ALS has no known cause. Many factors may play a role in whether or not someone develops ALS. These include genetics, sex, race, exposure to toxins, and other environmental factors.
Amyotrophic lateral sclerosis (ALS) is a neurological disorder that affects motor neurons — nerve cells that control muscle movement and breathing.
In ALS, motor neurons stop working and begin to die. This leads to muscle weakening, loss, and eventual paralysis.
The exact cause of ALS remains unknown. However, scientists have identified several potential risk factors.
Experts estimate
Scientists have identified several gene mutations that contribute to ALS. These include mutations in the following genes:
- C9ORF72
- SOD1
- TARDBP
- FUS
The ALS Association notes that mutations in these genes are found in up to 70% of familial ALS diagnoses.
Genes associated with ALS are usually linked to familial inheritance. But people with sporadic (nonfamilial) ALS may have genetic mutations triggered by environmental damage.
Males are
However, a 2024 review notes that this evens out with age, with older females having a similar prevalence of ALS to males.
ALS can affect people of all races and ethnicities. However, it’s much more common in white people.
In a
Smoking has several negative health effects on the body. Research also links it to an increased risk of ALS.
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Research has identified military service as a potential risk factor for ALS.
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Research links exposure to a variety of environmental toxins to ALS risk. For example, a
- heavy metals, such as lead, mercury, and selenium
- pesticides, including herbicides and insecticides
- solvents
A 2022 review also found that exposure to beta-N-methylamino-L-alanine (BMAA), a nonprotein amino acid made by a specific type of bacteria called cyanobacteria, was linked to ALS risk.
The review also noted that exposure to formaldehyde and heavy metals like mercury and manganese may also increase ALS risk.
Head trauma has the potential to cause damage to the central nervous system, which includes the brain and spinal cord. It’s possible that experiencing a head trauma may boost your risk of ALS.
A 2021 meta-analysis found a link between head injury and ALS risk. The risk was higher for people who had had a severe head injury.
A separate
A 2019 study linked a higher risk of ALS with exposure to electric shocks or extremely low-frequency magnetic fields above what is typical.
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While more research is needed overall, certain viral infections may contribute to ALS.
One group under investigation is enteroviruses, which
Enteroviruses can target motor neurons. Additionally,
Another viral infection under investigation is HIV. This is due to reports of people with HIV
Some research has linked excessive exercise to an increased risk of ALS. For example, a
Research links few medical conditions with ALS risk. There’s some
Some medical conditions are linked to a decreased prevalence of ALS. For example, a
Early symptoms of ALS
According to the
- muscle twitching, specifically in the limbs, shoulders, or tongue
- muscle cramping
- muscle weakness in a limb or in the neck
- muscles that feel tight and stiff
- speech changes, such as slurring or nasal-sounding speech
- trouble with chewing or swallowing
There’s currently no known way to prevent ALS.
However, addressing potential ALS risk factors may help lower your risk. This could include quitting smoking or avoiding exposure to pesticides or heavy metals.
There’s little evidence on diet and ALS. However, eating a diet
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- vitamins A, D, and E
- B vitamins
- curcumin
- ginkgo biloba
Other strategies that are beneficial for overall health but may also help reduce ALS risk
ALS has no known cause. For some people, ALS is familial and happens due to specific genetic mutations.
Sex and race also play a role in ALS risk, with males and white people at a higher risk. Other potential risk factors for ALS include exposure to environmental toxins, head injuries, and electrical shocks.
There’s currently no way to prevent ALS. Quitting smoking, if you smoke, and reducing exposure to environmental toxins may help lower your risk. Healthy lifestyle choices involving diet, exercise, and stress reduction may also be beneficial.