These two deserve their own joint listing together, because they're basically just as bad as each other when it comes to health. They're both highly processed and tend to contain high levels of AGEs, which, as we've explained above, is very bad news. They both contain nitrates and nitrites, which can turn carcinogenic at high temperatures (as you know, this is typically the case when cooking bacon and sausages).
The solution to this is making sure you buy uncured meats with no nitrites instead. There are plenty of responsible butchers around who will be able to supply you with the healthiest kind of sausages and bacon if that's what you're after (who can resist bacon with their breakfast on the weekend?). Cooking on low heat in the oven is another way to reduce the production of AGEs.