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Protein is seems a necessity for athletes. How healthy is a high protein diet actually? And is plant-based better than animal-based protein?
Introduction
Research shows that a high intake of protein may increase the risk of metabolic, cardiac, renal, bone and liver disease. Furthermore, some athletes tend to develop cardiovascular disease earlier than sedentary people. It is likely that nutrition plays an important role in the increased risk. It seems, if the supplementary energy is provided (even in part) by animal products, the saturated fats and cholesterol they contain, combined with the absence of plant antioxidants and fibers in the diet, end up contributing to the development of atherosclerosis. [1]
This raises two questions:
1. How healthy is a high protein diet?
2. Is a vegetarian diet better, especially for athletes?
How healthy is a high protein diet?
Protein sources and amino acids
Protein is available in animal- based and plant- based sources, and industrially processed supplements and snacks (How artificial is your food? and Do you need supplements? and How healthy is your protein snack?) Important characteristics of protein is its quality and digestibility. Quality refers to the availability of amino acids that it supplies, and digestibility refers to how the protein is best utilized.
“Proteins are nitrogen-containing substances that are formed by amino acids. They serve as the major structural component of muscle and other tissues in the body. In addition, they are used to produce hormones, enzymes and hemoglobin. Proteins can also be used as energy; however, they are not the primary choice as an energy source. For proteins to be used by the body they need to be metabolized into their simplest form, amino acids. There have been 20 amino acids identified that are needed for human growth and metabolism. Twelve of these amino acids (eleven in children) are termed nonessential, meaning that they can be synthesized by our body and do not need to be consumed in the diet. The remaining amino acids cannot be synthesized in the body and are described as essential meaning that they need to be consumed in our diets. The absence of any of these amino acids will compromise the ability of tissue to grow, be repaired or be maintained.”[2]
Animal-based sources of protein such as meat, fish and dairy, have been popular for many years because for many it has traditionally been part of nutritional habits,and products are easily available, and have a high bioavailability: Animal- based products contain all essential amino acids. Vegetable sources of protein have a lower bioavailability and lack one or more essential amino acids.
Protein for sports, weight loss and healthy ageing
The intake of protein is important for athletes and their intake should be and often is higher compared to the general population. Muscles play a crucial role in sports performance and contain the largest portion of protein in the body, around 40 percent. A sufficient intake of protein is necessary for a good balance between muscle breakdown and muscle build (muscle synthesis). A positive balance is required to maintain and build muscle mass.
Also during weight loss and for example for endurance athletes, the intake of a sufficient amount of protein is necessary to prevent loss of muscle mass. In addition, satiety after a meal occurs late when protein intake is low and this increases the risk of overeating and thus of obesity.
Furthermore, a sufficient intake of protein is important for healthy ageing. The loss of muscle mass is an inevitable part of the process of aging. (Healthy Ageing requires more training and eating than you think) Also people with certain health conditions or diseases can benefit from a higher intake of protein.[3]
Animal-based protein: benefits and risks
Benefits
Animanl- based protein provides a complete protein and numerous vitamins and minerals. Research shows several other benefits such as: A low intake of protein from dairy and meat sources during late pregnancy is associated with low birth weights, and therefor pregnant women can benefit from animal- based protein.
Furthermore, high animal- based protein diets seem to cause a significantly greater net protein (muscle) synthesis than a high vegetable protein diet. Also, in elderly a diets consisting of meat results in greater gains in lean body mass compared to subjects on a lacto-ovo-vegetarian diet.
Risks
Research also shows health risks of a high protein diet of animal-based products. This is for several reasons among which the amount of saturated fat, cholesterol and salt in these foods, compared to vegetable sources; and industrial techniques applied to process these types of food, for example canned meat. Other risks commonly mentioned are:
- High protein and low carb diets: Metabolic ketosis
Diets high in protein and low in carbs can potentially increase the risk of metabolic ketosis. As carbohydrate stores are reduced the body relies more upon fat as energy. The greater amount of free fatty acids that are utilized by the liver for energy will result in a greater production and release of ketone bodies in the circulation. This will increase the risk for metabolic acidosis and can potentially lead to a coma and death. In addition, research shows low carb diets increase the risk of premature death. (Paleo kills ya!)
- High protein diet with fatty products: Cardio- vascular risk
When the sources of protein are primarily animal- based and high in saturated fat, cholesterol and salt such as fatty meat, the risk of increased blood lipids levels, blood pressure and cardiovascular diseases increases. (How bad is eating meat?)
- High protein diet and renal function: Only in existing diseases
The advice for individuals with existing kidney disease is to limit protein intake to 50%of the daily recommended intake, in order to prevent the kidneys from becoming overstressed. In healthy individuals there does not seem to be any adverse effects of a high protein diet.
- High protein diet and bone health: inconclusive
High protein diets are associated with an increase in calcium excretion. This is apparently due to a consumption of animal-based protein, not plant- based protein. Research is still inconclusive about the relation between dietary protein and bone health. (Calcium supplement or dairy?)
- High protein diet and liver disease: Inconclusive
High protein diets are associated with negatively affecting liver function. Research is still inconclusive about the relation between the both.[4]
Is a vegetarian diet better, especially for athletes?
Research shows that although animal products have health benefits, a high protein diet with mainly animal- based protein also has increased health risks. This raises the second question: Is a vegetarian diet better especially for atrhletes who have a high protein intake?
