Male Fertility: What the Research Really Says

by Kate Morton June 12, 2025

When people talk about fertility and getting pregnant, the focus often falls on women’s health. That makes sense, since pregnancy happens inside the body of the person who carries the baby. But it’s important to remember: male factors contribute to nearly half of all infertility cases. Male fertility—specifically, sperm health—is a crucial part of conception and pregnancy outcomes.

The good news? Research shows there are many proven ways men can support sperm health and fertility through lifestyle and diet. Many of these changes also boost overall health, energy, and wellbeing. This blog will explain the science behind male fertility, the factors that impact sperm health, and practical, approachable steps men can take to improve their chances of conception.

Whether you’re just starting to think about growing your family or have been trying for some time, this guide will empower you with the latest evidence without judgment or pressure.

Why Does Male Fertility Matter?

Sperm aren’t just tiny cells that swim to the egg—they carry the genetic blueprint for half of your child. Healthy sperm have several important qualities: concentration (how many sperm are present in each milliliter of semen), motility (how well the sperm move and swim), morphology (the shape and structure of sperm cells), and DNA integrity (the stability and damage level of the genetic material inside sperm).

When these qualities are compromised, it can lead to:

Longer time to achieve pregnancy
Increased risk of miscarriage
Greater chances of pregnancy complications such as preeclampsia and gestational diabetes (research suggests sperm quality influences early placental development)
Challenges with assisted reproductive technologies (e.g., IVF success rates)

In fact, male factors are estimated to contribute to 40–50% of infertility cases globally.

What Influences Male Fertility?

Male fertility is influenced by many factors, including genetics, age, medical conditions, and lifestyle/environmental factors. While some elements like age and genetics can’t be changed, many lifestyle factors are modifiable.

Nutrition and Diet

Your diet fuels the production of sperm, which develop over approximately 2.5 to 3 months. Eating patterns rich in antioxidants, vitamins, and minerals help protect sperm from oxidative stress (damage caused by free radicals) and support healthy sperm formation.

Research consistently shows:

Men following a Mediterranean-style diet—rich in fruits, vegetables, whole grains, nuts, fish, and healthy fats—have better sperm concentration, motility, and morphology.
Diets high in processed meats, refined carbohydrates, trans fats, and added sugars are linked to poorer semen quality.

Key nutrients for sperm health include:

Zinc: Supports sperm production, motility, and testosterone levels. Food sources: pumpkin seeds, lentils, oysters, beef.
Folate: Crucial for DNA synthesis and lowers DNA fragmentation. Food sources: leafy greens, beans, fortified cereals.
Coenzyme Q10: An antioxidant that improves sperm motility and energy. Food sources: fatty fish, organ meats, supplements.
Selenium: Protects sperm from oxidative damage. Food sources: Brazil nuts, tuna, sunflower seeds.
Omega-3 fatty acids: Improves sperm morphology and motility. Food sources: salmon, walnuts, flaxseeds.
Vitamins C & E: Antioxidants that protect sperm DNA from damage. Food sources: berries, citrus fruits, almonds, spinach.

Simple dietary tips:

Include colorful fruits and vegetables daily for antioxidants.
Choose fatty fish like salmon or sardines 2–3 times per week.
Snack on nuts and seeds for selenium and zinc.
Limit processed and fast foods, sugary drinks, and trans fats.

Physical Activity and Metabolic Health

Exercise supports hormone balance, reduces oxidative stress, and helps maintain a healthy weight, all of which benefit sperm health.

What the science says:

Moderate regular exercise (e.g., brisk walking, strength training) has been linked with improved sperm count and motility.
Exercise helps boost testosterone naturally, a hormone critical for sperm production.
However, very intense endurance exercise (such as marathon training) may lower testosterone and impair fertility in some men.

Practical advice:

Aim for about 150 minutes of moderate physical activity per week.
Find enjoyable ways to move—this can be walking, swimming, cycling, or light weightlifting.
Avoid overtraining or excessive long-duration endurance workouts if fertility is a concern.

Sleep and Stress Management

Both sleep quality and stress levels impact hormone levels and sperm production.

Sleep:

Studies show men who get less than 6 hours of sleep per night tend to have lower sperm counts and poorer motility.
Aim for 7–8 hours of consistent, quality sleep each night to optimize fertility.

Stress:

Chronic stress elevates cortisol and disrupts reproductive hormones like testosterone and luteinizing hormone.
Psychological stress is associated with poorer semen quality, including reduced motility and higher DNA fragmentation.

Stress reduction strategies:

Practice mindfulness, meditation, or deep breathing exercises regularly.
Prioritize downtime and hobbies that help you relax.
Talk to a mental health professional if stress or anxiety feels overwhelming.

