His Health Matters Too: What Science Says About Men's Fertility

Sperm 101: why his habits right now matter

Unlike eggs, which a woman is born with, sperm is manufactured continuously — a full production cycle takes roughly two to three months. That means the sperm involved in a conception reflects his health over the previous season of his life, not his entire history.

Researchers describe the three to six months before conception as a key preconception window: the period when a father's habits leave their deepest mark on sperm quality — and, through chemical marks on sperm, potentially on the child's early development too.

Translation: it's never too late for him to matter, and it's never too early to start.

What the research shows

Food and drink

• Ultra-processed food: In a 2025 study of men at a fertility clinic, those with the highest ultra-processed food intake had nearly 4x the odds of abnormally low sperm concentration compared to the lowest-intake group.
• Sugary drinks: A large North American study of couples trying to conceive found that men drinking 7+ sugar-sweetened beverages per week had about 22% lower monthly conception odds — and the effect was even stronger for sodas specifically (33% lower).
• His diet affects her odds too: In a 2025 Dutch study of 651 male partners, higher ultra-processed food intake in men was linked to lower monthly chances of conception and a 36% higher risk of subfertility per increment of intake.

Weight

• Men with obesity face a 30% to 66% higher risk of infertility, with lower sperm counts, poorer motility, and more breaks in sperm DNA — changes tied to metabolic and hormonal disruption.
• A 2024 study of over 1,000 couples undergoing fertility treatment found that men with obesity had significantly lower semen volume than men at a healthy weight.
• Here's the hopeful part: when men lose weight, the chemical patterns on their sperm begin to rewrite themselves — measurable within about a year. Everyday changes in food and movement improve sperm in ways that go beyond the number on the scale.

Age

• A 2020 systematic review and meta-analysis found that advanced paternal age is linked to a higher risk of miscarriage: fathers aged 40–44 had a 23% higher risk than fathers aged 25–29, and fathers 45+ had a 43% higher risk — rising to 74% higher for first-trimester loss.
• One proposed mechanism: the DNA fragmentation index of sperm roughly doubles between ages 20 and 60.
• The paternal age effect is smaller than the maternal age effect — but it's real, and worth factoring into family timing conversations.

Everyday chemicals

• Microplastics: In 2024, researchers detected microplastics in all 23 human testicles examined, averaging 328 micrograms per gram of tissue. A separate 2024 multi-site study found microplastics in men's semen and linked PTFE exposure (the coating on nonstick pans) with lower sperm counts.
• BPA: A 2024 systematic review and meta-analysis found that higher BPA exposure was linked to lower sperm concentration and count, plus disrupted reproductive hormones — higher estradiol and lower bioavailable androgens.
• Pesticide residues: At the 2024 American Society for Reproductive Medicine congress, researchers reported that high pesticide-residue produce intake in male partners was tied to lower fertilization rates during IVF.

What he can actually do: the husband's checklist

No lectures, no shame — just the highest-impact moves, roughly in order of payoff:

• Eat like it matters — because it does. Shift toward whole foods: vegetables, fruit, whole grains, legumes, fish, olive oil. Cut back on ultra-processed snacks, fast food, and sugary drinks.
• Move toward a healthy weight — even modest, sustained weight loss improves sperm markers. His body is rebuilding sperm constantly, so progress shows up within months.
• Retire the worst kitchen offenders — scratched nonstick pans, microwaving in plastic, daily canned foods. Glass storage and stainless or cast-iron cookware are simple upgrades.
• Filter water, ditch the plastic bottles — food, water, and air are all documented routes for microplastic exposure.
• Limit alcohol, quit smoking, and talk to his doctor about medications — all three show up consistently in fertility research.
• Keep things cool, literally — prolonged heat (laptops on laps, very hot baths, tight synthetic underwear all day) isn't doing sperm any favors.
• Get a semen analysis early — not after a year of trying. It's simple, noninvasive, and it prevents months of guessing.

References

1. The association between consumption of ultra-processed foods and sperm quality parameters — 2025
2. Intake of sugar-sweetened beverages and fecundability in a North American preconception cohort — Epidemiology, 2018
3. Periconceptional ultra-processed food intake and fertility outcomes — Human Reproduction, 2025
4. Fathers shape childhood obesity risk long before birth — review of paternal origins of health research, 2026
5. Effect of paternal overweight or obesity on semen parameters and IUI outcomes — 2024
6. Advanced paternal age is associated with an increased risk of spontaneous miscarriage: a systematic review and meta-analysis — Human Reproduction Update, 2020
7. Microplastic presence in dog and human testis and its potential association with sperm count — Toxicological Sciences, 2024
8. Association of mixed exposure to microplastics with sperm dysfunction: a multi-site study in China — eBioMedicine, 2024
9. Bisphenol A exposure interferes with reproductive hormones and decreases sperm counts: a systematic review and meta-analysis — 2024
10. Fruit, vegetable pesticide exposure may impair sperm during IVF cycles — ASRM Scientific Congress, 2024
11. Fathers may influence childhood obesity before a baby is conceived — review of paternal preconception research

Rachel Gould is a birth doula and maternal wellness coach serving the Phoenix Valley through Holista Health Collective — 1-on-1 support for preconception, pregnancy, birth, and postpartum.