What you eat has a direct effect on your physical and mental performance. Many athletes with the best of dietary intentions have found themselves deficient in essential nutrients that end up limiting their performance—zinc, magnesium, vitamin D, among others. Vegetarians are especially susceptible to performance-limiting nutrient deficiencies, and the more restrictive their diet is (for example, strict vegans), the greater the chance they have of not reaching their physiological potential.
This article provides information on the nutrients that non-meat eaters need to watch out for, with tips on how to get them. In some cases, there are suitable plant-based sources for important nutrients, but in other cases there simply are not. I say this because I know that vegetarianism and what people choose to eat can be an emotion-filled topic. If I do not include a plant-based option, that is only because I am not aware of one.
Meat eaters will even benefit from these tips because we are all faced dietary factors like poor quality food and stress-filled lifestyles, making everyone susceptible to low levels of various nutrients that compromise performance. It’s best to have all the information, so you can make the best dietary decision to help you meet your performance goals.
The Basic Vegetarian
Dietary analyses show that vegetarians tend to eat a comparable amount of protein as meat eaters, but the bioavailability of that protein tends to be reduced by about 10 percent in the typical fiber-rich vegetarian diet. Less bioavailability means the body just can’t use vegetable-derived proteins as efficiently.
There is evidence that there is something about “the meat itself” that makes meat a better quality protein for the body to use for muscle building and optimal hormone function. There is not a lot of research on vegetarian eating by strength and power athletes, but there have been studies that show meat eaters tend to have significantly more muscle mass than vegetarians and that lean mass correlates directly with the amount of animal protein in the diet.
One study that compared hypertrophy and strength gains in men doing resistance training who were on either a vegetarian diet or a omnivorous diet found that the meat eating group had much greater hypertrophy than the vegetarian group. The omnivores lost an average of 6 percent fat mass, gained 4 percent lean mass, and increased Type II fiber area by 9 percent relative to the vegetarians. This study was used self-reported food journals from participants, and researchers noted that the vegetarian group’s protein intake dropped off by a few percent as the study progressed, which may have been a factor. It’s unclear whether it was the quantity or quality of the protein that made a difference in muscularity, or if it may have been a nutrient deficiency in the vegetarian group.
Another study in the British Journal of Nutrition
compared muscle mass in women who were already eating a vegetarian diet with that of women who ate meat. Food journals showed both groups ate the same amount of protein, but the meat eaters had significantly more muscle mass with an average of 23 kgs of lean mass compared to 18 kgs in the vegetarians—a large amount in women who were not doing any strength training.
Aside from having less muscle mass, the typical vegetarian tends to eat less cholesterol and rely on soy protein for a substantial portion of their protein intake, which leads to a high amount of phyto-estrogens in the diet. Vegetarian males tend to have lower free testosterone and diminished anabolic hormone levels, which may be one reason for less lean mass.
The link between lower testosterone and lack of meat is not entirely understood, although it is thought that lower cholesterol intake may play a role because testosterone is made from cholesterol. Nutrient deficiencies likely are involved, and the trend that vegetarians eat more soy may be another factor since soy can mimic estrogen in the body by binding to estrogen receptors and altering endocrine levels.
Common nutrient deficiencies for vegetarians and vegans are iron, zinc, omega-3 fats, and B12. Just as important, vegetarian athletes and anyone interested in being active and lean needs to focus on getting adequate taurine, carnitine, creatine, glutamine, carnosine, and glycine into their diet for peak performance and energy. Many of these nutrients can be gotten by eating eggs and whole milk dairy, but even so, research shows deficiencies are still a problem, and some nutrients such as omega-3 fats can’t be gotten in large enough quantities from these sources.
Vegetarianism And Protein Malnutrition
Vegetarians tend to eat an adequate ratio of total protein (studies show that vegetarian athletes can easily eat a diet that is at least 15 percent protein), but plant-based proteins lack certain amino acids that can lead to malnutrition. It is this restriction that leads to greater health risk and poorer performance.
