There are additives in processed meats that are highly cancerous. They cosmetically improve the pink appearance (and have a little preservative effect).
The WHO advised that consuming 50g of processed meat a day – equivalent to just a couple of rashers of bacon or one hotdog – would raise the risk of getting bowel cancer by 18% over a lifetime.
Apparently, the meat lobbyist have been using the same techniques as the tobacco & sugar industry to hide this from the public
The part of the story we haven’t been told – including by the WHO – is that there were always other ways to manufacture these products that would make them significantly less carcinogenic. The fact that this is so little known is tribute to the power of the meat industry, which has for the past 40 years been engaged in a campaign of cover-ups and misdirection to rival the dirty tricks of Big Tobacco.
The article highlights some evidence of the coverup.
The meat industry’s tactics in defending bacon have been “right out of the tobacco industry’s playbook”, according to Marion Nestle, professor of nutrition and food studies at New York University. The first move is: attack the science. By the 1980s, the AMI was financing a group of scientists based at the University of Wisconsin. These meat researchers published a stream of articles casting doubt on the harmfulness of nitrates and exaggerating the risk from botulism of non-nitrated hams.
The entire article is a long read but gives a balanced view. Nitrites are not as damaging as tobacco in real terms, but still a proven, significant risk.
Yes, bacon really is killing us | News | The Guardian : https://www.theguardian.com/news/2018/mar/01/bacon-cancer-processed-meats-nitrates-nitrites-sausages