What are Antioxidants and How Do They Affect Sperm Quality?

By (gynecologist), BSc, MSc (embryologist), BSc, MSc (embryologist) and (invitra staff).
Last Update: 04/22/2020

Antioxidants are the molecules responsible for preventing oxidation and aging of the cells in our body.

Also, antioxidants play a fundamental role in male fertility, as they contribute to good seminal quality.

The human body has complex systems of antioxidants, but these can also be consumed in the diet, especially with the intake of fruits and vegetables.

Oxidative stress on sperm

Reactive Oxygen Species (ROS) are a type of molecules that occur naturally in the body as a result of normal oxygen metabolism. ROS play an important role in cell signaling and are therefore necessary for basic cell functions.

However, a significant increase in ROS in the body can cause significant damage to cellular structures, leading to a situation known as oxidative stress.

As for the effect of this oxidative stress on fertility, several studies have shown that between 30 and 80% of male sterility problems are caused by the presence of ROS in semen.

In particular, there are two molecules that most affect sperm development and quality:

Free radicals
highly unstable chemical species capable of damaging cell structures.
Active oxygen
is the most oxidizing substance in our body, so it oxidizes the cells causing cellular aging.

The consequences of oxidative stress on sperm quality are as follows:

  • Sperm DNA fragmentation
  • Alterations in the spermatic membrane.
  • Decreased sperm mobility that can lead to asthenozoospermia.
  • Defects in the shape of the sperm that can lead to teratozoospermia.
  • Difficulty for the sperm to interact with the egg and fertilize it.

Because of this, it is quite common to find an excess of free radicals in males suffering from infertility.


Several factors contribute to increase the level of ROS in the body and therefore affect the quality of the semen in the case of males:

Lifestyle factors
consumption of alcohol, tobacco or following a diet rich in refined vegetable fats and oils. In smokers, the antioxidant capacity in the blood is reduced by half compared to non-smokers.
Environmental factors
excessive exposure to solar radiation and environmental pollution.
Health state
some infections, autoimmune and/or chronic diseases, etc..

On the other hand, the harmful effect of ROS will also depend on the dose and time of exposure.


Antioxidants are natural substances with the ability to delay or prevent cell damage caused by oxidative stress by counteracting the effect of reactive oxygen species.

The human body has different antioxidative systems such as the following enzymes and molecules: glutathione peroxidase, superoxide dismutase, coenzyme Q, uric acid, etc.

Besides, there are other exogenous antioxidants that we acquire with food, among which we highlight the vitamins and flavonoids.

As for the antioxidants that can be found in semen and which are responsible for protecting the sperm, these include vitamins C and E, the enzyme superoxide dismutase, glutathione, and thioredoxin.

Numerous studies have shown that men with infertility have a lower concentration of these antioxidants in their semen, which would increase oxidative stress and poor semen quality.

In nutrition

Eating foods rich in antioxidants can be an advantage for these infertile males and help improve sperm quality.

Below, we will detail the main antioxidants for male fertility and their most important sources:

in carrots, spinach, lettuce, kale, pumpkins, etc.
in tomatoes, watermelon, papayas, grapes, etc.
Vitamine A
in dairy, egg, carrots, mango, liver, etc
Vitamine C
in citrus fruits, cereals, fish, etc.
Vitamine E
in nuts, seeds, virgin olive oil, broccoli, etc.
in blackberries, raspberries, cherries, soya, chocolate, oregano, tea, coffee, red wine, etc.

Also, elements such as selenium, zinc, or manganese are very important in the diet because they enhance the action of antioxidants.

In dietary supplements

In addition to the above, it is also possible to supplement the diet with antioxidants to reduce oxidative stress in men and thus improve their seminal quality.

These are nutritional complexes containing these vitamins and minerals, which can be purchased at the pharmacy.

However, it is recommended that there be medical supervision of the consumption of these drugs since an excess of vitamins could also be harmful.

Some of these antioxidant supplements are:

Complexes with Andean maca
Maca is a Peruvian plant with properties that increase fertility and improve libido. It can be consumed as an infusion, in capsules or in powder form./dd>

contains carnitines and antioxidants such as coenzyme Q10, zinc, folic acid, selenium, vitamin B12, vitamin C and vitamin E

has a high content of DHA, a fatty acid of the Omega-3 family, in addition to other antioxidants such as folic acid, vitamins C and E, and minerals such as selenium and zinc.

Normally, between 3 and 6 months of treatment with one of these compounds, some improvement could already be seen in seminal parameters such as concentration, motility, and morphology of the spermatozoa.

FAQs from users

How do antioxidants help male fertility?

By Dr. Mónica Aura Masip (gynecologist).

Oxidative stress is an imbalance in the cellular environment, produced by toxic factors that surround us and that are especially aggressive to sperm. It can affect sperm in several ways: their development throughout their evolution, their morphology, their ability to move (motility), and their fertile capacity since it damages their DNA. This explains the sperm damage.

Antioxidants are substances, essentially natural products, that we find in our food and try to rebalance the balance of sperm metabolism between free radicals (oxidative stress) and antioxidants in the body (the body's ability to combat them), increasing the latter and repairing the damage caused.

Multiple studies have shown that antioxidants (L-Carnitine, Coenzyme Q10, Vitamin E, Vitamin C, Selenium, Zinc) produce an increase in both the number of spermatozoa and their mobility.

In spite of all this, the effectiveness of antioxidants is only given by correct diagnosis and an adequate therapeutic guideline when faced with a certain process of infertility.

Does garlic help improve sperm motility?

By Zaira Salvador BSc, MSc (embryologist).

Garlic is a powerful antioxidant food since it is rich in vitamins A, B, and C, selenium, phosphorus, silicon, sulfur, zinc, copper, potassium, etc. Therefore, it does contribute to reducing oxidative stress in the spermatozoa and to improving both their mobility and their concentration and morphology.

Also, garlic has antibiotic, anti-cancer, and skin-regenerative properties.

Do antioxidants also improve female fertility?

By Zaira Salvador BSc, MSc (embryologist).

Indeed, a healthy diet rich in fruits and vegetables and the contribution of antioxidant substances can help to have a better ovarian response, as well as prevent the aging of the ovaries.

Vitamin C improves hormone levels and a balanced level of vitamin E prevents miscarriage.

Read more about this topic here: Benefitial foods to boost female fertility.

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Authors and contributors

Dr. Mónica  Aura Masip
Dr. Mónica Aura Masip
Dr. Mónica Aura has a degree in Medicine and General Surgery from the Autonomous University of Barcelona (UAB). She is also a specialist in Gynecology and Obstetrics from the Hospital de Santa Creu y Sant Pau and has a Master's degree in Human Assisted Reproduction from the University Juan Carlos I of Madrid and another in Health Center Management from the UB. More information about Dr. Mónica Aura Masip
Licence number: 31588
 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
 Zaira Salvador
Zaira Salvador
BSc, MSc
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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