Male sub-fertility is a complex medical condition as fertility is based on a wide range of interdependent factors. There has been a steady decline in male fertility over the recent years. While there are many physiological characteristics associated with low fertility, often lifestyle factors have an important role to play.
Some causes of fertility problems include unhealthy diets, inactivity, alcohol and tobacco use, and obesity. However, dietary changes can help by elevating levels of important amino acids and nutrients associated with fertility.
Amino acids are the essential building blocks of proteins. There are 22 amino acids that are common within the human body. Some of these can be manufactured internally; while other must be externally sourced from diet.
In addition to protein synthesis, amino acids also perform a wide range of other functions within the body, some of which relate to fertility.
A recent Austrian study published in the European e-Journal of Clinical Nutrition and Metabolism has highlighted the important role that amino acids have in assisting men with sub-fertile problems1.
The study assessed changes to sperm quality in sub-fertile males following supplementation with micronutrients. Results revealed that men who took the supplement had a 215 percent improvement in the density of sperm cells, 33 percent improvement in the volume of ejaculated sperm, and a 23 percent improvement in overall sperm motility.
These figures were considerably higher than those observed within the control group. A more in-depth, randomised, double blind, placebo-controlled trial is sunsequently underway to further verify these initial findings.
Which Amino Acids Improve Fertility?
There were several key amino acids used within the Austrian study to boost fertility. These included arginine, carnitine and glutathione. All three of these amino acids can be synthesised within the body. However, at times they become conditional amino acids. This means that during periods of stress or illness the body may be unable to manufacture enough of these amino acids to support the body functions they are involved in.
This is where supplementation and diet can help to elevate amino acid levels and provide the body with the necessary boost. Arginine, carnitine and glutathione all have specific roles associated with male fertility.
This amino acid is found in high concentrations within sperm, particularly in sperm heads. It’s also the precursor in the synthesis of spermidine, putrescine and spermine. These three compounds are all important components of sperm. Although sperm may still be produced without adequate levels of arginine, their form is more likely to be abnormal. Poor sperm health will lower fertility. Arginine supplementation can help to boost healthy sperm count and improve fertility2.
Not only is arginine required to make sperm, it also plays a role in sperm motility. Research has shown that arginine stimulates forward motility through assisting with the conversion of glycol into energy, helping to enhance the chances of fertilisation3. Low concentrations of arginine can hinder motility by restricting the energy needed to propel the spermatocyte flagellum.
Arginine is also the precursor to nitric oxide (NO). This gas is a critical signalling molecule that triggers a variety of processes throughout the body. It’s particularly important in regulating blood flow and optimising circulation. This gas opens up the penile vessels and boosts blood flow to the penis to stimulate an erection. Erectile dysfunction is associated with insufficient NO4. As arginine is essential for the production of NO, it’s vital that the male body has enough of this amino acid to facilitate NO synthesis in order to support healthy erections. Studies have shown that arginine supplementation can significantly improve male sexual dysfunction and subsequently lift fertility5.
In addition to supporting fertility, arginine can help to boost overall well-being. This amino acid is very important within the immune system and can help safeguard the body against a wide range of disease. It is also important for metabolism, increasing lean muscle mass and assisting in weight loss. In order to support a healthy level of arginine it’s recommended to eat foods rich in this amino acid. Try to include whole grains, seeds, nuts, poultry, soy, dairy products, and seafood within your diet.
Produced within the kidneys and liver, carnitine is a compound synthesised from two essential amino acids, lysine and methionine. Carnitine has important antioxidant properties and is known to help protect sperm DNA and the membrane from damaged caused by free radicals6. Oxidative stress is one of the leading causes of sub-fertility in men7. Through boosting carnitine concentrations it’s possible to reduce oxidative stress and improve sperm quality8.
Also, several studies have investigated carnitine supplementation in association with sub-fertility and noted an increase in sperm concentration9, quality10 11, and motility12. The overall vitality of sperm is closely associated with carnitine due it its role in energy production. Carnitine facilitates the transportation of fatty acids into mitochondria. Thus, sperm motility can be improved with more carnitine available.
