P-013 A potential therapeutic approach of intermittent fasting on sperm viscosity
Authors: Kljajic M , Korac L , Constantin S  M , Baus S , Kasoha M 
Published: July 2024

Study question

Does intermittent fasting affect sperm viscosity and motility?

Summary answer

The obtained results demonstrate that intermittent fasting significantly improves sperm viscosity and motility, and might be considered as a potential therapeutic approach for sperm hyperviscosity.

What is known already

Numerous factors influence sperm quality, functionality, and, consequently, male fertility. In the last decade, nutritional deficiency and lifestyle, have been grouped as popular factors that affect human sperm function and fertilization processes. Semen hyperviscosity which occurs in 12-29% of ejaculates is another condition that can contribute to male subfertility, as it is associated with changes in the chemical and physical characteristics of semen. Additionally, semen hyperviscosity contributes as well to poor sperm motility. Based on the aforementioned facts, focusing on identifying factors to enhance sperm viscosity and motility is crucial for improving IVF outcomes.

Study design, size, duration

The present study was based on semen analyses of 60 samples from 30 IVF patients. Following the purpose of the study and inclusion criteria, all 30 patients were diagnosed with abnormal sperm viscosity. Out of this number, 13 patients had asthenozoospermia, 4 patients were diagnosed with asthenoteratozoospermia, 7 patients were diagnosed with teratozoospermia and 6 patients had normozoospermia. All patients followed 4 days of sexual abstinence. All specimens were analyzed within 1 hour of collection.

Participants/materials, setting, methods

Sperm analysis including sperm viscosity was processed according to the WHO laboratory manual sperm criteria (Sixth edition 2021). For the study purpose, all the participants followed an intermittent fasting period of 14-16 hours for 30 days. Samples were analyzed twice, the first time before fasting and the second time after 30 days of fasting. Most of the patients did not consume food from 6 pm until 8 or 10 am.

Main results and the role of chance

The average age of the patients included in the study was 37.53 ± 4.6 years, while the BMI ranged from 21.26 to 32.28 kg/m2. Abnormal viscosity (hyperviscosity) was diagnosed when the drop formed a thread more than 2 cm long, while normal liquefied ejaculate fell as small discrete drops.

The obtained results indicated that sperm parameters were improved after intermittent fasting.

The most significant difference was observed in semen viscosity where out of the 30 patients who were diagnosed with abnormal semen viscosity after 30 days of intermittent fasting only 9 patients still had viscose semen (p&lt;0.0001). Additionally, a significant difference was revealed in sperm motility before and after the fasting period as well(33.73±12.15 vs 44.10 ±11.54; respectively p &lt; 0.001). Among the 17 subjects initially diagnosed with abnormal motility, following the implementation of intermittent fasting, 11 demonstrated a sperm improvement and were diagnosed with normal motility.

The difference in sperm viability (52.8± 7.71 vs 61.3±8.37; respectively p &lt; 0.01) and Ph values before and after fasting as well were statistically significant.

On the other side, although sperm concentration (Mil/ml) was increased after fasting, the difference was not statistically significant (39.03±19.52 vs 41.53±19.19; respectively p = 0.92). Additionally, intermittent fasting did not affect sperm morphology either.

Limitations, reasons for caution

The limitation of the presented study was a relatively small patient cohort. Further research should link intermittent fasting with IVF outcomes.

Wider implications of the findings

Until today there are no clear dietary guidelines created for infertile males. As far as we know this is the first research, that includes a comparison of sperm parameters, based on intermittent fasting, and the obtained results confirm that intermittent fasting can be used as a potential therapeutic approach.

Trial registration number

not applicable