Research Shows Diet Can Potentially Cause—And Prevent—Depression

Photo credit: Flickr / Ian Sane

I’m always sensitive to reporting with regard to nutrition and depression, because I’m someone who specializes in talking about nutrition and someone who lives with depression.

People never want to acknowledge that depression isn’t simply ‘choosing to be down in the dumps;’ in the same vein, people also refuse to acknowledge that the foods people eat are rarely about ‘choice.’ Part of what makes it hard for people to respect those two points is because it seems so antithetical to how they themselves live. “I don’t just choose to stay unhappy when I’m upset” is said with the same comfort as “I simply choose to put down the cheese puffs.” Neither situation is that easy for everyone.

And that’s why I’m so sensitive to how this stuff is covered, because if the truth really is that nutrition affects mood, then it could easily be turned into “well if you choose choose different foods, you’ll come out of depression.” Same with the link between exercise and depression—it quickly becomes, “Well, if you just worked out…”

It’s never that simple.

Having said all that, let’s get into it:

Researchers from the University College London recently conducted an study, published in Molecular Psychiatry, to explore the role of nutrition in depression.

To do so, they examined 41 observational trials on the topic, which included data on more than 32,000 adults. The participants followed a traditional Mediterranean diet, which is rich in plant foods like vegetables, fruits, legumes, nuts, olive oil and fish.

After analyzing the results, they found the Mediterranean diet was associated with a 33 percent reduced risk of depression, compared with diets unlike it.

“There is compelling evidence to show that there is a relationship between the quality of your diet and your mental health,” lead author Camille Lassale said in a statement. “This relationship goes beyond the effect of diet on your body size or other aspects of health that can in turn affect your mood.”

They also revealed a pro-inflammatory diet was linked to a higher risk of depression. They defined a pro-inflammatory diet as one that typically has high amounts of sugar, processed foods and saturated fat. [source]

The Mediterranean Diet is, by all accounts, virtually 100% unprocessed ingredients. It’s basically fresh produce, high in healthy dietary fats, and smaller amounts of meat than typically found in the American diet. It has been considered the healthiest diet on the planet by numerous sources, but I’m skeptical of that—what makes it such a healthy diet is its reported absence of processed food, and the Mediterranean isn’t the only region with a diet free of hyperprocessed items. Not only that, but not even the Mediterranean is eating their own diet as much as they used to. The more they introduce processed foods to their diet, the unhealthier they become.

When I think about what it means to eat your feelings, I think it means to use food to control your mood instead of using healthy coping mechanisms that don’t have harmful consequences. The moment you begin using food to manage your emotions, you wind up caught in a cycle where your highs and lows are centered around what food you have had, are having, and will have throughout the day. It’s an isolating, shame-inducing cycle, and many of us have experienced it to varying degrees.

I think that using food to control your mood requires certain kinds of food, eaten in certain ways, because the eater is looking for a certain feeling… and they will eat until that feeling is achieved. I know that, from my personal experiences, that “ahhhhhh” feeling was always the goal, combined with the satisfaction of having “cleaned my plate.” Perverse though it may have been, it was my reality. And it was a feeling I chased through processed foods.

What happens when you decide to stop?

Researchers found that people attempting to cut down on eating highly processed foods experience some of the same physical and psychological symptoms — such as mood swings, cravings, anxiety, headaches and poor sleep — as those quitting smoking cigarettes or using marijuana, according to the study, which was published online Sept. 15 in the journal Appetite.

The new study offers the first evidence that these withdrawal-like symptoms can occur when people cut down on highly processed foods, said lead study author Erica Schulte, a doctoral candidate in psychology at the University of Michigan.

Based on the participants’ self-reported symptoms, withdrawal symptoms were most intense between the second and fifth days after attempting to reduce junk-food consumption, which parallels the time span people live through during drug withdrawal, Schulte told Live Science.

The idea that food may be addictive after “heavy” use by some individuals is a controversial subject, Schulte said. Although prior research studies in animals and humans have shown some biological and behavioral similarities between substance-use disorders and addictive-like consumption of highly processed foods, no studies have looked at whether reducing junk food can trigger withdrawal symptoms in people, she noted.

In the study, the researchers developed a new tool modeled after the withdrawal scales that are used to assess symptoms that occur after people quit smoking or stop using marijuana. This modified questionnaire was given to more than 200 adults who had dieted during the past year by attempting to cut down on junk food.

The results showed that the symptoms people experience during withdrawal from tobacco or marijuana may also be relevant to cutting out highly processed foods from the diet, Schulte said. Withdrawal is a key feature of addiction and showing that it may also occur when reducing junk-food consumption provides more support for the hypothesis that highly processed foods may be addictive, she added. [source]

The research I’ve done with regard to food addiction—which is functionally similar to emotional eating—leads me to believe that food addiction isn’t simply an issue of nutrition, but of behavior and psychology. If food has the potential to impact your mood positively, then you have the ability to become attached to that food; when you remove something that you’ve become attached to, then you have the potential to suffer withdrawals. And if that is a reality for some people, then we have to change the way we talk about weight loss and fitness, and the ways in which we help those particular people achieve their goals.

I’ve tied these two articles together because it highlights something that people try to downplay as a matter of personal choice. If the only food options you have in your area are the kinds that would cause you to suffer withdrawals when you try to change, should we judge you if you struggle with quitting? If a junk food diet causes withdrawals, can withdrawals also contribute to depression? In other words, can junk food contribute negatively in the same way that fresh produce can contribute positively?

And, if that’s the case, shouldn’t we let this information influence the way we think about supporting better public health?

My personal theory on all this is that the more processed food one introduces into their diet, the more their food choices become guided by how the food makes them feel and, therefore, not about how filling or satisfying it is. Because their brain will slowly become accustomed to how much they’re eating and then not deliver the same feeling in response to the same quantity of food, people naturally increase the amount of food they eat because they’re still chasing that feeling. I think this chasing of feelings also means people are susceptible to even deeper crashes after the high that results in the feeling of depression… and, because you’re talking about brain-level hormones, you’re talking about clinical depression. And, if my theory is correct, then it has to change the way we talk about food choices, how we encourage people to eat, and why we encourage them to add some things and subtract others.

Thoughts?