Researchers compared seminal plasma from 20 men with reduced sperm motility and 20 men with normal semen results. Tyrosol concentrations differed between the groups. Adding tyrosol to sperm in the laboratory improved progressive motility and showed favorable effects on DNA preservation after freezing and thawing.
Even a large number of sperm may have difficulty reaching an egg if they cannot move effectively. A study suggests that reduced movement may be associated with lower levels of a particular substance in seminal plasma, the fluid surrounding sperm.
The research, published online in the Asian Journal of Andrology on September 18, 2026, found relatively low tyrosol concentrations in men with reduced sperm motility. Treating sperm with the substance in the laboratory improved their ability to move forward. The findings suggest that sperm function may relate both to the sperm themselves and to the chemical environment around them.
What differed in men with reduced sperm motility?
The researchers compared semen from 40 men, including 20 with reduced sperm motility and 20 with normal semen analysis results. They examined differences in chemical compounds in seminal plasma alongside the usual questions about sperm number and shape. Tyrosol concentrations were relatively low in the group with reduced motility.
Tyrosol occurs naturally in some plant foods, including olives. Researchers have studied its antioxidant properties and potential to protect cells from damage.
Sperm use energy to move. This process produces reactive oxygen species, which can damage sperm membranes or DNA when present in excess. This imbalance is called oxidative stress. Sperm need both energy and defenses against damage associated with their activity.
The investigators considered whether tyrosol might be involved in these functions. Finding less tyrosol in men with reduced motility does not, however, establish that the deficiency directly caused the reduced movement.
Sperm moved forward more effectively after laboratory treatment
The team added tyrosol to sperm in the laboratory to examine whether it affected movement. They observed improved progressive motility.
Progressive motility describes sperm moving forward, rather than simply beating their tails or moving in place. It is a central part of a semen assessment. A sperm cell can move vigorously without making useful progress toward an egg.
Forward movement helps sperm travel toward the egg, although fertilization and pregnancy depend on many other factors too. The study provides laboratory evidence that tyrosol may help improve progressive movement.
Favorable findings after freezing and thawing
Another finding concerned sperm cryopreservation. Freezing and thawing can damage sperm, including their membranes and DNA, as temperatures change rapidly.
Cryopreservation is important for men preserving fertility before cancer treatment and for storing sperm for fertility care. After tyrosol treatment, researchers observed favorable changes in measures including DNA preservation following freezing and thawing.
The results suggest that tyrosol may help reduce damage during these procedures as well as improve movement. Better DNA preservation does not establish that fertilization or pregnancy rates improve. Whether these effects translate to fertility treatment requires further investigation.
Would eating more olives help?
Because olives contain tyrosol, it is natural to ask whether eating more olives or olive oil could improve sperm motility. The study does not answer that question.
It tested tyrosol applied directly to sperm in the laboratory. It did not study men taking tyrosol in food or supplements.
Ingested substances undergo digestion, absorption and metabolism. Separate research would need to establish how much tyrosol reaches seminal plasma and whether it can reach the concentrations that produced an effect in the laboratory. Evidence is insufficient to conclude that consuming more tyrosol-containing foods or supplements improves sperm motility.
Male infertility involves more than sperm count
Sperm count often dominates discussions of male infertility. A normal count alone does not establish favorable fertility, however. How sperm move, whether they progress forward and how well their DNA is preserved also matter.
This research adds another possible factor: differences in the chemicals surrounding sperm may relate to their function. Lower tyrosol levels in men with reduced motility, together with improved movement and DNA preservation after direct treatment, suggest a direction for further work.
The study was small, with 40 men, and it was not a clinical trial in which men received tyrosol to test a fertility treatment. Larger studies need to investigate the relationship and establish whether tyrosol could be used safely and effectively in fertility care.
Understanding reduced motility may require examining the environment in which sperm swim as well as the cells themselves. Men with reduced sperm motility should discuss the possible causes and appropriate care with a urologist or fertility specialist rather than relying on a particular food or supplement.
Source: “Changes in Seminal Plasma Metabolites and the Vital Role of Tyrosol in Men with Asthenozoospermia.” Asian Journal of Andrology, first published online September 18, 2026. DOI: 10.4103/aja202626. The findings were established in laboratory experiments and do not demonstrate improved pregnancy rates following treatment of men.
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