An interesting study in the journal Nutrition
shows how easy it is for nutritional deficiencies to arise from a vegetarian diet, even when milk and dairy are included. This study compared plasma levels of various nutrients in a group of Africans who ate a traditional vegetarian diet with a group from a nearby region that ate an omnivorous diet. Neither group supplemented with any nutrients.
Results showed the vegetarian group had significantly less muscle mass, and low levels of taurine, glutathione, and much higher levels of homocysteine than the group that ate meat. Less lean body mass in the vegetarians was likely due to the poorer quality of protein in the diet that led to an imbalance in amino acids.
Persistently high levels of the amino acid homocysteine is called hyperhomocysteinemia, which is known to play a role in poor muscularity, but it also increases risk of heart disease. High homocysteine is also linked with greater stroke risk, elevated cholesterol levels, and hardening of the arteries.
High homocysteine typically comes from B vitamin deficiency (especially B12 and B9), but this vegetarian group had normal concentrations of these vitamins, probably because they ate eggs and dairy. Researchers believe that homocysteine was high due to a long-term deficiency of specific amino acids and very low levels of glutathione. Glutathione is the most important antioxidant that is produced inside of the body out of three amino acids, glycine, glutamine, and cysteine, all of which are primarily gotten in a carnivorous diet (all three are found in eggs, milk, and some nuts as well).
Low glutathione is a big problems for vegetarians because not only is this biological marker necessary for a healthy immune function, it’s directly involved in the removal of toxins from the body. People who have higher glutathione have much less chance of getting a chronic disease because of its importance in maintaining overall health and homeostasis in the body. Athletes can rapidly deplete glutathione but with the adequate diet, it’s possible to replenish it. Vegetarian athletes are at even greater risk for low glutathione unless they supplement.
Avoid Low Glutathione:
Supplement with the three amino acids that make glutathione (glycine, glutamine, cysteine) and ensure you get enough B vitamins (see below). Leafy green vegetables contain glycine, glutamine, and cysteine, and dark colored berries will help with glutathione enzyme production.
The Nutrition study highlights the need to prevent nutrient deficiencies for vegetarians and especially vegetarian athletes. For example, the third finding of this study was that the amino acid taurine was very low in the vegetarians, and lack of taurine can negatively alter mood and impair brain function.
Taurine is extremely important for the function of the central nervous system and neurotransmitter production—think of the effect this can have on motivation to train, team cooperation, focus, precision, and skill! And, one of the worst side effects of nutrient deficiencies common in the vegetarian diet is the lack of taurine, which leads to elevated anxiety, unhappiness, and stress.
Get Adequate Taurine:
Aside from meat and seafood, taurine can be gotten from some seaweeds, and some eggs, but studies show not all eggs contain taurine. It can also be taken in supplement form.
Methylated B Vitamins Are Essential
B12 (cobalamin) is the most important B vitamin for vegetarians because you can die without it. If you don’t eat meat, dairy, or eggs, there’s no proven way to get B12 without supplementing. Even avid meat eaters have been found to have low B12, making it a good nutrient for everyone to take, especially in methylated form.
Methylated B vitamins ensure your body will be able to absorb the B vitamin supplement because they include a methyl group that allows them to bypass a common genetic predisposition that makes non-methylated versions unusable. In the case of B12, it is commonly bound with a cyano group, which is then converted to a methyl group and you will see it called cyanocobalamin on supplements.
B12 is essential for nervous system function and to avoid something called pernicious anemia, which is an autoimmune disease that destroys the cells in the stomach. Lack of B12 leads to chronic fatigue, cancer, male infertility, heart disease, and altered metabolism.
Get Adequate B12:
Take it in a methylated B vitamin supplement. B12 is also found in eggs and dairy.
Omega-3 Fats: Rebalance Fat
The omega-3 fats are absolutely critical for vegetarians because non-meat eaters naturally have a high level of omega-6 fats in their diets from all the vegetable-derived oils and nuts. It’s necessary to balance omega-6 intake with omega-3 fat intake because extensive evidence show much greater risk of chronic disease and inflammation if you have a skewed omega-6 to -3 intake.
