Many people wonder whether a Vegetarian or Vegan diet is compatible with getting stronger, gaining muscle, getting faster or just meeting the needs of athletes. This article covers the most important nutrients for VEG athletes to focus on.
Vegetarian diets and vegan diets are two things that bring some very contrasting reactions depending on who you bring them up with. It’s almost like talking politics. The reactions are silly and uninformed the majority of the time. While meat-lovers are unwavering in their loyalty, vegetarians & vegans are staunch in their defense. Bring this topic to a group of athletes and discuss the diet in context of sport – and be ready for a highly amplified response. Rather than focus on the factors that may influence your decision as an athlete, I prefer to focus on the information you’ll need to be successful if you do decide that you want to be a crusader for the earth. ;)
Being vegetarian or vegan requires a lot more planning, as does any diet with food group restrictions. In order to be a healthy vegetarian, you’ll need to make sure to compensate in your diet for the lacking animal products by replacing them with foods you’ll either need to introduce or increase consumption of. Because being healthy as a vegetarian/vegan (VEG) requires this compensation, it follows that the performance benefits that may come from these same processes requires the same compensation. Let’s take a look at some of most important vitamins and minerals for VEG athletes to focus on, discuss the compensatory dietary adjustments, and provide some strategies on meeting the unique needs of a VEG athlete.
I should state that, in considering the details of a VEG diet – we must assume that they are already following a whole-food plant based diet, and not relying on processed foods to fill the voids. The only way to take advantage of a VEG diet is to do it right. Many of the benefits of vegetarian diets health and performance wise is due to the increased consumption of whole food fruit and vegetables- not the omission of meat itself. Processed foods and animal products account for 90% of calories consumed in the typical American diet, and these foods lack antioxidants and supportive phytochemicals abundant in unrefined plant foods (1). If all you do is take out the animal products, you’re still left with a ton of processed foods. If you are going to be a vegetarian/vegan, you better be ready for some of these:
Two of the most common concerns for a vegetarian, and even more so for a vegan athlete who is eating a largely micro-nutrient rich diet, is the intake of overall calories and protein. I will touch on these two issues towards the end of the article, after covering some of the micronutrients that may be of concern even for these VEG athletes who are eating very healthfully.
Calcium
U.S. recommended daily intake (RDI): 1000 mg
The concept that dairy is our best source of calcium is largely a product of the milk industry’s lobbying and advertising. Low-oxalate vegetables such as bok choy and kale have higher levels of calcium bioavailability than milk (approximately 50% vs 30%) (2). Nuts and seeds also are rich in several minerals including calcium. Seeds are invaluable in the diet of an athlete, whether vegan or nonvegan. Seeds are protein- and mineral-rich, contributing to fulfilling the increased caloric and protein needs of athletes while simultaneously delivering many useful micronutrients. Because of the great availability of calcium in vegetables, nuts, and seeds, calcium deficiency is an invalid concern for vegan athletes who are consuming these foods.
Blend seeds and nuts such as cashews, almonds, and unhulled sesame seeds with hemp milk for a delicious cream sauce, used over steamed kale and bok choy for a high-calcium dish with complete protein and a favorable fatty acid profile. Calcium-rich plant foods include watercress, bok choy, arugula, kale, tofu, unhulled sesame seeds, chia seeds, kidney beans, and almonds. One cup of cooked bok choy provides 160 mg calcium.
Iron
U.S. RDI: men - 8 mg; women - 18 mg
The concern for iron deficiency is based on reduced bioavailability of iron from plant foods. However, vegetarian diets often contain more iron than omnivorous diets. Plant foods contain non-heme iron, which generally is not as absorbable (10%) as heme-iron contained in animal foods (18%). However, when iron stores are low, non-heme iron has greater absorption efficiency than heme-iron. This efficiency, however, also depends on absorption enhancers and inhibitors present in foods. Plant foods contain inhibitors such as phytate (in legumes and grains), but also contain absorption-enhancing substances such as vitamin C and carotenes.
However, all athletes may be at risk for iron deficiency due to exercise-induced iron losses. Among female professional athletes, there is a historically high prevalence of iron depletion and anemia.
Vegan athletes should include iron-rich plant foods in their diets, but iron supplementation is not essential except in cases of iron insufficiency marked by a very low ferritin or anemia, or in women with heavy menstrual bleeding (4,5). Men typically do not need iron supplementation on a vegan diet, but should adhere to the same dietary principles. My personal recommendations would highly depend on the individual, but know that Iron supplementation may be essential for some individuals.
