New research findings help clarify mixed results from previous studies.
By MASSACHUSETTS GENERAL HOSPITAL
The findings are published
in JAMA by a team led by investigators at
Massachusetts General Hospital (MGH) and Brigham and Women’s Hospital (BWH).
Experts have recommended omega-3 supplements for reducing the
recurrence of depression in some high-risk patients, but there are no
guidelines related to the use of these supplements for preventing depression in
the general population. Also, studies on this topic have generated mixed
results.
To provide clarity, the Vitamin D and Omega-3 Trial-Depression
Endpoint Prevention (VITAL-DEP) was designed to test the potential of daily
vitamin D and/or omega-3 supplements for preventing depression. A total of
18,353 adults aged 50 years or older without depression at the start of the
trial were randomized to receive vitamin D and/or omega-3 supplements or
matching placebos for a median of 5.3 years.
“This study is a significant step. It requires many thousands of people to conduct this type of study of preventing depression in adults—something we call universal prevention—and the participants were taking randomized study pills for between 5 to 7 years on average,” says VITAL-DEP lead investigator and lead author Olivia I. Okereke, MD, MS, director of geriatric psychiatry at MGH and an associate professor of psychiatry at Harvard Medical School. “So, it is rare to see a long-term randomized trial of this kind.”
Okereke and her colleagues observed no net benefit of omega-3 supplements for preventing depression or boosting mood over the course of the study. Equal attention was given to risk of developing a clinical depression at any point and to overall mood scores for the duration of follow-up.
While a
small increase in risk of a depression was inside the statistical margin of
significance, Okereke says “there was no harmful or beneficial effect of
omega-3 on overall course of mood during the roughly 5 to 7 years of
follow-up.”
“There are still health reasons for some people, under the guidance of their health care providers, to take omega-3 fish oil supplements. For example, these supplements increasingly have been found to have benefits for cardiac disease prevention and treatment of inflammatory conditions, in addition to being used for management of existing depressive disorders in some high-risk patients,” says senior author JoAnn E. Manson, MD, DrPH, chief of the Division of Preventive Medicine at BWH, a professor of medicine at Harvard Medical School, and director of the parent VITAL trial.
“However, our findings
indicate there is no reason for adults without depression in the general
population to take fish oil supplements solely for the purpose of preventing
depression or for maintaining a positive mood.”
Reference: “Effect of Long-term Supplementation With Marine
Omega-3 Fatty Acids vs Placebo on Risk of Depression or Clinically Relevant
Depressive Symptoms and on Change in Mood ScoresA Randomized Clinical Trial” by
Olivia I. Okereke, MD, SM; Chirag M. Vyas, MBBS, MPH; David Mischoulon, MD,
PhD; Grace Chang, MD, MPH; Nancy R. Cook, ScD; Alison Weinberg, MA; Vadim
Bubes, PhD; Trisha Copeland, MS, RD; Georgina Friedenberg, MPH; I-Min Lee, MBBS,
ScD; Julie E. Buring, ScD; Charles F. Reynolds III, MD and JoAnn E. Manson, MD,
DrPH, 21 December 2021, JAMA.
DOI: 10.1001/jama.2021.21187
Other authors include Chirag M. Vyas, MBBS, MPH, David Mischoulon,
MD, PhD, Grace Chang, MD, MPH, Nancy R. Cook, ScD, Alison Weinberg, MA, Vadim
Bubes, PhD, Trisha Copeland, MS, RD, Georgina Friedenberg, MPH, I-Min Lee,
MBBS, ScD, Julie E. Buring, ScD, and Charles F. Reynolds III, MD.
The study was supported by the National Institute of Mental
Health.