How Can Sperm Quality Be Improved? The Facts About Lifestyle, Heat, Weight and Supplements

For many men who are trying for a child, or who have been handed a low semen analysis result, the first question is: “What can I do?” Bold claims and contradictory advice online only complicate it further. Yet the effect of lifestyle on sperm quality is real; it is simply that not every recommendation rests on the same level of evidence, and lifestyle does not take the place of an underlying medical cause.

This article explains the lifestyle factors that affect sperm quality, the place of heat, weight and supplements, which recommendations are backed by strong or limited evidence, and when lifestyle alone is not enough.

Why is patience needed? Sperm production is a cycle of about three months

The formation and maturation of sperm cells in the testicles, and their arrival in the semen, is a process lasting about three months. For this reason, it takes at least three months for a change to be reflected in a semen analysis; seeing no difference in a test a few weeks later does not mean the effort has been wasted.

For the same reason, decisions are not made on the basis of a single test. Even in the same man, values can vary considerably because of factors such as a feverish illness; assessment is usually based on analyses repeated at intervals. Going a long time without ejaculating does not improve sperm quality either and may, on the contrary, reduce motility. The period of abstinence before a test should be kept within the range recommended by the laboratory or the doctor.

Not all factors carry the same weight: the effects of smoking, excess weight and external hormone use rest on strong evidence, whereas the evidence on tight underwear, mobile phones and supplements is limited or disputed.

Smoking, alcohol and other substances

Smoking is one of the factors with the strongest evidence. Many studies have shown that men who smoke can have lower sperm count and motility and greater damage to sperm DNA.

• Alcohol: Although occasional, light drinking appears to have a limited effect, regular and heavy use can disturb hormonal balance and adversely affect sperm production.
• Cannabis and other recreational substances: There are findings that these substances can reduce sperm count and motility. Sharing their use with the doctor is important; the consultation is conducted in confidence.
• E-cigarettes: Evidence on their effect on sperm is still limited. However, as they contain nicotine, they should not be considered harmless.

Weight, diet and exercise

Excess weight, particularly fat around the abdomen, can disturb hormonal balance by causing part of the male hormone to be converted into female hormone. Obesity is associated with low testosterone, reduced sperm count and increased heat around the testicles. Losing weight can correct this picture to some extent; the size of the effect, however, varies from person to person.

Some studies report an association between a Mediterranean-style diet, rich in vegetables, fruit, pulses, fish and olive oil, and better sperm values. Most of these studies are observational; they show an association but cannot on their own prove cause and effect.

Regular, moderate-intensity exercise such as brisk walking or swimming supports weight control and hormonal balance. By contrast, temporary deterioration in sperm values has been reported with very intense endurance sport, particularly cycling training lasting many hours.

Heat and the testicles: what matters?

The testicles sit outside the body, in the scrotum, because sperm production works better a few degrees below body temperature. The evidence for the factors that warm the testicles, however, differs:

• Sauna, hot tub and hot baths: Frequent and prolonged use has been shown to reduce sperm count and motility. This effect is generally reversible; improvement is expected in the months after exposure is reduced.
• Laptop on the lap and prolonged sitting: Both can raise the temperature around the testicles. Using a desk and getting up to move at intervals are simple precautions.
• Tight underwear and mobile phones: Some studies report slightly better sperm values in men who wear loose underwear, but the evidence is limited. The effect of carrying a phone in a front trouser pocket is disputed.

These measures can be recommended because they are harmless and simple; however, heat alone is not expected to explain a marked sperm abnormality.

Sleep, stress and environmental factors

Very short or irregular sleep and shift work have been associated with lower sperm values in some studies; the evidence in this area is still limited. Prolonged, intense stress is also thought to affect hormonal balance. As trying for a child can itself be a source of stress, it is important for this burden to be shared within the couple.

Some occupations involve exposures that can affect sperm production; in these environments, using protective equipment and mentioning the exposure to the doctor is advised:

• High heat: Working for long periods in hot environments such as ovens, foundries or welding
• Chemicals: Agricultural pesticides, paint and varnish solvents, and certain heavy metals
• Radiation: Exposure to ionising radiation without protective measures

External hormones and certain medicines

One of the factors clearly known to suppress sperm production is male hormone taken from outside. Testosterone and anabolic steroids used for sport can markedly reduce, and even stop, sperm production by suppressing the hormonal signal from the brain to the testicles. The same effect can be seen in men receiving testosterone therapy on medical advice; men planning a child should discuss this with their doctor.

Some treatments, above all the medicines used in cancer treatment and radiotherapy, can also affect sperm production; in that case the option of sperm freezing should be considered before treatment together with the relevant specialist. Other groups of medicines, such as some prostate medicines and antidepressants, may also have an effect. A regularly used medicine should not be stopped on one's own initiative; the matter should be raised with the prescribing doctor.

Supplements and ‘sperm-boosting’ products: what is known?

Whether supplements containing antioxidants benefit some men by reducing oxidative damage to sperm is being researched. The results, however, are not consistent: some studies report small improvements, while some well-designed studies have shown no clear difference. Their effect on what really matters, pregnancy and live birth rates, is not clear.

• ‘Natural’ does not always mean safe: The contents of products marketed as ‘sperm-boosting’ may not match what is declared; some may contain undeclared hormone-like substances.
• More is not better: Excessive antioxidant intake is also thought to have the potential to impair sperm function.
• A supplement does not replace treating a cause: If there is a correctable cause, a supplement does not remove it; it can only delay diagnosis and treatment.

When lifestyle is not enough: when should you see a doctor?

Lifestyle changes support sperm health but do not solve every problem. Correctable causes are common in male infertility: varicocele, an enlargement of the veins of the testicle, hormonal disorders, infections of the reproductive tract and blockages in the ducts that carry sperm are among them. Assessment is recommended in the following situations:

• No pregnancy after a year of regular, unprotected intercourse; six months if the female partner is over 35
• A semen analysis result that has come back low
• Pain, swelling, a palpable lump in the testicle or the appearance of twisted veins in the scrotum
• A history of undescended testicle, testicular inflammation due to mumps, or groin or testicular surgery
• Previous use of external hormones, or planned cancer treatment

If a known risk factor is present, there is no need to wait a year. It is important for the assessment to be carried out as a couple; having the female partner assessed by a gynaecologist during the same period speeds up the process.

Sperm quality is influenced by modifiable factors such as smoking, weight, heat, sleep and external hormone use, and changes take around three months to be reflected in a semen analysis. The place of supplements has yet to be established, and no lifestyle measure replaces investigating a correctable medical cause. Assoc. Prof. Zülfü Sertkaya practises in urology and andrology in Istanbul; assessment and treatment planning for sperm quality and male fertility are carried out with individual assessment and confidentiality.

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