Avoiding Harmful Exposures

Sperm cells are vulnerable to damage from environmental toxins, heat, and lifestyle choices.

Key exposures to limit or avoid:

Tobacco smoking: Causes oxidative damage and lowers sperm count and motility.
Alcohol: Excessive consumption impairs testosterone and sperm production. Moderate drinking is recommended.
Recreational drugs: Marijuana use is linked with lower sperm concentration and motility; anabolic steroids severely impair sperm production.
Heat exposure: Frequent use of hot tubs, saunas, tight underwear, or prolonged laptop use on the lap increases testicular temperature and impairs sperm quality.
Endocrine-disrupting chemicals (EDCs): Chemicals like BPA and phthalates found in some plastics and personal care products can interfere with hormone function.

Tips to reduce exposure:

Quit smoking or avoid secondhand smoke.
Drink alcohol in moderation or consider abstaining when trying to conceive.
Avoid recreational drugs, especially if fertility is a priority.
Wear loose-fitting underwear, limit hot tub use, and avoid placing laptops directly on the lap.
Use BPA-free containers, choose glass over plastic, and opt for fragrance-free personal care products.

Supplements: Helpful or Not?

Certain supplements have been shown to improve sperm quality, particularly in men with oxidative stress or low motility.

Common supplements studied include:

Coenzyme Q10 – improves motility and sperm concentration.
L-carnitine – supports energy production in sperm.
Zinc and selenium – antioxidants important for sperm structure and function.
Vitamins C and E – protect sperm DNA from oxidative damage.
N-acetylcysteine (NAC) – an antioxidant that may improve semen parameters.

Important: Always consult a healthcare provider before starting supplements, especially if undergoing fertility treatment or having medical conditions.

Addressing Underlying Medical Issues

Sometimes fertility issues arise from medical conditions that require treatment.

Common issues include:

Varicocele: Enlarged veins in the scrotum that can raise testicular temperature and impair sperm. Surgery may improve fertility.
Hormonal imbalances: Conditions like hypothyroidism or low testosterone can affect sperm production.
Infections: Sexually transmitted infections or prostatitis can negatively impact sperm quality.
Metabolic diseases: Diabetes and obesity can impair sperm function.

If you have known medical conditions or suspect fertility issues, consider consulting a reproductive urologist or fertility specialist for evaluation and personalized care.

How Long Does It Take to See Improvements?

Sperm develop through a process called spermatogenesis that takes about 72 to 90 days. This means that lifestyle changes may take about 3 months to show measurable improvements in sperm quality.

The key is consistency and patience. Making sustainable changes to diet, exercise, sleep, and exposure habits offers the best chance of improving fertility over time.

Supporting Fertility Is a Team Effort

It’s worth emphasizing that fertility is a shared journey. Partners supporting each other’s health and wellbeing can strengthen their chances of conception and foster emotional resilience.

If you and your partner are trying to conceive, consider approaching preconception health as a team effort—encouraging each other, sharing lifestyle improvements, and communicating openly about challenges.

Final Thoughts

Male fertility is an important, yet often overlooked, part of the conception process. Fortunately, sperm health is dynamic and responds well to positive lifestyle and environmental changes.

By adopting a nutritious diet rich in antioxidants and healthy fats, staying physically active without overdoing it, prioritizing quality sleep, managing stress, avoiding harmful exposures, and seeking medical care when needed, men can support optimal sperm health.

Remember, there’s no need for perfection—small, consistent steps can make a meaningful difference. Fertility is about partnership, health, and hope. Your efforts today can help create a healthier tomorrow for you and your future family.

References

Salas-Huetos A, et al. Hum Reprod Update. 2017;23(6):646–659.
Mínguez-Alarcón L, et al. Fertil Steril. 2018;109(5):889–896.
Attaman JA, et al. Fertil Steril. 2012;97(2):411–418.
Gaskins AJ, et al. Br J Sports Med. 2015;49(4):265–270.
Hackney AC, et al. Sports Med. 2005;35(9):739–753.
Liu L, et al. Sci Rep. 2016;6:24845.
Li Y, et al. Reprod Biol Endocrinol. 2011;9:47.
Sharma R, et al. Reprod Biol Endocrinol. 2016;14(1):33.
Gundersen TD, et al. Am J Epidemiol. 2015;182(6):473–481.
Patel AS, et al. Transl Androl Urol. 2016;5(6):909–916.
Ricci E, et al. Fertil Steril. 2017;107(5):1052–1057.e2.
Jung A, Schuppe HC. Andrologia. 2007;39(6):203–215.
Jurewicz J, et al. Int J Occup Med Environ Health. 2015;28(3):403–426.