As carnitine depends upon lysine and methionine for biosynthesis, it’s important to include foods rich in these essential amino acids within your diet. Dairy products, fish and red meat are ideal sources. Vegetarians can boost lysine and methionine concentrations from seeds, pulses, legumes, whole grains, apricots, bananas, asparagus, broccoli, parsley, artichokes and collard greens; amongst other plant sources. When buying carnitine supplements, look for Carnipure, which has pharmaceutical grade quality and is more effective than the standard form carnitine tartrate.
This is one of the human body’s most powerful antioxidant. It’s biosynthesised from the amino acids glycine, glutamic acid and cysteine. It has many roles in the body, including the neutralisation of reactive oxygen compounds and free radicals, iron metabolism, nitric oxide regulation, and a wide range of other biochemical and metabolic reactions. Essentially, every system within the body is affected by the availability of glutathione, including the reproductive system.
Similar to carnitine, glutathione helps to protect sperm through reducing oxidative stress. Sub-fertile males have been shown to have lower levels of glutathione in comparison with fertile males13. Several studies have shown that glutathione supplementation has a very positive effect on sperm morphology and motility14 15. With oxidative stress such a key inhibitor of fertility, ensuring that the body has access to adequate concentrations of glutathione is essential to treat sub-fertility.
There are a variety of foods that can help boost glutathione concentrations. They include fish, red meat, poultry, watermelon, walnuts, eggs, onion, garlic, avocados, peaches, spinach, tomatoes, peas, broccoli, rice bran and Brussels sprouts.
Other Important Nutrients
While arginine, carnitine and glutathione are of vital importance to male fertility, there are also a number of other nutrients and trace elements that should be taken into consideration.
This trace element is needed to support antioxidant enzymes. When zinc is deficient, male fertility is negatively impacted16. Some good food sources for zinc include oysters, wheat germ, liver, pumpkin seeds, beef, lamb and peanuts.
Also an antioxidant, selenium is involved in spermatogensis and testicular development, as well as assisting motility. Like zinc, several studies have shown that selenium deficiencies also reduce male fertility17 18 19. Some of the best food sources for selenium are Brazil nuts, fish, sunflower seeds, poultry, mushrooms, grains, eggs, and onions.
This vitamin is known to prevent sperm agglutination (sticking or clumping together), reduce oxidative stress, and increase healthy sperm count20 21. Some of the best food sources of vitamin C include strawberries, cauliflower, broccoli, Brussels sprouts, kiwi fruit, oranges, papayas, and capsicum.
Found mainly within the mitochondria, this vitamin-like substance has been shown to improve sperm motility, sperm count and sperm morphology22. Good food sources for coenzyme Q10 include avocado, grapeseed oil, sesame seeds, spinach, chicken, beef, peanuts, olive oil and soybean oil.
Incidences of sub-fertility are on the rise. Understanding how the body supports fertility gives men an opportunity to make appropriate lifestyle adjustments. There is a growing accumulation of scientific research that supports nutrient supplementation to boost fertility.
Amino acids such as arginine, carnitine and glutathione have been shown to play an integral role in elevating sperm concentration, motility and quality. Deficiencies in these nutrients have a detrimental effect on the quality and quantity of sperm, both directly and indirectly. Other important nutrients such as coenzyme Q10, vitamin C, zinc and selenium are also needed to support healthy fertility.
Through altering diets to include foods rich in these amino acids and other important nutrients, it’s possible to address some of the common problems associated with sub-fertility, such as oxidative stress. As a result, not only should fertility improve, overall well-being and vitality will be enhanced.
