The Impact on Sperm Quality of Lifestyle Choices and Social Toxins
Introduction to Social Habits and Toxins Which Can Impact a Man’s Fertility Potential
Optimizing the overall testicular environment in which the sperm are being produced can often improve sperm quality. There are a wide variety of adverse lifestyle-related activities that can make the environment for sperm production suboptimal.
As mentioned previously, the human spermatogenic cycle is approximately 75 days (or a little over 10 weeks). Negative lifestyle choices (such as using a hot tub or sauna) can potentially have a negative effect on all of the sperm in the body. After one of these negative factors has occurred, it generally takes the body at least 2.5 months to completely get the old “damaged” batch of sperm out and a new “undamaged” batch of sperm back in the ejaculate. Along the same lines, any positive lifestyle changes that have been made (such as quitting smoking, decreasing alcohol intake, etc.) take at least one spermatogenic cycle (two and a half months) and sometimes two cycles (5 months) to be fully reflected in the semen parameters.
There are a number of activities that are known to decrease the quantity and/or quality of sperm. An important point to remember is that the biology of each man is different, so the degree of negative impact of each of these activities on each individual can vary widely from person to person. For example, some men could sit in a sauna for 4 hours a day and not have any change in their semen parameters, while others could start to have significant changes after just 10 minutes of sauna use. Since there is no way to determine each individual’s distinct response to each risk factor, I recommend trying to avoid all potentially detrimental activities while a couple is actively trying to conceive a pregnancy.
One final point to consider is the constant barrage of news articles in the popular media that claim to show that certain foods, supplements, or activities have been found to be associated with improvements or decreases in sperm numbers and/or quality. Whether it’s avocados, non-stick pots and pans, or the type of laundry detergent you are using, everything seems to have some scientific study associated with it showing that this breakthrough finding is either your ticket to pregnancy or your ultimate barrier to conceiving. Almost all of these studies are small and uncontrolled and have little scientific merit by themselves. In this website I have tried to identify the risk factors and beneficial activities that have decent scientific data backing up their use or avoidance. So before you rip up your carpet (because of those nasty perfluorochemicals), throw away your bedding and sofas (because of insidious off-gassing from the flame retardant chemicals), or stop taking showers (due to the evil phthalates in your shower curtain), read through this section to see which interventions are actually based on sound scientific findings at this time. Leave the sensationalism to the newspapers and cable TV- they constantly need new fresh content to try and catch your eye, regardless of the scientific merit of their claims.
Tobacco Products and Their Impact on Sperm Quality
Tobacco products are known to contain over 4000 chemicals, and in all of its forms (cigarettes, cigars, chewing tobacco, snuff) can be detrimental to fertility (as well as to a man’s general health). [Sharma R. ReprodBiolEndocrinol 2013]. Although nicotine by itself has been shown to have a negative effect on male fertility in animal studies [Malays J. MedSci 2017], the greatest impact is felt to be from the tobacco-related toxic byproducts (e.g. polycyclic aromatic hydrocarbons, vinyl chloride, benzopyrene, etc.). These dangerous byproducts are known to have a dose-dependent negative impact on fertility in several ways, including increased oxidative stress, hormonal imbalances, and a direct toxic effect on sperm production. [Soares SR. CurrOpinObstetGynecol 2008]. Decreases in sperm counts and motility have been documented as well as lower semen volumes with the use of tobacco products. [Ramlau-Hansen CT. HumReprod 2007]. Increased levels of sperm DNA fragmentation and sperm aneuploidy have also been shown to increase with male tobacco use, as have decreased fertilization and implantation rates with IVF. [Soares SR. CurrOpinObstetGynecol 2008].
