PLANT BASED DIETS FOR ATHLETES – BY BODYHERO HEAD OF NUTRITION KATE SHILLAND
With more and more athletes showing an interest in the benefits of plant based diets for health, environmental or ethical reasons, we thought it would be a good idea to put some information together on the key nutrients that differ between plant-based and omnivorous diets and how this may influence athletic performance.
In health terms, there is widespread recognition that plant based diets can lower the risk of many diseases. Studies consistently report reductions in cardiovascular disease, hypertension, diabetes, obesity and several types of cancer.
In terms of performance links, so far, there don’t seem to be any significant differences between plant based or animal based diets in muscle power & strength, contrary to expectation, but there is new data to suggest plant based diets may enhance aerobic capacity and endurance performance. As ever though, the inevitable line is that further research is needed!
Due to the high carbohydrate content in plant based diets, they are great for maintaining glycogen levels which we all know is a key performance fuel. As well as adding fuel to the tank, the high fibre content is great for gut health, the health benefits of which are widespread. There’s now evidence to suggest that prioritising gut health may be a good, targeted approach for athletes as it appears that elite athletes have a unique make up of gut microbes that benefit health and performance. A recent multi study review concluded that gut microbiota plays a key role in controlling oxidative stress and inflammatory responses as well as improving metabolism and energy expenditure during endurance exercise.
The high levels of antioxidant and anti-inflammatory nutrients help reduce oxidative stress and inflammation and can result in enhanced endurance performance, reduced muscle damage, improved immunity and more efficient recovery from training and competition.
This is all great news but there are certain nutrients in plant based diets that need additional planning and consideration to optimise health and performance.
The first question that everyone asks is how you get enough protein from plant based diets. The American College of Sports Medicine suggests athletes should consume 1.2-2.0 g/kg to support adaptations to exercise and increased protein turnover. No specific recommendation is given for plant based athletes and studies looking at the diets of vegan and vegetarian endurance athletes show that they are consistently meeting their recommended daily protein intake.
Good foods to include that are high in protein are soy products (tofu, tempeh, edamame, soymilk), grains & pulses (beans, lentils, peas, quinoa), nuts & seeds and there is a growing range of plant-based milks, meat substitutes and protein powders.
These help maintain strength and enhance recovery from heavy exercise through their anti-inflammatory effects. ALA is converted to EPA and DHA, and it is found mainly in nuts, seeds and plant oils. DHA and EPA are found in oily fish so it’s important to consume plenty of sources of ALA if you follow a plant based diet to compensate, or consider taking an algae based omega 3 supplement.
Vitamin B12 is important for normal brain and nervous system functioning and helps to make DNA. It is also associated with red blood cell formation. Low levels can lead to megaloblastic anaemia which limits the blood’s oxygen carrying capacity, which negatively impacts performance. B12 is mainly found in meat, eggs, and dairy products. The only reliable and recommended plant based sources of B12 are fortified breakfast cereals, nutritional yeasts and fortified plant based milks products, so a B12 supplement is recommended if you follow a plant based diet.
Iron intake is so important for all of us, but particularly for athletes as it is responsible for the transport & storage of oxygen and also supports proteins and enzymes essential for physical and cognitive performance. Iron-deficiency anaemia is the most common type of anaemia among athletes, who have higher iron requirements due to higher intensities and volumes of training. Female athletes are at particular risk of iron deficiency due to menstruation and typically a lower total food intake compared to males.
The risk of iron deficiency is greater in plant based athletes due to low bioavailability of iron from plant foods. So, it is recommended that individuals following plant based or vegan diets consume 1.8 times more iron than omnivores - 32 mg/day vs. 18 mg/day for premenopausal adult women and 14 mg/day vs.8 mg/day for adult men and postmenopausal women.
The sunshine vitamin plays a crucial role in bone health and immunity, but it is very tricky to get enough in all diets, not exclusively plant based diets. In fact, there is little difference in vitamin d status of plant based individuals and omnivores, so it’s recommended that everyone supplements with 1000IU per day in winter months, particularly if you train inside. Some good food sources are UV radiated mushrooms, fortified cereals, and fortified plant milks.
Zinc is a catalyst for many enzymes in the body and plays an important role in immunity. Plant-based sources of zinc have lower bioavailability due to the presence of phytates that bind zinc and reduce absorption. Because of this, those following a plant based diet may require 50% more zinc compared to omnivores – 16.5mg for males and 12mg for females. Good sources are soy, legumes, grains, fortified cereals.
Lastly, calcium is another nutrient that needs more consideration, and it seems people who follow vegan diets tend to consume less calcium. We’re aiming for 1000mg per day. Plant based sources may also be less bioavailable due to the presence of oxalic acid and phytates. The International Olympic Committee consensus statement on supplements and athletes notes that, as with vitamin D, calcium is a nutrient that often needs to be supplemented for athletes, regardless of dietary preference. Good plant based calcium sources are tofu, soyabeans, sesame seeds, leafy greens, figs, and fortified plant based milk.
In summary, all athletes, professional or recreational, plant based or otherwise, should be mindful of taking care of their nutrition, as there’s no question that we get out what we put in, so the better quality the nutrients, the better quality the health and performance.
For plant based based athletes, a well-designed diet that includes some fortified foods and Informed Sport regulated supplements, can definitely provide adequate macro and micro-nutrient intakes to support health and enhance performance whilst supporting the environment in the process. It’s a win-win, or winner-winner non-chicken dinner.
Author: Kate Shilland – Bodyhero Head of Nutrition