It’s one of the biggest health stories most people have never heard about. Around the world, sperm counts are falling, and infertility is becoming more common for men and women alike. The good news: some of the everyday habits linked to low sperm count are surprisingly easy to change, starting with what you wear.
Sperm counts have fallen by more than half
In 2022, an international team led by Professor Hagai Levine of the Hebrew University of Jerusalem and Dr. Shanna Swan of Mount Sinai published the largest analysis of its kind in Human Reproduction Update. Pooling data from 53 countries, they found that sperm counts declined by more than 50% over 46 years, with a drop of over 1% per year. Even more worrying, the decline appears to have sped up since 2000.
Infertility isn’t only a men’s issue, of course. The World Health Organization estimates that roughly 1 in 6 people worldwide experience infertility at some point in their lives. In about half of couples who struggle to conceive, a male factor is involved.
What’s behind the decline?
Researchers point to a mix of causes, and many of them are modern:
- Endocrine-disrupting chemicals such as phthalates and some pesticides, which can interfere with reproductive hormones. Dr. Swan has spent decades studying how these exposures affect fertility.
- Heat. Testicles hang outside the body for a reason: sperm production works best a few degrees cooler than core body temperature.
- Lifestyle factors like smoking, heavy drinking, excess weight, poor sleep and long hours of sitting.
Boxers vs. briefs: what the science says
A Harvard study published in Human Reproduction in 2018 followed 656 men and found that those who usually wore loose boxers had about 25% higher sperm concentration and 17% higher total sperm count than men who wore tighter underwear. The researchers believe heat is the likely reason: tight styles hold the testicles close to the body and keep them warmer. (The men were patients at a fertility clinic, and the study shows a link rather than proof, but the finding fits what we know about heat and sperm.)
If you’re wondering how to increase sperm count naturally, switching to looser, breathable underwear is one of the easiest places to start.
Why organic, breathable fabrics are a smart choice
When it comes to the fabric against your most sensitive skin, natural fibers make sense. Organic cotton is grown without synthetic pesticides, and natural fibers breathe better than many synthetics, helping you stay cooler and drier. That’s why so many health-conscious men are switching to organic underwear for men.
What about silver underwear?
You may have seen silver underwear woven with silver threads and marketed as EMF-shielding. We believe in being honest with you: silver fibers are well known for being naturally antibacterial, so they help with odor and freshness. But experts say there isn’t yet solid evidence that phones or Wi-Fi harm sperm, or that silver-lined underwear protects fertility. If you love the feel and the freshness, wonderful. Just choose a loose, breathable cut, because the heat benefit of boxers is the part the research actually supports.
Our sister shop, Tried and True, curates organic and silver-woven underwear and other clean essentials for men. Shop men’s organic underwear at Tried and True →
More ways to protect your fertility
- Keep laptops off your lap and take breaks from long periods of sitting.
- Go easy on hot tubs and saunas if you’re trying to conceive.
- Eat plenty of zinc-rich foods (like oysters and pumpkin seeds) and antioxidant-rich fruits and vegetables. See our guide to foods that support a healthy libido.
- Choose fragrance-free personal care products and a clean, paraben-free lube, especially if you’re trying for a baby.
- Store and heat food in glass rather than plastic to cut down on phthalate and BPA exposure.
- Stop smoking, limit alcohol, and prioritize sleep.
If you and your partner have been trying to conceive for a year (or six months if the woman is over 35), it’s worth seeing a fertility specialist. A simple semen analysis is quick and painless.
This article is for general information and isn’t medical advice. Please talk with your doctor about any fertility concerns.
Sources
- Hebrew University of Jerusalem: Follow-up study shows significant decline in sperm counts globally (Levine et al., Human Reproduction Update, 2022)
- ScienceDaily: Type of underwear worn may be associated with sperm production (Mínguez-Alarcón et al., Human Reproduction, 2018)
- STAT News: Experts on silver-lined underwear and fertility
- World Health Organization: 1 in 6 people globally affected by infertility (2023)