By: Extracted from Dietetically Speaking written by Zachary Wenger
The Game Changers - How much truth is in it?
Like many people I watched with interest the new documentary on Netflix called The Game Changers. As someone who heavily promotes eating plant-based produce for our own health and that of the environment, I found some flaws in the discussion.
For those of you who haven't seen the show, I'm not giving much away by telling you that it shows how elite athletes' performances improve on a vegan diet. It may seem counterintuitive to find flaws in a compelling film which encourages the public to do precisely what I've been asking people to do for nearly two decades (eat more plant food) , however I worry about the consequences of people migrating to a totally vegan diet purely on the information given in this film, particularly if people stop eating animals based foods and replace them with the many meat free alternatives appearing in our supermarkets. Most of us are not elite athletes and a vegan diet with sufficient plant-based protein will be higher in energy (kJ) than a diet with some amount of animal foods AND, ironically because many of the meat free meat substitutes in the supermarket are extremely high in salt, the quick fix vegan diet may ironically cause our blood pressure and risk of heart disease to increase even further.
I was interested to read what others are saying about the documentary and found a terrific guest post on the website dieteticallyspeaking.com. What I particularly liked about this post was that it was written by a dietetics major Zachary Wenger, who, for ethical reasons, is a vegan and who in his own words says my stance on the ethics, will not and cannot overshadow the current knowledge we have on nutrition.
Here is an excerpt from the article.
Whether it's for environmental, ethical, or nutritional reasons, veganism is growing exponentially in popularity, and many professional athletes are now following this lifestyle.
We can look at Venus Williams, professional tennis player, to Kyrie Irving, professional basketball player, to Kendrick Farris, olympic weightlifter. All vegan and all at the top of their game.
Plant vs Animal Protein
The issue with plant based protein, is protein quality. Protein quality is characterized by the amino acid composition and digestibility.
On average, animal based protein is digested at a 90% or higher rate, while plant protein ranges anywhere from 55% to 80% (1).
In the film, they compare 1 cup of cooked lentils and 3 oz (90g) of beef as equivalent sources of protein. The protein digestibility corrected amino acid score (PDCAAS), is widely used as a routine scoring method for protein quality evaluation. For example, an individual would have to consume 5 times the amount of a food with a PDCAAS score of 0.20 in order to equate another food with a score of 1.00.
If we look at whole green lentils, they have a PDCAAS score of 0.63-0.67 (5). Compare that to beef, and we see that it has a PDCAAS score of 0.92 (6). Lentils have their own sets of unique benefits, but it's false to equate the protein quality of lentils to beef. In the lentils vs beef example, to get the same amount of protein you have to consume more energy (kJ) which may be an issue for people who are trying o maintain or lose weight. Remember that most of us are not elite athletes.
Plant proteins also contain less essential amino acids (EAA) than animal based proteins. EAA's cannot be produced by the body, therefore they are essential to obtain through our diet. Plants are especially low in the EAA leucine compared to animal based proteins. Leucine is well known for being a trigger for muscle protein synthesis (i.e. muscle growth) (7). While leucine is most important, compared to the other EAA's, we need all of the amino acids to generate muscle protein synthesis.
Bottom line, we do not *need* animal based protein to build muscle. We can properly build muscle on plants, and get enough protein, but that might require more kilocalories. For an athlete that wants to limit kilocalories while keeping protein high, a vegan diet may not be the *best* choice when compared to other diets.
plant vs animal burrito blood lipid experiment
For those of you watched the film you may remember the plant vs animal burrito blood lipid experiment where cardiologist, Robert Vogel, conducted an experiment with 3 NFL players, where he gave them each a plant based burrito and a meat based burrito, then compared the blood drawn 2 hours after each meal.
The blood after consumption of the plant based meal was clear and transparent, while the meat based meal resulted in a cloudy effect. This made major headlines because according to the film, the cloudy serum we see with the meat based burrito, symbolizes endothelial dysfunction.
It is physiologically normal to see a rise in triglyceride rich lipoproteins in the blood post-consumption of dietary fat.
The way this experiment was conducted was scientifically flawed however they cited a paper which replicated the results (8) and brought some interesting points into the equation.
The study looked at different foods in relation to the rise in postprandial triglycerides.
Olive oil, which is vegan, had the same postprandial rise in triglycerides as cheesecake and hamburger/fries!
The researchers even found that salmon had *half* the rise in triglycerides compared to olive oil! They also found that omega-3 fatty acids, vitamin C, and vitamin E improved endothelial function.
According to the research that The Game Changers linked, and our current knowledge on postprandial lipemia, this is not an issue with consuming plants vs animals. It is simply what we see when we draw blood from an individual that just consumed a fatty meal.
Vegan Diets and Health Outcomes
The film shares success stories of individuals that have lowered their cholesterol, blood pressure, BMI, etc - from going vegan. Which raises the question of whether you need to go fully vegan to achieve these benefits and the answer to that is no you don't?
