The food we consume can have impact on our emotions and mood.
Our diet may be linked to symptoms associated to attention deficit hyperactivity disorder (ADHD), bipolar disorder, and other neurodevelopmental disorders.
Although several studies have discovered links between diet — mostly sugar — and the attitudes seen with these conditions, the justification for the connection is not understandable.
A group of researchers from the University of Colorado are of the opinion that the answer may lie in our evolutionary past.
Researchers point out feasible role for fructose, a type of sugar found in fruit and honey, in heightening the chance of these neurodevelopmental disorders in a paper published October 16 in the journal Evolution and Human Behavior.
Fructose gives the body energy. However, it triggers a foraging response in many animals, comparable to what occurs in starvation. This reaction is beneficial for animals building up energy stores before hibernation or long-distance migration.
Foraging pertains to attitudes that support seeking out new sources of food and water — risk taking, impulsivity, raised movement, abrupt processing of information with less attention to details, and occasionally aggression.
The researchers note that many of the behaviors detected with the foraging reaction are comparable to symptoms of ADHD, bipolar disorder, and other disorders.
They also pinpoint that these disorders have heightened among the population in likeness with the rate of obesity, which comes together with a rise in the intake of sugars over the past century.
Fructose is fairly rare in nature, but it is particularly common in our modern food environment, and can be seen in many refined foods and beverages as refined sugars and high fructose corn syrup.
Dr. Shebani Sethi Dalai, a physician in obesity medicine and psychiatry at Stanford University, also acknowledges the fact that diet can influence our mental health.
“There’s a mismatch between our modern lifestyle and our ancestral potential, or our genes,” she said. “That’s why I think we’re seeing more illnesses today than before.”
Although the parallel rise in refined food intake and certain neurodevelopmental disorders is not validation that sugar is to blame, some research agrees that immoderate sugars may facilitate foraging-like attitudes.
Sethi Dalai explains that many mechanisms have been suggested for how sugar and ultra-processed foods might worsen indications of mood disorders and even psychosis, like an upgrade in inflammation or oxidative stress in the brain.
“Some of the medications for [mood disorders] can lead to metabolic side effects,” she adds. “Those can include increasing your blood glucose, or putting somebody into a category of higher weight gain or a prediabetic state.”
Further research is required to completely discern the link between diet and ADHD, bipolar disorder, or aggressive behavior, says Dr. Richard Johnson, lead author of the Evolution and Human Behavior paper.
However, “there is already sufficient evidence that reducing sugar intake is good for overall health as well as mental and behavioral health, especially for sugary beverages,” said Johnson.
Sethi Dalai approves. She utilizes the ketogenic diet with many of her patients who have bipolar disorder.
“Clinically, I have seen it improve a lot of patients’ symptoms, and even reduce the medication dosage to some extent,” she said.
Keto diet has also been used for years as a means to decreasing symptoms of epilepsy.
But research on the advantages of this diet for bipolar disorder is just commencing.
Sethi Dalai is presently calling up patients for a pilot clinical trial looking at whether a ketogenic diet can boost symptoms and metabolic measures in patients with bipolar disorder or schizophrenia.
“It would be a huge leap to say that you could cure bipolar [disorder] with the ketogenic diet,” said Sethi Dalai.
“For some patients, [diet] might be something that can be used in the place of medication. But I think for the vast majority of patients, medications still play a role.”