Can Diet Affect Depression?

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Eating healthy is easier said than done. We all know it’s important for our physical health.

In addition to this, science is still unraveling the many ways that food can affect our mental health.

Depression is on the rise around the world. In 2012 The World Health Organization estimated 350 million people worldwide suffered from depression.

So studying depression and its causes is an important topic in research. In an effort to understand it better, a team of scientists have tried to uncover a link between diet and depression. Their study was published in the journal BMC Medicine.

Eat Your Veggies

Making associations between two complex issues like depression and diet isn’t easy. Large populations are needed to uncover if there is a concrete link between them.

So to tackle the question, researchers looked at data of over 15,000 people. It is one of the first studies of this size that has looked at multiple types of diets, their patterns, and depression.

Almudena was the lead researcher on this study. She and her team were curious if any dietary patterns could have positive effects for our brains. She explains:

“We wanted to understand what role nutrition plays in mental health, as we believe certain dietary patterns could protect our minds. These diets are all associated with physical health benefits and now we find that they could have a positive effect on our mental health.”

What diets is she speaking about?

They mainly looked at three different diets. The Mediterranean diet, the Pro-vegetarian Dietary Pattern and Alternative Healthy Eating Index-2010. The most popular is the Mediterranean diet. So if you haven’t heard of the other two don’t worry. I wasn’t familiar with them either.

Moody Food

The study took data from two different points in time. This consisted of diet questionnaires where participants reported on their food intake and patterns. The first time they were assessed was back in 1999. The second time was 10 years later.

The subjects were scored on how well they adhered to the selected diet. Things like meat and sweets were negatively scored. Foods like nuts, fruits, and vegetables were positively scored.

At the beginning, all 15,000+ participants were depression free. Over the course of the 10 years, more than 1,500 had been clinically diagnosed with depression, or used antidepressant drugs

The Winner

Which diet came out on top?

First, all 3 diets were associated with lower risk of depression. The diet that came out ahead, though, was the Alternative Healthy Eating Index-2010.

It’s interesting to note that there isn’t much difference between this diet and the Mediterranean diet. Largely they both emphasize eating nuts, fruits, vegetables, legumes, omega-3 fatty acids, and moderate use of alcohol. They are amazingly similar.

There was another interesting discovery in the data. It appeared when they started looking at how closely people were following the diets. Almudena explains the finding:

“A threshold effect may exist. The noticeable difference occurs when participants start to follow a healthier diet. Even a moderate adherence to these healthy dietary patterns was associated with an important reduction in the risk of developing depression.”

So you might be asking yourself “How well do I have to keep to the diet?” Good question. Almudena continues:

“However, we saw no extra benefit when participants showed high or very high adherence to the diets.”

So after a certain point, it seems like the benefits of following the diet closely fall off. A moderate approach yields the biggest results. Not that following it closely is a bad thing.

Diet Diagnosis

The study isn’t perfect, of course. Self-reported data isn’t always going to be the most reliable. Studies dealing with health consequences can be hard to gather consistently over large lengths of time.

Another issue is that depression doesn’t always get clinically diagnosed. On top of that, there are also different degrees of depression. People may very well be depressed, but not see anyone about it.

However, this large study points to what a lot of current research is saying. That diet affects our moods, our bodies, and our brains. If it seems like you’re outlook on life is a bit gloomy, it may not hurt to look at what you are putting into your body.

Image:
David Saddler