Over the past few years, both the conventional drug Prozac and the herbal remedy St John's Wort (Hypericum perforatum) have received much acclaim as anti-depressants.
Yet, while these agents may be valuable weapons in the fight against depression, recent evidence suggests that it can be related to a deficiency of certain nutrients in the diet.Of prime importance seem to be the healthy fat found in oily fish, such as salmon and trout, tuna, mackerel, herring and swordfish.
Research clearly shows that depressed individuals tend to be low in fish fats, and there is good reason to believe that consuming more oily fish may help stabilise mood and combat depression.
It appears as though fish does, indeed, deserve its reputation as the original 'brain food'.
Although some fats have been linked to an increased risk of conditions such as heart disease and cancer (such as those found in red meat, dairy products and many processed foods), others appear to have a diseaseprotective effect.
Healthy fats, known as essential fatty acids (EFAs) come in several different forms including the omega-3 and omega-6 type.
Many foods in the modern diet including margarine, oilbased salad dressings and most vegetable oils are rich in omega-6 fats.
In comparison, our intake of omega-3 fats tends to be low. A rich natural source of omega-3 fats is oily fish.
These contain two main types of omega-3 fatty acid; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Within the body, EPA and DHA are found in very high concentration in brain tissue and are believed to play an important role in nerve function and mood regulation.
There is a lot of evidence linking depression to omega-3 fat deficiency. One study published in 1996 found that depression was associated with a relative deficiency of EPA.
In another study published in 1998, levels of omega-3 fatty acids, particularly DHA, were found to be low in depressed individuals compared to nondepressed subjects. This trend was found again in yet another study published in 1999.
In addition to consuming oily fish at least twice a week, it can help to supplement with fish oils. Concentrated fish oil supplements rich in EPA and DHA are available in health food stores.
An effective dose in the long term might be 1g of fish oil, once or twice a day.
While certain foods can help enhance mood and reduce the risk of depression, others seem to have the opposite effect.
The chemistry of the brain is finely tuned, and can be upset by certain foodstuffs.Perhaps two of the most disruptive dietary elements are sugar and caffeine.
At least one study has shown significant and sustained improvement in the mood of depressed people who give them up.
The effects take a little time, so you need to eliminate them from your diet for two weeks before it is possible to judge the benefits.
Another important dietary factor in depression is a tendency to have a lower than normal level of sugar in the bloodstream - a condition known as 'hypoglycaemia'.
Although the body can run on a variety of fuels, the brain can derive the energy it needs only from sugar. If levels fall, there can be profound changes in mood, and can be a common trigger in problems such as irritability and depression.
Other common symptoms of hypoglycaemia include fluctuating energy and cravings for sweet and/or starchy foods.
Anyone suffering from some form of mood disturbance who is also prone to these symptoms might do well to eat regular meals based around foods which tend to stabilise blood-sugar levels such as meat, fish, brown rice, wholemeal bread, wholewheat pasta and vegetables other than potatoes.
Eating fruit and raw nuts between meals may help keep the blood- sugar level from dropping into the danger zone, and maintain mood throughout the day.
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