Are neurotoxins only present in blue-green algae?

As you have reported, the effects of animal based omega-3 supplements can prove to be ironically, inflammatory. While you recommend utilizing algae as an alternative, is there concern over the neurotoxins (as you have discussed in other videos as present in spiralina), or are these only present in the blue-green algae?

GrantMM77ni / Originally posted in Plant-Based Omega-3 Supplements


All the algae-oil omega-3 supplements currently on the market are made from phytoplankton that are in an entirely different biological kingdom than the blue-green algae known to produce toxins (such as spirulina, detailed here:

Image Credit: Oddman47 / Wikimedia Commons

  • anna

    Dr. Greger, I had a high reading of mercury last year (36) but the doctors kept reassuring me that it wasn’t a level I should be worried about. A naturopath here in Ontario suggested I do a heavy toxin detox with him that seems like quite the commitment but I’m willing to do it if you think I might benefit from it. What do you recommend. I have been vegan for 4+ months and going strong. Will this be enough to counteract any harmful effects of that previous mercury reading? Thank you so much for telling it like it is!!!! Anna

    • Hi Anna, Mercury is a toxic substance which caused neurologic and renal problems primarily. The first step is to avoid exposure. The most common source is fish. Although some workers are at risk for exposure (e.g. dental work, alkali battery factories). Coal burning is the greatest source of air borne mercury. Your body will cleanse itself of the mercury with a half life generally between 40 and 60 days. If you have no obvious signs of effect you could go that route, avoid exposure and recheck your level in 6 – 12 months to document it is decreasing. Chelation is most often used for sudden large exposures and its use in chronic exposure is less clear. I would also make sure your vaccinations are mercury free which usually means you should insist on in single dose vials. I would review the 20+videos re: mercury on the website and keep tuned to as you never know what science will turn up next. Congratulations on your new diet.

  • Thanks for this posting this answer. I had the same question as the post about Vegan DHA after reading on the bottle that it came from algae.

  • Hi!

    As a chef recently switched to veganism I have been exploring the substitutes used for many ingredients. One commonly used instead if gelatine is Irish moss – who’s active ingredient is kappa carrageenan. I have worked with carrageenan before but there seems to be some negative research on this – if only in animal models from what I could find. What are your views on this vs gelatine – or are there better substitirs I’m unaware of?