The heart attack was first described in a medical journal in 1912, and the man who described it had trouble finding a second case. Doctors had been opening chests for 300 years. They had dissected kings, paupers, drunks and the obese, and the blocked coronary artery was a rarity you wrote up. A young Boston cardiologist started practising in 1911. He later said he did not see his first heart attack patient until 1921, and then they came in a flood. By 1950 it was the biggest killer in the United States. By 1960, in Britain. Victorian England ate butter, dripping, suet, bacon and cream, and smoked like a chimney, and the coronary ward did not exist. The Masai lived on milk, meat and blood, and the doctors who went looking in the 1960s could not find heart disease among them. So what arrived between the dissecting rooms of 1900 and the coronary care units of 1960? Crisco launched in 1911. Cottonseed oil hardened into a block that looked like lard. Margarine followed it into every kitchen. By 1960 a quarter of American fat came out of a seed press that had not existed in 1900. The seed oil goes into your blood on the LDL particle. It is the part of the particle that oxidises. The oxidised particle is what the artery wall takes in. The cholesterol was in the butter for a thousand years and the artery stayed open. Then the fat changed, and a disease nobody had heard of became the way most people die. The guideline blames the butter. The butter has an alibi going back to the Bronze Age.