Amyotrophic lateral sclerosis (ALS) is also referred to as motor neuron disease or Lou Gehrig's disease, after the famous baseball player who developed the condition. It is a disease that causes nerve muscles to break down and eventually die. Muscles gradually weaken, and the individual loses all control over voluntary movements. The majority of people with ALS die within 3-5 years of the onset of symptoms.
According to the National Institute of Neurological Disorders and Stroke (NINDS), between 20,000-30,000 people in the US have developed Lou Gehrig's disease, and an estimated 5,000 people are newly diagnosed with the condition each year.
In the majority of cases, the disease occurs seemingly randomly, and it is uncertain as to precisely what some of the risk factors are. The condition most commonly appears in people between 40-60 years old, more often in men than women, and 5-10% of cases are inherited.
Inflammation and oxidative stress have previously been implicated in the cause of neurodegenerative diseases such as Lou Gehrig's disease, and polyunsaturated fatty acids (PUFAs) are known to help modulate them.
Flax seeds are one of the best sources of omega-3 polyunsaturated fatty acids available.
Before now though, there has been little to no data regarding a link specifically between PUFA intake and the risk of developing Lou Gehrig's disease. This lack of data was the reason for the new study from the Harvard School of Public Health research team.
The authors examined a total of 1,002,082 participants from five different study groups. The diet of the participants was assessed by questionnaires throughout the duration of each of the five studies. The follow-up period ranged from 9-25 years, depending on the study group.
The authors reported 995 deaths as a result of Lou Gehrig's disease during this period. Alongside this, the authors found that a greater intake of omega-3 PUFA was associated with a reduced risk of Lou Gehrig's disease. This association was contributed to by the consumption of marine omega-3 PUFAs with alpha-linolenic acid (ALA).
The authors say their results suggest that individuals who have a higher dietary intake of omega-3 PUFA and ALA face a reduced risk of Lou Gehrig's disease. They state the following as directions for future study:
"Further research, possibly including biomarkers of PUFA intake, should be pursued to confirm these findings and to determine whether high omega-3 PUFA intake could be beneficial in individuals with [Lou Gehrig's disease]."
The authors also acknowledge that their study had some limitations. Death was used rather than incidence as the measuring factor in several of the study groups, potentially biasing results in favor of shorter-term survivors. Prior research had also indicated that between 70-90% of Lou Gehrig's disease cases are recorded as motor neuron disease in terms of cause of death, raising the possibility of misclassification.
In an accompanying editorial, Dr. Michael Swash, of the Royal London Hospital, England, describes the results of the study as "persuasive" despite the study's limitations and believes that it is consistent with suggestive earlier studies.
Dr. Swash writes that, in addition to male sex, smoking, BMI and physical exercise, the dietary intake of PUFAs is a risk factor in the development of Lou Gehrig's disease that requires further investigation.
The following foods are recognized as being good sources of omega-3 PUFAs:
- Flax seeds
- Brussels sprouts.
ALA can be found in foods containing vegetable oils such as canola, flaxseed and walnut, as well as green vegetables such as Brussels sprouts, kale, and spinach.
Recently, Medical News Today reported on a study that suggested a key way to fight diseases such as Lou Gehrig's disease could lie in boosting the "appetite" of cells.
Written by James McIntosh