A diet that includes foods rich in omega-3 polyunsaturated fatty acids like alpha-linolenic acid — an essential plant-derived fatty acid found in flaxseed, canola, and other oils — is linked to a lower risk of developing amyotrophic lateral sclerosis (ALS), researchers report.
But their work also found that diets rich in arachidonic acid — another polyunsaturated fatty acid found in meats like chicken and beef, and in eggs — was associated with a higher ALS risk.
These results were in the presentation, “Pre-diagnostic Plasma Polyunsaturated Fatty Acids and the Risk of Amyotrophic Lateral Sclerosis,” given at the 2018 Annual Meeting of the American Academy of Neurology on April 22. The AAN conference runs in Los Angeles through April 27.
The presence of polyunsaturated fatty acids (PUFAs) in the human brain is known to modulate several “triggers” for ALS, such as oxidative stress, over-excitation of neurons (a condition called excitotoxicity), and inflammation.
Diets rich in omega-3 PUFAs were previously reported to be linked to a lower ALS risk. However, research has also shown that high consumption of omega-3 PUFAs accelerated disease progression in a mouse model.
For this reason, researchers examined whether PUFAs levels in the blood — prior to an ALS diagnosis — were linked to a greater or lesser risk of developing the disease.
They compared 275 people who went on to develop ALS while part of five U.S. study groups to two control groups (no ALS). Participants were matched for age, sex and race.
Results showed that individuals with higher blood levels of alpha-linolenic acid had a lower risk of ALS.
Alpha-linolenic acid is an essential omega-3 fatty acid that can only be obtained from diet, as we are not able to synthesize (produce) it. This essential omega-3 fatty acid is found in high amounts in flaxseeds and flaxseed oil, and in canola, soy and walnut oils (although in low amounts).
“Adjustment for BMI [body mass index, a measure of body fat based on height and weight], smoking, education attained, plasma urate [also called uric acid] and other n−3 polyunsaturated fatty acids [omega-3 PUFAs], did not materially change the findings,” the researchers wrote.
But people with higher blood levels of arachidonic acid — part of the omega-6 PUFA family, and found in foods like meats, eggs and dairy products — had a higher risk of ALS.
Overall, these results suggest that,“polyunsaturated fatty acid profile may modulate the risk of ALS. Consumption of foods high in alpha-linolenic acid may help prevent or delay the onset of ALS,” the study concluded.