Anecdotally it appears that depression is increasing in prevalence in Western nations. This is supported by the data showing a large increase in the prescription of antidepressants such as the selective serotonin reuptake inhibitors (SSRIs) in the same countries. The reason for this is not clear but may relate to the types of lifestyles Westerners live. These lives tend to be very psychologically stressful and this may be contributing significantly to feelings of helplessness and despair that can trigger depressive episodes. A number of coping strategies are employed by individuals exposed to this daily stress. For example, many turn to exercise which is a positive coping strategy because it helps to reduce the buildup of stress hormones that can accumulate and may contribute to feelings of depression. Other individuals withdraw from the stress of life and this can also be a positive coping strategy as it removes the individual from the cause of the stress, although total withdrawal from normal life can be damaging.
High sugar, high fat foods can be addictive because they cause the release of opioids in the brain which create feelings of euphoria. Many people are unaware that these sorts of foods have drug like effects and can be addictive.
Another coping strategy people can use to overcome stress and self treat depression is the use of highly palatable refined carbohydrates. Such foods, often found alongside with fat in low quality foods such as cakes, doughnuts and biscuits are able to reduce the symptoms of stress and depression because they have drug like effects in the brain. In particular, they may increase the synthesis of serotonin through their ability to rapidly increase insulin levels, and this may give such individuals a feeling of well being. In addition, overeating high energy foods may stimulate the opioid system in the brain leading to euphoria. This latter point is now one of the theories used to explain the addictive nature of food to bulimics and the same or similar mechanism may be at work in the brains of normal, supposedly healthy individuals. The ability of certain foods and combinations of foods to act like drugs is well known to the fast food industry who uses it to assure that their foods are as addictive as possible.
Exercise is beneficial at reducing depression because it can increase the synthesis of chemicals in the brain that have antidepressant effects. In particular opioids and serotonin may increase following exercise.
Overseeing refined carbohydrates is a negative coping strategy, because while it reduces the feelings of depression in the short term, in the long term is is highly damaging to the health. In effect the individual becomes a drug addict, using highly palatable, sugary foods in order to satisfy an addiction. One of the consequences of such action is that insulin sensitivity is impaired and this leads to a gain in weight, and this can be a further cause for feelings of depression. Such a negative spiral is difficult to break, just as it is difficult to remove oneself from drug addiction. However, it is essential that this cycle is broken and such foods are avoided. I am not a huge advocate of aerobic exercise for fat loss, but this is one situation in which exercise can be useful. Not only does exercise increase excretion of stress hormones, it can also increase the release of opioids that may be involved in the addiction to high energy foods. Timing exercise for periods when overeating occurs is also useful as it will limit overconsumption of these foods.
RdB
