Men's fertility: an expert explains how to improve it

Nutritional therapist Amy Swan says up to 50% of infertility cases involve a male factor and that lifestyle and nutrition — including heat exposure, diet and stress — can influence sperm quality.

Amy Swan, a nutritional therapist based in Blackrock, Co Dublin, highlights the role of male factors in infertility and discusses how lifestyle and diet affect sperm health. She notes that global sperm counts have fallen by about 50% since the 1970s and links much of the decline to nutrition and other lifestyle influences. Swan describes sperm DNA fragmentation as a concern tied to oxidative stress and says many common habits can make that worse. The article also shares that she uses tailored, evidence-based plans with clients and includes recipes intended to support nutrient-dense eating. What the article reports: - Up to 50% of infertility cases involve a male factor, according to Amy Swan. - Global sperm counts have fallen by around 50% since the 1970s, the article notes. - Sperm DNA fragmentation increases with oxidative stress, which Swan links to lifestyle and nutrition. - Heat exposure such as tight underwear, saunas and excessive cycling is mentioned as harmful to sperm. - Alcohol intake, smoking or vaping, ultra-processed foods and chronic stress are identified as contributing factors. - Swan says changes in diet and lifestyle take at least three months to affect egg and sperm quality. Summary: The article highlights that male factors are a significant part of infertility and that diet, heat exposure and stress are among the influences on sperm quality. Undetermined at this time.