Leafy greens are an often overlooked but rich source of iron. For most people, greens are eaten in small serving sizes that do not supply adequate iron alone. That is why it is important that athletes consume large portions of greens in vegetable-based meals, and smoothies to receive the benefit of iron from those greens. Iron content is not low on an adequately whole food based vegan diet, but a vegan diet using grain products and protein powders as major calorie sources without attention to including iron-rich plant foods could contribute to suboptimal athletic performance. Iron-rich plant foods include spinach, asparagus, swiss chard, broccoli rabe, bok choy, tofu, lentils, pumpkin seeds, sesame seeds, and soybeans.
Zinc
U.S. RDI: men - 11 mg; women - 8 mg
Zinc is essential for healthy immune function and supports enzymatic reactions related to DNA stabilization and gene expression- important considerations for an athlete looking to improve performance. Zinc, similar to iron, is provided in abundance by a vegetarian diet, but is not absorbed readily from plant foods. Approximately 25% of the zinc in the standard U.S. diet comes from beef. Beans, whole grains, nuts, and seeds have high zinc content. However, these foods contain phytate, which inhibits absorption of both iron and zinc. Bioavailability of zinc also is enhanced by dietary protein and inhibited by supplemental folic acid (the synthetic form of food folate, added to a lot of cereal and processed foods), iron supplements (not food iron), and other essential minerals (calcium, copper, magnesium). Based on these factors, the most recent estimate of zinc requirements for vegans is approximately 50% higher than the U.S. RDI, that is, 12 mg·d−1 for female vegans and 16.5 mg·d−1 for male vegans. Unrefined plant foods provide a significant amount of zinc. Refined grains contain far less phytate, but also far less zinc (7).
For these reasons, absorption efficiency may be quite low and attention to foods high in zinc cannot be expected by most vegans. A 2009 study of vegetarians found a high prevalence of zinc deficiency (7). Zinc supplementation or a multivitamin/multimineral containing zinc is a wise choice for vegan athletes. For those athletes who refuse supplementation or those who wish to increase their food-based zinc intake, pumpkin seeds, sesame and hemp seeds are good sources. Vegetarians can find zinc in dairy – and will likely not need a supplement. You can boost the zinc content of whole grains, beans, and seeds by soaking them.
Iodine
U.S. RDI: 150 μg
Iodine is another nutrient identified by the ADA as a key nutrient for vegetarians. Most iodine is added into our diets via white bread and salt, which may or may not be part of the vegetarian’s diet. Most plant foods are low in iodine because of soil depletion. Seaweeds are a potential iodine source for vegans, but commonly are consumed only occasionally. White potatoes are also surprisingly high in Iodine.
One study based on iodine excretion concluded that 80% of vegans, 25% of vegetarians, and 9% of conventional eaters are iodine-deficient. Thus it is important for vegan athletes to supplement with iodine in a multivitamin/multimineral or regularly consume a small amount of kelp or other seaweeds. There are also some foods that inhibit the absorption of iodine. These include cruciferous vegetables such as cabbage, Brussels sprouts and cauliflower. Rutabagas are also iodine antagonists.
Vitamin B12
U.S. RDI: 6 μg
Vitamin B12 is essential for proper nervous and immune system function, many constituents in blood, and DNA synthesis. After long-term insufficient intake of B12, stores become depleted, resulting in neurological and hematological(blood) symptoms. Irreversible damage in these areas can occur.
Vitamin B12 is synthesized only by microorganisms and therefore is more abundant in animal foods than in plant foods. Supplementation of a minimum of 6 μg·d−1 vitamin B12 is essential for vegans. It has now become common knowledge that vegans need to supplement with B12. (6).
Docosahexaenoic Acid (Omega-3; DHA)
No RDI
There is overwhelming evidence that the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contribute to brain and heart health. Alpha-linolenic acid (ALA), an omega-3 fat that can be elongated to produce EPA and DHA, is present in flaxseeds, chia seeds, hempseeds, and walnuts. Unfortunately, our bodies don’t do this very well in general, and it is even harder to elongate ALA to DHA. A reasonable option is to take an algae-based DHA supplement, which is vegan. Since ALA is readily converted to EPA and DHA can undergo retro-conversion to EPA, an algae-based DHA supplement plus ALA sources (such as flax or hemp) is your best option as a vegetarian or vegan in getting adequate essential fatty acids. Fish oil, the best option for EPA and DHA as an omnivore, is off table as a VEG dieter.
Although clear requirments are not yet known for DHA, it is reasonable to expect VEG dieters to reach at least most omnivores level of intake, which would require 200-300mg/day on average. Those pregnant, breast feeding, or just wanting to increase their levels of DHA can exceed these recommendations.