- Imhof M, Lackner J, Lipovac M, Chedraui P, Riedl C. Improvement of sperm quality after micronutrient supplementation. e-SPEN Journal. 2012. 7(1): e50-e53 ↩
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- Patel AB, Srivastava S, Phadke RS, Govil G. Arginine activates glycolysis of goat epididymal spermatozoa: an NMR study. Biophysical Journal. 1998. 75(3): 1522-8 ↩
- Burnett AL. The role of nitric oxide in erectile dysfunction: implications for medical therapy. Journal of Clinical Hypertension. 2006. 8(12 Suppl 4): 53-62 ↩
- Chen J, Wollman Y, Chernichovsky T, Iaina A, Sofer M, Matzkin H. Effect of oral administration of high-dose nitric oxide donor L-arginine in men with organic erectile dysfunction: results of a double-blind, randomized, placebo-controlled study. BJU International. 1999. 83(3): 269-73 ↩
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- Tremellen K. Oxidative stress and male infertility—a clinical perspective. Human Reproduction Update. 2008. 14(3): 243-258 ↩
- Ahmed SD, Karira KA, Jagdesh, Ahsan S. Role of L-carnitine in male infertility. Journal of the Pakistan Medical Association. 2011. 61(8): 732-6 ↩
- Cavallini G, Ferraretti AP, Gianaroli L, Biagiotti G, Vitali G. Cinnoxicam and L-carnitine/acetyl-L-carnitine treatment for idiopathic and varicocele-associated oligoasthenospermia. Journal of Andrology. 2004. 25(5): 761-70 ↩
- Lenzi A, Lombardo F, Sgrò P, Salacone P, Caponecchia L, Dondero F, Gandini L. Use of carnitine therapy in selected cases of male factor infertility: a double-blind crossover trial. Fertility and Sterility. 2003. 79(2): 292-300 ↩
- Costa M, Canale D, Filicori M, D’lddio S, Lenzi A. L-carnitine in idiopathic asthenozoospermia: a multicenter study. Italian Study Group on Carnitine and Male Infertility. Andrologia. 1994. 26(3): 155-9 ↩
- Vitali G, Parente R, Melotti C. Carnitine supplementation in human idiopathic asthenospermia: clinical results. Drugs Under Experimental And Clinical Research. 1995. 21(4): 157-9 ↩
- Shamsi MB, Venkatesh S, Tanwar M, Talwar P, Sharma RK, Dhawan A, Kumar R, Gupta NP, Malhotra N, Singh N, Mittal S, Dada R. DNA integrity and semen quality in men with low seminal antioxidant levels. Mutation Research. 2009. 665(1-2): 29-36 ↩
- Tremellen K. Oxidative stress and male infertility-a clinical perspective. Human Reproduction Update. 2008. 14(3): 243-58 ↩
- Lenzi A, Culasso F, Gandini L, Lombardo F, Dondero F. Placebo-controlled, double-blind, cross-over trial of glutathione therapy in male infertility. Human Reproduction. 1993. 8(10): 1657-62 ↩
- Chia SE, Ong CN, Chua LH, Ho LM, Tay SK. Comparison of zinc concentrations in blood and seminal plasma and the various sperm parameters between fertile and infertile men. Journal of Andrology. 2000. 21(1): 53-7 ↩
- Atig F, Raffa M, Habib BA, Kerkeni A, Saad A, Ajina M. Impact of seminal trace element and glutathione levels on semen quality of Tunisian infertile men. BMC Urology. 2012. 12:6 ↩
- Keskes-Ammar L, Feki-Chakroun N, Rebai T, Sahnoun Z, Ghozzi H, Hammami S, Zghal K, Fki H, Damak J, Bahloul A. Sperm oxidative stress and the effect of an oral vitamin E and selenium supplement on semen quality in infertile men. Archives of Andrology. 2003. 49(2): 83-94 ↩
- Scott R, MacPherson A, Yates RW, Hussain B, Dixon J. The effect of oral selenium supplementation on human sperm motility. British Journal of Urology. 1998. 82(1): 76-80 ↩
- González ER. Sperm swim singly after vitamin C therapy. JAMA. 1983. 249(20): 2747-2751 ↩
- Fraga CG, Motchnik PA, Shigenaga MK, Helbock HJ, Jacob RA, Ames BN. Ascorbic acid protects against endogenous oxidative DNA damage in human sperm. Proceedings of the National Academy of Sciences of the USA. 1991. 88(24): 11003-6 ↩
- Safarinejad MR, Safarinejad S, Shafiei N, Safarinejad S. Effects of the reduced form of coenzyme Q10 (ubiquinol) on semen parameters in men with idiopathic infertility: a double-blind, placebo controlled, randomized study. Journal of Urology. 2012. 188(2): 526-31 ↩