But a new study suggests we may be overstating the connection between spreadable goodness and the spread of heart disease and other ailments.

Researchers at the Friedman School of Nutrition Science and Policy at Tufts University in Boston examined data from more than 600,000 participants in 15 countries and found that eating a tablespoon of butter a day does not increase the risk of heart disease or stroke in any meaningful way.

Indeed, it actually found that butter might play a role in preventing Type 2 diabetes.

“Even though people who eat more butter generally have worse diets and lifestyles, [butter’s effects] seemed to be pretty neutral overall,” said Laura Pimpin, Ph.D., one of the study’s lead authors.

“This suggests that butter may be a ‘middle-of-the-road’ food,” said Pimpin, a data analyst in public health modelling for the UK Health Forum. “A more healthful choice than sugar or starch – such as the white bread or potato on which butter is commonly spread and which have been linked to higher risk of diabetes and cardiovascular disease – and a worse choice than many margarines and cooking oils.”

“Overall, our results suggest that butter should neither be demonised nor considered ‘back’ as a route to good health,” said Dr. Dariush Mozaffarian, the Friedman School’s dean and another of the study’s authors. “More research is needed to better understand the observed potential lower risk of diabetes, which has also been suggested in some other studies of dairy fat. This could be real or due to other factors linked to eating butter. Our study does not prove cause-and-effect.”

But why was butter ever considered a deadly, delectable assassin in the first place? What act of cruel defamation took place and why was the libel allowed to fester?

We could blame the World Health Organisation’s Ancel Keys and his 1955 lipid hypothesis, which claimed that butter, eggs, meat and other foods high in saturated fats contributed to heart disease. We could blame the heart associations around the world that quickly embraced the theory. Or we could blame the seed oil industry, which saw an opportunity to take butter down, to go for butter’s jugular, sullying the dairy product’s good name and claiming its share of the market for margarine. It was a sad time.

There were those of us who never gave up hope, of course. Who believed that butter’s good reputation could be rehabilitated. There were those of us who could believe that I Can’t Believe It’s Not Butter! was not butter.

For us, this is the sweetest victory of all. A victory for the true believers.

It’s hard not to celebrate, though, isn’t it? Given you can’t go five minutes these days without being told that something wonderful’s going to kill you – remember when we were told that bacon causes cancer? – it’s nice to learn that something that’s going to kill you probably isn’t going to kill you after all.