Because you could get selenium poisoning. You learn something new every day. I used to eat those things by the multiple handfuls as a kid at Christmas. 

Hi,
 
Worse ... they could get "soccer fever" .... and not recuperate!

Thanks for sharing. Don't stand too close to a microwave. Keep yr hands in yr pockets when walking near a dog. Never expose yr skin to any sun without sunscreen. No white bread.

Pussyville.

backwoods
Pussyville.

I'm inclined to agree in general, but selenium is one of those things you really don't want too much off because of how it can mess with your thyroid function. 
 

Isn't Selenium one of those new, annoying pop artists like Bieber? 

Buy the ones still in shells, I can never manage to open more than 2 in any 24 hour period.

Shambler
Buy the ones still in shells, I can never manage to open more than 2 in any 24 hour period.

LOL!!! So true. If all foods were so hard to eat there'd be no market for diet books.
 

Chronic (long-term) exposure to high levels of selenium in food and water results in discoloration of the skin, deformation and loss of nails, reversible loss of hair (baldness), excessive tooth decay and discoloration, a garlic odor to the breath, weakness, lack of mental alertness, and listlessness.

(Source)
 
Yikes. I exhibit a few of those symptoms. But I haven't had a Brazil nut in ages. Now the bad news: selenium is also abundant in tuna, crab and lobster! This is why I do not eat more than one lobster per day. 
 
 

I also read that too much selenium can make a person irritable. Which could explain Christmas.

This explains everything!

craigb
Isn't Selenium one of those new, annoying pop artists like Bieber? 

Selenium Rectifiers were used in electronics back in the day,and we handled/inhaled fumes threw away blown open ones,and nobody knew...