High-fat diets can cause depression, study finds

The results show how diets high in saturated fat can cause fatty acids to build up in the hypothalamus, disrupting its normal functioning.

  • A new study explores the relationship between obesity, fat intake, and depression.
  • The results showed that obesity induced by a high-fat diet, caused depression in mice, but that this was related to changes in the hypothalamus and not the extra weight.
  • The study could pave the way for new depression treatments, which could help the nearly 50 percent of patients who don't respond well to current antidepressants.

A new study suggests that a diet high in saturated fats can cause depression by disrupting the normal functioning of the hypothalamus.

Publishing their findings in the journal Translational Psychiatry, the researchers describe how there has long been an established correlation between obesity and depression. What's been less clear, however, is whether obesity causes depression and, if so, which biological mechanisms drive the process.

To explore these questions, the researchers examined the relationship between obesity and depression-like symptoms within two groups of mice. One group was fed a normal diet, the other a high-fat diet in which 60 percent of calories came from fat. After three weeks, the mice on the high-fat diet showed depression-like symptoms, as measured by immobility during a forced swim test and a tail suspension test — both of which are commonly used to measure the effectiveness of antidepressants.

Interestingly, the researchers found that, though some mice were overweight, higher weights "did not correlate with increased immobilization during the tail suspension and forced swim tests after 3 weeks, suggesting that the performance of the mice in these tests was not affected by their increased body weight.

"In agreement with that, the depression-like phenotype developed on mice fed an HFD [high-fat diet] was not accompanied by less locomotor or rearing activity during the open field test compared with mice on [the control diet]," they wrote.

These results suggested that something in the mice's brains — and not the extra weight — was causing depression.

After conducting protein and mRNA analyses, the researchers found that a high-fat diet disrupts the cAMP/PKA signaling pathway in the hypothalamus. This seems to be caused by the accumulation of fatty acids in the hypothalamus, a result of a high-fat diet. These accumulated fatty acids interfere with the normal functioning of the hypothalamus, leading to depression.

"This is the first time anyone has observed the direct effects a high-fat diet can have on the signaling areas of the brain related to depression," George Baillie, lead author on the study, told New Atlas. "This research may begin to explain how and why obesity is linked with depression and how we can potentially better treat patients with these conditions."

The researchers noted how half of all people with depression — and most obese individuals with the condition — don't respond to antidepressants. This new research, however, could pave the way for a "a new generation of antidepressants" that can help restore normal functioning to the hypothalamus.

3D printing might save your life one day. It's transforming medicine and health care.

What can 3D printing do for medicine? The "sky is the limit," says Northwell Health researcher Dr. Todd Goldstein.

Northwell Health
Sponsored by Northwell Health
  • Medical professionals are currently using 3D printers to create prosthetics and patient-specific organ models that doctors can use to prepare for surgery.
  • Eventually, scientists hope to print patient-specific organs that can be transplanted safely into the human body.
  • Northwell Health, New York State's largest health care provider, is pioneering 3D printing in medicine in three key ways.
Keep reading Show less

Beyond Meat announces plan to sell ‘ground beef’ in stores. Shares skyrocket.

Beyond Beef sizzles and marbleizes just like real beef, Beyond Meat says.

Culture & Religion
  • Shares of Beyond Meat opened at around $200 on Tuesday morning, falling to nearly $170 by the afternoon.
  • Wall Street analysts remain wary of the stock, which has been on a massive hot streak since its IPO in May.
  • Beyond Meat faces competition from Impossible Foods and, as of this week, Tyson.
Keep reading Show less

Thumbs up? Map shows Europe’s hitchhiking landscape

Average waiting time for hitchhikers in Ireland: Less than 30 minutes. In southern Spain: More than 90 minutes.

Image: Abel Suyok
Strange Maps
  • A popular means of transportation from the 1920s to the 1980s, hitchhiking has since fallen in disrepute.
  • However, as this map shows, thumbing a ride still occupies a thriving niche – if at great geographic variance.
  • In some countries and areas, you'll be off the street in no time. In other places, it's much harder to thumb your way from A to B.
Keep reading Show less

Can you guess which state has the most psychopaths?

A recent study used data from the Big Five personality to estimate psychopathy prevalence in the 48 contiguous states and Washington, D.C.

Surprising Science
  • The study estimated psychopathy prevalence by looking at the prevalence of certain traits in the Big Five model of personality.
  • The District of Columbia had the highest prevalence of psychopathy, compared to other areas.
  • The authors cautioned that their measurements were indirect, and that psychopathy in general is difficult to define precisely.
Keep reading Show less