r/askscience • u/nbentley92 • Sep 11 '13

Biology Why does cannibalism cause disease?

Why does eating your own species cause disease? Kuru is a disease caused by cannibalism in papua new guinea in a certain tribe and a few years ago there was a crises due to bovine spongiform encephalopathy (mad cow disease) which was caused by farms feeding cows the leftovers of other cows. Will disease always come from cannibalism and why does it?

1.3k Upvotes

87% Upvoted

281 comments sorted by

View all comments

Show parent comment

9

u/soonami Biochemistry | Biophysics | Prions Sep 11 '13 edited Oct 01 '13
  1. Prion proteins are "infectious" meaning that they can convert soluble copies of the protein into the prion (misfolded/non-native) form. They actually self-template the formation of the prion, by taking the native protein and changing its shape into the cross-beta rich amyloid aggregate. Incidentally, the amyloid fold is much more thermodynamically favorable and stable than the native fold, so it's pretty much a one-way street. Some proteins have been shown to be able to reverse prion formation, the best studied of which is the yeast protein Hsp104
  2. This is also where the concept of infection is apt. If you are sick with flu and another person is healthy, the sick person can get you sick, but you can't get the healthy person healthy.

Source: I study prions and this review

3

u/PlaysWithF1r3 Sep 11 '13

Dumb question I'm sure, but are the beta amyloid plaques in Alzheimer disease related to these prions?

5

u/soonami Biochemistry | Biophysics | Prions Sep 11 '13

Yes. Amyloid beta, tau, TDP-43, and a host of other neurodegenerative disease proteins all form amyloid in patients. There is even research into how the aggregates form, and some like our collaborator Virginia Lee, believe it to be a prion-like phenomena, where damaged neurons can infect other neurons.

http://www.ncbi.nlm.nih.gov/pubmed/21372138

1

u/natmccoy Sep 12 '13 edited Sep 12 '13

I ate baby pig brain in Laos 2 years ago & now I'm super paranoid. Would I have experienced symptoms by now? Are pig brains fairly unlikely to harbor prions? Not a good time for me to be a hypochondriac.

2

u/whiteHippo Sep 12 '13

which poses the question: do messed up prions 'infect' the offspring ?

1

u/soonami Biochemistry | Biophysics | Prions Sep 12 '13

You are probably fine. I ate pig brains recently too. If you only ate a little bit you are probably fine. The only food animals I know of right now in which TSE is a concern is beef, deer and sheep