Harvard Doctors Discover a Link Between a Certain Type of Diet, Depression, and Frailty

The impact of dietary inflammation on the development of frailty and other health problems may be more pronounced in middle-aged and older people who are depressed.

According to recent research published in The Journal of Gerontology: Medical Sciences, there is a link between depression, diet, and the development of frailty. Frailty affects 10-15% of elderly adults and often co-occurs with other medical conditions, such as depression. It is characterized as an identifiable state of heightened vulnerability brought on by a loss in function across multiple physiological systems.  The development of frailty is thought to be significantly influenced by diet.

Previous studies have shown a correlation between an inflammatory diet, which includes artificial trans fats (like partially hydrogenated oil), refined carbohydrates, and saturated fats, and the risk of developing frailty. However, this is one of the first studies to attempt to understand the impact of depression on dietary inflammation and frailty.

The researchers hoped to determine if those who experience depressive symptoms are more prone to developing frailty in response to dietary inflammation. The Framingham Heart Study Offspring cohort provided the data used in the study. The 1,701 non-frail individuals provided information on their diet and depressive symptoms at the start of the study. They were followed for about 11 years when frailty status was reassessed.

The research discovered a link between an inflammatory diet and an elevated risk of frailty, which was somewhat greater among individuals with depressive symptoms. Researchers believe that since people who experience depressive symptoms often have greater levels of inflammation, adding dietary inflammation on top of that might hasten the onset of frailty.

Courtney L Millar, Ph.D., Post-Doctoral Fellow, Marcus Institute of Aging Research, Hebrew SeniorLife, and Harvard Medical School, is the lead author. “This study found that depressive symptoms may exacerbate the development of frailty in response to consuming an inflammatory diet. This suggests that consuming a diet rich in anti-inflammatory compounds (e.g., fiber and plant-based compounds called flavonoids) may help prevent the development of frailty,” Dr. Millar said.

“Our exploratory data also suggests that when middle-aged and older adults consume a pro-inflammatory diet, they are more likely to newly develop depressive symptoms and frailty at the same time rather than develop either condition alone,” she added.

This research follows two prior studies conducted by Dr. Millar, one published in May 2022 in the American Journal of Clinical Nutrition that showed that consuming a Mediterranean-style diet may prevent the development of frailty, and one published in February 2022 in the American Journal of Clinical Nutrition that showed a pro-inflammatory diet increased the risk of frailty development.

“This study contributes to the understanding of the relationship between dietary inflammation, depression, and frailty,” Dr. Millar said. “For those with depression, it may be even more important to increase their intake of fruits and vegetables that are rich in fiber, flavonoids as well as other dietary antioxidants.”

Reference: “Association of Proinflammatory Diet With Frailty Onset Among Adults With and Without Depressive Symptoms: Results From the Framingham Offspring Study” by Courtney L Millar, Ph.D., Alyssa B Dufour, Ph.D., James R Hebert, DSc, Nitin Shivappa, Ph.D., Olivia I Okereke, MD, MS, Douglas P Kiel, MD, MPH, Marian T Hannan, DSc, MPH and Shivani Sahni, Ph.D., 13 July 2022, Journal of Gerontology.
DOI: 10.1093/gerona/glac140

The study was funded by the National Institute on Aging, the Beth and Richard Applebaum Research Fund, and the Boston Claude D. Pepper Center OAIC.