Dieting for mental well-being: Keto diet found to lower depression symptoms

Sixteen US college students following a well-formulated ketogenic diet for at least ten weeks experienced a 70% decrease in both self-reported and clinician-rated depression symptoms, according to a new research.

The students reported that their overall well-being increased nearly threefold. They also recorded improvements in their ability to perform several cognitive tasks. All but one lost weight while on the eating plan.

The students involved in the pilot trial were receiving medication, counseling, or both for major depressive disorder before beginning the keto diet.

The findings suggest reaching nutritional ketosis through diet is a feasible complementary therapy for depression, which paves the way for a larger clinical trial.

“So many people are suffering right now, so it’s rewarding to potentially bring forward a solution,” says lead author Jeff Volek, Ph.D., professor of human sciences at The Ohio State University.

“There is more science yet to do, but because there is evidence of a benefit, expanding accessibility to a well-formulated ketogenic diet as an augmentation to treatment for depression is something to think about.”

Beginning with preliminary guidance

Volek’s lab collaborated with Ohio State mental health experts to design and complete the trial. The students, ten women and six men, had an average age of 24.

Study facilitators relayed extensive education about the keto diet to students, which comprises less than 50 g of carbs per day, high fat, and moderate protein.

Clinician-rated assessments of depression at week six and around weeks ten to 12 decreased by 59% and 71%, respectively.

A keto diet converts fat into ketones, used by cells in the body and brain as an alternative to glucose. Research has found that it places the body in a state of nutritional ketosis, which is when it has more access to ketones as both fuel and a signaling molecule.

“It was very important to make sure participants knew what they were getting themselves into,” said Drew Decker, first author of the study and a graduate student in Volek’s lab.

“And a big part of increasing chances for adherence to the diet was talking to each individual about what they like and don’t like to eat, so we could tailor some suggestions for how they could structure their diet.”

Calories not accounted for

For the first half of the trial, researchers supplied the students with ten complete starter meals and additional snacks while conveying consistent advice. They also communicated with participants through a private app during the study timeline.

The students were instructed to eat when they were hungry and finish eating when they were full, without worrying about calories.

The students reported depressive symptoms using the Patient Health Questionnaire-9 — the standard instrument to measure the severity of depression in clinical settings — at baseline and over the course of ten to 12 weeks.

They also completed the WHO-Five Well-Being Index, alongside a series of cognitive tests that assessed episodic and working memory, processing speed, executive function, attention, and inhibitory control.

“One of the things we really wanted to make sure of is that we were providing a treatment for people who met the diagnostic criteria for having major depressive disorder,” says co-author Jennifer Cheavens, Ph.D., professor of clinical psychology at Ohio State, who oversaw clinical assessments of participants before and throughout the trial.

“Each participant had about a two-and-a-half-hour interview at the beginning and then weekly assessments of their symptoms.”

Additionally, students were screened to ensure that they did not have any contraindications to a ketogenic diet, such as a body mass index of under 20, eating disorders, pregnancy, or high alcohol consumption.

Reaching ketosis

Based on measurements of blood ketone levels, the researchers identified that participants had achieved ketosis 73% of the time. This indicated good adherence to the diet.

By week two, self-reported depression scores had decreased 37%. Moreover, perceived ratings of global wellness had increased two-fold, which improved to nearly three-fold at the end of the intervention.

Between weeks ten to 12, they had improved by 69%. Symptom severity varied, but none of the participants reported worsened symptoms.

Clinician-rated assessments of depression at week six and around weeks ten to 12 decreased by 59% and 71%, respectively.

Co-author Ryan Patel, a psychiatrist in Ohio State’s Office of Student Life Counseling and Consultation Service, who monitored students during the trial, highlights the notable reduction in depressive symptoms linked to the keto diet.

“The average effect size for medications and counseling after 12 weeks is about 50%, and we saw a substantially greater result,” he reports.

“That is an impressive finding, that across the board, in this real-world setting, everybody got better, and across the board, our participants did not need more treatment or emergency intervention.”

Weight loss and cognitive function

Collectively, participants lost 11 lb on average, while their body fat decreased by 2.4%. Most exceeded the clinically significant drop of 5% weight loss.

As a group, participants’ performance improved on cognitive tasks assessing episodic memory, processing speed, and executive function.

There were no reported significant changes in cholesterol or triglycerides.

Ketosis as a therapy aid

Volek has been studying therapeutic applications of ketosis for over two decades for various conditions, including heart disease, cancer, and athletic performance and resilience. for over two decades.

“The idea is that the ketogenic diet is working through a variety of potentially different mechanisms — there’s a whole range of physiological metabolic adaptations to the diet that could overlap with some of the pathophysiology of depression,” he says.

To help inform future research, the team collected a range of biological data on changing levels of proteins related to inflammation and brain function. Further research will examine potential mechanisms behind the diet’s effects.

“We haven’t teased out those mechanisms here because this is a proof-of-concept study for an adjunctive therapy,” Volek notes. “This is one of the first really well-controlled studies, and it has limitations, but the results encourage us to want to keep pursuing it.”

The pilot study, published in the journal Translational Psychiatry, did not have a non-keto control group for comparison. Previous research has suggested that medications and counseling reduce depressive symptoms by about 50% in a similar time period.

“We have a treatment gap in that we have more students suffering from mental health concerns than can feasibly receive professional treatment,” Patel concludes. “There is a need for finding ways of helping students on a large scale. And nutrition is one way we can do that.”

The study builds on clinical research last year linking keto diets to “dramatic improvements” in metabolic function and psychiatric symptoms in patients diagnosed with either bipolar disorder or schizophrenia.