Depression is a common disease. In North America, between three and five percent of men and eight and 10% of women suffer from major depression at any given time. Major depression affects 8.2% of Canadian and 8.7% U.S. residents annually. The recurrent rate is 90% in five years in those who are severely depressed and 70% in the average patient with major depression.
The current cure rate with antidepressants is about 75%. Recognizing the symptoms of depression is very important, because it might reduce suffering with early medical intervention and even save lives. Experts have devised one way to recognize them:
D = depressed mood
E = energy loss/fatigue
P = pleasure lost
R = retardation or excitation
E = eating changed-appetite/weight
S = sleep
S = suicidal thoughts
I = I’m a failure (loss of confidence)
O = only me to blame (guilt)
N = no concentration
Now, two types of essential fatty acids in your body are key here — namely, omega-6 fatty acid derived from cis-linoleic acid and omega-3 fatty acid from alpha-linolenic acid (ALA).
Fish is the main source of omega 3s, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). For example, three ounces of Pacific herring has the largest amount of omega 3: 1.06 g EPA and 0.75 g of DHA. Other fish and seafood that have high quantity of EPA and DHA include salmon, sardine, oysters, trout, tuna, and crab. Omega-3 fatty acid from plants such as flaxseed, canola oil and walnuts consists of ALA, which can convert into a small amount of EPA and DHA. That is why fish is the best.
More than 150 years ago, the omega-3 fatty acids in the human diet were from fish, plants and wild game with a ratio of omega-6 to omega-3 fatty acid of 1:1. A large increase in the ratio of omega-6 to omega-3 fatty acids (10:1) in the typical Western diet has been linked to many of the chronic diseases in modern societies. In recent years, omega 3 fatty acids have been highly recommended by health professionals for the prevention of heart disease and increasing attention has been paid to their role in the prevention of other diseases, such as depression, asthma, rheumatoid arthritis, irritable bowel syndrome, type 2 diabetes, and even cancer.
Omega-3 and omega-6 fatty acids play an important role in your nervous system:
- They are major structural components of the cell membranes, including brain cells
- DHA is required for the retina of the eyes to develop normally
- DHA is important in cognitive functions
- Omega-3 content in the brain affects brain cell survival by acting on a group of chemical known as neurotrophins
- Omega-3 brain levels may affect gene expression responsible for inflammation and fatty acid metabolism
- Omega-3 and omega-6 influence the production of chemicals known to provoke inflammatory response, which can cause depression
Over the next week or so, I will review the link between omega-3 and depression with recent evidence from both large population studies and high-quality double-blind, placebo-controlled studies with omega-3 supplements.