Rare, for sure, but I just got to see a guest lecture done by Dr. Paul Alan Cox, who is an Ethnobotanist. A truly brilliant man, who I just enjoyed so much, and he's doing mind blowing research with Cycads, specifically, on how cycads can cause ALS, Alzheimer's and Parkinson's. This work is done as the Institute for EthnoMedicine, and if you want the smart version, go check it out here.
In a nutshell, he discovered this protein [called BMAA] when he was checking out a village in Guam that had a really high percentage of all these diseases. He found out that it was produced by a known group of cyanobacteria [which are really cool themselves, their photosynthetic and nitrogen fixing, and they created Earth's oxygen atmosphere, they're one of the reasons we live on this planet, so before you think I'm blaming all these diseases on cyanobacteria, take that into account], and that these cyanobacteria can be found in the roots of cycads. Anything that eats cycad seeds gets some of this BMAA protein. Over time the accumulation increases risk of or causes these diseases.
This means that exposure to cyanobacteria may be one of the causes of ALS/Alzheimer's/Parkinson's. So that means that no matter where you live, don't eat things that eat cycad seeds. For the Chamorro people in Guam, that means no more fruit bats and deer, as well as the flour they make from the seeds themselves. Cycads aren't commonly consumed in such high quantities, and they're a largely tropical species, so most people don't have to worry about it, and all these diseases are probably cause by other things anyway, but it's worth the heads up. And don't just willy nilly chop your cycad down because you think it's trying to kill you. As long as you're not eating/licking it, you're fine.
The important stuff I'm hoping you'll take away from this article is that plants, while not cognizant like we are, have a far superior arsenal than we have. It's called biochemistry. BMAA protein is thought to have been developed as a defense against the dinosaurs [the herbivorous ones]. These plants have been around far longer than us, and we should be aware that their defenses are just as complicated and beautiful as ours. Also, this research has the potential to develop into drugs and cures, so you guys should really check it out. It's an extraordinary discovery.
Photo Credit to nybg.org