A type of omega-3 found in plants has been associated with a slower progression of the neurodegenerative disease ALS, new research shows. 

The study was published online recently in the journal Neurology. It was the work of a team of researchers associated with Harvard University and prominent hospitals in Boston. 

ALS, or amyotrophic lateral sclerosis, is a neurodegenerative disease that affects nerves in the brain and spinal column. The disease eventually destroys the nerve connections to the muscles, affecting balance and movement and eventually eating, speech, and, ultimately, breathing.  

Most people die within two to five years of the initial diagnosis. The disease has no known cause (although in a small minority of cases, there is a genetic component), no effective treatments and no cure. 

The new research was a retrospective analysis of data collected during a drug trial of the pharmaceutical dexpramipexole in the treatment of ALS. That trial, which was completed in 2012, showed no statistically significant results. 

However, looking at what some of the subjects ate, the authors of this more recent research found some useful results. 

The trial used data from 449 patients who had blood drawn during the drug trial and whose blood was analyzed for omega-3 levels. The patients were followed for 18 months. 

About 28% of the patients died by the end of the 18-month study.

For participants in the study, the progress of their disease was measured on 12 aspects of physical function including swallowing, speaking, chewing, and the ability to use muscles in the hands, arms, legs and torso, as well as respiratory function. Those symptoms were scored on a 0 to 4 basis, with 0 being most severely impaired and 4 being normal function. 

The researchers concluded that higher levels of the omega-3 alpha-linolenic acid (ALA) were linked to longer survival and slower functional decline in ALS patients. ALA is found in many plant sources, including flaxseed, walnuts, chia, hemp and many commonly used plant oils.

"After adjusting for age, sex and ethnicity, people with the highest amounts of alpha-linolenic acid had a 50% lower risk of death during the study compared to people with the lowest amount," according to a press release announcing the study results.

ALS places a crushing burden on caregivers, so slowing that decline not only benefits the ALS patients themselves, but those around them, too. 

“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 lead researcher Kjetil Bjornevik, M.D., Ph.D., of Harvard University, in the press release.

“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,” he added. 

William S. Harris, Ph.D., a professor emeritus at the Sanford School of Medicine at the University of South Dakota, said despite the authors’ focus first on ALA, the study’s results were important news for omega-3s generally.  

“Although the authors focused primarily on the associations between ALA levels and ALS progression (and death), the data supported an essentially equally strong relationship with EPA and/or DHA," Harris told Natural Products Insider in an email. "Interestingly, the omega-6 linoleic was also favorably associated with risk for adverse outcomes from ALS. Once again, higher levels of both omega-3 and omega-6 appeared to be linked to better outcomes."

The study adds to a slowly growing body of research related to ALA, which is sometimes regarded as the poor stepchild of the omega-3s sphere beside its much more well researched peers EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). 

For example, a study published in March in the journal Nutrients found higher ALA intake improved verbal fluency among a cohort of older adults. Another study published in January in the journal Phytotheraphy Research found perilla oil (a seed oil rich in ALA) improved bone health markers in a cadre of older adults.