Flaxseeds contain omega-3s but the problem is that they contain ALA, and the omega-3s you need are EPA and DHA for optimal health and athletic performance. The body converts about 10 percent of the ALA you eat into EPA, and even a tinier percentage into DHA, but the conversion rate is so pitifully small, that you’d have to consume a huge amount of flax to get enough DHA.
A plant called echium from Latin America is being used as a source of SDA (stearidonic acid) that converts into EPA at a higher rate than ALA (30 percent versus 10), and oil from algae can provide DHA. Again, the problem with algal and echium oils are that they have a low conversion rate and you’d have to consume a large quantity daily for optimal health. But they are an option for strict vegetarians.
Get Adequate EPA and DHA
: Supplement with fish oil. Not an option? Echium and algal oil are better than nothing.
Zinc and Iron: Don’t Be Deficient Due To Phytates
Zinc is a much more common nutrient deficiency than iron for everyone, especially vegetarians, but they are grouped together because the problem with both is phytates. Phytates are present in plant foods that contain zinc and iron (beans, grains, nuts, seeds), which inhibit absorption of these minerals by the body. Adequate vitamin C will help bypass the phytates and make iron and zinc bioavailable.
Still, even with high intake of food that contains zinc, athletes are commonly deficient. Adequate zinc is essential for male strength and power athletes because zinc plays a major role in testosterone production. Really everyone should be aware of zinc for performance because it’s involved in proper hormone and brain function, and zinc stores are rapidly lost from exercise, especially strenuous exercise.
Iron is not as much of a problem, although females are at risk of low iron, especially if they are vegetarian and may need to supplement or take extra vitamin C to avoid a drop off in performance.
Avoid Zinc And Iron Deficiency:
Supplement or eat dairy and eggs. Get extra vitamin C from strawberries, cruciferous vegetables such as broccoli and cauliflower, dark leafy green vegetables, cherries, kiwis, and citrus fruits.
Creatine, Carnitine & Carnosine: Limiting Factors For Vegetarians
Creatine, carnitine, and carnosine are nutrients that are well proven to enhance athletic performance. They are found only in meat in quantities that have the ability to load in the muscles and make you faster and stronger. There’s ample evidence that vegetarians have lower levels of all three, and the question is, do you want your meat-eating opponent to have the carnitine/creatine/carnosine advantage?
For example, a study in the American Journal of Clinical Nutrition
showed that vegetarians have a significantly lower muscle carnitine content as well as reduced capacity to transport carnitine into the muscle. People deficient in carnitine have difficulty mobilizing fat to burn as energy, and elevated carnitine levels have been shown to translate into greater work capacity and faster time trial performance on endurance tests.
Creatine is well known for enhancing performance because it is a short-term energy source. Low levels mean you will have less power and less capacity to build muscle. Creatine can be made by the body out of the amino acids methionine, glycine, and arginine, but research shows that vegetarians who get adequate intake of these three amino acids still have much lower muscle creatine than meat eaters.
Carnosine is an amino acid derivative that is stored in the fast-twitch fibers and used for anaerobic energy production. Elevating carnosine will improve performance and can help maintain muscle pH during exercise—a major benefit for strength and endurance athletes. Carnosine is found in meat, and in eggs and diary in very small quantities.
For best results, supplement if you are a vegetarian. If that’s not an option, carnitine is found in small amounts in avocados, wheat, peanuts, and soy. For creatine, try boosting intake of methionine, glycine, and arginine. For carnosine, eat eggs and whole-fat dairy. Unfortunately, vegans are out of luck on carnosine and creatine.
Ingenbleek, Y., McCully, K. Vegetarianism Produces Subclinical Malnutrition, Hyperhomocysteinemia, and atherogenesis. Nutrition. 2012. 28, 148-153.