An eminent WDDTY panel member shows which foods can make you depressed,
Although all of us experience periods of intense sadness, true depression can range from mourning to chronic and complete disability, characterized by overwhelming feelings of hopelessness and suicidal thoughts. People who are depressed also find it difficult to function; they may have disturbed eating and sleeping and bowel habits, they can't concentrate, they can't enjoy anything in life and they frequently suffer low self-esteem.
What most people don't realize is how closely depression is tied in with diet. Although a lack of appetite can cause malnutrition and therefore depression, the reverse is also true: poor eating habits can cause depression by failing to provide the adequate nutrition necessary for proper functioning.
Many cases of depression may be due to too high or low levels of dietary fat. In the Italian study WDDTY reported on last month, virtually every single person who'd tried to kill himself had too low levels of cholesterol. Many other studies show that a very low fat diet also causes depression (see WDDTY Guide to Your Heart).
An earlier study which examined the suicide rates of 16 Western European countries found that suicide rates corresponded with the average intake of fat, particularly from animal products, but were unrelated to intake of total calories, protein, stimulants or alcohol (J Orthomol Med, 1990; 5 (1): 20-21.
Besides too much or too little fat, caffeine and sugar can make you depressed. Drinking more than 700 mg of caffeine a day (which translates into four or five cups of coffee a day) can cause depression, as can a diet with a large amount of refined sugar. Studies have shown that cutting out caffeine and sugar for as little as one week can lift depression, while adding them back to the diet can cause symptoms to resume. In one study, those patients who felt better were challenged with Kool-Aid, a sugary American drink, and daily doses of caffeine. About half showed a significant and sustained deterioration in mood right after the challenge (Behav Thera, 1988; 19: 4593-604).
Besides caffeine and sugar, food allergies and moulds have been proven to provoke depression. In fact, one study showed that the nearly a third of a group of depressed patients suffered from allergies, compared to only 2 per cent of schizophrenics (J Affective Disord, 1981: 3: 291); another found that 85 per cent of depressed children and adults were atopic that is, were inherently allergic (Compr Psychiatry, 1976; 17: 335).
One 67-year-old woman suffered from depression for many years. She also had a long history of diarrhea with abdominal pain and bloating. Once she was placed on an elimination diet, not only did her gut problems improve but she reported feeling much more cheerful, alert and confident. It was then discovered that milk was behind her bowel problems, and she eliminated it from her diet. Both her irritable bowel and depressive episodes disappeared.
The most usual deficiency in patients with depression is one of the B vitamins, which are powerful regulators of mood. Of all vitamin deficiencies, folic acid tends to be the most common; the average American only manages to consume 60 per cent of the US Recommended Daily Allowance for folic acid every day.
Depression is a common symptom of folic acid deficiency; at least eight studies have shown that patients with depression have lower levels of folic acid than other populations. The worse the depression, usually the lower the level of folic acid in the blood. The most common problem is affective disorder (BMJ, 1980; 281: 1036-42). Depressive illness has been shown to begin at the point where patients become deficient in folic acid (Biol Psychiatry, 1989; 25 (7): 867-72).
The reason for the association has to do with the fact that folic acid deficiency lowers brain 5-hydroxytryptamine (the brain hormone serotonin) and S-adenosylmethionine, which raises serotonin levels. There is evidence that 5-HT is decreased in depression (Br J Psychiatry, 1967; 113: 1237-64). So what probably happens is that a depressed person low in folic acid is also low in brain 5-HT
levels (Prog Neuropsychopharmacol Bio Psychiatry, 1989; 13(6): 841-63). A number of studies showed that patients improve significantly with folic acid supplements (The Lancet, 1990; 336; 392-95).
Another common deficiency in depression is B6. Again, laboratory evidence of vitamin B6 deficiency is common in depression. Of all the possible psychiatric diagnoses, patients in a psychiatric hospital who are deficient in B6 are most likely to be diagnosed with "endogenous depression" that is, inherent depression, rather than a response to an outside event (Nutr Rep In, 1983; 27 (4): 867-73; Br J Psychiatry, 1979; 135: 249-54).