Tobacco cessation is typically a very difficult process due to the highly addictive nature of nicotine. Improvements in fertility have been seen with cessation of all tobacco-related product use, although this can prove to be a very hard process. Strategies to help with tobacco cessation include:
1) Pharmacotherapy-To help decrease cravings for nicotine. Examples include:
a) Buproprian (Zyban)- a prescription medication
b) Varenicline (Chantix)-a prescription medication
2) Behavioral Therapy/Group Therapy/Self Help programs
-Example: Freedom from Smoking Program (American Lung Association)
3) Cognitive therapy (working with a psychologist)
4) Nicotine replacement therapy
Nicotine replacement
Nicotine replacement therapy can help to satisfy the cravings for nicotine while avoiding the toxic byproducts of tobacco. It is often used as an adjunct therapy to some of the other tobacco cessation techniques listed above, with a slow weaning of the nicotine replacement leading towards complete cessation of all nicotine products. Other people simply use the nicotine replacements long-term, with no intention of stopping the use of nicotine, but thereby avoiding tobacco products. As mentioned above, nicotine by itself has been found in some studies to potentially have a mild negative effect on male fertility. However, eliminating the other 4000+ chemicals found in tobacco can only benefit a man’s fertility potential. If nicotine replacement is needed to achieve this, then it is well worth the trade-off in terms of relatively smaller potential negative impact of nicotine itself on sperm function. Types of nicotine replacement include:
1) Gum
2) Inhaler
3) Lozenges
4) Patches
5) Nasal spray
6) Electronic cigarettes
Electronic cigarettes (vapes) are currently a very controversial form of nicotine replacement. Many men have found them to be a useful and effective tool in stopping the use of cigarettes. However, their high rates of usage in adolescents is alarming and a proven gateway to starting the use of tobacco products. The association with severe lung damage in some users is also a significant concern with the use of these products. Studies have shown associations between e-cigarette use and lower sperm counts in men. [LaPointe S. FertSteril 2023]
Illicit Drug Use and Male fertility potential
The use of illicit (at least by federal law) drugs has been shown to have a negative impact on male fertility potential and their use should be discontinued in men trying to conceive. [Sharma R. ReprodBiolEndocrinol 2013]
Cannabinoids (e.g. marijuana) Numerous studies have correlated THC exposure from marijuana use with lower sperm production and motility, hypogonadism, and elevated levels of sperm DNA fragmentation. [Nassan FL. FertSteril 2018][Bash JC. AUAUpdate 2023] However, a meta-analysis of 9 studies in 2021 did not find a significant relationship between marijuana use and semen parameters. [Belladelli F. WorldJMensHealth 2021]. Higher rates of miscarriage have been reported in couples with male marijuana use. [Harlow AF. Epidemiol 2021]. There are also significant concerns with male marijuana use altering epigenetic regulation during sperm production resulting in abnormal brain and neurobehavorial development in the offspring. Human studies have shown increased levels of psychiatric disorders and substance abuse correlating with prenatal paternal THC use. [Bash JC. AUAUpdate 2023]
Cocaine use has been found to correlated with decreases in semen parameters though hormone levels are usually not significantly changed. [Hurd WW. FertSteril 1992][Bracken MB. FertSteril 1990]
Amphetamines, methamphetamines, MDMA (Ecstasy)- The use of these substances has been associated with hypogonadism in humans as well as damage to testicular spermatogenic cells in animal studies. [Duca Y. JClinMed 2019][Pham MN. Andrologia 2022]
Opioids- The use of opioids like heroin have been clearly linked to the development of hypogonadism, as well as decreased semen parameters (especially motility and morphology). [Nazmara Z. UrolJ 2019][Safarinejad MR. ReprodToxical 2013]
Alcohol intake and its potential impact on the quality of sperm
Mild alcohol intake (4-6 or fewer drinks per week) by the male partner has not been found to have a significant negative impact upon fertility when studied in men of reproductive age. However, greater amounts of alcohol intake have been associated with testicular atrophy and decreased semen parameters, as well as an increased time to establishing a pregnancy. [Yanglai EV. HumReprodUpdate 2006]. Decreased sperm densities, motilities, and morphologies can all be seen with increased alcohol intake. Heavy alcohol use has been found to decrease average sperm densities by 64%, and studies have found that only 12% of alcoholic men have normal semen analysis testing. [Sharma R. ReprodBiolEndocrinol 2013]
A 2014 study of 1,221 men aged 18-28 years found an adverse impact on sperm quality in men consuming 5 or more alcohol units per week, with especially severe decreases in men consuming more than 25 units of alcohol weekly. [Jensen TK. BMJOpen 2014]. A pooled analysis of several prospective studies in 2020 showed decreased fertility in men consuming more than 6 drinks per week. [Hoyer S. HumReprod 2020]. In addition, a 9% lower live birth rate was noted with IVF/ICSI in couples where the man consumed more than 6 drinks per week. [Rao W. ActaObstetGynScand 2022]
Therefore, the recommendation for men trying to conceive is to try and limit alcohol intake to no more than 4-6 drinks per week (with one drink being the equivalent of 1 beer or 1 shot of hard alcohol).
Cell phone use and male fertility
Cell phones generate radiofrequency electromagnetic waves (RF-EMW) which have been shown to have a negative impact on sperm motility in animal studies. [Mailankot M. Clinics (SaoPaolo) 2009]. In humans, early studies suggested decreases in semen parameters with increased used of cell phones. [Agarwal A. FertSteril 2008]. A follow-up meta-analysis of in 2014 found evidence that increased cell phone use appears to be associated with decreases in sperm motility and morphology, but not density. [Adams JA. EnvironInt 2014] In contrast, lower sperm counts were seen men with higher self-reported cell phone use. [Rahban R. FertSteril 2023]
However, further study clearly needs to be performed to determine the mechanisms of damage as well as the true impact of cell phone use on semen parameters. It remains unclear whether regular cell phone use (where the cell phone is held up to one’s ear) can significantly impact sperm quality, since the radiation generated by these devices generally travels only a short distance.
