Nutrients of Interest for Vegetarian and Vegan Athletes

Plant-based diets are all the rage right now, and with good reason. Epidemiological research has shown that plant-based diets may lower body mass index, blood pressure, blood sugar and cholesterol levels. Plant-based diets may also lower the risk of cardiovascular disease and reduce the number of medications needed to treat chronic diseases. A move to a more plant-based society could potentially increase individual wellness and reduce health care costs in addition to benefiting the environment.

What is the definition of a Plant-Based Diet?
A plant-based diet consists of minimally processed fruits, vegetables, whole grains, legumes, nuts and seeds, herbs, and spices. This diet excludes animal products, including red meat, poultry, fish, eggs, and dairy products. A plant-based diet is akin to a vegan diet, whereas a vegetarian diet can contain eggs and dairy. Scientists believe that simply reducing the amount of animal products we consume confers positive health and environmental benefits. Meaning you don’t have to go all out vegan to realize some benefit. We know that vegetarian and vegan diets can be beneficial to the general population, but can they work for serious athletes?

Are Plant-Based Diets Right for Athletes?
The answer is yes. Well-planned vegan and vegetarian diets can fuel athletes adequately for both performance and recovery. The key word here is well-planned. It is important to get enough macro- and micro-nutrients to support health and training. This requires a knowledge of the nutrients that can be under consumed as well as typical challenges that are unique to vegetarian and vegan athletes. We will look at several sports nutrition considerations for such athletes as well as the consequences of not meeting nutritional needs.

Sports Nutrition Considerations for Vegan and Vegetarian Athletes

Energy
First and foremost, athletes must ensure that they are getting enough calories to support training. If an athlete is deficient in calories, training adaptations are not as pronounced and performance suffers. With the high fiber content and lower relative energy density of plant foods, it can be challenging for vegetarian/vegan athletes to consume enough calories. Basically, plant foods are far more filling and contain less energy relative to other types of foods. Vegetarian and vegan athletes need to carefully plan their diet to ensure that caloric needs are met.

Protein
The Institute of Medicine has concluded that vegetarian/vegan athletes do not need more protein than their meat-eating counterparts. The only exception to this rule is when an athlete gets most of their protein from hard to digest sources such as legumes and cereal grains (as opposed to foods like soy protein).

Ideally, a vegetarian or vegan athlete would consume a variety of plant-based protein sources. This might include soy products, legumes, nuts, seeds, cereal grains, eggs, dairy products (vegetarian), meat substitutes and certain vegetables. This variety is important because, unlike most animal proteins, plant-based proteins do not generally contain all of the amino acids you need to get from the diet (essential amino acids). Consuming different sources of plant-based protein throughout the day will ensure that the athlete is getting all of the essential amino acids. Previous thinking around plant-based diets emphasized the need to complement proteins with different amino acid profiles at the same meal. Researchers now believe that eating various sources throughout the day is adequate.

For athletes, who do not consume dairy and eggs, it is imperative to eat legumes and/or soy products to ensure adequate lysine intake (lysine is an essential amino acid). It is also important to get adequate leucine post-workout. Leucine is the branched chain amino acid (BCAA) most closely associated with muscle adaptation. Whey protein is an ideal source of leucine, while soy and other legumes are also high in this BCAA. 

Fat
Fat intake for all athletes should range from 20-35% of total calories. Consuming less than 20% fat can impair endurance performance, interfere with the female menstrual cycle and negatively impact lipid profiles. Vegetarian and vegan diets are generally high in omega-6 fatty acids and can be low in omega-3 fatty acids. Because omega-3s (particularly DHA and EPA) play a role in reducing inflammation, brain health and more, it is important to incorporate plant-based sources. Walnuts, flax and chia seeds as well as walnut and hemp oils are all sources of plant-based omega-3’s (ALA).  ALA can be converted to DHA and EPA in the body, though conversion rates are low. Microalgae supplements (on the other hand) are rich in DHA and are better absorbed than other plant-based sources. In particular, pregnant athletes or people with chronic inflammatory injuries or cardiovascular disease should consider consuming a microalgae supplement.

