Sperm quality relies on the presence of several nutrients

Poor sperm quality, which is a bit of a taboo, is one of the main causes of involuntary infertility. Evidence suggests that Western diets can impair sperm quality, whereas the Mediterranean diet does the opposite. Vegan diets are somewhat controversial, according to a review article published in International Journal of Molecular Sciences. Previous research has shown that supplementation with selenium, zinc, fish oil, and coenzyme Q10 can improve sperm cell quality.

Men’s sperm quality has plummeted in the past decades and it is a worldwide problem. Poor sperm quality is a result of reduced sperm cell production and impaired sperm cell motility. Moreover, sperm cells may be increasingly vulnerable towards oxidative stress that can destroy the sperm cells’ DNA. This is known as DNA fragmentation and is the reason why a fertilized egg cell fails to develop and is eventually rejected. Low levels of male testosterone are also a factor. Although the diet is known to affect the quality of sperm cells, we still lack knowledge about the different biochemical mechanisms that are involved.
The aim of the new review article was to take a closer look at this.
It appears that Western diets, which contain high amounts of refined carbohydrates, animal protein, omega-6 fatty acids, and trans-fatty acids at the same time as lacking fiber, omega-3 fatty acids, and antioxidants, can increase the risk of type 2 diabetes, cancer, and impaired fertility. On the other hand, Mediterranean diets with their high content of beans, vegetables, fruit, nuts, fish, olive oil and smaller amounts of meat and dairy products – plus a little red wine – can improve sperm quality by influencing different parameters.
The study authors looked specifically at how consuming too much omega-6 (especially from plant oils, margarine, and junk-food) and too little omega-3 (mainly from fish) has a negative effect on sperm quality. This same is the case with a lack of dietary antioxidants (especially from vegetables, fruit, and fish) because they help protect against oxidative stress where free radicals attack sperm cells and their DNA.
Another thing to be aware of is that a purely plant-based vegan diet does not contain vitamin B12. It is also difficult to get enough iron, selenium, and zinc with such a diet and that can also affect sperm quality. Moreover, many people have difficulty with utilizing the form of omega-3 called ALA (alpha-linolenic acid) and converting it into the biologically active forms of omega-3 called EPA and DHA (which are found in fish).

Did you know that Danish, Norwegian, and German men have the poorest sperm quality in Europe?

Nutritional supplements can improve sperm cell quality

Scientists from the University of Guadalajara in Mexico have studied the results of 28 large nutritional studies and found that supplementation with selenium, zinc, omega-3, and coenzyme Q10 is associated with improved sperm cell quality. Also, supplements of selenium, omega-3, and coenzyme Q10 help to prevent misshapen sperm cells.

How do selenium and Q10 increase sperm cell motility?

Right after ejaculation, the sperm cells race each other to be the first to reach the egg in the fallopian tube. The active sperm cells need a lot of Q10 to fuel the cellular energy production. The sperm cells also need various selenium-dependent enzymes (selenoproteins) to fuel the whip-like motion of the tail piece that enables forward propulsion.

How can selenium and zinc protect sperm cells and their DNA?

Modern living is typically associated with too much stress, lack of sleep, and being exposed to smoke and other environmental toxins. This increases the risk of oxidative stress, which is an imbalance between harmful free radicals and protective antioxidants.
Both selenium and zinc are important antioxidants that protect against DNA fragmentation in the sperm cells caused by free radicals. As mentioned earlier, damaged sperm cell DNA may result in the failure of an egg to develop.

• Around one billion people globally are believed to lack selenium and zinc

How do selenium and zinc affect testicles and testosterone levels?

Testicles are glands that produce sperm cells and the male sex hormone, testosterone. Selenium and zinc are involved in a host of different enzyme functions that are of importance to testicular function. Blood levels of selenium and zinc are therefore related to testosterone levels. It has been found that men with poor sperm quality have significantly lower levels of selenium and zinc in their blood compared with fertile men. This was shown in a study from a Nigerian fertility clinic. The study is published in African Journal of Medical Sciences.

• Were you aware that Danish farmers for decades have supplemented their livestock with selenium to prevent fertility problems and other deficiency diseases?

Why do so many people lack the mentioned nutrients?

The agricultural soil in Europe and many other parts of the world is low in selenium and this is reflected throughout the entire food chain. For that reason, it can be challenging to get enough selenium, even if you eat a healthy and balanced diet. Zinc deficiency can be a result of poor eating habits and excessive alcohol intake. In addition, consuming too much iron and calcium, having low stomach acid, and using antacids can block the uptake of zinc in the body.
Oily fish contain the biologically active omega-3 types, EPA and DHA. If you don’t eat oily fish or only eat very little, you risk not getting enough omega-3. It is also worth mentioning that farmed fish typically contain less omega-3 because of the unnatural fodder they are given.
We humans are able to synthesize our own Q10, but our endogenous Q10 synthesis decreases as we grow older. What is more, cholesterol-lowering statins inhibit the body’s Q10 synthesis.
When you choose nutritional supplements to support fertility and healthy sperm cells, always make sure to but high-quality products that the body can absorb and utilize.

Important note: Sperm quality may also be impaired by wearing tight trousers that can raise the temperature in the scrotum. This is also the case with prolonged laptop use.

References:

Alessandra Ferramosca and Vincenzo Zara. Diet and Male Fertility: The Impact of Nutrients and antioxidants on Sperm Energetic Metabolism. International Journal of Molecular Sciences. 2022

Salas-Huetos a et al. The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-analysis of Randomized Clinical Trials. Advances in Nutrition. 2018

Menezo Yj et al. Antioxidants to reduce sperm DNA fragmentation: an unexpected side effect. Reprod Biomed Online 2017

Oluboya AO el al. Relationship between serum levels of testosterone, zinc and selenium in infertile males attending fertility Nnewi, south East Nigeria. African Journal of Medical Sciences. 2012

Christensen BT et al. Selenanvendelse i dansk landbrug. Rapport fra DJF 2006. Videncentret for landbrug.

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