The rise of male infertility
In 2015 Agarwal and collages published a review of global male fertility trends. The study was based on meta-analyses, systematic reviews, and population-based studies. Researchers estimate that across the world 30 million men are infertile, with Eastern Europe and Africa reporting the highest rates1. Male infertility is continuing to rise and scientists are investigating many interventions to turn the tide and improve reproductive vigor.
Research into tomatoes and male fertility
The UK is about to launch a new study looking at tomatoes and male fertility. These fruits are enriched with a compound called lycopene. A bright red carotene, this compound can also be found in other fruits and vegetables such as watermelon, papaya and carrots.
During this new twelve week trial, scientists based at the University of Sheffield will be attempting to determine if elevating lycopene levels can improve the quality of sperm. The researchers are particularly interested to see if this compound will decrease DNA damage to developing sperm. Also of interest is determining if lycopene supplementation will enhance mature sperm count.
What we know about lycopene
This compound is not an essential nutrient for humans. However, it is widely consumed due to its high concentration within tomatoes. The body actually produces its own lycopene. This pigment is concentrated in the liver, blood, lungs, prostate, adrenal glands, colon, skin and prostate.
Lycopene has attracted the attention of research scientists due to its antioxidant effects. There have been many studies investigating the benefits of this compound in the prevention and therapy of certain cancers. Prostate cancer in particular may respond to lycopene treatment2, 3.
There is also some evidence that lung, stomach, colon, breast, cervix, and pancreas cancers may also benefit from this compound4. Other studies have indicated the lycopene may help to minimise low density lipoprotein (LDL) oxidation and subsequently reduce the risk of atherosclerosis and coronary heart disease5, 6, 7.
However, more research and human-based clinical trials are necessary to back the findings of epidemiological studies.
Lycopene antioxidant activity
This pigment has been shown to have high levels of reactive oxygen species (ROS) scavenging activity8. This enables lycopene to stop lipid peroxidation and DNA damage.
Furthermore, this compound activates the antioxidant response element transcription system. This processes triggers the release of enzymes that make up the cellular antioxidant defense systems to further boost immune function.
Studies show that the combination of lycopene, beta-carotene, vitamin E, and lutein provides synergistic antioxidant activity9. This combination elevates immune function with each compound more effective than if acting alone. Lycopene and vitamin E are particularly effective together.
Given that tomatoes contain high concentrations of these nutrients it’s possible that this synergy of compounds is responsible for the observed findings in epidemiological studies. Lycopene itself may not sufficient to explain the positive health benefits associated with tomato consumption. This is another reason why more research is necessary.
Antioxidants and sperm health
Antioxidants have been proven to be very important for male fertility. They help to protect developing sperm from free radical damage and possible DNA damage. Numerous studies have found that antioxidants can elevate sperm count, motility and concentration.
Lycopene and male fertility
As lycopene is a known antioxidant with powerful free radical scavenging ability it stands to reason that this compound can help to enhance sperm health. However, how effective it is still needs to be determined.
Is lycopene supplementation alone enough to boost sperm quality? How important are tomatoes for male fertility? These are just couple of the questions that this new study investigating tomatoes, lycopene and male fertility will hopefully help to answer. In the meantime, men should continue to include tomatoes in their diet and the whole body can benefit from their high antioxidant content.
- Agarwal, A et al (2015). A unique view on male infertility around the globe. Reproductive Biology and Endocrinology. Volume 13, Issue 37 doi 10.1186/s12958-015-0032-1.” ↩
- “Chen, J et al. (2013). Lycopene/tomato consumption and the risk of prostate cancer: a systematic review and meta-analysis of prospective studies. Journal of Nutritional Science and Vitaminology. Volume 59, Issue 3, (pp. 213-13)” ↩
- Zu, K et al. (2014). Dietary lycopene, angiogenesis, and prostate cancer: a prospective study in the prostate-specific antigen era. Journal of the National Cancer Institute. Volume 106, Issue 2, doi 10.1093/jnci/djt430.” ↩
- “Giovannucci, E. (1999). Tomatoes, Tomato-Based Products, Lycopene, and Cancer: Review of the Epidemiologic Literature. Journal of the National Cancer Institute. Volume 91, Issue 4, (pp. 317-31).” ↩
- “Agarwal S and Rao, A (1998). Tomato lycopene and low density lipoprotein oxidation: A human dietary intervention study. Lipids. Volume 33, Issue 10, (pp. 981-8).” ↩
- Rissanen, T. et al (2002). Lycopene, Atherosclerosis, and Coronary Heart Disease. Experimental Biology & Medicine. Volume 227, Issue 10, (pp. 900-7).” ↩
- Rissanen, T. et al (2003). Serum lycopene concentrations and carotid atherosclerosis: the Kuopio Ischaemic Heart Disease Risk Factor Study. The American Journal of Clinical Nutrition. Volume 77, Issue 1, (pp. 133-38).” ↩
- Kelkel, M et al (2011). Antioxidant and anti-proliferative properties of lycopene. Free Radical Research. Volume 45, Issue 8, (pp. 925-40).” ↩
- Shi, J et al (2004). Antioxidative properties of lycopene and other carotenoids from tomatoes: synergistic effects. Biofactors. Volume 21, Issue 1-4, (pp. 203-10).” ↩