There are a number of lifestyle factors that can cause DNA fragmentation:
Heat: Heat can cause increased testicular temperature, which negatively affects spermatogenesis, i.e. sperm formation and development. The temperature in the testicles is usually around 2°C lower than in the rest of the body, so that the sperm can develop optimally. Sperm DNA fragmentation has been observed in animal studies where testicular temperature was at or above body temperature. What can you do? First, your doctor may recommend wearing loose underwear, such as boxer shorts, rather than briefs.
Laptop computers: They generate a lot of heat and can damage sperm DNA if left on the lap for long periods of time. Put something between your lap and the laptop.
Hot Tubs : Hot tub temperatures are higher than body temperature. Baths in it should be avoided during attempts to conceive. Also, avoid taking long, hot baths.
Obesity: Overhanging abdominal fat causes heat trapping, which can lead to sperm DNA damage. When sitting, you can put an air seat cushion on top of your seat pad/chair etc. (often used by long haul truckers). Thus, the testicles are close to the “air cooling pad”.
Diet: Eating a balanced diet of whole foods packed with vitamins and minerals is important for both women and men and should be part of your TTC plan.
There are a number of lifestyle factors that can contribute to DNA fragmentation:
Heat : The reason men have a scrotum containing the testes outside the body is that the testes should be about 2 degrees cooler than body temperature for normal sperm production. In animal experiments where the testes were exposed to temperatures at or above body temperature, results clearly showed that environmental heat to the testes causes sperm DNA fragmentation and is related to infertility. How does this affect men? First, your doctor may recommend that when trying to conceive, it is preferable to wear boxers rather than briefs.
Lap Top Computers : They generate a huge amount of heat and if used directly on the lap could damage sperm DNA. Place something between your lap and the computer.
Hot Tubs: Hot tubs are above body temperature and should be avoided during times attempting conception. Likewise, do not take long, hot baths; use the shower.
Obesity : Overhanging belly fat will cause a heat trap that can cause sperm DNA damage. One can at least place an air seat cushion (often used by long distance truckers) on whatever one is sitting on. Thus, the testis is close to the air cooling cushion.Diet : A proper diet of wholesome foods full of vitamins and minerals is sensible when trying to conceive for both women AND men and should be part of your TTC plan.
To mimic elevated testicular temperatures caused by clothing, for example, a bull’s testicles were placed in a woolen sock for 48 hours. Elevated scrotal temperature adversely affected both epididymal and testicular sperm, as evidenced by a doubling of %DFI (4% to 8%) within three days. After 12 days, a 5-fold increase in %DFI was observed. Interestingly, the sperm showed a significant presence of nuclear vacuoles 12 days after the stressor. (Karabinus et al. (1997) J Androl 18:549-555.
Mouse body temperature is around 37°C. Placing mice in a heated water bath so that only the testicles are exposed to the high temperature, slight effects on sperm DNA are observed after 1 hour at 38°C. Even 3 days at elevated temperatures has little effect on sperm DNA fragmentation. However, an increase in temperature from just 2°C to 40°C caused a doubling of the %DFI and a tripling of the %DFI by day 14. Testicular weight did not decrease after 35 days. Therefore, the damage from what appeared to be a minor exposure to heat caused very significant sperm DNA fragmentation. Studies clearly show the negative effects that excessive heat can have on the testicles/episodes and therefore on sperm.
Sailer et al. (1997) J Andrology 18:294-301
To mimic elevated testis temperatures caused by clothing and other insulating items, a wool sock was placed over bull testes for 48 hours. This elevated scrotal temperature adversely affected both epididymal and testicular sperm seen by an increased doubling of the %DFI (4% to 8%) within three days and a 5 fold increase by 12 days after the sock removal. Of interest, sperm at 12 days post stress had significant presence of sperm nuclear vacuoles. (Karabinus et al (1997) J Androl 18:549-555.
Mouse body temperature is about 37C. Placing mice into a heated water bath so just the testes are exposed showed that after 1 hr at 38C had minor effects on sperm DNA fragmentation 3 days after the increased temperature had very little effect on increased sperm DNA fragmentation. However, raising the temperature only 2C to 40C caused a more than doubling of %DFI and a more than tripling of %DFI by day 14. Testicular weights of mice under such exposure did not decrease after 35 days; thus, the damage from what may seem as a minor exposure to heat caused very significant sperm DNA fragmentation.
These results from animals and that seen from humans clearly shows the highly negative effect that excess heat to testis/epididymis can have on DNA fragmentation, and likely negative pregnancy outcomes from the damaged sperm.Sailer et al (1997) J. Andrology 18:294-301