[LUM#10] Junk Food, Poor Health
Eating better for better physical… and mental health. This is what Tasnime Akbaraly’s research reveals, showing that adopting a healthy diet may help reduce the risk of depression.
Cardiovascular disease, cancer, diabetes, obesity… The list of diseases linked to poor diet keeps growing. To this list, we must now add a new condition: depression. It affects 350 million people worldwide, or 7% of women and 4% of men. “Depression is the most costly brain disease in Europe, ” says Tasnime Akbaraly of theMolecular Mechanisms in Neurodegenerative Dementias laboratory.
The nutritional epidemiologist has been studying the link between diet and mental health for 10 years. “We don’t have a perfect treatment for depression,” she laments. “Drug and non-drug therapies are effective in only one out of three cases, and the risk of relapse after a major depressive episode is 50%.”
A multifactorial disease
A multifactorial condition involving both genetic and environmental factors, “which we cannot influence, ” notes Tasnime Akbaraly. Researchers therefore set out to identify modifiable factors to address the causes of depression. “Many studies highlight the importance of nutrients in brain function, so it seemed logical to conduct research to investigate the link between diet and depression.”
By analyzing the diets of volunteers while monitoring their mental health, researchers found that a healthy diet is associated with a lower risk of depressive symptoms. “Conversely, eating fatty and sugary foods and favoring processed foods increases the risk of depressive symptoms by 60%, ” the researcher explains.
In a study published in 2018 in the journal Molecular Psychiatry, Tasnime Akbaraly and her colleagues analyzed data from a follow-up study of 36,556 adults. The results speak for themselves: those who adhere most closely to the Mediterranean diet (see box below) have a 30% lower risk of developing depression. How can this link between diet and depression be explained? The researchers identified two metabolic pathways that may be involved: inflammation and the microbiome.
Pro-inflammatory diet
The study published in *Molecular Psychiatry* showed that a pro-inflammatory diet—rich in saturated fats, sugar, and refined foods—was associated with a higher risk of depression. “The chronic inflammation potentially induced by this type of diet could be directly involved in the onset of depression. These findings support the hypothesis that avoiding pro-inflammatory foods helps prevent depressive symptoms, ” explains the researcher.
Numerous studies have also demonstrated the importance of diet in shaping the composition of the gut microbiota. “The gut-brain axis is very important and remains poorly understood, but we know that the bacteria that make up our microbiota play a role in the permeability and inflammation of the intestinal barriers,” explains Tasnime Akbaraly. The relationship between the gut and the brain therefore appears to play a key role in the onset of depressive disorders.
No adverse side effects
Given these links, Tasnime Akbaraly advocates for giving diet the importance it deserves in the treatment of depressive disorders. “There is a study that followed two groups of patients with depression who were advised either to adopt the Mediterranean diet or to socialize more. The result: those who changed their diet saw their risk of depression decrease more than those who focused on their social lives.”
When will we see a recommendation for a healthy diet to treat depression? “Psychiatrists should address the issue of nutrition,” argues Tasnime Akbaraly. “It’s an additional tool in the therapeutic arsenal available to doctors, one that empowers patients to take an active role in their own treatment, and one that is completely free of negative side effects. What are we waiting for?”
The Mediterranean Diet: A Guide
The Mediterranean diet draws directly from the traditional eating habits of people living around the Mediterranean. It is based on a high intake of fruits and vegetables, nuts, whole grains, legumes, and olive oil. Fatty fish rich in omega-3 and seafood are recommended on a regular basis. Consumption of meat, processed meats, dairy products, salt, and sugary foods should be strictly limited. Alcohol may be consumed in moderation.
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