What is a hormone?
A hormone is a chemical produced by the body that can control and regulate the activity of certain cells or organs. An example of a non-sex specific hormone is vasopressin. This hormone is released by the pituitary gland (which is found on the underside of your brain) when we are dehydrated in order to preserve water. This hormone travels in the blood from your head to your kidneys where it acts on kidney cells to instruct them to hold onto more water.
What are sex hormones?
Sex hormones are chemicals that tend to affect sexual development and reproduction. Most people think that men produce testosterone and women produce oestrogen and progesterone. However, both sexes actually produce all 3, but in varying amounts.
Do sex hormones affect our immune systems?
Studies that go back as early as the 1940’s have shown that women tend to have better immune systems as they are better at producing antibodies. This can actually work against them as there may be a greater chance that their immune system could become overactive and start to attack healthy cells instead of the pathogens in our blood (this is called autoimmunity). If you want to know more about what an antibody is, what a pathogen is and some more information on autoimmunity, take a look at this article.
The difference between men and women’s immune responses can be directly related to the sex hormones that each gender has. This article suggests that sex hormones have an impact on the amount and type of bacteria found in the body.
How do these sex hormones affect our immune systems?
Testosterone (which is generally higher in men) has been shown to lower your immune system (also known as immunosuppression). Oestrogen on the other hand, has been shown to boost your immune system (also known as immunoenhancing).
A model of these immune system differences were put to test in mice. Scientists tested the amount of inflammation in male mice by injecting them with oestrogen and decreasing their testosterone through castration (removal of the testicles). They discovered that these mice were at greater risk of developing autoimmunity, much like what is seen in autoimmune women.
As mentioned earlier, women have a more active immune system and are more at risk of autoimmune disorders like rheumatoid arthritis or lupus. Whilst men, (who have a less active immune system) are more at risk of developing cancer as they cannot get rid of faulty cells as quickly as women can.
Why do men and women have different immune systems?
One of the reasons men and women may have different immune systems could be due to the evolution and preservation of humankind. In order for women to reproduce, it makes sense for their immune systems to be stronger so that they are healthy enough to have children.
What does this research mean for the future?
Currently there are no disease treatments that are based on the sex of a patient (unless specific to their reproductive organs). This research has highlighted that more research should be undertaken on the role of sex-specific immune responses, as one day we may be able to treat men and women differently to match their immune systems.
Journal: Frontiers in Immunology, Volume 9, August 2018
Author: Veena Taneja
Copyright: Open Access