For some years now, protein has been seen in something of a bad light by the general public. Routinely denounced by the media, protein nonetheless continues to be viewed positively by nutritionists, for whom its rightful place in the diet has never been in question, unlike fats and carbohydrates which have each been singled out for criticism. The reason for this paradox is simple: misinformation about protein continues to proliferate – perhaps you’re even one of those who’ve helped spread it. Here we explode the common myths surrounding protein - so you can hopefully start preaching the right message!
Eating animal-source – as opposed to plant-source - protein is associated with long-term harmful effects
Probably one of the most common misconceptions is that eating animal protein can cause cardiovascular events. This view is all the more surprising given the many studies that point to the benefits of a higher protein intake for reducing cardio metabolic risk factors.
In reality, this misunderstanding is based on the association between consumption of products rich in animal protein
(primarily meat, cheese, smoked meats, etc) and cardiovascular mortality. A new observational study1
has confirmed this well-known and undisputed link: the greater your intake of animal-source protein, the higher your apparent risk of dying from a cardiac event (an increase of 10% in animal protein intake equates to an 8% higher risk of mortality). Conversely, it appears that in those with any existing risk factors (smoking, excessive alcohol consumption, excess weight, sedentary lifestyle), substituting animal source with plant source protein is beneficial: a 3% increase in intake of plant-source protein equates to a 10% decrease in cardiovascular mortality.
I’m sure you can see the problem with these studies: the health effects relate not to animal protein per se but to its sources, and in particular, the constituents of those sources
. Most (though by no means all) sources of animal protein contain high levels of sodium, nitrates, nitrites, trans fats and saturated fats, all of which are strongly-associated with an elevated risk of cardiovascular disease2-4
. The authors of the publication do note this, as well as the fact that plant source protein contains antioxidants and micronutrients that are potentially very beneficial in preventing certain chronic diseases.
So if you separate the animal protein from the (mostly) problematic forms in which it is consumed, is there still a link with increased cardiovascular mortality? Research suggests not. On the contrary, no negative health effects have been reported in studies observing the long-term effects of whey protein supplementation. This is therefore a safe and effective way of benefiting from animal source protein without suffering the disadvantages which normally come with it.
Plant-source protein is better quality
Though we see this claim more and more in the media, it really makes no sense at all. And here’s why.
Essential for the growth, repair and protection of body tissues, proteins are the main structural components of every cell in the human body. They are made up of chains of amino acids which form part of the muscles, skin, blood etc. Some of these amino acids are termed ‘essential’ because the body cannot produce them. We therefore have to rely on food sources, and try to obtain dietary amino acids of the highest quality. But how do you measure the ‘quality’ of a protein?
There are two elements to consider here.
The first relates tothe ability of dietary protein to provide nitrogen and essential amino acids
in order to ensure that any losses are renewed, and to supply the surplus needed for tissue development for optimal growth (after weight-training, for example). In this respect, plant-source protein is somewhat lacking. With few exceptions, it does not contain all the amino acids essential for growth and for sustaining the body. You have to judiciously combine several types of plant sources (over a whole day rather than at the same meal as was believed for many years) in order to ensure you are getting the benefits of all amino acids and try to find the best balance. So in this regard, animal source protein is undoubtedly the better option.
The second element concerns the impact of regular ingestion of dietary sources of protein on various physiological and physiopathological processes. And as you now know, here it is plant-source proteins which come out on top.
In short, animal-source protein is best for ensuring we get all the amino acids we need, but over time, some of the constituents in its sources damage the body and cause heart disease. For those with higher protein requirements, surely the best solution is to ingest animal protein from high quality supplements that are free from harmful substances.
Protein supplements are unnecessary for sports enthusiasts
For some time now, the idea has been circulating that protein supplementation is a waste of money for sportspeople – that such individuals, particularly those who do weight-training, really have no need for these supplements given our high-protein diets.
But here’s why this argument does not hold water.
If we follow the Recommended Daily Amounts (RDAs) for protein, an adult should consume 0.83g per kg of bodyweight a day. In other words, an individual weighing 75kg, who we will call ‘Eric’, should consume around 62g of protein a day to meet his needs: an amount easily obtainable from the diet.
But what about those people actively engaged in sporting activities?
