If you had trusted the settled science of the day, here is how it would have gone. 1890s: you dose the baby with Bayer's new cough syrup, the non-addictive alternative to morphine, marketed for children. It was heroin. They named it after the German for heroic. 1900s: you rub calomel teething powder on your infant's gums. It is a mercury compound, and it leaves a generation with pink disease. Swollen, peeling hands and feet, screaming for months, and some of them died. 1910s: you cook in Crisco, launched by a soap and candle company, because cottonseed oil is modern and lard is what your mother used. The process that made it solid produced trans fat, banned outright a century later. 1920s: you drink Radithor, certified radioactive water, on prescription. Eben Byers took fourteen hundred bottles for his vitality. His jaw was removed in pieces and he was buried in a lead coffin. 1930s: a chemist dissolves a new sulfa drug in diethylene glycol, which is antifreeze. It kills 107 people, mostly children, and only then does America give the FDA power to demand safety testing. 1940s: your doctor lights a Camel in the surgery. More doctors smoke them than any other brand, and the advert runs in the Journal of the American Medical Association, which sold him the page. 1950s: DDT is sprayed over your kitchen, your garden and your children at school. The man who found its insecticidal properties has already been given a Nobel Prize. 1960s: your wife takes thalidomide for morning sickness because it is remarkably safe. More than ten thousand children are born with missing and shortened limbs. 1970s: the country puts down the butter and picks up the margarine, on the instruction of the American Heart Association. The fat everybody switched to was banned in 2015 as unsafe at any level. 1980s: the fat comes out of everything and sugar goes back in to make it edible. Obesity begins a climb it has never come off. 1990s: your father is prescribed OxyContin, because fewer than one per cent get addicted. The company later pleads guilty to criminal misbranding, and the overdose count runs into hundreds of thousands. 2000s: you take Vioxx for your knee. It is pulled in 2004, and the FDA's own safety officer estimates tens of thousands of excess heart attacks. Not one of those was fringe. Every one had a professional body, a literature and a man in a white coat standing behind it. Nobody who followed that advice was stupid. They were obedient, to the most qualified people available. Settled is a word about money. It means the questions stopped being funded, so they stopped being asked. So which of today's instructions will your grandchildren read out in disbelief. The oil washed in hexane and built into every cell you own. The statin that blocks the pathway making your hormones, to prevent one heart attack per hundred people. The injection where a third of the loss is muscle. The infant formula built out of vegetable oil. All settled. None of it funded to be otherwise.