Age alone does not indicate whether the product is safe to eat. Poorly canned items can be dangerous
                            after a couple of months, whereas well prepared can last many years in jars without becoming
                            dangerous, BUT it looses it's nutritional value! (as well as texture, taste, etc.)

                            Rule of thumb I was taught as Maximum for storage is:

                            jellies= 5 to 7 years
                            Fruits in syrup- 5-7 years
                            fruits in water- 3-5 years
                            low acid vegetables- 3 to 5 years
                            High acid vegetables- 2-4 years(more chance of rust to lids)
                            meats without bone- 3-5 years
                            meats with bones- 2 to 3 years

                            The biggest problem is, that stored longer than the above times, the food will loose such a large
                            percentage of it's nutritional value that eating it becomes a futile thing.

                            It is quite possible for the canned food to remain safe for much longer than this, much depends upon
                            the humidity (rust on lids), if the product is stored in darkness or light or mix (dark lasts longest