Symptoms of depression: do omega-3s help?
The body of data collected over many years of experimentation has led to the hypothesis that irregular Omega-3 consumption and altered metabolism of essential fatty acids (Omega-3 and Omega-6) could contribute to the development of the major known forms of depression .
Not only that, several studies suggest that Omega-3s could be helpful in treating symptoms of depression.
The first indications of the existence of a link between the function performed by these fatty acids in the human body and this disease date back to the past 1990s, when a series of research showed the existence of a close correlation between depressive states and low Omega-3 levels.
In fact, in those suffering from depression, reserves of these fatty acids are less abundant than normal.
In particular, a study conducted at the Base Hospital in Rockhampton, Australia, published in the journal Lipids, showed that the poorer these reserves are, the more severe the symptoms of depression.
According to research published in Biological Psychiatry in 1998, an altered ratio from Omega-3 to Omega-6 fatty acids and a lower amount of Omega-3 in blood plasma is associated with severe forms of depression.
In later years, a further study showed that in old age the fatty acid composition of phospholipids in the blood is closely related to mood disorders and potential depressive states.
Mangeating well to feel better
Supporting these early findings came data from other research that delved into the role of anOmega-3-rich diet in improving mood.
As early as 1998, the Journal of Nutrition published the results obtained by researchers at the Laboratoire de Biophysique Medicale et Pharmaceutique in Tours, France, who found that in rats Omega-3s taken in the form of fish oil promoted the activity of dopamine, a molecule that regulates mood.
In the same year, experts at the University of Sheffield (UK) showed that a diet rich in these fatty acids is associated with a lower tendency to show symptoms of depression.
Finally, large studies conducted in Finland and the Netherlands have confirmed that the more Omega-3-rich the diet, the less likely it is to suffer from depression.
Omega-3 for the treatment of depression
But the first to demonstrate the real efficacy of Omega-3s in improving emotional balance were researchers at Harvard Medical School in Boston (United States).
Here Andrew Stoll and colleagues were searching for a method to treat bipolar syndrome, also called manic-depressive syndrome, a particular disorder in which severe bouts of depression alternate with periods of intense euphoria.
The drug of choice for the treatment of this disorder is lithium. However, this remedy causes toxic and serious side effects.
Looking for a less harmful alternative, Stoll decided to test the effectiveness of the Omega-3 EPA and DHA contained in fish oil. For this he gave one group of patients 9 grams a day of EPA and DHA, respectively, at a ratio of 1 to 1.5. As a control, another group of patients took olive oil, which contains no Omega-3s.
After only 4 months of treatment, the study was discontinued: the benefits shown by the patients who were taking EPA and DHA were so great that it was deemed ethically unacceptable to continue giving only olive oil to the control group.
In fact, in those on fish oil treatment, disease symptoms tended to stabilize, while other patients showed a marked worsening of clinical conditions. And only in one case aftertaking Omega-3 did a relapse occur.
The results obtained by Harvard researchers have been confirmed by subsequent studies.
Specifically, scientists at Ben Gurion University of the Negev in Beer-Sheva, Israel, compared the effectiveness in treating depression of a purified fish oil extract consisting of pure EPA with that of an equivalent dose of olive oil.
The patients involved in this study showed signs of relapse despite being treated with an antidepressant. In less than 3 weeks more than half of the patients treated withfish oil showed a reduction in symptoms of, at least, 50%.
A short time later, researchers at Swallownest Court Hospital in Sheffield, UK, came to the same conclusions.
The results of the study they published in the Archives of General Psychiatry led them to conclude that Omega-3s can improve a whole range of symptoms characteristic of depression:
- sadness
- lack of energy
- anxious states
- insomnia
- decreased libido
- suicidal tendency
Finally, the efficacy of Omega-3s was also extended to the treatment of disorders of the psychological sphere typical of women who, due to a changing mood and often uncontrollable emotions, had complicated emotional relationships.
Experts at McLean Hospital in Belmont, US, showed that 8 weeks of treatment with EPA-rich Omega-3 dietary supplements was enough to make these patients' moods more stable and tended to be more positive.
Not only that, the treatment also reduced the aggression of women who were taking Omega-3s.
A mood aid for mothers and children
Some research has, however, focused on the benefits of Omega-3s in treating depressive states that may accompany or follow pregnancy.
During pregnancy, expectant mothers selectively transfer DHA to the fetus to ensure proper development of the nervous system. This causes new mothers to be at high risk of depressive symptoms in the postpartum period without adequate dietary intake of omega-3 fatty acids.
Based on these assumptions, researchers from the National Institute on Alcohol Abuse and Alcoholism in Rockville, US, have shown that lower DHA content and lower seafood consumption are predictive of the risk of postpartum depression.
These findings were confirmed by Dutch scientists at the University Medical Center Rotterdam, who showed that in women suffering from depressive disorders after childbirth, DHA availability is lower.
And the benefits are not only for the mother, but also for the children. A study from the Universidade Federal do Paraná in Curitiba, Brazil, showed that an initial antidepressant effect can be achieved through regular consumption of fish and fish oil by the mother during pregnancy and lactation.
These in fact increase EPA and DHA concentrations in 2 specific areas of the brain, the cortex and hippocampus, decreasing the offspring's tendency to suffer from depression.
All-round benefits for mood
The body of data collected over the years shows that Omega-3 fatty acids can be effective in prevention, control and treatment of various psychiatric disorders.
These can range from simple mood alterations to postpartum depressive states, through stress-induced aggressive behaviors, neurological damage and visual impairment caused by alcohol, to serious conditions such as schizophrenia and dementia.