It’s More Than Just The Testicles

June 24th, 2013 § 4 comments § permalink

An article in press in Fertility and Sterility is getting a lot of media attention. The study connected men seeking infertility care to a cancer registry in the State where the clinic was located. The researchers found that men with infertility had almost twice the chance of getting cancer and almost three times the chance if the man had no sperm in his ejaculate.

The authors of the study have a few theories about why cancer and male infertility may be connected. Cells need to divide just right to make sperm in the testes, and problems with division could lead to both problems with making sperm and the kind of bad division that makes cancer. It could also be that toxic substances in the environment may lead to both infertility and cancer.

Whatever the reason, we’re beginning to understand that problems with male fertility are just a tip of a much bigger iceberg that involves health in general. It’s more than just about the testicles.

Are Cell Phones Bad for Sperm?

May 12th, 2013 § 0 comments § permalink

Radiofrequency

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: 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.

Declining Sperm in France?

December 22nd, 2012 § 0 comments § permalink

By Jim Hotaling, M.D.

Gawker recently reported on an article in the scientific journal Human Reproduction 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.  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.  Each man had two semen analyses, which adds to the strength of the paper as sperm counts change much even from day to day.  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, 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.

Radiation and Sperm

March 21st, 2011 § 0 comments § permalink

The horrific earthquake and tsunami in northern Japan remind us that no matter how powerful we become or careful we are, nature asserts itself in ways that we can’t imagine.  The nuclear engineers and technicians working to contain the radiation leaking from the damaged power plant in Fukushima are nothing short of heroic.  Radiation can cause all sorts of ills, from acute sickness to cancer and infertility.

In the testis, developing sperm cells are exquisitely sensitive to radiation.  Kyodo News reported that after an explosion at the Fukushima No. 2 reactor on March 15, radiation levels measured as high as 8,217 micro sievert or 0.8217 rem per hour.  (Micro sievert and rem are units of radiation dosage.)

Does that amount of radiation harm developing sperm cells?  I asked Marvin Meistrich, Ph.D., Professor of Experimental Radiation Oncology and the Florence M. Thomas Professor of Cancer Research at the University of Texas M. D. Anderson Cancer Center, a world’s expert in radiation and sperm.  Dr. Meistrich explained that sustained exposure to 20 rem of radiation over 4 weeks caused sperm counts to drop to 1/10th of their original amount.  At doses of 40-80 rem, sperm counts fell to about 1/100th of the starting number, and in some cases were wiped out entirely.  At 200 rem, that drop to zero sperm became permanent. For one-time doses, Dr. Meistrich explained that 15-20 rem caused a short-term fall in sperm count, and 400 rem or more resulted in permanent loss of sperm.

We know that radiation changes DNA, the sperm’s precious genetic cargo.  What we don’t know is what dose causes a harmful DNA change that damages a developing embryo or causes disease later in life.

The radiation leakage in Fukushima seems to be in the range at which damage to sperm occurs.  I can only hope that the workers at Fukushima and the people near the plants are aware of the dangers and take action to protect themselves.