty and refreshing in the heat! Overall, eat a healthy diet with lean protein and skip the supplemental carnitine.