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Surprising Science

We know diet causes depression. This one might help cure it.

Going back to the basics is often the best path forward.
Mediterranean Food. (Photo by: Media for Medical/UIG via Getty Images)

Last week, my Twitter feed was dominated by news about a “new organ” that has recently been discovered. Given how many centuries we’ve been conducting autopsies, this newsflash was rather hard to believe. The interstitium is not new, exactly, but its role has been greatly expanded. Once believed to a dense layer of collagen, it turns out these fluid-filled spaces might aid the spread of cancer tumors to lymph nodes. 

This discovery will likely lead to new lines of research in cancer. It also highlights how complex our bodies are, as well as why continual research is necessary for helping us fight disease. In this light, cancer research is not the only field we’re making progress in.

Depression is one of the most common psychological disorders on the planet. While there are no biological markers (as with cancer), the feeling of depression, defined in part by an inability to imagine a hopeful future, is spreading across the planet. While depression can (and does) manifest in every age group, the startling uptick in teens should be treated as a public health crisis. 

As author Lauren Slater, who’s been suffering from depression for over three decades, recently told me, though rates of SSRI prescriptions are increasing every year, so is the rate of people diagnosed with the disorder. That is not a good sign for this intervention except for the companies producing the drugs. 

SSRIs supposedly target serotonin in the brain. The problem is serotonin interacts with numerous other systems. It is impossible to isolate. Add to that the fact that 95 percent of serotonin is produced in the gut and it becomes obvious that psychiatrists and psychologists have been looking in the wrong place.

Over 90 percent of sensory information collected in your gut never reaches conscious awareness, writes UCLA professor Emeran Mayer. Turns out that’s the same percentage of information sent from the gut to the brain. The brain, treated as the most important organ in the body, only sends 10 percent of information back to the digestive system, a stunning conversational imbalance.

The notion that the food you eat causes depression is not new. As Olga Khazan writes at The Atlantic, “the connection between diet and depression is so well-established that more studies…aren’t really necessary.” 

Connecting those dots is ultimately unsatisfying without discussing a diet that reverses those effects. Some researchers believe the DASH diet might fulfill that role. Otherwise known as “dietary approaches to stop hypertension,” the DASH study kicked off in August 1993 when the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH), noticed our increasing waistlines. The study ended in July 1997.

In a media environment dominated by holistic wellness bloggers pontificating on the next “superfood” and professional trainers touting another breakthrough nootropic, DASH is relatively tame. Being basic has its advantages, however—this diet is easy to understand and financially accessible for most: fruits, vegetables, whole grains, olive oil, and moderate meat intake, with a focus on fish. Throw in some nuts and cut down on dairy. That’s about it.

Not sexy, I know. Yet the recent obsession with “clean” eating and supercharged, antioxidant-rich foods is more indicative of neuroses than good science. While I’m a fan of the ketogenic diet—I question DASH’s wisdom regarding “low-fat dairy” given what we’ve learned about fats, cholesterol, and cardiovascular disease since the nineties—we have to admit the so-called “Western diet” is not working.

Perhaps the real problem is processed food we’re consuming. While “processed” is a vague term—most every food is processed in some manner before meeting your mouth—what’s often left out in discussions on the Western diet is the list of unpronounceable preservatives and emulsifiers interacting with whatever quantities of actual food are in the packaging. The connection between sugar and obesity and sugar and depression is well established, so beyond the many names sugars are disguised as, the main point is to buy whole foods and cook them yourself.

Regardless, leaning heavily on plants is never a bad thing. As Khazan notes,

When people eat a plant-heavy diet, the fiber from the plant matter ferments in the gut and creates short-chain fatty acids, which, in turn, regulate the immune system and influence gene expression in the brain and elsewhere. People who eat fiber have more diverse gut bacteria, and these bacteria make various chemicals that influence our mood.

Terms like “emotional eating” and “comfort food” signify real phenomena. Unfortunately, those tend to be sugar- and carb-heavy foods, often eaten at night as our willpower levels drop. Along with an excess of processed foods, there is nothing comforting about the emotional distress that such products create in our bodies. A few days or even weeks of withdrawal to change a bad habit is a worthwhile sacrifice, especially when the result is the alleviation of depression.

Derek Beres is the author of Whole Motion and creator of Clarity: Anxiety Reduction for Optimal Health. Based in Los Angeles, he is working on a new book about spiritual consumerism. Stay in touch on Facebook and Twitter.


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