Nearly everyone you ask would say they have a pretty good handle on the biological differences between men and women, but it's a good bet that only a small minority would mention the immune system in their answer.
It has been known for some time now that men, in general, have weaker immune systems than women, and scientists have not known why.
A group of researchers representing many different disciplines recently put their heads together to come up with an answer to this puzzling question.
The researchers exposed human subjects to the human influenza vaccine, which mimics the effects of a virus without making the subject sick, and then looked at the response of a large number of immune system reactions, including gene and protein expression, blood cell number and type, and inflammation.
Firstly, the researchers verified what was already known. Women, regardless of age, really did show a greater immune response than men. So what was causing it? When the data was analysed, it was determined that low immune response was correlated to high activity from a group of genes that were known to be upregulated by testosterone.
Furthermore, the men with the highest serum testosterone showed the lowest immune response to he vaccine. This study provides us with some pretty strong evidence that testosterone suppresses the immune system.
Testosterone is the bodybuilders' holy grail. Low levels make it hard to put on muscle, and testosterone boosters are some of the most popular supplements around. On the other hand, nobody likes to be sick. A weak immune system makes you more susceptible to illness, which can keep you out of the gym and stop you from pushing that bit harder.
The best thing to do to protect yourself from this unfair twist of biology is to boost your immune system, and there are a number of approaches. Eating well, getting enough sleep and avoiding stress are all great tips, but as is obvious to anyone who has ever set foot in a gym, training to build muscle is very taxing on the body. To boost things a little further it's worth considering supplements like L-Glutamine, an amino acid well known for its immune system benefits, which is lost from the muscles during training or Vitamin and Mineral Supplements, which have a role in overall and immune health. There is a lot of information on immune boosting. Use it to your benefit and enjoy being ripped and healthy at the same time.
David Furmana, Boris P. Hejblumb, Noah Simonc, Vladimir Jojicd, Cornelia L. Dekkere, Rodolphe Thiébaut, Robert J. Tibshiranic and Mark M. Davisa. Systems analysis of sex differences reveals animmunosuppressive role for testosterone in theresponse to influenza vaccination. PNAS November 21, 2013 (sent for review September 23, 2013)