Although we don't have evidence of how frequently B6 improves depression, we do know that B6 can treat depression caused by the birth control pill. The Pill not only interferes with B6, but also speeds up the destruction of tryptophan, preventing it from being converted to serotonin. (Acta Vitaminol Enzymol, 1982; 4 (1-2): 45-54).
Other B vitamin deficiencies linked to depression are those of riboflavin (vitamin B2) and thiamine (vitamin B1). In early stages of thiamine deficiency, normal people become depressed, irritable and fearful. It's also common in hospitalized mental patients (Am J Clin Nutr, 1957; 5 (2): 109-20). As for riboflavin, in one study of 172 patients in a psychiatric hospital, more than one-fourth were found to be deficient. Those patients who had a riboflavin deficiency also had been diagnosed as having a mood disorder ((Br J Psychiatry, 1982; 141: 271-72).
Vitamin B12 is the final B vitamin deficiency often linked to psychiatric problems. About 5 per cent of people admitted to a psychiatric hospital are deficient in vitamin B12, and about 10 per cent have lower than normal levels of the vitamin (Acta Med Scanda, 1965; 177: 689-99).
Vitamin C also appears to have a role in maintaining mood. One of the first symptoms of mild scurvy, the vitamin C deficiency disease, is depression, along with tiredness and irritability (Am J Clin Nutr, 1971; 24: 432-3). Although we all tend to associate scurvy with Third World countries and sailors of several centuries ago, mild scurvy in industrialized countries isn't as rare as we think. When the diets of 12 depressed women who subsequently attempted suicide were compared with those of a similar control group, the only significant difference found was a lower intake of vitamin C (J Orthomol Med, 1987; 2 (4): 217-18). There's also evidence that giving vitamin C makes a difference. In one study, 40 chronic psychiatric patients were given vitamin C or a placebo. Three weeks later, only the patients given vitamin C were less depressed (Br J Psychiatry, 1963; 109: 294-9).
Besides vitamins, a number of mineral deficiencies may bring on depression. Both too much and too little calcium in the blood may be associated with depression, an interesting factor considering the tendency to push megadoses of calcium indescriminately on postmeno-pausal women (Br J Psychiatry, 1984; 145: 477).
Although we know that people with iron-deficiency anemia feel tired and depressed, even after iron supplementation cures the anemia, the depression may not resolve for months. The exact nature of the relationship is unknown, although we do know that some areas of the brain have high iron concentrations, and it may be that a reduced level of iron in the brain brings on the depression (Anabolism, Jan-Feb, 1984).
Inadequate magnesium is highly common in the West, largely due to modern-day farming methods, but it's also exacerbated by stress and many medications. A magnesium deficiency, which often goes hand-in-hand with a calcium deficiency, is common in depressed patients (JAMA, 1973; 224: 1749-51). Interestingly, the levels of magnesium in the spinal fluid is especially low in patients who are suicidal (Ann N Y Acad Science, 1986; 487: 221-30).
Another potential culprit is low levels of blood potassium, which is particularly common if you take diuretics (Psychosomatics, 1981: 22 (3): 199-203). It's also common for patients to have a raised level of sodium in their cells (Gerontology Clin, 1971; 13: 232-45).
Underpinning all these deficiencies may be faulty digestion. Besides food sensitivities, it's important to rule out a deficiency in hydrochloric acid. An insufficient amount of stomach acid may reduce the ability of your gut to absorb many nutrients, and you may develop many deficiencies, even if you are eating an adequate diet. In one case, a patient who'd suffered from depression for 17 years had a dramatic reversal as soon as he was given hydrochloric acid and a B vitamin supplement (Nutr Abstr Rev, 1959; 29: 273).
Dr Melvyn Werbach
Adapted from Dr Werbach's books Nutritional Influences on Mental Illness (Third Line Press) and Healing Through Nutrition (Thorsons).