Air pollution has long been known to affect male fertility as much as obesity, smoking or chemical pollutants, but the mechanism by which pollution affects men’s reproductive ability is unknown. Researchers at the University of Maryland have found that pollution actually causes inflammation in the brain, and the inflammation reduces sperm count. What is the connection between the brain and fertility? The brain has a direct connection with the reproductive organs. This is why stress is one of the causes of infertility in both men and women. Emotional stress can disrupt a woman’s ovulation and menstruation. In men, it can lead to a reduced sperm count and affect fertility. It’s not just stress that affects fertility through the brain. Researchers have found that breathing polluted air causes inflammation in the brain. This brain involvement has a number of consequences. One of them is that in addition to affecting male fertility, brain involvement can also cause high blood pressure, diabetes or heart problems. In experiments in laboratory conditions. researchers have found that reducing the levels of a single inflammatory marker in the brains of laboratory models can increase sperm count. The consequences of pollution 92% of the world’s population lives in areas where the level of fine particles – PM2.5, exceeds the minimum levels recommended by the World Health Organization. PM2.5 is produced as a result of combustion processes from motor vehicles, but also from industry, heating systems and the burning of coal and wood. These particles are so small that they pass through the lungs and reach the blood, which is why they are so dangerous to health. Pollution is already known to affect sperm, but previous studies have shown that it doesn’t always cause inflammation in the testicles, meaning pollution works through some other, unexplained mechanism. Knowing the direct connection between the brain and the genitals, researchers looked to see if air pollution increased inflammation in the brain. To that end, they grew laboratory models that lacked markers of inflammation located in specific neurons in the brain and exposed them to polluted air. They then quantified sperm and found that male gametes were not reduced in laboratory models with no markers of inflammation despite being exposed to polluted air. The researchers also found that a specific type of neuron, usually associated with sleep cycles and obesity, is responsible for the reduced sperm count that results from air pollution. These neurons are usually found in the hypothalamus, a part of the brain that controls hunger, thirst and sexual desire. The hypothalamus also functions together with the pituitary gland in the brain,which produces hormones that directly regulate the functions of the reproductive organs. Neurons in the hypothalamus are the main cause of maintaining this inflammatory response that leads to low sperm count, because we know that the hypothalamus is a major link between the brain and the reproductive system, the study authors concluded. Therapeutic Approach to Infertility This study will allow the development of new therapeutic approaches to improve fertility by developing therapies that succeed in reducing this marker of inflammation in hypothalamic neurons. This will counteract the harmful effects of air pollution on fertility. In addition, it will also make it possible to design therapeutic approaches that reduce brain inflammation to treat other equally serious diseases such as hypertension, diabetes and certain heart problems. References: https://www.sabervivirtv.com/salud-masculina/contaminacion-reduce-espermatozoios-afecta-fertilidad_6413 https://ehp.niehs.nih.gov/doi/10.1289/EHP8868