When Food Is Medicine
Asking about diet can improve outcomes in depression
Posted Sep 03, 2015
As medical visits get shorter and more specialized, one thing that often gets missed is a discussion of diet. The doctor might have a couple dozen other questions to ask that meet some sort of required standard, such as smoking status or pregnancy*. If someone just got fired or lost a dear relative, the current crisis trumps discussion of general lifestyle. Some patients don’t want to talk about diet, and some doctors get frustrated when patients continue to eat junk food and feel that asking about diet is a waste of time. After all, is there really a proven benefit that talking about diet can help a patient’s medical condition, particularly psychiatric conditions?
Dr. Sarah Stahl and her group out of Pittsburg asked this very question in a research study published in the American Journal of Psychiatry. The free full text is available on PubMed. This study was designed to see if a gentle form of “problem solving” therapy could prevent the onset of major depressive disorder in older adults at risk of developing depression. The subjects all scored positive for mild depression symptoms, but not full blown major depressive disorder. Prior research on older adults with mild depression shows that individuals have about a 20-25 percent chance of developing major depression over the next year. Since major depression has very detrimental effects on quality of life and health in older adults, it makes sense to see if some sort of intervention, if started early, could prevent depression. These particular patients were randomly assigned to either therapy or dietary coaching. The dietary coaching was meant to be the control group, because it was felt that talking to the patients about diet wouldn’t likely influence mental health, though it was similar to the therapy arm of the study in terms of giving people helpful attention.
In the intervention, patients were asked about their diet and then given instructions on making it healthier, primarily by advising more home cooking, healthier cooking methods, like baking instead of frying food, and reducing processed foods. Patients were also instructed to lower fat content. There were six sessions in the first nine weeks followed by “booster” sessions at longer intervals over the next two years.
Amazingly, patients involved in the dietary intervention arm of the study had on average a 40-50% reduction in depression symptoms in six weeks along with improved quality of life scores, and these gains were maintained for two years. While traditional methods for treating minor depression can be met with poor adherence and dropping out of the study, the subjects seemed to like this intervention. For the most part, subjects kept up with the visits for the whole two years.
Why was this intervention so effective even though the study designers picked it originally because they thought it wouldn’t impact mental health? Eating whole, minimally processed foods have been found again and again to work as a preventative measure against developing depression in many observational studies. The vitamins, minerals, and quality carbohydrates, fats and proteins in whole foods simply make the brain and body work better than the sub-optimal fuel found in most processed foods. A whole foods diet is anti-inflammatory and better for the microbiome too.
So there you have it. Eating whole foods is medicine! Doctors are not wasting time chatting with patients about recipes and home cooking, but performing a valuable clinical service for ongoing good health.
Copyright Emily Deans MD
*True story: I once got docked on a medical record audit by an insurance company for failing to document that I had asked the patient if she could be pregnant. While this question is very important in some circumstances, this particular patient was a man.