July 18th, 2013 § Comments Off on Radio interview! § permalink
May 12th, 2013 § Comments Off on Are Cell Phones Bad for Sperm? § permalink
Are cell phones bad for sperm? They emit electromagnetic radiation, and some have questioned whether that may be harmful for sperm.
Researchers exposed sperm in a test tube to the typical 850 and 900 MHz frequencies of cell phone transmitters and found that its movement worsened, its inner cell life decayed, and bad reactive oxygen molecules that are thought to damage sperm increased.
But a man doesn’t commonly hold his sperm up against his cell phone’s transmitter, and there’s a lot of distance and stuff between his cell phone and his sperm. So what’s the information about cell phones and sperm in real life?
In a study of sailors in the Norwegian navy, men who were exposed to high power military equipment transmitting radiofrequency electromagnetic radiation had problems with infertility. The higher the exposure, the worse the infertility, which argues that the electromagnetic radiation was the factor damaging a man’s reproductive chances. (An interesting observation in the study was that higher exposure resulted in less boys and more girls at birth.) But the high power electromagnetic radiation in that study is still not quite real life use of a cell phone for a typical man.
In another study of men going to a fertility clinic, researchers divided them into four groups based on how much time they spent talking on a cell phone each day:Â none; less than two hours per day; two to four hours per day; and greater than four hours per day. As talk time went up, sperm count, motility, inner sperm cell life, and the number of normally shaped sperm went down.
Should men stay away from using cell phones to protect their sperm? The pieces of the puzzle aren’t enough to make a blanket recommendation like that yet. But in the meantime, it’s probably a good idea not to go wild on the cell phone if a man is trying to impregnate his partner.
As I’ve written in earlier posts, clomiphene is a medication that a doctor can use to increase a man’s production of testosterone in his own body. (I’ve also written about how doctors can prescribe it. If you think that you’d benefit from this medication, you should see a doctor. I can’t answer personal questions about a man’s health on this blog. Medical care is always done best in person.) But clomiphene is “off-label” for use by men and didn’t go through the rigorous series of studies that the FDA mandates for a drug for a particular use.
One good question is whether clomiphene is safe for long term use by men. John Mulhall, a great doctor in New York, recently published a report in the British Journal of Urology studying the use of clomiphene for up to three years in 46 men diagnosed with low testosterone. Blood testosterone, bone scans, and symptom scores all improved, and men did not report problems with the medication.
There are limitations to this study. It wasn’t controlled, meaning that there wasn’t a group of men treated with a placebo, or sugar pill. 46 isn’t a lot of men, and three years isn’t really a very long time. But this kind of study is what needs to be done with more men and for a longer time to really determine the safety of clomiphene for long term use in men.
Clomid surely has its advantages compared to testosterone for use in men with low testosterone. It’s a pill, and other treatments are either shots or cumbersome skin applications. It also saves sperm, as testosterone itself reduces sperm production. But information about its use is less than that of testosterone, which puts men and their doctors in a kind of Catch-22. Mulhall and colleagues are to be commended for expanding what we know of the safety of this medication.
January 9th, 2013 § Comments Off on What I’ve Written § permalink
Google is an amazing place. It seems like almost everything is there. A traditional way for doctors and scientists to search published studies is by using the National Library of Medicine’s PubMed site. I use it a lot, as it contains only peer-reviewed medical studies. Google has a similar resource called “Google Scholar.” I made a Google Scholar profile, and you can see what I’ve written there. Check it out!
December 22nd, 2012 § Comments Off on Declining Sperm in France? § permalink
By Jim Hotaling, M.D.
Gawker recently reported onÂ an article in the scientific journalÂ Human ReproductionÂ that found sperm numbers and shape to worsen in France during a 16 year period. Studies that claim sperm are declining worldwide have been published for at least the last 20 years. Â If the trend is true, one guess for its cause was suggested by the Danish scientist Niels Skakkebaek, who argues that chemicals in materials such as plastics act as synthetic hormones that interrupt a man’s own internal natural hormones.
The Human Reproduction article is well designed, studying a very large group of 26,609 men from infertility clinics in France from 1989 to 2005. Â Each man had two semen analyses, which adds to the strength of the paper as sperm counts change much even from day to day. Â The scientists concluded that sperm count decreased 1.9% per year in France during the time period of the study.
Before jumping to the conclusion that the fertility of French men is dipping, there are some important limitations of the study. To their credit, the scientists state most of them clearly in their paper. The first is that the scientists studied men showing up in fertility clinics. These men as a group are probably different that the average guy in France. Second, the men got older during the study. While the age increase was small,Â 34.2 to 35.9 years, and may not mean much, the deCODE study suggests that changes in sperm may start early in a man’s life. Third, giving a sample in an fertility lab may not be the same as when it’s delivered naturally.
This study probably isn’t great cause for concern that sperm are on a steep decline in France. Even if the numbers are going down a bit, there’s still plenty of sperm in these men to do the job.