Let food be thy medicine and medicine be thy food.
Who said anything about medicine? Let’s eat!
Who hasn’t seen or heard Hippocrates’ famous quote about letting food be your medicine and your medicine your food? If you have Facebook friends who are the least bit into “natural” medicine or living, you’ve almost certainly come across it in your feed, and if you’re a skeptic who pays the least bit of attention to what’s going on in the quackosphere you will almost certainly have seen it plastered on a picture as a meme, either using a picture of Hippocrates or pictures of plates of green, leafy vegetables, or both. I like to view the fetishization of “food as medicine,” to cite Hippocrates, as one of the best examples out there of the logical fallacy known as the appeal to antiquity; in other words, the claim that if something is ancient and still around it must be correct (or at least there must be something to it worth considering).
Of course, just because an idea is old doesn’t mean it’s good, any more than just because Hippocrates said it means it must be true. Hippocrates was an important figure in the history of medicine because he was among the earliest to assert that diseases were caused by natural processes rather than the gods and because of his emphasis on the careful observation and documentation of patient history and physical findings, which led to the discovery of physical signs associated with diseases of specific organs. However, let’s not also forget that Hippocrates and his followers also believed in humoral theory, the idea that all disease results from an imbalance of the “four humors.” It’s also amusing to note that this quote by Hippocrates is thought to be a misquote, as it is nowhere to be found in the more than 60 texts known as The Hippocratic Corpus (Corpus Hippocraticum).
But Hippocratic doctors clearly saw a difference between food and medicines. In fact, food was considered as a material that could be assimilated after digestion (e.g. the air was also food) and converted into the substance of the body. For example, food was converted into the different parts of the body such as muscles, nerves, etc. By contrast, the concept of medicines at the time was a product which was able to change the body’s own nature (in terms of humor quality or quantity) but not be converted into the body’s own substance. Thus a food wasn’t considered a medicine. A possible root of the food-medicine confusion is the following cryptic phrase found in the work On Aliment: “In food excellent medication, in food bad medication, bad and good relatively”.3 This text is nowadays attributed to the Hellenistic period, but was considered to be Hippocratic in Antiquity by Galenus in particular.
Now, it is certainly true that Hippocrates and his followers used diet to treat many illnesses, it’s not really clear what sort of success they had. However, this ancient idea that virtually all disease could be treated with diet, however much or little it was embraced by Hippocrates, has become an idée fixe in alternative medicine, so much so that it leads its proponents twist new science (like epigenetics) to try to fit it into a framework where diet rules all, often coupled with the idea that doctors don’t understand or care about nutrition and it’s big pharma that’s preventing the acceptance of dietary interventions. That thinking also permeates popular culture, fitting in very nicely with an equally ancient phenomenon, the moralization of food choices (discussed ably by Dr. Jones a month ago).