At last week’s 70th Annual American Academy of Neurology (AAN) Meeting in Los Angeles, neuroscientists and neurologists from all over the world came together to present their important work and learn from each other. We are proud that many top ALS researchers we support attended and presented a wide range of research, on topics ranging from environmental risk factors to work leading up to clinical trials.
This is the first in a two-part series highlighting some of the exciting work presented at the AAN event. This first article discusses the research around environmental factors impacting ALS risk.
Polyunsaturated Fatty Acids and ALS
Dr. Eilis O’Reilly from Dr. Albert Ascherio’s laboratory at Harvard T.H. Chan School of Public Health gave an overview of how levels of pre-diagnostic plasma polyunsaturated fatty acids (PUFA) could impact the risk of ALS. They looked at 275 people with ALS compared to 550 controls and measured pre-diagnostic PUFA levels in plasma.
The team found significantly lower levels of plant-based omega-3 fatty acid linolenic acid in those who later developed ALS compared to controls. These results are in line with a previous prospective study assessing diet and ALS that showed individuals with a higher intake of omega-3 PUFA had a lower risk of ALS.
The team also found significantly higher levels of arachidonic acid, which is associated with inflammation pathways, in those later developing ALS compared to controls. The team concludes it is possible that consumption of foods with high alpha-linolenic acid may help prevent or delay onset of ALS.
ALS Disease: A Multi-Step Process
Dr. Adriano Chio from the University of Turin, in collaboration with Dr. Amar Al-Chalabi from King’s College London, further explored whether people with ALS have disease pathways that require a multi-step process. In previous studies, they found the process leading up to ALS needs, on average, six molecular (i.e. at the molecular level in cells) steps. For their latest research project, they tested whether a genetic mutation might account for one or more molecular steps, thus leaving fewer remaining steps before ALS begins.
They found that the number of steps vary with the type of ALS. For example, a person carrying a C9orf72 expansion mutation needs three steps to have ALS, with one step being having the mutation itself. On the other hand, a person carrying a SOD1 mutation needs two steps to have ALS. They conclude that people with genetic mutations have a reduced number of steps to have ALS, compared to those without ALS mutations.
This concept supports that ALS disease is a multi-step process and it is important to continue dissecting the underlying disease pathways leading to ALS. Also, the relatively limited number of steps leading to ALS, as compared to complex diseases such as schizophrenia, provides hope for the development of an effective ALS therapy.
Diesel Fuel Exposure Link to ALS
Dr. Aisha Dickerson from the Harvard T.H. Chan School of Public Health presented a study looking at how exposure to diesel exhaust in Denmark could be linked to increased ALS risk. Previous studies have suggested that people in occupations commonly exposed to diesel exhaust, such as construction workers, bus drivers, machine operators, and truck drivers, could have an increased risk of ALS.
To Dickerson and their team of researchers knowledge, this was the first study specifically looking at whether diesel exhaust exposure is related to ALS risk. They used the Danish National Patient Registry, which covers cases from 1982 to 2013, to conduct their study to compare 1639 people with ALS to 151,000 controls.
Their study suggests an association between consistently higher occupational exposure to diesel exhaust and ALS. Given the potential toxicity of diesel exhaust, their study suggests that exposure warrants more attention and further studies connecting it to ALS.