Consuming omega-3 fatty acids like flaxseed oil and walnuts may help slow the decline in physical function related to amyotrophic lateral sclerosis (ALS), new research suggests.

ALS (formerly known as Lou Gehrig’s disease) is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. People with ALS lose the ability to initiate and control muscle movement over time. The average life span after diagnosis is two to five years.

A slower decline in symptoms may also slightly extend survival for people with ALS, the researchers noted.

The new study findings were published online June 21 in the journal Neurology.

“The link our study found between diet and ALS is intriguing and suggests, but does not prove, that people with ALS may benefit from incorporating more omega-3 fatty acids into their diet,” said Dr. Kjetil Bjornevik, an assistant professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health, in Boston.

“It will now be important to conduct additional research looking specifically at the plant-based omega-3 fatty acid alpha-linolenic acid in people with ALS to further explore this possibility,” Bjornevik said in a journal news release.

Besides flaxseed oil and walnuts, good sources of omega-3 fatty acids include canola oil and pumpkin seeds.

Consuming more omega-6 fatty acid could also be beneficial, the investigators found.

To study the link between diet and ALS, the researchers followed 449 people with ALS for 18 months. Participants’ average age was 58. About 28% died by the end of the study period.

Analyzing omega-3 fatty acids in participants’ blood, the researchers grouped them into four categories from lowest to highest.

Participants were also tested on 12 aspects of physical function, including swallowing, speaking, chewing; the ability to use muscles in the hands, arms, legs and torso; and respiratory function.

Total scores ranged between zero and 48, with higher scores indicating better function and less severe symptoms.

An omega-3 fatty acid called alpha-linolenic acid was the most beneficial. This can be found in flaxseed, walnuts, chia, hemp and many common vegetable oils.

Participants who had the highest amount of alpha-linolenic acid had an average score of 38.3 at the start of the study. Those with the lowest amount had an average score of 37.6.

Fewer people from the group with the most alpha-linolenic acid died during the study, with 21 deaths (19%), compared to people in the lowest group, with 37 deaths (33%).

Those with the highest concentration of alpha-linolenic acid had a 50% lower risk of death during the study period compared to people with the lowest amount, the findings showed.

Higher levels of an omega-3 fatty acid called eicosapentaenoic acid was also associated with a lower risk of death during the study period. This can be found in fatty fish and fish oil supplements.

An omega-6 fatty acid called linoleic acid that is found in vegetable oils, nuts, meats, seeds and eggs was associated with improved survival, too, according to the report.

The researchers did not have access to participants’ overall diet or consumption of supplements, so that is considered a limitation of the study.

The ALS Association funded the research.

More information

The U.S. National Institutes of Health has more on ALS.

SOURCE: Neurology, news release, June 21, 2023