Why some sperm can't swim well
High cholesterol content and decreased membrane fluidity in human spermatozoa are associated with protein tyrosine phosphorylation and functional deficiencies.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Desmosterol, a cholesterol precursor, was 6.6x higher in poor-motility sperm—far more impactful than cholesterol alone.
Most people assume cholesterol is the main villain, but desmosterol—a lesser-known molecule—was the bigger disruptor, suggesting a deeper metabolic flaw in sperm development.
Practical Takeaways
If you're undergoing fertility testing, ask for sperm membrane fluidity or lipid analysis—not just count and motility.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Desmosterol, a cholesterol precursor, was 6.6x higher in poor-motility sperm—far more impactful than cholesterol alone.
Most people assume cholesterol is the main villain, but desmosterol—a lesser-known molecule—was the bigger disruptor, suggesting a deeper metabolic flaw in sperm development.
Practical Takeaways
If you're undergoing fertility testing, ask for sperm membrane fluidity or lipid analysis—not just count and motility.
Publication
Journal
Journal of andrology
Year
2009
Authors
M. Buffone, S. Verstraeten, J. Calamera, G. Doncel
Related Content
Claims (6)
Too much cholesterol in sperm makes it harder for them to get ready to fertilize an egg, because it stops key changes they normally need to make.
Cholesterol makes up about half of the fatty material in the outer layer of your body's cells, and it helps keep that layer flexible, strong, and able to control what comes in and out.
Sperm cells with too much cholesterol and a similar fat called desmosterol don't move as well when they're getting ready to fertilize an egg, and this might be because those fats mess with their internal signaling system.
Sperm that don't swim well have much more cholesterol and a related molecule called desmosterol than good swimmers, and they can't make their outer membrane more flexible when they're getting ready to fertilize an egg — this seems to be linked to weaker chemical signals and less powerful movement.
Sperm that don't swim well have stiffer outer membranes than sperm that swim well, and this stiffness doesn't go away even when the sperm are supposed to become ready for fertilization.