One of the most important and effective antioxidants in the human body is glutathione (GHS).
It can be found in fungi, animals, plants and some bacteria and prevents oxidative damage caused by reactive oxygen molecules. A non-essential nutrient, the body is able to produce glutathione itself.
Glutathione relies on the availability of the amino acids cysteine, glycine and glutamic acid for synthesis. For that reason, it is known as a tripeptide.
Cysteine is often the limiting factor in cellular glutathione synthesis as this amino acid is typically scarce in food sources.
Glutathione plays a key role in many important physiological processes. It is needed for tissue repair and building, enzymatic reactions and immune function.
Male infertility and glutathione
Human spermatozoa are encased in a membrane of polyunsaturated fatty acids. These acids are highly susceptible to oxidative stress as a result of lipid peroxidation. This free radical damage can significantly degrade the sperm membrane.
As a result, sperm motility decreases and abnormal sperm morphology increases. This results in a reduction in oocyte (female egg) penetration capacity and, consequently, overall statistical fertility.
The sperm glutathione “shield”
Consequently, spermatozoa and seminal plasma contain several antioxidant enzymes. These include glutathione reductase, glutathione peroxidase, and superoxide dismutase. These protect the sperm cell from the inside.
The pathogenesis of male infertility is thought to be influenced by imbalances between antioxidant defence and pro-oxidative stress. There has been a lot of research into the relationship between glutathione and male infertility.
Clinical Study: The Role of Glutathione in male infertility
In 2011, Naher et al. published their research evaluating a correlation between infertility and glutathione levels1.
Thirty-one infertile males and thirty fertile males of similar age participated in the study. Medical history was collected and a comprehensive semen analysis performed for each participant. To determine antioxidant capacity, seminal plasma and erythrocyte glutathione concentrations were measured.
This study found:
- Sperm count and semen volume was significantly reduced (p<0.001) in the infertile group compared with the control group.
- The percentage of men with abnormal sperm motility and morphology was higher in infertile males compared with fertile males.
- There was little deviation in the median erythrocyte glutathione levels between the two groups. However, glutathione concentrations within seminal plasma were significantly suppressed (1.64 (0.23-7.50)) within the infertile group compared with the control group (4.26 (2.32-7.50)) mg/dl (p<0.001).
This study has shown that low seminal plasma glutathione levels are associated with abnormal values for sperm concentration, semen volume, and sperm motility and morphology. Higher levels of seminal plasma glutathione corresponded with healthy, fertile men in this study.
The research therefore suggests that the concentration of glutathione in seminal plasma may impact male fertility.
Clinical Study: Glutathione, stress and fertility
A study published in 2005 highlighted the negative influence stress has on male fertility and seminal glutathione2. Thirty-four healthy medical students participated in this study.
Semen samples were collected during the fourth trimester, 3 weeks prior to their final examinations (stress period) and three months after the exams (non-stress period). Researchers measured standard semen parameters, as well as the concentration of glutathione within seminal plasma.
The study found:
- In the period leading up to exams, seminal plasma glutathione levels were low and sperm motility was reduced.
- The percentage of abnormal sperm was higher in samples collected during the stress period, compared with the non-stress period.
This study has shown that during periods of examination stress, seminal plasma glutathione concentrations decline. There is also a corresponding reduction in sperm quality.
During periods of stress, free radical activity increases. This may lead to a depletion of glutathione as it works to minimise oxidative stress, leaving spermatozoa vulnerable to damage.
Clinical Study: Glutathione and sperm motility
There are several studies investigating the effects of glutathione supplementation of male fertility. In one study, men suffering from subfertility as a result of germ-free genital tract inflammation (INF) or unilateral varicocele (VAR) were administered glutathione3.
Twenty men participated in the placebo-controlled double-blind cross-over trial. They either received a placebo or 600 mg of glutathione daily over a period of two months, and then crossed over to the alternative treatment. Before and during the trial, standard semen analysis was performed.
The study found:
- Men receiving glutathione treatment demonstrated statistically significant improvements in sperm motility compared with the control group. The percentage of forward motility was particularly enhanced.
The research suggests that glutathione therapy may be helpful for improving fertility in men suffering from INF and VAR. These results may also have wider implications as a deficiency in glutathione causes the sperm mid-piece to become unstable. This causes defective motility and morphology, ultimately lowering fertility. Based on this evidence, glutathione is necessary to support healthy fertility in all men.
Sources of glutathione
To boost glutathione levels it’s important to eat food rich in the amino acid cysteine. Good sources include broccoli, cabbage, cauliflower, brussels sprouts, avocados, peaches, watermelon, tomatoes, peas, garlic, and onions.
Glutathione can also be taken as supplement. During digestion, glutathione is mostly broken down into its amino acids building-blocks4. Nutritional experts therefore often recommend taking the limiting factor L-Cysteine (or N-Acetyl-l-cysteine) in combination with glutathione itself.
Glutathione is a very powerful antioxidant and essential for protecting the body. There is a clear link between low seminal plasma glutathione levels and abnormal sperm parameters. Preliminary research suggests that glutathione supplementation may help to elevate male fertility by protecting spermatozoa. More clinical trials are necessary.
Using Glutathione for sperm motility and DNA protection
Glutathione is a powerful male fertility enhancing nutrient, but it is also just one of several so called fertility-neutraceuticals. While it positively affects sperm motility and overall fertility, it does not enhance other key parameters such as morphology and sperm count.
Clinical research studies have consistently shown that
We have therefore compared 18 male fertility combination supplements in a transparent, side-by-side evaluation.
VIDEO: How to improve sperm naturally with food
Sperm motility-enhancing male fertility nutrients
- “Naher, Z. et.al. (2011). Role of glutathione in male infertility. Bangladesh Journal of Medical Biochemistry, Volume 4, Issue 2, (pp. 20-25).” ↩
- “Eskiocak, S., et al. (2005). Glutathione and free sulphydryl content of seminal plasma in healthy medical students during and after, Human Reproduction, Volume 20, Issue 9, (pp. 2295-600.” ↩
- “Lenzi, A. et.al (1993). Placebo-controlled, double-blind, cross-over trial of glutathione therapy in male infertility. Human Reproduction, Volume 8, Issue 10, (pp. 1657-67).” ↩
- “Hagen TM, Wierzbicka GT, Sillau AH, et al. Fate of dietary glutathione: disposition in the gastrointestinal tract. Am J Physiology 1990;259(4Pt1):G530-5)” ↩
- “http://humupd.oxfordjournals.org/content/14/3/243.full” ↩
- “Imhof, Martin et al., “Improvement of sperm quality after micronutritient supplementation” ↩