A whole food plant based diet primarily works because it promotes a frequent intake of fruits, vegetables and whole grains. It promotes the intake of fibre, which can lower cholesterol, increase satiety, lower blood pressure, lower risk of certain gut diseases, lower risk of heart disease, and more (9). Consuming only whole foods completely eliminates processed junk food, which could assist one in lowering kilocalories. Plants are typically lower in kilocalories, which can aid in creating a caloric deficit, and in result, helps one lose weight. We know from current research that a healthy BMI is associated with lower all-cause mortality (10). Plants are also typically lower in saturated fat. Decreased intake of saturated fat is associated with lower LDL cholesterol (11).
While I do agree that we are eating too much meat, I do not think that is the primary issue. The issue is that the excess of meat, is replacing what should be plants.
Animal products aren't essential to the diet, but are a great source of vitamins that are harder to obtain on a vegan diet, like Vitamin D and Vitamin B12.
In terms of health, there are numerous benefits related to plant-based diets. but plant-based doesn't mean plant-only!
There is no such thing as one perfect diet, as we are all so individual, therefore different types of plant-based diets will work for different people. A vegan diet works really well for some people, whereas a more flexitarian approach works for others.
It is vital that we are make informed choices about our diet, rather than fear-induced choices on the back of biased and sensational documentaries like The Game Changers.
Follow Zachary on Twitter @_zachwenger
1. Sarwar Gilani, G., Wu Xiao, C., & Cockell, K. (2012). Impact of Antinutritional Factors in Food Proteins on the Digestibility of Protein and the Bioavailability of Amino Acids and on Protein Quality. British Journal of Nutrition, 108(S2), S315-S332.
2. Sarwar Gilani, G., Wu Xiao, C., & Cockell, K. (2012). Impact of Antinutritional Factors in Food Proteins on the Digestibility of Protein and the Bioavailability of Amino Acids and on Protein Quality. British Journal of Nutrition, 108(S2), S315-S332.
3. Gupta, R. K., Gangoliya, S. S., & Singh, N. K. (2015). Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. Journal of food science and technology, 52(2), 676-684.
4. Schlemmer, U. , Frřlich, W. , Prieto, R. M. and Grases, F. (2009), Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol. Nutr. Food Res., 53: S330-S375.
5. Nosworthy, M. G., Neufeld, J., Frohlich, P., Young, G., Malcolmson, L., & House, J. D. (2017). Determination of the protein quality of cooked Canadian pulses. Food science & nutrition, 5(4), 896-903.
6. Gertjan Schaafsma, The Protein Digestibility-Corrected Amino Acid Score, The Journal of Nutrition, Volume 130, Issue 7, July 2000.
7. Witard, O. C., Wardle, S. L., Macnaughton, L. S., Hodgson, A. B., & Tipton, K. D. (2016). Protein Considerations for Optimising Skeletal Muscle Mass in Healthy Young and Older Adults. Nutrients, 8(4), 181.
8. Vogel R. A. (1999). Brachial artery ultrasound: a noninvasive tool in the assessment of triglyceride-rich lipoproteins. Clinical cardiology, 22(6 Suppl), II34-II39.
9. James W Anderson, Pat Baird, Richard H Davis, Stefanie Ferreri, Mary Knudtson, Ashraf Koraym, Valerie Waters, Christine L Williams, Health benefits of dietary fiber, Nutrition Reviews, Volume 67, Issue 4, 1 April 2009, Pages 188-205
10. Global BMI Mortality Collaboration, Di Angelantonio, E., Bhupathiraju, S., Wormser, D., Gao, P., Kaptoge, S., … Hu, F. B. (2016). Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents. Lancet (London, England), 388(10046), 776-786.
11. Sacks FM, Lichtenstein AH, Wu JHY, Appel LJ, Creager MA, Kris-Etherton PM, Miller M, Rimm EB, Rudel LL, Robinson JG, Stone NJ, Van Horn LV; American Heart Association. Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association. Circulation. 2017; 136:e1-e23.
12. James W Anderson, Pat Baird, Richard H Davis, Stefanie Ferreri, Mary Knudtson, Ashraf Koraym, Valerie Waters, Christine L Williams, Health benefits of dietary fiber, Nutrition Reviews, Volume 67, Issue 4, 1 April 2009, Pages 188-205
13. Angela Sotelo, Liliana González-Osnaya, Argelia Sánchez-Chinchillas & Alberto Trejo (2010) Role of oxate, phytate, tannins and cooking on iron bioavailability from foods commonly consumed in Mexico, International Journal of Food Sciences and Nutrition, 61:1, 29-39
14. Yabuta, S., Urata, M., Wai Kun, R. Y., Masaki, M., & Shidoji, Y. (2016). Common SNP rs6564851 in the BCO1 Gene Affects the Circulating Levels of β-Carotene and the Daily Intake of Carotenoids in Healthy Japanese Women. PloS one, 11(12), e0168857.
Be the first to comment!