Sperm quality – what affects and how to improve it?

What Does Good Sperm Quality Mean?

Sperm quality is an umbrella term that includes several different factors. When we talk about sperm quality, we generally mean a combination of:

• Sperm concentration: The number of sperm per milliliter of semen. The normal value is at least 15 million sperm per milliliter, but higher concentrations generally increase the chances of fertilization.
• Motility: The sperm’s ability to move. At least 40% of the sperm should be motile, and ideally at least 32% should have progressive motility — meaning they swim forward in a straight line.
• Volume: The amount of semen released during ejaculation, which is normally at least 1.5 milliliters. Too little fluid can affect the sperm’s ability to travel through the reproductive system.
• DNA integrity: The degree of DNA damage within the sperm.

What Affects Sperm Quality?

Sperm quality is influenced by a range of factors — some are modifiable, while others are fixed. Here are the most important ones:

Age

Although men produce sperm throughout their entire lives, the quality gradually declines with age. After age 35, a slow decrease begins, and after age 50 the change becomes more noticeable. Older men generally have lower sperm concentration, reduced motility, and increased DNA fragmentation in their sperm. This not only affects the chance of achieving a pregnancy but also the risk of miscarriage and certain genetic conditions in the child.

Lifestyle factors that affect sperm quality

• Smoking: Smoking is one of the most harmful factors for sperm quality. Studies consistently show that smokers have lower sperm concentration, poorer motility, and a higher number of abnormal sperm compared to non-smokers. Passive smoking can also have negative effects.
• Alcohol: High alcohol consumption affects testosterone production and can lead to reduced sperm concentration and impaired quality. Moderate consumption appears to have less impact, but caution is recommended when trying to conceive.
• Drugs: Drugs — particularly anabolic steroids, marijuana, and other illegal substances — have well-documented negative effects on sperm production. Anabolic steroids can even cause temporary or permanent infertility.
• Overweight: Being overweight or obese affects hormonal balance and can lead to lower testosterone levels, which in turn negatively impacts sperm production and quality.
• Stress: Stress is often underestimated. Chronic stress raises cortisol levels, which can disrupt hormonal balance and affect both sperm production and sexual function.

Temperature and overheating

The testicles are located outside the body for a reason — sperm production requires a temperature a few degrees lower than normal body temperature. Anything that increases the temperature in the scrotum can negatively affect sperm quality:

• Tight underwear or trousers that push the testicles close to the body
• Long periods of sitting, especially with a laptop on the lap
• Hot baths and saunas (particularly regularly or for prolonged periods)

Certain work environments with heat exposure

The effect is often temporary — sperm can recover once the overheating stops, but this takes time since it takes about three months for new sperm to fully mature.

Environmental factors affecting sperm quality

Exposure to certain chemicals and environmental toxins can affect sperm quality. This includes pesticides, solvents, heavy metals (such as lead and mercury), and certain plastic chemicals like phthalates and BPA. Men who work in industry, agriculture, or with chemicals should be extra careful with protective equipment.

Medications affecting sperm quality

Some medications can influence sperm production, including calcium channel blockers, certain antidepressants, and chemotherapy. Chronic conditions such as diabetes, high blood pressure, and certain autoimmune diseases can also affect fertility. Infections of the testicles or epididymis, especially if left untreated, can lead to long-term problems.

Tips for Improving Sperm Quality

Sperm quality can often be improved through lifestyle changes. Since new sperm are produced continuously, improvements can be noticeable relatively quickly — often within 2–3 months.

Tip 1: Diet and Nutrition

A nutrient-rich diet is fundamental for good sperm quality. Focus on:

• Antioxidants that protect sperm from damage. Find them in berries (especially blueberries), nuts (walnuts are particularly beneficial), leafy green vegetables, tomatoes, and dark chocolate.
• Omega-3 fatty acids from fatty fish such as salmon, mackerel, and herring, or from flaxseed and walnuts. Omega-3s improve sperm membrane flexibility and motility.
• Zinc, which is essential for testosterone production and sperm quality. Good sources include oysters, meat, legumes, pumpkin seeds, and whole grains.
• Selenium, another important mineral that acts as an antioxidant. Brazil nuts are an excellent source — just a few nuts per day are enough.
• Folic acid and B vitamins, which are important for DNA synthesis and cell growth. These can be found in leafy greens, legumes, citrus fruits, and whole grain products.
• Vitamin D, which has been shown to have a positive effect on sperm quality. Sunlight is the best source, but supplements may be appropriate during the winter months.

Tip 2: Physical Activity

Regular exercise improves both overall health and sperm quality. Moderate training 3–5 times per week is ideal. Focus on a mix of cardiovascular exercise and strength training, but avoid overtraining, which can have the opposite effect. Studies show that men who exercise moderately have better sperm quality than those who train very intensively or are sedentary.

Tip 3: Sleep and Recovery

Adequate sleep is essential for hormonal balance and sperm production. Aim for 7–8 hours of sleep per night. Poor sleep quality or too little sleep can lower testosterone levels and negatively affect sperm production.

Tip 4: Manage Stress

Chronic stress affects the hormonal system in many ways. Find stress-management techniques that work for you — such as meditation, yoga, regular exercise, spending time in nature, or speaking with a therapist. Even small changes in daily routines can make a significant difference.

Tip 5: Avoid Overheating

Practical ways to keep the testicles cool:

• Choose loose boxer shorts instead of tight underwear
• Take breaks from sitting, especially if using a laptop on your lap
• Limit time in saunas and hot baths
• Avoid tight trousers for extended periods

Tip 6: Limit Alcohol and Stop Smoking

If you smoke, quitting is the single most important thing you can do for your sperm quality. Improvements can be noticeable after just a few months. When it comes to alcohol, moderation is key — no more than 1–2 drinks per week if you are actively trying to conceive.

Tip 7: Regular Ejaculation

Contrary to what many believe, regular ejaculation is beneficial for sperm quality. Every 2–3 days is optimal when trying to conceive. Long periods without ejaculation can actually worsen sperm quality, as older sperm accumulate and DNA damage increases.

Waiting for Results

It’s important to remember that changes in sperm quality take time. Since sperm development takes about 74 days, you need to maintain lifestyle changes for at least 2–3 months before expecting results. Be patient and focus on sustainable habits rather than quick fixes.

When to Seek Help

If pregnancy does not occur after a year of regular attempts, it is recommended to seek a fertility evaluation. Men with known risk factors — such as previous chemotherapy, previously documented reduced sperm quality, or recurrent infections in the testicles or epididymis — may need to be evaluated earlier. If you are over 35 or suspect hormonal issues, it may also be wise to contact a healthcare provider after around six months of trying.

Source: www.1177.se and fact-checked by RFSU clinic.