Calcium and Vitamin D
Athletes who do not consume dairy products need to ensure they are getting adequate calcium and vitamin D to support bone health. Plant-based sources of calcium are plentiful and include tofu, fortified orange juice, soy, almond and rice milk, broccoli, Chinese cabbage, kale, collard/mustard/turnip greens, almonds, tahini, texturized vegetable protein and certain legumes. Plant-based sources of Vitamin D include some soy and rice milks, orange juices, cereals and sun-dried mushrooms. In addition, the body can produce vitamin D with small periods of sun exposure. Athletes who generally wear sunscreen or live in northern climates should test Vitamin D levels and supplement if necessary. Lack of Vitamin D can lead to fatigue in addition to decreased bone health.

Iron
Iron needs are higher for vegetarian and vegan athletes due to lower absorption rates of plant-based iron (non-heme iron). It is estimated that only 2 to 20% of non-heme iron is absorbed while 15 to 35% of heme iron (found in animal products) is absorbed. Therefore, vegetarian/vegan athletes need 1.8 times the amount of iron as meat-eating athletes. In addition, non-heme iron is more sensitive to inhibitors of absorption such as calcium and polyphenolics found in coffee, tea and cocoa. Because iron is critical to athletic performance, I recommend that vegetarian and vegan athletes test iron and ferritin levels regularly.

Zinc
Plant foods have lower bio-availability of zinc than animal products. Thus vegetarian and vegan athletes should ensure that, at minimum, they are meeting the RDA for zinc. Plant-based sources of zinc include: legumes, nuts and seeds, whole-grain products, fortified cereals, soy products, hard cheeses and meat analogues.

Iodine
Recent research has shown that vegetarian and vegan athletes may be at risk for iodine deficiency. This is likely due to lower use of iodized salt in plant foods, the growth of plants in soil with low-iodine concentration and limited or no consumption of seafood and cow’s milk. Vegetarian and vegan athletes should ensure that they are getting ½ teaspoon of iodized salt per day.

Vitamin B12 and Riboflavin
Riboflavin helps us convert energy from food and is also important for normal vision. Vitamin B12 on the other hand helps us create new cells and is a vital component of a healthy nervous system. Athletes who do not consume eggs or dairy are at risk of Vitamin B12 and Riboflavin deficiency. To get adequate B12, vegan athletes should take a supplement or consume B12-fortified foods (e.g. nutritional yeast, cereals and some types of soy and rice milk). Riboflavin intake should meet RDA recommendations. Plant-sources of Riboflavin include: fortified breads and cereals, legumes, tofu, nuts, seeds, tahini, bananas, asparagus, figs, leafy greens, avocado and most types of seaweed. Again, if athletes can not meet Riboflavin needs, a supplement is advisable.

In Conclusion
Many athletes are successfully making the switch to a vegan or vegetarian diet. Brendan Brazier, Canadian pro triathlete and endurance runner, is perhaps the most famous vegan triathlete. Brazier authored The Thrive Diet and is a two-time Canadian 50km Ultramarathon Champion. Other notable vegetarian/vegan athletes include Ironman 70.3 pro Laura Philipp, running icon Bart Yasso and ultra endurance runner Scott Jurek.

These athletes have experienced notable success, all while fueling with plants. If you are looking to fuel your training and racing with a plant-based diet, it is certainly possible. The key to being a healthy, successful vegetarian or vegan athlete is careful planning and working with an expert to ensure you are meeting your needs.

References
[1] Tuso, Phillip et. al. (2013) Nutritional Update for Physicians: Plant-Based Diets. Permanente Journal. Spring 17(2): 61-66. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662288/.

[2] NIH. (2018). Omega-3 Fatty Acids: Health Sheet for Professionals. Retrieved from: https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/.

[3] Karpinski, C. and Rosenbloom, C. (2017). Sports Nutrition: A Handbook for Professionals, 6th Edition. Chicago: Academy of Nutrition and Dietetics.