Geschatte leestijd: 8 minuten
“Extra proteins are nonsense and money grabbing.” Apparently, another book needs to be sold.
“Extra proteins are nonsense”
Jaap Seidell is a professor at VU Amsterdam. Last week, various media outlets highlighted his new book [1]. The best way to draw attention to it apparently was by highlighting the claim that taking extra proteins is nonsense. Many people supposedly already get enough or even too much. Too many proteins could also be dangerous, causing cancer and damaging the kidneys.
“It sells, but it’s nonsense and money grabbing.”
At least, that’s what various media outlets reported. I hope the book itself is more nuanced and puts this in context.
Now, as a blog that shows advertisements for supplements, we’re naturally not entirely free from conflicts of interest. However, that has never stopped me from questioning the alleged effect of most supplements I’ve described. In many cases, the conclusion is indeed that you can question whether the investment translates into results. However, I always try to place this in the right context.
There can be dozens of studies on the ‘same’ supplement, but under different circumstances and with different outcomes. There’s also a huge amount written about protein supplementation.
Like last week, for example:
It is well established that consuming dietary protein proximate to resistance-type exercise sessions promotes a positive net protein balance during post-exercise recovery.
This is a quote from researchers at Purdue University who compared 34 randomized controlled trials to study the effect of proteins around exercise [2]. The British researchers wanted to know in particular whether it’s better to take proteins separately or with a meal. However, I got stuck on that first sentence: “It’s well established….”
That sounds quite different from “extra proteins are nonsense.”
The Americans specifically look at protein intake in combination with strength training. They also distinguish between losing weight or gaining more muscle mass as goals. Jaap Seidell’s quotes mainly concern the total intake of proteins per day.
Proteins in the right context
So, context is very important. When I write about a supplement, I try to ask a few important questions:
- Which substance is being researched?
- What effect is being measured exactly?
- What is the status of the people using the supplement?
- How is it used (dosage, duration, and timing)?
- What is its place within the diet?
This way, I often arrive at specific situations and circumstances of use.
For example, I don’t write, “BCAAs are nonsense.” After all, there are enough studies showing that taking BCAAs after a workout leads to faster muscle recovery than not taking BCAAs. However, many, if not most, people who buy BCAAs already pay attention to their protein intake. Often, they also take a protein shake after a workout. So, I ask the question more specifically. “Does taking BCAAs make sense if you already consume enough protein?” I also distinguish between the goal of gaining extra muscle mass or maintaining muscle while cutting (reducing fat mass). I also try to describe the doses and compositions used as clearly as possible. Ideally, I also look at studies involving trained individuals to make it more relevant to most of our readers.
Exception for bodybuilders
In what context should we view the statements from Jaap Seidell’s book?
The average Dutch man weighing 85 kilograms needs 68 grams of protein per day but typically consumes 95 grams. The average Dutch woman weighing 70 kilograms needs 56 grams but typically consumes 68 grams.
As a serious strength athlete, you laugh at those kinds of numbers. “That’s for normal mortals, not for a young god like me.”
Seidell also mentions bodybuilders and people who train a lot as possible exceptions. But: “Even these people must be very precise about when they take something extra and when not.” I can only agree with that. Knowing if, where, and when supplementation fits into your diet is essential for its potential added value.
“More than 150 grams of protein per day is dangerous”
However, the warning does not only concern usage for optimal results. There is also talk about the potential dangers of high protein intake. Especially people who consume more than 150 grams of protein per day are said to have an increased risk of cancer and kidney damage.
We have also written about the influence on the kidneys. However, we came to a different conclusion. We found no studies showing that high protein intakes cause kidney problems in healthy people. Only studies that did not see this effect. In the studies on this, sometimes high intakes of 2.8 grams per kilogram of body weight were used. That is 238 grams for someone weighing 85 kilograms. Some researchers go even further: They see that the deterioration of kidney function with age is not inhibited by restricting protein intake. To slow down this deterioration, a higher intake (than the current one) is actually recommended.
That doesn’t mean that proteins can’t be dangerous for the kidneys. They certainly can;
for people with existing kidney problems. If kidney function is already impaired and the kidneys already struggle with their filtering work, you should not burden them extra with a lot of proteins. An example is the story of Bryan van Bentum that we shared here a few years ago.
Because not everyone is aware of existing kidney problems, as initially also applied to Bryan, this can pose an unknown risk.
For example, overweight people have a higher risk of kidney problems. A group with a higher chance of reduced tolerance for proteins, while the use of them can be popular for weight loss.
It’s also good to know that different types of proteins cause different burdens on the kidneys. Many protein shakes use proteins from dairy such as whey and casein. These demand less from the kidneys than other animal proteins from meat. In addition, proteins from red meat pose a higher burden than white meat.
So, context.
Proteins and cancer
But what about the increased risk of cancer?
I suspect that Seidell refers to the influence of protein on the levels of insulin-like growth factor 1 (IGF-1). Animal proteins have been associated with higher levels of IGF-1, which in turn have been associated with a higher risk of cancer and death. Studies with mice show that an IGF-1 deficiency can have a significant positive effect on lifespan.
There are studies that show a relationship between high protein intake and a higher risk of cancer and death. Like the 2014 study that saw a higher risk of both in people aged 50 to 65. For the study, data from 6,381 American men and women from the NHANES III study were used. When more than 20% of daily calories were derived from proteins, they fell into the ‘high intake’ category. Less than 10% fell into the ‘low intake’ category.
A high protein intake increased the risk of death by 75 percent and quadrupled the risk of cancer compared to the group with low intake. However, the same study also showed that in people over 65, a high protein intake actually reduced the risk of death and cancer. The benefits on the natural decrease in IGF-1 and muscle mass apparently outweigh the disadvantages.
