ALS, also known as Lou Gehrig’s disease, is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. It causes loss of muscle control, paralysis, and eventually respiratory failure. ALS is relatively rare, affecting around 5 cases per 100,000 people globally each year. But what are your individual chances of developing this devastating disease? Let’s take a look at the data.
Who Gets ALS?
ALS can strike adults of any age, but it is more common between the ages of 40 and 70. The average age of diagnosis is 55. Men are slightly more likely to develop ALS than women.
In the US, ALS affects white people more than any other race or ethnicity. The rate of ALS among Black people is about half that of white people. Some research suggests that East Asians, Hispanics, and Native Americans also have lower rates.
Most cases of ALS occur randomly with no clear risk factors. These are called sporadic ALS. A smaller percentage of cases (around 10%) are inherited. This familial ALS means the gene mutation runs in families.
ALS Statistics
According to the ALS Association, here are some key statistics on the prevalence of ALS in the US:
- About 5,000 new ALS cases are diagnosed each year
- At any given time, around 16,000-20,000 Americans are living with ALS
- The lifetime risk of developing ALS is 1 in 350 for women
- The lifetime risk for men is 1 in 320
This means that on average, 1 out of every 300 Americans will get ALS within their lifetime. But the odds increase as you age.
ALS Risk by Age
Let’s take a closer look at how ALS risk increases based on age demographic:
| Age Range | Risk of ALS |
|---|---|
| 0-39 | 1 in 1,000 |
| 40-49 | 1 in 1,250 |
| 50-59 | 1 in 600 |
| 60-69 | 1 in 350 |
As shown in the table, the risk of getting ALS nearly doubles from the 40-49 age group to the 50-59 group. After age 60, the chances increase further to 1 in 350.
The peak incidence rates occur between 70-79 years old for men and in the late 50s for women. So men tend to develop ALS slightly later than women on average.
Causes and Risk Factors
The exact causes of ALS are not fully understood. Research suggests that both environmental toxins and genetic factors play a role. Here are some of the leading risk factors and theories behind what triggers ALS:
Genetics
Most ALS cases do not run in families. But as mentioned earlier, about 10% of cases are hereditary. The most common gene mutation is in the C9orf72 gene. Other gene variants have also been linked to familial ALS.
If you have a close relative (parent, sibling, child) with ALS, your risk is slightly higher. The odds increase the more closely related the relative is.
Age
ALS risk increases substantially after about age 40 and continues rising. The peak occurs between 65-75 years old.
Gender
Men have a 50% higher chance of developing ALS compared to women. The reason for this difference remains unclear.
Race
ALS disproportionately affects white individuals more than other races in the US. The lowest rates are seen among Black and Asian people.
Environmental Toxins
Exposure to certain environmental toxins and chemicals may trigger ALS in some cases. Toxins linked to ALS include:
- Lead
- Pesticides
- Formaldehyde
- Solvents
For example, studies show higher rates of ALS among football and soccer players, possibly due to exposure to toxins on fields. Rates are also high among military veterans, perhaps due to chemical agents.
Traumatic Injury
Severe trauma to the spinal cord or head may increase ALS risk slightly. One theory is that injury to motor neurons makes them more prone to degeneration.
Smoking
There is some evidence that smoking tobacco cigarettes may be associated with increased ALS risk. More research is needed to confirm the possible link.
Virus Infections
Some scientists believe ALS may be triggered by a virus in certain cases, possibly an autoimmune reaction. Retroviruses or enteroviruses are possible viral culprits being investigated.
Preventing ALS
Currently, there are no proven ways to prevent ALS altogether. But leading an overall healthy lifestyle may lower your risk slightly. Steps like these may help:
- Avoiding tobacco use
- Exercising regularly
- Eating a nutritious diet high in fruits and vegetables
- Avoiding excessive alcohol intake
- Preventing viral infections through handwashing and vaccines
- Using proper protective gear to prevent head injuries
- Taking precautions around chemicals and toxic materials
For those with a family history of ALS, talking to a neurologist about genetic testing may help assess your risk. Currently no treatments exist to prevent ALS altogether even for those with high-risk genes. But this kind of knowledge can help with family planning.
ALS Prognosis and Life Expectancy
ALS causes progressive paralysis and muscle wasting over time. It eventually impairs the muscles involved in breathing. There is no cure for ALS at this time. But treatment can help manage symptoms and prolong life.
Without any treatment, the average life expectancy from time of diagnosis is 2-5 years. About 20% of patients survive for 5 years, 10% for 10 years or more.
With optimal care at specialized ALS treatment centers, life expectancy improves for many patients to 3-5 years on average. Up to 50% may live 3 years and 20% live 5 years. About 10% survive 10 years or longer.
There are exceptional cases of patients living 20 years or more with ALS. But this is less common. In general, slower disease progression predicts longer survival. Younger age at diagnosis is also associated with slightly longer life expectancy.
ALS Early Symptoms
The first symptoms of ALS often include:
- Tripping or dropping things
- Weakness in the arms or legs
- Slurred speech
- Muscle cramps and twitches
Later symptoms include:
- Difficulty walking or controlling arm movement
- Weakness chewing, swallowing or breathing
- Weight loss
- Emotional changes (depression, mood swings)
Seeing a neurologist right away for evaluation of early symptoms gives the best chance for early treatment.
Conclusion
ALS is a serious but relatively rare condition affecting about 1 in 300 people in the US. The odds increase after age 40, with men having a higher lifetime risk than women. There are also some genetic and environmental factors that may increase risk slightly. But in most cases ALS occurs randomly with no known cause.
While ALS shortens life expectancy significantly, modern treatment can prolong survival. Managing symptoms and getting specialized care from an ALS clinic provides the best outcome. Increased awareness of early symptoms is critical for rapid evaluation. Research into new treatments provides hope for better managing and eventually curing ALS in the future.