Decreased levels of serum folate appear to be linked to a higher risk for depressive symptoms, according to a large population-based, cross-sectional study.
This is important because scientific research is finding that SSRI anti-depressants may not help depression because serotonin levels don’t appear to affect depression symptoms.
Data on US adults from the National Health and Nutrition Examination Survey (NHANES) show elevated depressive symptoms were inversely associated with folate status, particularly among women.
Lead investigator, May A. Beydoun, Ph.D., MPH, stated: “We found that the odds of having elevated depressive symptoms among individuals with the highest serum folate levels were about half that of those with the lowest levels.”
Prior research suggests that high levels of total homocysteine and low levels of folate and vitamin B12 are associated with depression or elevated depressive symptoms in adults.
However, earlier studies examining the impact of low folate, low vitamin B12, and elevated homocysteine status simultaneously on depressive symptoms did not examine the interaction among those 3 risk factors. The findings have been inconsistent.
The study noted: “To our knowledge, this is the first nationally representative study conducted among U.S. adults after mandatory fortification of food with folic acid that examines associations of serum folate, vitamin B12, and homocysteine levels with depressive symptoms.”
The study also showed that women with the highest serum folate experienced depressive symptoms far less than women with the lowest serum folate levels. The incidence of depression in women with high serum folate was approximately 67% less.
Elevated homocysteine level was linked with elevated depressive symptoms in adults 50 years and older. Although a significant link between folate levels and a higher risk for depression in women, the scientists believed this was due to the underrepresentation of men in the study.
The study also suggested that clinicians with patients presenting with depression should screen for serum folate. If indicated, patients may want to add supplements along with other therapy methods.
In addition, dietary and lifestyle advice to enhance serum folate should also be considered. Foods high in folic acid include dark green leafy vegetables (turnip greens, spinach, romaine lettuce, asparagus, Brussels sprouts, broccoli), beans, peanuts, sunflower seeds, fresh fruits, fruit juices, whole grains, liver, seafood, and eggs.
Commenting on the study, Felice Jacka, Ph.D., a researcher from the University of Melbourne in Australia, stated “the NHANES data are very good quality and, therefore, a very good vehicle to examine the relationships between nutritional status and mental health. This is the first large-scale population-based study in the US to show that folate status is associated with the presence of depressive symptoms since the fortification of foods with folate became mandatory.”
Now that studies are questioning the role of serotonin levels in depression, it is a good time to get back to basics like diet and supplements. Blood tests to determine folate and homocysteine levels (and levels of other nutrients) in individuals with depressive symptoms may be useful in clinical settings. If nutrient deficiencies and/or excess homocysteine are identified, dietary and/or supplementation strategies could then be considered.