How Have Views on Nutrition and Mental Health Changed?

Human knowledge of the relationship between nutrition and mental function probably goes back in time for many thousands of years, but it has been documented for “only” ~2,700 years. Join us now for a fun ramble through history.

When was the first report of a clinical trial on the impact of nutrition on mental/cognitive health? It’s in the Bible, in the first part of the Book of Daniel. At the beginning of the Babylonian Exile that lasted about 50 years until ~538 BCE, King Nebuchadnezzar pillaged Jerusalem and took captives back to Babylon. Nebuchadnezzar wanted the captured youths, who would train for 3 years to serve in his palace, to eat the same food as the royal family. One captive, Daniel, did not like the idea of “defiling” his body with a diet that seems to have been rich in meat and alcohol. So Daniel proposed a 10-day trial in which he and 3 friends would be given only legumes and water, and then the king could compare the 4 of them with those eating the royal diet. The result, variously translated, was that after 10 days, “in all matters of wisdom and understanding, … he found them ten times better” than the others. In other words, diet affected brain function! (Side note: Some people now follow a “Daniel diet.”)

What was the view of the ancient Greeks toward food and nutrition? Is there any quotation more frequently attributed to Hippocrates than this one? “Let food be thy medicine, and medicine be thy food.”

How did people in the modern era view nutrition and mental health prior to the explosion of pharmaceuticals in the mid-20th century?Mrs Beeton’s Book of Household Management, first published in 1861, provided a guide to running a household in Victorian Britain. This 1,112-page tome mostly contains recipes but also has sections on how to manage children, the servants, and properties, as well as a section dedicated to how to keep well—a large portion of which discusses the role of food. A section devoted to “invalid” cookery shows the wisdom of the time about the importance of diet:

Diet can often cure where drugs are useless or worse. Diet is always harmless where drugs are usually dangerous. Every year diet plays a larger part in the skilled treatment of disease. And yet we often see unskilled women, who would hesitate before changing their children’s diet from roast meat and milk puddings, more than before pouring down their throats all manner of powerful medicines. For the majority of common ailments, some slight change of diet is by far the best remedy.

For the most part, Mrs Beeton was talking about the treatment of physical ailments; however, she also appreciated the role that food played in the expression of psychological symptoms: “If we consider the amount of ill-temper, despondency, and general unhappiness which arises from want of proper digestion and assimilation of our food, it seems obviously well worth while to put forth every effort, and undergo any sacrifice, for the purpose of avoiding indigestion, with its resulting bodily ills.”

Are there North American examples of Mrs Beeton-type wisdom before the current age of pharmaceuticals? We found a major reference used throughout the American west and the prairie provinces of Canada in the early 20^th century. The 1910 book The People’s Home Library was a source of in-depth, practical knowledge, especially for those living far from health care for themselves or their livestock. In three volumes, The People’s Home Library taught you how to cook, treat various ailments, make soap, increase your supply of breast milk, build a house, care for your livestock, and much more. One volume is entirely recipes (the other two are about medical and livestock issues). When we found a copy in rural Alberta, we found text that said, “The number one cause of acquired insanity is imperfect nutrition.” Food was always known to be important, including for mental health.

Has processing of food resulted in a poorer diet? Perhaps some of us heard our grandparents talk about how they ate prior to World War II, before processed food became widely available. Some will recall their attitude that food processing (in particular, preservation by canning and freezing) improved our nutrition enormously. It enabled the population-at-large to eat produce year round that otherwise was available only in the summer. But the early days of processing that broadened accessibility of fruits and veggies gradually gave way to packaged food. In a future post, we will review some of the research comparing the mental health of people who eat mostly processed food to that of people who eat a traditional diet.

So, our ancestors knew that nutrition is a big part of the mental health picture. We believe that the rise of the pharmaceutical era eclipsed the rich historical knowledge that our ancestors had about the importance of food for maintaining good mental health.

This blog entry is adapted from a previous entry that can be found athttp://www.madinamerica.com/2013/04/study-the-past-if-you-would-define-the-future-confucius/.

Financial disclosure:Drs Kaplan and Rucklidge had no relevant personal financial relationships to report, and no company has ever funded any of their studies.