I have eaten 10+ year old MRE's, and they are as "fresh" as the day they were packed. OK, maybe not that fresh, but still edible. Some parts like the M&M's, gum, jolly ranchers, coffee, etc are just good for the trash can, but sealed food inside *should* be ok.
timh70, I [i]HAVE[/i] eaten 10 year old M&M's and I know exactly what you are talking about. Crunchy M&M's that don't melt ANYWHERE aren't exactly the best. And without those naked green ones it just wasn't the same.
BTW, I have eaten 20+ year old C Rats also, and they are OK as long as they are sealed and not spoiled. A good way to tell this is to put some water on the can. When you puncture the can it should suck in the water, making a bit of a "slurp". If it blows out the water some nasty biological element has turned it into crap. It may look OK, but probably unsafe to eat.
Likewise DO NOT eat any mre pouches that are all bloated out, the same thing has probably happened. Some of the more fluid-like meals may appear bloated but are not really, so look at what the meal is too. That's just a generic guideline but when in doubt don't eat it.
Also JOHNO just because you [i]BOUGHT[/i] them in 87/88 doesn't necessarily mean they were made then. Look on the boxes or on the pouches themselves. There should be a 4 digit number like 5326 or 6139 as an example. That is when they were made, the first number is the year, and the last three are the day of the year. 6139 would have been made in 86 if brown wrapper or 96 if tan wrapper, and on the 139th day of the year.
And yes, if they have been stored in an attic or a Louisiana basement the last 10 years, I'd say they are less likely to be good.