About 20% of women who menstruate experience premenstrual mood disorder (PMD) characterized by depressed moods, irritability, anxiety and fatigue, as well as physical pain and food cravings.

Many women are more sensitive to stress in the days before their periods, and they find comfort by overeating high-fat foods. Does giving in to those cravings worsen their health?

Liisa Hantsoo, assistant professor of psychiatry and behavioral sciences, is teaming with Susan Carnell, associate professor of psychiatry and behavioral sciences and an expert in eating behavior, to study mood disorders among premenstrual women, and the potentially intertwined roles of stress, eating high-fat foods, and being overweight or obese.

The researchers posit that premenstrual women with PMD experience a “perfect storm” of stress-induced inflammation when mood symptoms and heightened stress sensitivity interact with overeating unhealthy foods, causing particularly elevated levels of inflammation in the body.

“We know that both stress and intake of foods that are high in saturated fat can increase levels of inflammation,” says Hantsoo. “So the questions we have are, number 1: Are people with premenstrual mood symptoms experiencing elevated levels of inflammation? And 2: Is this potentially exacerbated by dietary intake or high BMI?” (Body mass index — BMI — is a measure of body fat based on height and weight.)

Current research shows that inflammation, a protective response to stress, can be beneficial, but “over time,” Hantsoo says, “it puts wear and tear on the body,” with long-term negative effects on health. Yet it’s not known if premenstrual mood disorders elevate this inflammatory response to stress. And, if so, are there ways to mitigate the response?

For the study, Hantsoo and Carnell, collaborating for the first time, are recruiting 10 subjects in each of three categories: a healthy-weight control group without clinical premenstrual mood symptoms, a group with premenstrual mood symptoms and healthy BMI, and a group with premenstrual mood symptoms and high BMI.

Candidates, recruited from in and around Baltimore, must be between age 18 and 50, must not be taking birth control pills and must have regular periods.

Participants will be subject to physical and psychological stress, and then measured for inflammatory cytokines, which are excreted from immune cells during stress.

“We know that stress induces inflammation,” Hantsoo says. “We know, outside of any menstrual cycle effects, if you bring people into the lab and you stress them out, it spikes levels of inflammatory markers. We also know that high-fat foods and being overweight independently contribute to inflammation. What if we put them all together?”

Although the study is small, the researchers say, it could provide direction for future research that may help people manage premenstrual mood symptoms by using stress management or dietary interventions.

An earlier study, led by Hantsoo and published in the Archives of Women’s Mental Health in October 2022, asked users of a popular menstruation-tracking mobile app about premenstrual symptoms. More than 238,000 of the app’s users, from 140 countries, responded, with food cravings as the most common symptom (at 85.28%), followed by mood swings or anxiety (64.18%) and fatigue (57.3%). Almost 30% of respondents reported that premenstrual symptoms interfered with their life each menstrual cycle.

Though millions of women have these uncomfortable, life-interrupting symptoms for significant portions of their lives, the causes are rarely studied, says Carnell.

“This is the kind of neglected issue that is really important,” she says. “It’s something that impairs quality of life and physical health, and we need to understand more about it.”