1774: they blew tobacco smoke up drowning victims' backsides to revive them, and the kits hung along the Thames like lifebuoys. 1863: they sold cocaine wine as a daily tonic, and a pope pinned a gold medal on it. 1898: they sold heroin as a cough medicine, and spooned it into coughing children. 1918: they sold radium water as a health drink, and the millionaire who drank 1,400 bottles was buried in a lead-lined coffin with most of his jaw gone. 1921: they put lead in petrol, and Britain kept it in the pumps until 2000. 1930s: they X-rayed children's feet in shoe shops, and kids queued to watch their toes wiggle on the screen. 1940s: they rubbed mercury teething powder into babies' gums, and about 1 in 500 of those babies was poisoned. 1946: they sold cigarettes on the line that more doctors smoked their brand, and put a man in a white coat on the advert. 1949: they gave the lobotomy a Nobel Prize, and doctors went in through the eye socket with an ice pick. 1952: they sold a cigarette filter made of asbestos as the greatest health protection in smoking history, and smokers drew it into their lungs with every puff. 1957: they sold thalidomide to pregnant women for morning sickness, and around 10,000 babies were born with missing or shortened limbs. 1960s: they sold margarine as the heart-healthy fat, and spread trans fat on a generation's toast. 1996: they sold OxyContin as barely addictive, and started an overdose epidemic. 1999: they sold Vioxx for sore joints, and pulled it five years later after tens of thousands of heart attacks. 2026: they're selling seed oil as the heart-healthy fat, and it's in almost every packet in your kitchen. Every one of these came with an expert's blessing and the same total certainty. The people telling you which fat to fear today sit in the same chairs as the ones who put radium in the water and a doctor on the cigarette packet, and they're every bit as sure. "The experts recommend it" has the longest body count in medicine.