Phthalates as the silent saboteurs of male fertility via changes in semen quality: a systematic review.
Plain-language summary
This systematic review set out to examine how phthalates, chemicals widely used to soften plastics and to carry fragrance in cosmetics, affect male fertility by altering semen quality. It pulled together 38 studies published between 2014 and 2024, looking at sperm concentration, movement and shape. Higher exposure to phthalates such as DEHP and DBP was linked to worse semen quality on all three. The likely mechanism is a combination of interference with hormone signalling and oxidative stress, meaning damage from unstable molecules that outpace the body's ability to mop them up. The studies behind this were observational and used differing methods, so they show that exposure and poorer semen quality travel together rather than proving one causes the other.
Key findings
- Higher exposure to phthalates like DEHP and DBP was linked to reduced sperm concentration.
- Phthalate exposure was associated with worse sperm motility and morphology.
- The effects are likely due to endocrine disruption and oxidative stress.
How to analyze the study yourself
- Study type
- This pooled several observational studies rather than trials, so it can show that phthalate exposure and worse semen quality travel together but cannot show that one causes the other. The studies it drew on used different methods.
- Population
- The review included studies on human exposure to phthalates.
- Funding
- Not reported
- Watch for
- This review found that higher exposure to phthalates, common in plastics and cosmetics, was linked to worse semen quality. It may be worth reducing your exposure to these chemicals, especially if you are trying to conceive.