Vitamin D
U.S. RDI: 400 IU
Widespread vitamin D deficiency has been reported in the general population. This vitamin may be especially important for athletes because of its function in skeletal muscle, testosterone production, and mood (8).
The current U.S. RDI for vitamin D of 400 IU is likely, based on newer research, to be suboptimal. It is likely that much of the population has been vitamin D deficient, especially in areas where sun exposure is low. Vitamin D supplements of 2,000 IU typically are needed to ensure adequacy, though a range of intakes could be appropriate between 2,000 – 10,000 IU. It would be a good idea to also supplement with 50-1,000 mcg of Vitamin K1/K2 if supplementing with more than 5,000 IU of D / day (8). The sun is really the best supplement for Vitamin D, though due to decreased exposure, many will need to supplement. Make sure to select a VEG choice, as most are encapsulated in gelatin or use other animal products like fish oil. Your last option is to eat a LOT of shiitake mushrooms and other fungi. These are the only VEG food that has an appreciable amount of Vitamin D.
Beyond what the ADA has identified, those familiar with sports can recognize that protein and overall calorie intake are two important dietary factors in performance when it comes to diet. This is often cited as a reason why vegetarian diets won’t perform well for athletes. It is now well known by most professional organizations that protein is not an issue for vegetarians. Vegans may have more of an issue without the aid of dairy and eggs. Given adequate intake of legumes, seeds, nuts, and grains; a vegan should not have any issues obtaining the required minimum of 1.5g/kg bodyweight; though due to amino acid limitations and increased fiber intake, a slightly higher of intake of goal for protein of 1.7-2.0g/kg bodyweight would be a better goal if body composition and lean mass is a priority, or if endurance exercise volume is very high. Besides overall protein, many have become aware of the (non)issue of incomplete proteins and the strategy of combining them. It is not necessary to combine incomplete protein sources in the same meal. In fact, at an overall protein intake of 1.7-2.0g/kg, the common lysine amino acid deficiency will be a non-issue for vegans if consuming legumes (soy, white beans, lentils), a variety of seeds (pumpkin) and nuts.
The other issue for both vegetarians and vegans is calories, with the latter being more heavily affected due to the omission of high caloric foods like dairy and eggs. This is an effect of limited food choices and increased bulk and fiber content leading to lower overall food intake. There are a few things you can do as a VEG athlete to overcome these issues. The first is to be prepared, plan your meals ahead of time, and include lots of variety and higher calories foods. There is no reason to skimp on the seeds and nuts, as they provide valuable nutrients, protein, and calories. Get a large variety and large amount of seeds and nuts and focus on the ones mentioned above for each nutrient of interest. Another strategy would be to incorporate refined grains with lower fiber intake so that your carbohydrate intake can stay high. Lastly, if meeting caloric needs is an issue for you as an athlete, avoid low-fat, or low-carbohydrate diets. These two fad-style diets are incompatible with a VEG diet in my opinion. It is possible that as a side effect of high amounts of whole foods containing fiber, caloric needs may go up.
If you have any qualms about your diet as a VEG diet, it is very important to iron them out. Individuals become vegetarians for a lot of different reasons, but it is not usually because they are highly educated on how to eat as a vegetarian best. The determination and will of many athletes will keep their dietary downfalls over-looked by the self. It is important to not let food choices paralyze you into an unhealthy relationship with food or unbeknownst dietary inadequacies. If you need help planning a VEG diet - Enclave offers full dietary consulting, meal planning, and support along the way.
Sources:
1. http://www.ers.usda.gov/data-products/food-consumption-and-nutrient-intakes.aspx
2. Weaver CM. Choices for achieving adequate dietary calcium with a vegetarian diet. Am. J. Clin. Nutr. 1999; 70(Suppl.):543S-8S.
3. Hunt JR. Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. Am. J. Clin. Nutr. 2003; 78(Suppl.):633S-9S.
4. Rodenberg RE, Gustafson S. Iron as an ergogenic aid: ironclad evidence? Curr. Sports. Med. Rep. 2007; 6(4):258-64.
5. McClung JP, Karl JP, Cable SJ, et al. Randomized, double-blind, placebo-controlled trial of iron supplementation in female soldiers during military training: effects on iron status, physical performance, and mood. Am. J. Clin Nutr. 2009; 90:124-31.
6. Pawlak, et al. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. European Journal of Clinical Nutrition 68, 541-548 (May 2014) | doi:10.1038/ejcn.2014.46
7. Frassinetti S, Bronzetti G, Caltavuturo L, et al. The role of zinc in life: a review. J. Environ. Pathol. Toxicol. Oncol. 2006; 25(3):597-610.
8. Cannell JJ1, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10. doi: 10.1249/MSS.0b013e3181930c2b.
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