The most harmful health advice is the one passed from one person to another; if you heard it from many different sources, you will probably assume it is valid. But frequency is hardly validity. When I say I am hypoglycemic, 9 in 10 (among them 2 are medical doctors!) tell me I should always carry a sweet biscuit, a chocolate “just in case”, when in actual and objective fact, consuming high-glycemic index foods like processed sugar will create an even more vicious cycle of insulin spikes and even lower glucose levels. The same goes for all ailments. They dispense with advice but hardly consider how lethal their advice can be.