Geschatte leestijd: 5 minutenAre supplements harmful to health? According to a recently published study, the risk of testicular cancer is higher with the use of dietary supplements [1]. However, there are also other possible causes such as the use of anabolic steroids. This makes the research somewhat questionable in my opinion.
“Protein supplements harmful to health”
In my opinion, the point is being missed, both by the researchers at Yale, but even more so by Generation Iron, which came up with the spectacular headline:
“STUDY FINDS THAT PROTEIN SUPPLEMENTS CAUSE CANCER?”
So, protein causes cancer. By putting a question mark after it, they cover themselves for the incorrect reflection of facts and still attract a lot of readers. Because let’s be honest:
If you’ve just consumed yet another protein shake, you’ll definitely click on the link when you see it pass by.
Are supplements really harmful to health?
However, this message must be strongly toned down:
- It concerns the relatively rare form of testicular cancer. So, women can breathe a sigh of relief
- The study does not only refer to protein but to various forms of supplementation. A connection cannot only be linked to protein
- By the term “muscle building supplements,” the researchers apparently also mean the use of anabolic steroids or at least prohormones that are classified as anabolic steroids by various agencies.
Small-scale, poorly controllable, and lumping everything together
First, about the study itself. For this, a survey was conducted among 356 men in Connecticut and Massachusetts who used dietary supplements about supplement use and other habits such as smoking and drinking. A group of 513 men who did not use supplements served as a control. In both cases, about half filled out the survey, so we have a test group of about 200 men, not too many.
The results showed that there were more cases of testicular cancer among men who:
- Started using muscle-building supplements before the age of 25
- Used more than two different supplements
- Used supplements for more than three consecutive years
According to this list, I should immediately go to the doctor to have my balls checked because in my case, it’s really a “check” on all three points.
However, I’m not immediately afraid.
Firstly, because I know that I’m a bit of an oddball, a bit like a 40-year-old virgin. I have never used anabolic steroids (no, really not). However, if you, as a man, have been training for more than three years and using supplements to become more muscular for the same amount of time, you fall into the group statistically where anabolic steroids are often used.
My first thought was, therefore, that the influence of possible anabolic use has influenced the test results. The test subjects can, of course, lie when filling out the questionnaire. Nobody likes to admit to using anabolic steroids, so you should actually assume that you won’t get honest answers. Without methods to exclude or minimize that, your data becomes polluted.
However, it’s worse. To my surprise, there are 30 different supplements included in the list from which the researchers calculated the total amounts of the main ingredients that someone has ingested, such as creatine, protein, and androstenedione?
The interview included an assessment of 30 different types of MBS powders or pills. The major ingredients, including creatine, protein, and androstenedione or its booster*, were abstracted according to the product ingredients.
*Probably DHEA, see further.
Anabolic use is not only not excluded, but the use of prohormones within this group is even known (in some cases). Although there is also something to be said about the statistical analysis and conclusion associated with this, in my opinion, the research is already of little value because specific supplements cannot be examined since everything is lumped together.
Androstenedione?
If the study had been written in the 90s, I could understand this. At that time, androstenedione was still sold as a regular supplement “over the counter,” at least in the US. However, it is a precursor of testosterone. It can, therefore, be converted into testosterone in the body. In 2004, it was therefore classified as anabolic steroids by the Americans after use by well-known baseball players fueled the debate about the performance-enhancing properties. However, it has never been officially sold in the Netherlands.
The annoying thing is that we don’t get to see the data ourselves. Which 30 supplements were looked at and what amounts of androstenedione were included in them? The relationship between sex hormones and their precursors and damage to testicles will be less surprising than when we talk about protein and creatine. So, this is a bit like reading the text “cycling is life-threatening” and then reading that all fatal accidents with motorcycles were included in the study.
It is important to know that DHEA (Dehydroepiandrosterone) is a precursor of androstenedione. DHEA can therefore be converted into androstenedione (which can then be converted into testosterone). DHEA is still sold by supplement shops (such as Bodyenfitshop, which I just called to ask if this is still allowed, and they assure me that it is).
Cancer from supplements
Although testicular cancer is relatively rare, it is the most common form of malignant tumor among men aged 15 to 39 worldwide [2]. It is also the most common form among men aged 15 to 30 in the Netherlands [3].
Moreover, the number of cases is increasing [3]. The researchers at Yale indicate that this increase cannot be explained by known risk factors such as hereditary predisposition and undescended or shriveled testicles [4]. They refer to research showing that “some ingredients” of “muscle-building supplements” can cause damage to the testicles [5,6]. At least indirectly. They refer to one study showing that long-term creatine use in mice can lead to increased levels of formaldehyde [5]. They link this to another study showing that increased levels of formaldehyde offer an increased risk of damage to the testicles in rats [6].
However, there has not yet been any research that has demonstrated the actual effect of creatine on formaldehyde itself (and not its precursor) in humans.
Causes of harmful supplements
The researchers refer to studies showing that harmful supplements sometimes contain ingredients that should not be there. I have already written about this, but based on these studies, I will devote separate attention to it again. Taking this into account, it may not be the creatine, protein, or even androstenedione that would cause a higher risk of testicular cancer, but something else that you didn’t know you were ingesting.
However, there are also other possible reasons why testicular cancer is more common nowadays. A link has already been made between cannabis use and an increased risk of testicular cancer by as much as 70% [7]. Although the researchers at Yale did ask about smoking and drinking, I read nothing about excluding possible cannabis use, let alone testing for it to account for lying test subjects.
Conclusion: Don’t shout too quickly
The news of the Yale study was published last week on April 14 and has since been repeated in many places, with only a few exceptions without critical comment. Simply copied by media outlets looking to score quickly with sensational headlines.
The study is based on assumptions by possibly incorrectly linking various studies. Moreover, due to the design of the study itself, there are too many variables, both known and unknown, making it impossible to link specific causes to specific consequences. The most important of these is the possible use of substances other than those mentioned in the list, such as anabolic steroids and growth hormone.
Of course, attention is focused on a possible connection, and further research is always welcome, but my pots of protein and creatine will not be thrown in the trash for the time being.
References
- N. Li et al. Muscle-building supplement use and increased risk of testicular germ cell cancer in men from Connecticut and Massachusetts.British Journal of Cancer (2015) 112, 1247–1250 | doi: 10.1038/bjc.2015.26
- Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray F (2012) GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. International Agency for Research on Cancer: Lyon, France, Available from http://globocan.iarc.fr. Accessed March 2014.
- cijfersoverkanker.nl: Ferguson L, Agoulnik AI (2013) Testicular cancer and cryptorchidism. Front Endocrinol 4: 32.
- Ferguson L, Agoulnik AI (2013) Testicular cancer and cryptorchidism. Front Endocrinol 4: 32.
- Yu PH, Deng Y (2000) Potential cytotoxic effect of chronic administration of creatine, a nutrition supplement to augment athletic performance. Med Hypotheses 54(5): 726–728
- Han SP, Zhou DX, Lin P, Qin Z, An L, Zheng LR, Lei L (2013) Formaldehyde exposure induces autophagy in testicular tissues of adult male rats.Environ Toxicol; doi:10.1002/tox.21910.
- Kristin Woodward. Marijuana use linked to increased risk of testicular cancer. the Cancer paper February 9
