Sperm and antioxidants

By BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 09/17/2015

There are two main molecules which affect both sperm production and quality. They are free radicals and active oxygen, considered to be two of the main toxic reactive oxygen species (ROS).

  • Free radicals are chemically unstable species, which can lead to cellular damage.
  • Oxygen is the most oxidizing agent of our organism; it oxidizes the cells by promoting the cell aging process.

These molecules are produced by our bodies naturally as a result of oxygen metabolism and play a crucial role in cell-signalling pathways. However, a sharp increase of such molecules may cause severe harm on cellular structures. This leads to a situation known as oxidative stress. It is estimated that between 30 and 80 per cent of male infertility cases are causes by the impact of oxidative stress on semen.

Certain habits such as alcohol consumption, order cigarette, high-fat diets, and refined vegetable oils, among others, are sources of free radicals. Many studies have proved that, among people who smoke, the antioxidant capacity of the blood fails by roughly a half if compared to non-smoking people.

Excess exposure to UV radiation and pollution may lead to a rise in the quantity of free radicals as well as the development of certain infections and autoimmune and/or chronic diseases.

Sperm DNA fragmentation

In addition to sperm concentration, motility and morphology, the degree of sperm DNA fragmentation is another parameter defining sperm quality. Studies show that high sperm DNA levels are clearly linked to a further increase in reproductive problems.

As already observed, there is a connection between the degree of sperm DNA fragmentation and an excess of free radicals or oxidants. Men suffering from infertility can see their reproductive capacity improved thanks to vitamin supplements, since they contain certain antioxidants capable of diminishing the free radical levels.


Antioxidants stand for a type of molecules that are capable of inhibiting or preventing cell oxidation.

Human body contains complex systems of multiple types of antioxidants, such as enzymes (catalese, superoxide dismutase, and peroxidase) and vitamins C, E, and A. Selenium, zinc, and manganese increase the effectiveness of these vitamins.

Natural antioxidants found in semen include vitamin C and E, superoxide dismutase, glutathione, and thioredoxin.

There are studies which show that men with fertility problems present a lower concentration of antioxidants in sperm. In such cases, they are recommended to add antioxidant supplements to their diet in order to reduce oxidative stress and, therefore, improve their sperm quality.

Antioxidants are found in garlic, brown rice, coffee, cauliflower, broccoli, ginger, parsley, onion, citrus fruits, semolina, tomatoes, grape seed oil, tea, and rosemary, among many others.

Vitamin C and carotenoids are found in fruit and vegetables; vitamin E in virgin vegetable oils; vitamin A in carrot and mango; and polyphenol antioxidants in fruit, soybean, chocolate, oregano, tea, coffee, and red wine.

Compounds containing these vitamins and minerals are sold in pharmacies. However, medical supervision is strongly recommended while taking this sort of drugs, since getting excessive amounts may be also detrimental.

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 Neus Ferrando Gilabert
Neus Ferrando Gilabert
BSc, MSc
Bachelor's Degree in Biology from the University of Valencia (UV). Postgraduate Course in Biotechnology of Human Assisted Reproduction from the Miguel Hernández University of Elche (UMH). Experience managing Embryology and Andrology Labs at Centro Médico Manzanera (Logroño, Spain). More information about Neus Ferrando Gilabert
Adapted into english by:
 Sandra Fernández
Sandra Fernández
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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