I feel that with the currently available data, the bigger concern is the use/storage of these devices near the scrotum. When this cell phone-released radiation is near the scrotum, it has been shown to increase oxidative stress in the region of the testicles as well as impact cellular mitochondrial function. The Environmental Working Group (EWG) reviewed 10 research studies on the topic and found that significant changes in sperm density and motility were associated with men who kept their cellular phones in their pants pockets or on their belts. This group came up with 4 recommendations to decrease cell phone-related radiation exposure to the scrotum. These recommendations include:
1) Text more, talk less
-Phones emit less radiation with texting than calling
2) Skip radiation shields (antenna caps/keypad covers)
-These shields reduce the connection quality and force the phone to use more energy
(i.e. emit more radiation)
3) If using a headset, hold the phone away from your body (not in pants pocket or on belt)
-The constant low emission radiation emitting by the phone seeking to keep a constant
connection creates a zone of radiation around the scrotal area
4) Call when the signal is strong
-Radiation exposure increases significantly when cell phone signals are weak
With the currently available data, I feel that the key issue with cell phones is proximity to the scrotum while in use. Men are not going to stop using cell phones in today’s society so ways need to be found to try and minimize the degree of risk. It is known that the amount of radiation absorbed decreases dramatically with even small increases in the distance of the cell phone from the body. A cell phone that is turned off is fine to keep in your front pants pocket. However, if the cell phone is turned on, then the further away it is from the scrotum, the better. The least favorable scenario is having a turned on cell phone in your front pants pocket (and it is even worse to be talking on a Bluetooth headset at the same time). Better is to have the cell phone clipped to a belt or in the back pocket. Even better would be storing it in a lower pants pocket (like in cargo pants). The best scenario is to keep the cell phone in a coat pocket, shirt pocket, or bag/briefcase while carrying it around.
Caffeine Intake- Does it impact male fertility?
The relationship between caffeine intake and female fertility has been fairly well established with increased use showing a higher risk of spontaneous pregnancy loss. [Lyngso J. ClinEpidemiol 2017]. However, the impact of caffeine intake on male fertility is much less clear. A review of the literature in 2017 found that the evidence is “inconsistent and inconclusive” but that a negative impact due to such factors as increased sperm DNA fragmentation could not be ruled out. [Ricci E. NutritionJ 2017]. The study evidence appears to support the fact that the equivalent of a few cups of coffee a day do not have much negative impact on sperm quality, but significantly increased intake can potentially be detrimental. A 2010 study found that men with an intake of 800mg or higher per day showed decreases in semen parameters, but these were not seen with lower levels of caffeine intake. [Jensen TK. AmJEpidemiol 2010]. For reference, listed below are some examples of the average amounts of caffeine in different beverages:
Percolated Coffee ~100/cup 8 cups
Drip Coffee ~145mg/cup 5 ½ cups
Espresso Coffee ~100mg/cup 8 cups
Tea ~50mg/cup 16 cups
Coke ~35mg/12oz can 23 cans
Mountain Dew ~54mg/12oz can 15 cans
Red Bull ~80mg/8.5oz can 10 cans
Conclusion: As long as caffeine intake does not exceed 800mg/day, then it will probably not have a significant negative impact on male fertility. The type of caffeine may also be important as sugar-sweetened drinks (with or without caffeine) have been associated with decreased semen parameters. [Lapointe S. FertSteril 2023]. Another study also found reduced male fertility potential with the regular use of caffeinated energy drinks but not coffee or tea. [Wesselink AK. ReprodToxicol 2016]
Air Pollution and sperm quality
Air pollution can come from many different sources, including car exhaust, industrial production, the burning of coal and wood. There are thousands of potential toxins in air pollution, with some of the more common being carbon monoxide, sulfur dioxide, and ozone. Significant exposure to air pollution has been linked to decreases in sperm quality as well as increased sperm DNA damage. [Sharma R. ReprodBioEndocrinol 2013] Appropriate to an era of global warming, a 2024 study showed wildfire smoke exposure in men dropped average sperm counts from 91.25 to 66.5 million sperm/cc. [Rubin ES. FertSteril 2024]. Strategies to limiting air pollution exposure include limiting outdoor activity levels when local air quality conditions are poor. Also try to avoid traffic congested streets if possible. When driving in traffic, keep the windows up and hit use the ‘recirculate’ button, allowing the cars filters to clean the air.
the relationship between Sleep Deprivation and male fertility
A lack of sleep is a common problem in today’s modern economy. In studies, chronic restricted sleep (<6.0-6.5 hours per night) have been associated with a multitude of health problems including diabetes, obesity, coronary vascular disease and depression. [Caetano G. FertSteril 2020]. In addition, restricted sleep and later bed times have also been associated with decreases in semen parameters including counts and motility. [Chen Q. Sleep 2016]. Other studies have reported decreased testosterone levels with sleep deprivation [Andersen ML. BrainRes 2011] as well as shift work. [Balasubramanian A Urol 2020] In terms of sperm production, night and shift work have been associated disruptions in gonadotropin secretions but there has been conflicting results regarding impacts on semen parameters. [Caetano G. FertSteril 2020]
It has been recommended that men with trouble conceiving try and get between 7 to 9 hours of sleep each night if possible. [Wise LA. FertSteril 2018]. Problems like sleep apnea can also potentially cause fertility problems and have been linked to lower testosterone levels in men. [Leproult R. JAMA 2011]. Mice studies mimicking the effects of sleep apnea have documented increased levels of oxidative stress and decreased semen parameters. [Torres M. Sleep 2014]. Treatments like CPAP may therefore be beneficial to the fertility potential of men with sleep apnea.