Vegan for Life - Jack Norris [78]
Humans synthesize creatine in their liver and kidneys, and meat-eaters consume around 1 to 2 grams of creatine per day (although about 30 percent of it is destroyed in cooking). There is no creatine in vegetarian diets, though, and not surprisingly, vegetarians have lower levels of creatine in their blood, urine, red blood cells, and muscle tissue. Some studies have shown that vegetarians benefit more from creatine supplementation than meat-eaters.6 Fortunately, creatine supplements are vegan.
Creatine supplements are usually taken in two phases for loading and maintenance.
Loading: Take 20 to 30 grams of creatine per day, divided into small doses over the course of the day, for a total of six days.
Maintenance: The usual dose of 2 grams per day is meant for meat-eaters, which means that the dose for vegans may be closer to 2.7 to 3.4 grams per day. Some researchers suggest taking creatine only every other month to maximize its effects. Taking it with a sugar solution, such as a sports drink or fruit juice, increases the rate at which muscles absorb creatine.
According to the ACSM, the most common adverse effects of creatine supplementation are fluid gain, cramping, nausea, and diarrhea. Although its use is widely debated, the ACSM says that it is generally considered safe for adults. That said, there have been anecdotal reports of dehydration, muscle strains or tears, and kidney damage, so it’s important to let your health-care professional know if you are taking creatine.
Carnitine
Carnitine (also known as L-carnitine and acetyl-L-carnitine) is an amino acid found in meat and dairy products. It’s needed for fat metabolism and is promoted for weight loss and improved performance. According to the ACSM, however, it hasn’t been shown to help with either.
While there is very little carnitine in plant foods, it can be synthesized by the liver and kidneys. Vegans, vegetarians, and people who consume lower-fat, high-carbohydrate diets have lower blood levels of carnitine. There is no indication that this is unhealthy, and we don’t know if it has any bearing on athletic performance. In one study, vegans who took supplements of 120 milligrams of carnitine per day for two months excreted more carnitine in their urine, but the levels in their plasma didn’t increase significantly. This suggests that most of the carnitine was being lost in the urine.7
There is no evidence that vegans need to take carnitine, but since non-vegetarians typically eat 100 to 300 milligrams of carnitine per day, it is probably safe for vegans to take supplements providing that amount. Solgar brand carnitine is made by yeast fermentation of beet sugar and is one option available to vegans. If you take carnitine, watch for side effects, including nausea and diarrhea.
Carnosine and Beta-Alanine
Carnosine (also known as beta-alanyl-L-histidine) is a molecule made up of two amino acids, beta-alanine and histidine. Animals, including humans, produce it in various tissues, especially the muscles and the brain. Plant foods don’t contain any, and one study has shown that vegetarians have 50 percent less carnosine than meat-eaters in their muscle tissue.8
Although the amino acid beta-alanine isn’t required in the diet (the body makes its own), beta-alanine supplements have been shown to increase muscle carnosine levels. In fact, only supplements of beta-alanine, not carnosine itself, have been tested on athletic performance in human subjects.
In the ACSM position paper, beta-alanine doesn’t appear on the list of performance enhancers “that perform as claimed.” But about half a dozen studies have shown that approximately 6 grams of beta-alanine in doses spread over a day, for a period of four or more