At this time, research is still unclear about whether the long-term consumption of a vegetarian diet can improve recovery, prevent inflammation, and mitigate oxidative damage that occurs with intense workouts, or if it can enhance athletic performance. [5]
Nevertheless, a well- balanced diet with plant- based protein sources may offer a healthy and less risky alternative due to a reduction in saturated fat and cholesterol and an increase in fibers and several other nutrients.
Well-balanced plant- based diet
Well- balanced means the diet provides all essential amino acids, a sufficient amount of calories to function properly; as well as vitamins and minerals only found in animal-based products.[6] Consuming a variety of vegetables, fruits, grains and legumes ensures the consumption of all essential amino acids.
When the diet meets the standard criteria of The VegPlate for Sports, there is no scientific evidence to suggest that a vegetarian diet should be different in terms of quality and quantity, when compared to an omnivorous diet for an athlete.
These standard criteria are [7]:
- The diet includes a wide variety of plant foods (grains, legumes, vegetables, fruits, and nuts and seeds.
- Dairy products and eggs are considered optional forreaching the diet’s adequacy.
- The diet includes fats of plant origin, while consuming good sources of n-3 fatty acids (flaxseeds, chia seeds, and walnuts)
- The diet includes reliable sources of calcium, and paying attention to the status of both vitamin B12 and vitamin D.
Furthermore, the basic principles of a vegetarian sports should meal remain the same as those of a non- vegetarian meal, with the same need for timing (Timing iseverything), quality and quantity of macronutrient choices, hydration (Why you need a hydration plan), and supplementation.
Soy
Soy is a special kind of plant- based protein, because it is a complete protein containing all essential amino acids. There are indications that soy has a positive effect on blood cholesterol levels and on blood pressure. Furthermore soy intake seems associated with lower risk of cancer and cardiac conditions, and improved menopausal symptoms and osteoporosis in women. Obviously assuming an overall diet low in saturated fat, salt and cholesterol.
The health benefits associated with soy protein are related to the physiologically active components that are part of soy, such as isoflavones. Some studies show isoflavones are beneficial for cardiovascular health. Furthermore, considering that isoflavones are considered phytoestrogens (exhibit estrogen- like effects), soy might reduce the risk of breast cancer, although the association between soy intake and breast cancer risk remains inconclusive. However, other studies have demonstrated positive effects of soy protein supplementation on osteoporosis and reducing the severity of menopausal symptoms.[8]
Concluding
Given the fact that:
1. A high protein diet with animal- based protein (in foods and supplements) can have health risks, and
2. there is no scientific evidence to suggest that a vegetarian diet should be different in terms of quality and quantity, when compared to an omnivorous diet, and
3. a well- balanced diet with plant- based protein sources may offer a healthy and less risky alternative
It seems justifiable to conclude that a plant- based diet, or at the least a flexitarian- diet, is a healthier option for athletes who have a high protein intake. (Practical tips for vegan athletes)
Create your own health!©
References
[1] BaroniL, Pelosi E, Giampieri F, Battino M. The VegPlate for Sports: A Plant-BasedFood Guide for Athletes. Nutrients. 2023 Apr 3;15(7):1746. doi:10.3390/nu15071746. PMID: 37049586; PMCID: PMC10097385.; Hoffman JR, Falvo MJ.Protein - Which is Best? J Sports Sci Med. 2004 Sep 1;3(3):118-30. PMID:24482589; PMCID: PMC3905294.
[2] Idem
[3] Jeukendrup,A., Gleeson, M. Sport Nutrition: An Introductionto Energy Production and Performance. Second edition.
[4] Baroni L, Pelosi E, GiampieriF, Battino M. The VegPlate for Sports: A Plant-Based Food Guide for Athletes. Nutrients.2023 Apr 3;15(7):1746. doi: 10.3390/nu15071746. PMID: 37049586; PMCID:PMC10097385.; Hoffman JR, Falvo MJ. Protein - Which is Best? J Sports Sci Med.2004 Sep 1;3(3):118-30. PMID: 24482589; PMCID: PMC3905294.
[5] Baroni L, Pelosi E, GiampieriF, Battino M. The VegPlate for Sports: A Plant-Based Food Guide for Athletes. Nutrients.2023 Apr 3;15(7):1746. doi: 10.3390/nu15071746. PMID: 37049586; PMCID:PMC10097385.
[6] Baroni L, Pelosi E, GiampieriF, Battino M. The VegPlate for Sports: A Plant-Based Food Guide for Athletes. Nutrients.2023 Apr 3;15(7):1746. doi: 10.3390/nu15071746. PMID: 37049586; PMCID:PMC10097385.; Hoffman JR, Falvo MJ. Protein - Which is Best? J Sports Sci Med.2004 Sep 1;3(3):118-30. PMID: 24482589; PMCID: PMC3905294.
[7] Baroni L, Pelosi E, GiampieriF, Battino M. The VegPlate for Sports: A Plant-Based Food Guide for Athletes. Nutrients.2023 Apr 3;15(7):1746. doi: 10.3390/nu15071746. PMID: 37049586; PMCID:PMC10097385.
[8] HoffmanJR, Falvo MJ. Protein - Which is Best? J Sports Sci Med. 2004 Sep1;3(3):118-30. PMID: 24482589; PMCID: PMC3905294.; Mariotti F, Gardner CD.Dietary Protein and Amino Acids in Vegetarian Diets-A Review. Nutrients. 2019Nov 4;11(11):2661. doi: 10.3390/nu11112661. PMID: 31690027; PMCID: PMC6893534.
