You Ask — We Answer
Dr. Fabio Castiglione Urologist London
Do men go through male menopause?
Like women, men see their sex hormone levels drop as they get older. Sometimes, this process is called male menopause or andropause, but it differs greatly from female menopause.
Doctors may use other terms to describe this process, such as testosterone deficiency syndrome, androgen deficiency, and late-onset male hypogonadism. (Hypogonadism is another name for low testosterone.)
Does consuming soy affect a man’s testosterone levels?
No. Soy intake does not raise or lower a man’s testosterone levels.
Derived from soybeans, soy is a high-protein substance found in many foods, such as edamame, tofu, soy flour, and soy milk. It can also be found in some supplements.
Many people add soy to their diets for health benefits. Research has shown that soy can lower cholesterol. Soy can also alleviate hot flashes for some menopausal women.
However, there have been some concerns that soy might lower a man’s testosterone levels. This is because the active ingredients in soy – isoflavones – are phytoestrogens – plant-based compounds that behave much like estrogens.
Estrogens are hormones that are heavily involved in a woman’s reproductive system. Men’s bodies produce estrogens too, but at much lower amounts.
Still, some men worry that consuming phytoestrogens may reduce their testosterone levels. Low testosterone can be linked to diminished sex drive, erectile dysfunction, reduced muscle mass, depression, fatigue, and osteoporosis.
In 2010, a group of American researchers from the University of Minnesota and Loma Linda University in California analyzed 47 studies that examined the relationship between soy and men’s sex hormones, including testosterone.
The researchers concluded that soy intake did not significantly affect testosterone levels.
“These results suggest that consumption of soy foods and isoflavone supplements would not result in the adverse effects associated with lower [testosterone] levels,” they wrote.
Men who are concerned about soy and their reproductive hormones should talk to their doctor.
In addition, men should know that testosterone’s synthesis begins with cholesterol. But this type of cholesterol comes from internal bodily sources and is not the same as dietary cholesterol. Therefore, cholesterol-lowering drugs and dietary changes should not affect the production of testosterone.
Can a man’s testosterone levels affect his immune system?
In January 2014, researchers from the Stanford School of Medicine published a study on testosterone and immunity. They discovered that men with higher levels of testosterone had a reduced immune response to the flu vaccine.
Past research has shown that women often have stronger immune responses to bacterial, viral, fungal, and parasitic infections than men. Women’s responses to certain vaccines, like flu, measles, and hepatitis also tend to be stronger. Scientists are not sure why.
The Stanford study involved 53 women and 34 men of various ages. The participants had been part of ongoing research since 2008. Each year, they had their blood drawn before and after receiving an annual flu vaccine.
To determine the strength of the participants’ immune systems, the researchers looked at levels of antibodies. Antibodies are proteins that fight harmful substances when they enter the body. A flu vaccine contains dead viruses that cannot give a person the flu. However, the body’s immune system still recognizes these killed viruses as threats and builds up antibodies.
The researchers found that the women had a stronger antibody response to the flu vaccine than the men. Men with lower testosterone levels had a similar response.
However, men with higher testosterone levels had a weaker response. The researchers explained that testosterone appears to interact with a particular set of genes called Module 52 genes. This interaction may hinder immune response.
The study was published in the Proceedings of the National Academy of Sciences.