Can fries promote depression? A new study suggests so.

A new study links high-fat and fried foods to mental illness. But questions remain.

Eating a balanced and healthy diet is not only good for the body. Numerous scientific studies have now shown that mental health is also related to the diet. The Mediterranean diet, for example, lowers the risk of developing depression, as several studies have shown in recent years.

Conversely, high-fat, highly processed foods can negatively impact mental health. A study from China now provides new evidence that regular consumption of fried foods such as French fries significantly increases the risk of developing depression or anxiety disorders.

For their analysis, the researchers from Hangzhou, China, observed the eating habits and mental health of more than 140,000 subjects over a period of around 11 years.

It turned out that those who regularly consumed fried food showed a roughly seven percent higher risk of depression and a roughly twelve percent higher risk of anxiety over the observation period compared to those participants who did not eat any fried food.

The research team wrote in the journal “PNAS” that fried potato products in particular attracted attention. With these products, the risk of depression was two percent higher than with fried white meat.

The scientists suspect that one reason for this is that when potatoes are fried, acrylamide is produced – a chemical substance that is also produced in other starchy foods such as baked goods or bread during preparation or processing at high temperatures, for example roasting and baking at over 120 degrees Celsius.

According to the authors of the study, the intake of acrylamide over a longer period of time can disrupt the fat metabolism in the brain. This could lead to neuroinflammation – i.e. to inflammatory processes in the central nervous system – which in turn could trigger behaviors similar to anxiety and depression.

In a 2011 study, Spanish researchers had already described the connection between the consumption of certain food components and the occurrence of depression. Her study, published in the journal “Plos One” with more than 12,000 test persons, showed what influence the type of fat can have.

According to this, people who consume a lot of trans fats and saturated fats through their diet have an increased risk of mental illness. The researchers identified trans fats (TFA, abbreviation for trans unsaturated fatty acids) as the greatest risk factor. These unsaturated fatty acids are formed when vegetable oil that is actually healthy is hardened through industrial processing. They can be found in french fries, crisps, baked goods and a number of finished products.

Even if the current Chinese study seems to support the assumptions of previous studies, it must be viewed with caution. Because it is still not possible to say with certainty whether certain foods actually cause psychological problems, or whether people with certain mental illnesses eat differently and eat unhealthy fast food such as French fries particularly often.

This is also confirmed by Yu Zhang, one of the authors of the Chinese study, to the US broadcaster “CNN”: There is “no reason to panic about the negative effects of fried foods,” said Yu Zhang. Nevertheless, he recommends avoiding fried goods for the sake of health and maintaining a healthy lifestyle.

Numerous studies assume that mental illnesses such as depressive symptoms arise from a complex network of factors that interact and influence each other. In addition to hormonal, cognitive and genetic factors, the composition of the bacteria in the intestine and stress can also play a role.