Heading soccer balls seems to take a greater toll on women than on men. That’s the conclusion of a new study. It focused on the brains of amateur soccer players.
Head knocks — such as hitting a soccer ball with your head — can really rattle the brain. Female athletes tend to suffer more symptoms than males do after brain injuries, the study's authors note. But until now, no one had directly compared damage in men and women after heading balls.
Michael Lipton is a brain-imaging expert. He works at the Albert Einstein College of Medicine in New York City. From 2013 to 2016, he was part of a group that recruited 98 soccer players from amateur teams (including college teams). The players estimated how often they had headed a ball in the past year. The researchers then compared men and women who had reported similar numbers of headers.
The median estimate among men was 487 headers. For women, the median was 469 headers. (The median is the middle number when all the player’s counts were put in order from fewest to most.)
The researchers then pored over the brain scans of each player looking for microscopic signs of damage. They used a type of scan known as diffusion tensor imaging. It’s a form of magnetic resonance imaging. This type of MRI scan can highlight changes in the brain’s white matter. Bundles of fibers make up that white matter. These fibers, called axons, carry electrical signals from nerve cells in one part of the brain to those in another. So damage to white matter risks limiting how well the brain works.
The scans turned up more widespread brain damage in the female players, Lipton’s team now reports. In women, eight regions showed potential damage linked to frequent headers. In men, only three regions did. Overall, these white-matter changes affected some five times more of the brain’s volume in women than in men.
The brain changes studied here weren’t big enough to cause symptoms of concussion or other types of brain damage. But repeated blows to the brain can contribute to memory loss, depression and other problems. One concern is CTE, short for chronic traumatic encephalopathy (En-seff-uh-LAH-puh-thee). This disorder can develop in football players, soldiers and others whose brains had suffered repeated head trauma. CTE can lead to confusion, trouble remembering things and emotional outbursts.
Researchers don’t know why women’s brains appear at greater risk. Differences in their heads and necks may play a role. So might genetics and hormones, the authors noted July 31 in Radiology. They add that greater vulnerability that they found in women points to why it is important to study both sexes.
amateur One who engages in a pursuit as a pastime, not as a profession.
axon The long, tail-like extension of a neuron that conducts electrical signals away from the cell.
brain scan A technique to view structures inside the brain, typically with X-rays or a magnetic resonance imaging (or MRI) machine. With MRI technology — especially the type known as functional MRI (or fMRI) — the activity of different brain regions can be viewed during an event, such as viewing pictures, computing sums or listening to music.
cell The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall.
chronic A condition, such as an illness (or its symptoms, including pain), that lasts for a long time.
chronic traumatic encephalopathy Also known as CTE, it's a term for long-lasting brain disease brought on by head injuries (often sustained in sports or military service). This disease often is progressive, meaning it worsens with time.
concussion Temporary unconsciousness, or headache, dizziness or forgetfulness due to a severe blow to the head.
depression A low spot, such as in a field or the surface of a rock. (in medicine) A mental illness characterized by persistent sadness and apathy. Although these feelings can be triggered by events, such as the death of a loved one or the move to a new city, that isn’t typically considered an “illness” — unless the symptoms are prolonged and harm an individual’s ability to perform normal daily tasks (such as working, sleeping or interacting with others). People suffering from depression often feel they lack the energy needed to get anything done. They may have difficulty concentrating on things or showing an interest in normal events. Many times, these feelings seem to be triggered by nothing; they can appear out of nowhere.
diffusion tensor imaging A technique for identifying microscopic changes or differences in the structure of brain regions. It can map the three-dimensional diffusion of water into tissues, which can change with disease. It’s often used to study the brain’s white matter.
disorder (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.
encephalopathy A term for any type of disease that alters the structure of the brain or how well it functions.
fiber Something whose shape resembles a thread or filament.
genetic Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.
hormone (in zoology and medicine) A chemical produced in a gland and then carried in the bloodstream to another part of the body. Hormones control many important body activities, such as growth. Hormones act by triggering or regulating chemical reactions in the body.
magnetic resonance imaging or MRI An imaging technique to visualize soft, internal organs, like the brain, muscles, heart and cancerous tumors. MRI uses strong magnetic fields to record the activity of individual atoms.
median (in mathematics) The value or quantity that lies at the midpoint of a group of numbers that had been listed in order from lowest to highest.
microscopic An adjective for things too small to be seen by the unaided eye. It takes a microscope to view objects this small, such as bacteria or other one-celled organisms.
nerve A long, delicate fiber that transmits signals across the body of an animal. An animal’s backbone contains many nerves, some of which control the movement of its legs or fins, and some of which convey sensations such as hot, cold or pain.
radiology The science dealing with X-rays and other high-energy radiation, especially the use of such radiation for the diagnosis and treatment of disease.
risk The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)
symptom A physical or mental indicator generally regarded to be characteristic of a disease. Sometimes a single symptom — especially a general one, such as fever or pain — can be a sign of any of many different types of injury or disease.
trauma (in medicine) An injury, often a fairly severe one. This term also can refer to a severely disturbing incident (such as witnessing a battlefield death) or memory.
white matter One of the two main tissue types found in the brain and spinal cord. It consists mainly of bundles of nerve fibers.
Journal: T.G. Rubin et al. MRI-defined white matter microstructural alteration associated with soccer heading is more extensive in women than men. Radiology. Published online July 31, 2018. doi:10.1148/radiol.2018180217.