A new study has found that an extract from green tea affects sperm quality (1).
The research, published last month in the journal Molecular Nutrition and Food Research, found that low doses of a chemical compound (epigallocatechin gallate or EGCG) which is present in green tea can improve sperm quality.
Sub-fertility among men is common, and numbers of men affected are increasing. Recent data suggests that 1 in 5 men between the ages of 18-25 now have fertility problems linked to semen quality (2). In around 50% of cases, the cause of male subfertility is unknown, and in such cases nutritional and lifestyle measures are often recommended as a means of boosting sperm quality.
In this recent study, researchers exposed human sperm samples to a range of concentrations of EGCG, a chemical compound present in green tea. Results showed that, at low concentrations, EGCG was associated with increased sperm motility, viability, and phosphorylation of proteins controlling cell survival.
The aim of the study was to find out whether the extract from green tea increased the sperm’s ability to fertilize an egg by improving a process called ‘capacitation’. Capacitation is simply a series of biological processes needed to ‘activate’ the sperm so that it can fertilise the waiting egg.
At low and medium doses, the results were positive. The researchers reported that “depending on the used concentration, ECGC/estrogen receptors are able to improve fertilization potential of the human male gamete, evidencing the specific effects on motility, viability and energy expenditure in human sperm”.
In short, the sperm treated with ECGG helped sperm to swim well. It also increased the number of living sperm, and supported essential signalling inside the sperm.
At very high concentrations, ECGC had the opposite effect. Such results highlight the need for further research in this area.
There is in fact a growing amount of research surrounding the potential benefits of nutrients in boosting male fertility, with previous studies assessing the effectiveness of nutrients such as l-carnitine and coenzyme Q10.
Previous studies support the value of antioxidants in boosting male fertility (3). The high antioxidant value of green tea is well known, and this characteristic may therefore play a role in its fertility-boosting potential. Sperm damage is thought to occur when highly reactive particles called free radicals circulate in the body, causing damage to sperm cells.
This damage may reduce fertility by lowering sperm counts or reducing the sperm's ability to fertilise an egg. For this reason, antioxidants, which fight those free radicals, are thought to be helpful.
Further controlled trials are certainly needed to provide solid guidelines on the benefits of nutrients in treating male fertility.
My feeling is that further research will serve to confirm the crucial role for diet and lifestyle in this area. The European Science Foundation recently reported new figures showing a rapid increase in male reproductive disorders. This indicates that these fertility issues are caused by environmental factors or changes in our lifestyle rather than genetic factors, meaning that they may be entirely preventable with a natural approach focussing on nutrition and lifestyle.
References 1.De Amicis et al (2012) Epigallocatechin gallate affects survival and metabolism of human sperm Mol Nutr Food Res Nov;56(11):1655-64. 2. Male Reproductive Health – Its impacts in relation to general wellbeing and low European fertility rates. ESF Science Policy Briefing 40, October 2010 3. Showell et al (2011) Antioxidants for male subfertility. Cochrane Database Syst Rev. Jan 19;(1):CD007411