Most expend considerable energy in pursuing their chosen activity and their main concern is to increase their food intake to achieve the right caloric balance
. In general, our satiety processes are sufficient to ensure we eat the right amount. However, we know that there are three nutrients, not counting alcohol, which provide us with energy: carbohydrates, protein and fats. It may therefore be wise to eat more protein than normal so as to maintain the proportion of carbohydrates and fats in our diet. This caloric balance often eludes sports enthusiasts who are keen to ‘maintain their ideal weight’ while ‘increasing muscle mass’. But what actually results is a decrease in muscle mass …
The other concern common among sportspeople is nitrogen balance
. When they engage in physical activity, a breakdown of muscle (muscle proteolysis) occurs which leads to a deficit in nitrogen. In order to activate muscle synthesis, the body needs a certain amount of amino acids to restore this balance, and even more if it wants to increase muscle mass. This is referred to as an anabolic state: nitrogen balance must be positive
The protein requirements of a someone undertaking
an endurance sport, may therefore be around 50% higher. For top level or elite athletes
(who are training more than three times a week for example), protein requirements may be 1.5-2 times higher than recommended intakes. In other words, if Eric became a highly active sportsman, he would need to consume between 93g and 124g of protein a day. And for his long-term health, it would be better for him if this high protein consumption had as few as possible of the characteristic elements of red meat (saturated fatty acids, sodium, etc) that are associated with a higher risk of cardiovascular mortality. For those sportspeople engaged in weight lifting and body-building, protein requirements may be even higher.
Researchers compared two groups of sportspeople engaged in weight training for six weeks. One group’s protein intake was in line with RDAs (0.8g/kg/day), while the other’s was twice the RDA8
. There was a notably higher increase in muscle mass in the second group as compared with the first. The same observation was made among sportspeople consuming a similar amount of calories but where the proportion of protein differed – intake was either 2.8g/kg or 1.4g/kg a day9
Superiority of whey protein
Whey protein supplementation, when combined with strength or muscle mass training, has been shown conclusively to increase lean mass, strength and muscle hypertrophy10-15
. When combined with a suitable exercise regime, it also reverses the muscle loss generally seen in older people. Contrary to what you might think, protein requirements increase with age due to less effective nitrogen metabolism. Yet intake normally declines because of loss of appetite and avoidance of certain foods for medical reasons.
You should ideally opt for hydrolysed whey protein as it is more readily available to the muscles. If you want to get the most out of whey protein supplements, remember to take them just before or after exercise for maximum effect16-18
Though protein continues to attract misinformation, you now have the facts on key aspects such as its quality and effects. Take the opportunity to spread the word to those around you - even your GP - to counter the myths that proliferate about this nutrient. Now that you know, you need to inform others: knowledge should translate into action!
1. Song M et al. Association of Animal and Plant Protein Intake with All-Cause and Cause-Specific Mortality. JAMA Intern Med., 2016.
2. Aseem Malhotra, Saturated fat is not the major issue, BMJ 2013;347:f6340 doi: 10.1136/bmj.f6340
3. Danaei G, Ding EL, Mozaffarian D, et al. The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors. PLoS Med 2009;6:e1000058.
4. Hu FB, Stampfer MJ, Manson JE, et al. Dietary fat intake and the risk of coronary heart disease in women. N Engl J Med 1997;337:1491–9
5. Candow DG, Burke NC, Smith-Palmer T, Burke DG. Effect of whey and soy protein supplementation combined with resistance training in young adults. Int J Sport Nutr Exerc Metab 2006;16:233-44.
6. Fukushima Y, Kawata Y, Onda T, Kitagawa M. Long-term consumption of whey hydrolysate formula by lactating women reduces the transfer of beta-lactoglobulin into human milk. Nutr Sci Vitaminol (Tokyo) 1997;43:673-8.
7. Tarnopolski et al. Influence of protein intake and training status on nitrogen balance and lean body mass. J Appl Physiol (1985). 1988 Jan;64(1):187-93.
8. Torun B et al. Effect of isometric exercises on body potassium and dietary protein requirements of young men. Am J Clin Nutr. 1977 Dec;30(12):1983-93.
9. Consolazio CF et al. Protein metabolism during intensive physical training in the young adult. 1975 Am J Clin Nutr, 1975,28 : 29-35
10. Cribb PJ, Wiliams AD, Carey MF, Hayes A. The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine. Int J Sport Nutr Exerc Metab 2006;16:494-509.
11. Cribb PJ, Williams AD, Stathis CG, et al. Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Med Sci Sports Exerc 2007;39:298-307.
12. Candow DG, Burke NC, Smith-Palmer T, Burke DG. Effect of whey and soy protein supplementation combined with resistance training in young adults. Int J Sport Nutr Exerc Metab 2006;16:233-44.
13. Burke, D. G., Chilibeck, P. D., Davidson, K. S., Candow, D. G., Farthing, J., and Smith-Palmer, T. The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength. Int J Sport Nutr.Exerc.Metab 2001;11(3):349-364. View abstract.
14. Brown, E. C., DiSilvestro, R. A., Babaknia, A., and Devor, S. T. Soy versus whey protein bars: eff