Monday, October 4, 2010

Nutrition and Depression

Apart from the normal dietary recommendations of more vegetables, beans, nuts, fish and fruit and less junk food, sugar laden starches and fatty foods, it’s important to reduce both nicotine and caffeine.

From a biochemical perspective, depression is thought to be an imbalance of brain chemicals, usually identified as a lack of serotonin. If you look at the biochemical pathway for the manufacture of serotonin, there are many reasons as to why it may be low. Sometimes this can be rectified simply through dietary modifications.

Serotonin is made in the hippocampus (a part of the brain) from the amino acid tryptophan. For this chemical to be converted to serotonin, it needs Vitamins B3, B6, Folic acid, C, and the minerals calcium, iron, magnesium, zinc and a particular essential amino acid called tryptophan. A deficiency in a couple of these nutrients can result in low levels of serotonin and depression.

In one experiment people who had a history of depression were given nutritionally balanced but tryptophan depleted foods. Within seven hours 10 of the 15 participants reported worsening moods and began to show signs of depression. When the tryptophan was replaced their more positive mood quickly returned.

Supplementing with tryptophan should be around one gram for low moods and up to three grams for depression. It’s best eaten on an empty stomach or in conjunction with carbohydrates. Because tryptophan is converted first to serotonin and then to melatonin, it is best taken at night before going to bed, as it will help you sleep.

Tryptophan rich foods include fish, turkey, chicken, cheese, beans, tofu, oats, eggs, nuts, seeds and milk. Ironically, following a protein rich meal, brain levels of tryptophan and serotonin levels decrease. This is because some of the other amino acids (the LNAA’s such as valine, leucine, tyrosine and phenylalanine) in the meal out compete tryptophan for carrier molecules into the neurons. In contrast, it’s a meal rich in carbohydrates and a small serve of protein which increases brain tryptophan and serotonin. Even though the food may lack tryptophan completely, it causes the release of insulin which stimulates the uptake of most of the amino acids (the LNAA’s) other than tryptophan. This phenomenon explains why some people suffering depression crave carbohydrate snacks.

The best way to get more tryptophan in your diet is to eat some of the foods rich in tryptophan with food high in carbohydrates food such as fruit (bananas) and vegetables, including potatoes and wholmeal bread. A little bit of protein should be consumed with every meal to ensure a constant supply of tryptophan for the brain. Not a huge piece of meat just a small serve of protein rich food.

During the day adrenalin levels are higher, keeping you stimulated. As adrenalin levels decline, serotonin levels rise. As the day progresses and it gets darker, melatonin levels rise and serotonin levels decline. Melatonin’s main role is to regulate the sleep-awake cycle. Without enough serotonin you can’t manufacture melatonin. This is probably why poor sleep patterns are often associated with depression.

A man’s average synthesis rate of serotonin is around 52 per cent higher than that of a woman and as a result women are more prone to low serotonin and depression.

SAMe (S-adenosyl methionine) is a naturally occurring chemical in the body that’s linked with reducing joint problems and cardiovascular disease. It’s also involved in the production of various other chemicals in the body. However, more than 100 double blind studies have shown that supplementing with SAMe is equal or superior to using antidepressants. SAMe doesn’t appear to have side effects and has many potential side benefits. SAMe has also been shown to increase the levels of serotonin and dopamine in depressed patients. Deficiencies in SAMe may be brought about by a diet low in the amino acid methionine or Vitamin B12. This can occur if you are following a stricitly vegetarian or fad diet ; in the case of stomach infections with helicobacter pylori; in situations which generate low stomach acid, or in the presence of excessive copper, lead or mercury.

The Omega 3 fats are linked with improved reception of serotonin. Studies using omega 3 fats alone and in conjunction with antidepressants have shown significant benefits. Again, no side effects and lots of side benefits. The EFAs are converted into the hormone-like prostaglandins, which stimulate the brain’s manufacture of serotonin and other neurotransmitters. Understanding this shows how very low fat diets and bad fat diets can lead to depression. Research has shown that countries, such as Japan, that have a high daily intake of fish have a much lower rate of depression than countries with a low intake of omega 3 fatty acids, such as Australia and the US.

Stress can have a depleting effect on the body and lead to particular deficiencies that may affect our mood. Stress has a negative effect on the production of DHEA, adrenalin and serotonin. This increases our need for the raw materials to build the mood enhancing neurotransmitters. Stress also increases our need for the B vitamins and tryptophan. Depression is an exhausting experience that depletes the body of mood enhancing chemicals.

Supplements for depression include: SAMe, about 200 mg twice a day building up to 200 mg four times a day after 14 days; High potency vitamin B complex with 1000 milligrams folic acid and 1000 micrograms of Vitamin B12; and, St John Wort extract (0.3 per cent hypericin) at 300 mg three times a day. St John’s Wort has been shown to be effective in dozens of clinical trials. St John’s Wort does interact with some medications, so check with your doctor or pharmacist if you are uncertain.

By adopting the nutritional approach you not only work towards the solution to depression, you may also solve other problems such as joint pain and cardiovascular risk factors


  1. Some good advice there for those who want to supplement with some proven alternatives to pharmaceutical anti-depressant medication which so often can be disappointingly ineffective or prone to producing 'side effects'.

    Having said that, I always feel concerned whenever I hear advice for solving depression skewed towards a more biochemical approach. I don't know discount the immense importance of having a diet suited to our bodies, nor do I disregard the suggestion that mood problems can be caused by a disruption to neurochemicals. I just think we should never overlook the importance of our minds and how best to understand how they work.

    Ditch the junk food, take the supplements Dr D talks about, but perhaps most importantly involve yourself in Vipassana, Yoga or some other contemplative practice. I know you are an advocate of these practices Peter, why not include some of the research done on these practices in your advice?


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