Findings suggest more study to protect mothers and children is warranted
by Craig Weatherby
Some of the most exciting news we heard at the recent Seafood & Health Conference in Washington, D.C. came from presentations by psychiatrist Joseph R. Hibbeln, M.D.: a world-renowned researcher and clinician who holds the rank of Commander in the U.S. Public Health Service.
Dr. Hibbeln is unusual in that he works both sides of the biomedical divide: laboratory research and clinical practice. He is both a Senior Clinical Investigator at the National Institutes of Health’s Laboratory of Membrane Biophysics and Biochemistry and a clinical psychiatrist at the National Institute of Alcohol Abuse and Alcoholism, where he works directly with patients.
We’ll cover several of his findings in future issues, but his most recent research involves post-partum depression—that is, depression occurring in a mother after the birth of her child. Post-partum depression (PPD) is especially disturbing, since it occurs at a time that should bring great joy, and may harm the child’s development.
While some PPD can result in serious harm to the mother and child, most of the 10 to 15 percent of new mothers who suffer from PPD experience less dramatic but significantly disturbing bouts of depression.
However, research results indicate that the children of mothers who develop PPD—especially boys—suffer impaired intellectual development and an increased risk of asthma.
Population study and data gaps prompt new clinical research
In 2002, Dr. Hibbeln published the results of an international survey designed to uncover any statistical correlation between lower omega-3 intake and greater risk of PPD. As he concluded, “Both lower DHA content in mothers' milk and lower seafood consumption were associated with higher rates of postpartum depression. These results do not appear to be an artifact of cross-national differences in well-established risk factors for postpartum depression. Interventional [i.e., clinical] studies are needed to determine if omega-3 fatty acids can reduce major postpartum depressive symptoms.”
Such correlations, while indicative of a possible causal relationship, cannot prove that omega-3 deficiencies cause PPD, or that either omega-3 supplements or omega-3-rich fish like salmon can prevent or alleviate PPD.
The results of two small, uncontrolled clinical studies, published in 2003 (Llorente AM, et al) and 2004 (Marangell LB, et al), tested the effects of omega-3 supplements on preventing or alleviating PPD, and detected no benefit.
These findings were counterintuitive, given the considerable evidence that omega-3s may help prevent regular depression, so Dr. Hibbeln and colleagues decided to conduct another trial: this time with very positive results.
As Dr. Hibbeln noted in the introduction to the current study, we know very little about the efficacy of standard antidepressant drugs for the treatment of PPD, because many women refuse medications during pregnancy and breastfeeding, and because the long-term effects of antidepressants on infants are unknown.
And, as he went on to say, “Omega-3 fatty acids are intriguing as a treatment option for PPD. Because of the demands placed on the mother's supply of omega-3 fatty acids during pregnancy and lactation, PPD may be particularly responsive to treatment with DHA and EPA [the key omega-3s in fish oil].”
Findings support omega-3s and warant more research
In Dr. Hibbeln's study, 16 women with PPD were given varying doses of omega-3s for eight weeks: six received 0.5 grams per day, three took 1.4 grams per day, and seven consumed 2.8 grams per day.
Women in all three groups were given standard psychological tests designed to detect depression, both before and after the omega-3 treatment period. All of the women scored about 50 percent lower (i.e., better) on depression tests after treatment, with little difference among the dose groups, and no adverse side effects were reported.
Surprisingly, a relatively low dose (0.5 grams per day) appeared to impart as much anti-depressive benefit as the highest dose (2.8 grams per day).
While this study is not conclusive, because it involved a small number of participants and lacked a control (placebo) group, the results are encouraging, and warrant further study of omega-3 fatty acids as a treatment for PPD. .
Pregnant women need ample amounts of omega-3s to foster optimal child development, so it makes sense for them to take them. And since a relatively low dose appeared to impart as much anti-depressive benefit as the highest dose, it makes sense for pregnant and post-partum mothers to take omega-3s as a preventive measure.
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