You don’t like to hear that as a young strength athlete only thinking about your biceps. You probably know that IGF-1 as a growth factor has a positive effect on muscle mass. Unfortunately, the same positive influence can also have on cancer cells in general.
There are studies that do not show a significant relationship between high protein intake and specific forms of cancer such as colorectal cancer [3]. There are also studies that show a negative relationship with specific forms of cancer. For example, the risk of breast cancer was found to be reduced by eating fewer carbohydrates and more proteins [4]. Other research showed a relationship between the amount of proteins in the diet and the risk of cancer. But only from red meat and processed meat, not from plant proteins, dairy, and eggs.
Fats can also increase IGF-1. Some minerals and vitamins also. Chronic high blood sugar and insulin too (explained in the breast cancer study), so carbohydrates also don’t escape the dance.
So, context.
Converting proteins into fat mass?
Even when Seidell himself indicates that intakes lower than 150 grams per day are safe, he still manages to place proteins in another negative light.
“It’s not that bad. Your body either burns the proteins or stores them as fat in your body.”
Burning or storing as fat makes a big difference, of course. Both for people who want to gain muscle mass or want to lose weight.
It’s possible to convert the amino acids from proteins into glycogen, which can then be converted into glucose and then into fatty acids for storage. However, carbohydrates are much easier to use as fuel and will therefore be the first choice for this. Fats can provide more energy, but this already costs the body more effort. Proteins can provide as much energy as carbohydrates, but also less quickly. For all of them, there must be an excess of energy before energy is stored in body fat instead of in more readily available sources such as glycogen.
But even if there is such an excess of calories, proteins will hardly ever be used to be stored as body fat. This is shown, among other things, in a study from 2012 [5]. In that study, participants were divided into three groups:
- Low protein intake: 5% of daily calorie intake (average 47 grams)
- Normal protein intake: 15% of daily calorie intake (average 140 grams)
- High protein intake: 25% of daily calorie intake (average 230 grams)
All participants had to eat 140% of their calorie needs daily. This was done in a laboratory environment, where occasional coercion/motivation was needed.
In all groups, 41 to 42 percent of the calories came from carbohydrates. The amount of fats was respectively 33%, 44%, and 52% in the ‘high’, ‘normal’, and ‘low’ intake groups. After all, if fewer proteins are taken and
carbohydrates remain the same, you need more fats to reach the same amount of calories. During and after the 8 weeks on this diet, body composition was measured using a DXA scan. You can see the results in the graph.
The group that received little protein had the smallest increase in weight. However, this was because this group had decreased in lean mass. In fat mass, this group had gained the most, although not significantly more than the other groups. However, what is significant is the difference in lean mass, which increased by over three kilos in the groups receiving an average of 140 and 230 grams of protein per day.
A high intake of protein, during a calorie-high diet, did not lead to more fat but to more lean mass. Exactly what a bodybuilder wants during the so-called bulking phase. You would, however, want to see a different ratio of increased lean mass and fat mass instead of 50-50, but no one says, of course, that you should eat 140% of your daily needs.
Is it worthwhile to take extra proteins?
So far, I’ve mainly addressed the alleged dangers. But let’s also look at perhaps the biggest accusation: That it is not useful at all. Once again, I miss the context. No use for what? Building muscle mass and burning fat are two different goals with different roles for proteins.
The aforementioned study is just one of many examples of studies showing a positive relationship between protein intake and muscle mass. We’re talking about the total intake per day, but also specifically around a workout (see the quote at the top of the article). I completely miss this latter aspect. Even people who want to limit their daily protein intake can consciously choose to have a protein shake to have the best proteins at the best time.
I also miss the context when not compared to the possible disadvantages of carbohydrates and fats. Proteins during weight loss are often a replacement for sugars and fats. Both will contribute much more quickly to overweight and related diseases.
So, whether it makes sense to take proteins depends on the circumstances in which you use them. Unfortunately, there’s no juicy one-liner in there.
“Better eat a banana,” says Seidell. Yes, that probably sells better.
Kill the messenger?
For clarity, I haven’t read Seidell’s book. If I had to read every book on fitness and nutrition from which I hear rather odd quotes, then I also oblige myself to read, for example, about menstruating chickens. So, I’m mostly annoyed by the statements about it in the media. They are, as you might expect, aimed at a short, simple message that grabs attention.
In fact, I wouldn’t pay any attention to it until three people in the gym came up to me this week with the same question: “Is it true that taking extra proteins is useless?” Sigh…
References
- rtlnieuws.nl/nederland/voeding-met-extra-proteine-is-onzin-en-pure-geldklopperij
- Joshua L Hudson, Robert E Bergia, Wayne W Campbell. Effects of protein supplements consumed with meals, versus between meals, on resistance training–induced body composition changes in adults: a systematic review. Nutrition Reviews, 2018; DOI: 10.1093/nutrit/nuy012
- Lai R, Bian Z, Lin H, Ren J, Zhou H, Guo H. The association between dietary protein intake and colorectal cancer risk: a meta-analysis. World Journal of Surgical Oncology. 2017;15:169. doi:10.1186/s12957-017-1241-1.
- Moulton CJ, Valentine RJ, Layman DK, et al. A high protein moderate carbohydrate diet fed at discrete meals reduces early progression of N-methyl-N-nitrosourea-induced breast tumorigenesis in rats. Nutrition & Metabolism. 2010;7:1. doi:10.1186/1743-7075-7-1.
- Bray GA, Smith SR, de Jonge L, Xie H, Rood J, Martin CK, Most M, Brock C, Mancuso S, Redman LM: Effect of dietary protein content on weight gain, energy expenditure, and body composition during overeating: a randomized controlled trial. JAMA 2012, 307:47-55.
