by Craig Weatherby
Two years ago, we reported the conclusions of an expert panel of the American Psychiatric Association, which concluded that omega-3s from fish are capable of reducing depression risks.
(See “Top Psych Panel Says Omega-3s Deter Depression, Biploar Disorder.”)
Now, Greek researchers have reported the results of two population studies… one that links fish to better mood, and one that does the same for olive oil.
Fish may fuel better mood
The first study involved people living in various Greek islands and in Cyprus (Bountziouka V et al. 2009).
They recruited 1,190 men and women aged over 65, and gathered data on the participants' diets, lifestyles, and personal characteristics.
The Greek team then administered a psychological tests designed to detect depression, called the validated Geriatric Depression Scale (GDS).
People who had the healthiest GDS scores were more educated and physically active, but they also reported higher fish consumption than their sadder peers.
Importantly, the study detected a “dose-response” effect that strengthens the association between eating more fish and being less prone to depression.
After adjusting for various factors associated with depression, their analysis showed that each extra portion of fish a participant reported eating per week further lowered their chances of having a GDS score above the “clinical threshold” that indicates depression.
As the Greek team concluded, “These findings may assist public health policy makers in better preventing emotional disorders among the elderly by promoting healthier eating habits” (Bountziouka V et al. 2009).
Olive oil may help mood… other vegetable oils may harm it
Several studies have linked the standard American diet's imbalance between omega-6 (too many) and omega-3 fats (too few) to increased risk of depression.
Now a study from the Athens area of Greece suggests that diets high in olive oil may boost mood, while diets high in omega-6-rich vegetables oils may promote depression (Kyrozis A et al. 2009).
Researchers from the University of Athens Medical School recruited 610 healthy men and women aged 60 years or older and gathered data on the participants' diets, lifestyles, and personal characteristics.
Six to 13 years later, their mood was evaluated using the same GDS test used in the fish study.
Their analysis showed that people who consumed more olive oil had healthier GDS scores, while people who consumed lots of cheap “seed oils”—that is, corn, soy, safflower, sunflower, and cottonseed oils—had worse scores.
To be precise, the link was between monounsaturated fats and mood. And olive oil—specifically extra virgin grade oil—was by far the main source of monounsaturated fats in the diets of the participants who had the highest intakes.
As they wrote, “We conclude that… lower intake of [omega-6-rich] seed oils and higher intake of olive oil… predict a healthier affective [mood] state” (Kyrozis A et al. 2009).
We take their results as positive affirmation that extra virgin olive oil helps make people feel good!
In contrast to the study described above, the researchers found no association between higher fish intake and reduced depression risk.
Given the many studies that link higher fish intake to better mood—including the study summarized above—that result is a bit surprising, but not very significant.
- Bountziouka V, Polychronopoulos E, Zeimbekis A, Papavenetiou E, Ladoukaki E, Papairakleous N, Gotsis E, Metallinos G, Lionis C, Panagiotakos D. Long-term fish intake is associated with less severe depressive symptoms among elderly men and women: the MEDIS (MEDiterranean ISlands Elderly) epidemiological study. J Aging Health. 2009 Sep;21(6):864-80. Epub 2009 Jul 8.
- Kyrozis A, Psaltopoulou T, Stathopoulos P, Trichopoulos D, Vassilopoulos D, Trichopoulou A. Dietary lipids and geriatric depression scale score among elders: the EPIC-Greece cohort. J Psychiatr Res. 2009 May;43(8):763-9. Epub 2008 Oct 25.