(NaturalNews) The old expression, "You are what you eat," may go a long way towards explaining what research increasingly says is a causal link between diet and depression.
The good news for depression sufferers; however, is that because diet may be affecting your mood, your condition is very treatable naturally.
A recent meta-analysis of 11 longitudinal studies involving unipolar depression and/or symptoms of depression in adults between the ages of 18-97 years found a distinctive link between said depression and diet. Follow-up for these studies ranged from two to 13 years, according to Diet and the risk of unipolar depression in adults: systematic review of cohort studies.
"Researchers found an inverse association between depression risk and folate, omega-3 fatty acids, monounsaturated fatty acids, olive oil, fish, fruits, vegetables, nuts and legumes. Results indicate that diet and nutrition may influence depression risk," says an abstract of the findings by a team of researchers from Oxford University in Great Britain.
Yet more evidence of a link between diet and depression
The meta-analysis confirmed findings from earlier, unrelated studies, in which researchers from the U.S. essentially found a similar link between nutrition and depression, though traditional clinical practice is to treat depression chemically.
"When researchers came up with the term 'brain chemical imbalance' to explain depression, the next step should have been to supply the brain with nutrients. However, chemicals were prescribed instead," Carolyn Dean, M.D., an author and medical director of the Nutritional Magnesium Association, told Everyday Health.
The website noted that earlier studies have shown that a diet rich in what medical professionals describe as "whole foods" also lowers the risk of depression, while diets that consist primarily of processed foods may actually work to increase the incidence of depression.
That's because, researchers say, whole foods are natural and thus have all of their nutrients intact. They are also devoid of additives, unlike processed foods which contain many additives and have most often lost much of their nutritional value.
It is this loss of vital nutrients scientists believe is likely the root cause of depression.
"We know that nutrients such as magnesium, essential fatty acids, and vitamin B6 and B12 help create neurotransmitters, and we are also learning that a deficiency in these nutrients can lead to a chemical imbalance in the brain," Dean said, adding that neurotransmitters are chemicals in the brain that transmit signals between nerve cells.
Depression can result with these neurotransmitters becoming deficient.
Series of studies provide better understanding
A growing body of research has strengthened the belief among health practitioners and scientists alike that diet and depression are inextricably linked:
-- A recent study in the American Journal of Psychiatry contrasted a diet of whole-food fruits, vegetables, grains and fish with a diet high in processed meats, grains and fast foods. Researchers found that study participants who ate the whole foods had a third less risk of developing depression.
-- A study published in the British Journal of Nutrition found that, after five years, people who ate a diet rich in veggies, fruits and fish versus those whose diets were loaded with sweetened desserts, processed meats and grains had less risk of developing depression.
-- Yet another small study, this one published in the British Journal of Nutrition, found that people with decreased fat intake had a 25 percent higher risk of depression than those who consumed healthy sources of dietary fat such as omega-3 fats, which are found in fish (salmon and tuna), as well as flaxseed and walnuts.
-- Still another study published in the Archives of General Psychiatry found that diets high in processed foods, sugar and non-healthy dietary fat increases the risk of obesity, and that the additional weight then led to an increased risk of depression.