By Dr. John Bagnulo, Director of Nutrition

In last decade, many studies have supported the theory that ALS and Parkinson’s Disease are caused by predominantly environmental factors, rather than genetics.

As the number of ALS and Parkinson’s patients continues to climb and the medical system develops new drugs, epidemiologists are considering the role of bacteria — most notably the blue-green algae family cyanobacteria — as the root cause of both of these neurodegenerative diseases.

This certainly isn’t a new concept. Cyanobacteria were first associated with Parkinson’s as early as 1950. At that time, the Island of Guam had the highest incidence of Parkinson’s Disease, as well as a large number of significant dietary sources of blue-green algae bacteria, or, more importantly, the neurotoxin that the bacteria produce.

BMAA (β-Methylamino-L-alanine) is an amino-acid-like toxin that interferes with normal protein coding and transcription, especially within neurons. Neurons accumulate greater amounts of BMAA over their lives, primarily because they have longer lives than any of our other cells. As we get older, we rely more on older neurons. If our neurons are compromised, our neurological system and brain suffer.

The increase in ALS and Parkinson’s in and around areas with documented blue-green algae blooms is well known. People who have eaten fish from or spent time in these bodies of water have enormous upswings in their risk of developing either disease.

Now, because of wastewater treatment effluent (the final product from a wastewater treatment plant), increases in average ambient temperature, and a variety of other human/industrial influences, many waterways are warming. This fuels more and bigger algae blooms and more human exposure. Recent research in Sweden showed that much of the seafood supply there contained BMAA. Sources have been identified in the U.S. as well.

As we continue to learn more about this environmental threat, it makes sense to be very careful about what we eat from the ocean and where it is sourced. Areas with histories of algae blooms (many bays and popular fisheries) should be avoided in favor of colder waters with stronger currents (less favorable for algae blooms). Also avoid larger species of fish that spend time in warmer waters and that are higher in the food chain (such as sharks), as they bio-accumulate the toxin and can be among the richest sources.

Researchers are investigating how to help our nerve cells better cope with exposure to BMAA; in the meantime, please check out our recent post on ALS to learn more about the best dietary interventions and the potential benefits of a ketogenic diet.


Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain. Cox PA, Davis DA, Mash DC, Metcalf JS, Banack SA. 2016 Proc. R. Soc. B 283: 20152397:

Detection of Cyanotoxins, β-N-methylamino-L-alanine and Microcystins, from a Lake Surrounded by Cases of Amyotrophic Lateral Sclerosis. Sandra Anne Banack, Tracie Caller, Patricia Henegan, James Haney, Amanda Murby, James S. Metcalg , James Powell, Paul Alan Cox, Elijah Stommel. Toxins 2015, 7, 322-336; doi:10.3390/toxins7020322.

Detection of cyanobacterial neurotoxin β-N-methylamino-l-alanine within shellfish in the diet of an ALS patient in Florida. Banack SA, Metcalf JS, Bradley WG, Cox PA. Toxicon. 2014 Nov;90:167-73. doi: 10.1016/j.toxicon.2014.07.018. Epub 2014 Aug 11.

The Emerging Science of BMAA: Do Cyanobacteria Contribute to Neurodegenerative Disease? Wendee Holtcamp. Environ Health Perspect. 2012 Mar; 120(3): a110–a116. Published online 2012 Mar 1. doi:  10.1289/ehp.120-a110

Quantification of neurotoxin BMAA (β-N-methylamino-L-alanine) in seafood from Swedish markets. Liying Jiang, Nadezda Kiselova, Johan Rosén, Leopold L. Ilag. Scientific Reports 4, Article number: 6931 (2014) doi:10.1038/srep06931

Dr. John Bagnulo is the Director of Nutrition at Functional Formularies and leads nutrition research and development initiatives. Learn more about Dr. Bagnulo here.