Depression and Nutrition

by Bonnie Beardsley, MPH, LDN, RD

The human body functions amazingly well regardless of how we actually take care of ourselves. There are built-in mechanisms that control the acidity of the stomach and various fluids. Another mechanism controls blood pressure, and another regulates the amount of glucose allowed in the blood stream, regardless of the food eaten. Other mechanisms ensure that enough calcium is present in the blood to participate in nerve transmission and heart beat regulation. When these mechanisms begin to malfunction, whether from age, disease, injury, or poor diet and other lifestyle factors, we see high blood pressure, osteoporosis, and diabetes.

While many people understand the connection between nutrition and a physical disease state, fewer people are aware of the connection between nutrition and depression. Depression is more typically thought of as strictly emotional or biochemical. Nutrition, however, can play a key role, both in the onset, severity, and duration of depression, including daily mood swings. Many of the same food patterns that precede depression are the same food patterns that occur during depression. These patterns may include skipping meals, poor appetite, and a desire for sweets. People who follow extremely low carbohydrate diets also run the risk of feeling depressed or blue, because the brain chemicals that promote a feeling of well-being, tryptophan and serotonin, are triggered by carbohydrate rich foods. Anti-depressant drugs like Prozac also target serotonin production.

How and which carbohydrates affect mood and depression is not very clear. And, some people tend to be more sensitive to the quality and quantity of carbohydrates eaten. However, some general guidelines will fit for most people. Refined carbohydrates, primarily sugar and sugary foods, tend to provide immediate, but temporary relief. Once the benefit is gone, you may go looking for more foods to bring up your mood and energy level. Complex carbohydrates, such as whole grains, cereals, breads, pastas, and fruits and vegetables, are more likely to supply a moderate, but lasting effect on brain chemistry, mood, and energy level.

Depression is also linked to a lack of certain vitamins, especially the B vitamins which are used in nervous system function. Although vitamin B6 deficiency is rare in the United States, many women do not get enough in their diets. A less than adequate intake may produce subtle changes in mood, even before a deficiency could develop. B6 also plays a role in the brain chemical production of serotonin. Studies show that people who are depressed have low levels of B6 and serotonin. Certain drugs, such as hormone replacement therapy, oral contraceptives, and anti-tuberculous medication can interfere with the body's use of B6, creating a borderline deficiency.

Other B vitamins also participate in mental health. Folic acid deficiency can cause personality change and depression. Vitamin B12, at just marginally low levels can contribute to depression and memory problems. Folic acid deficiency is one of the most common vitamin deficiencies in the United States. Not only is it easily destroyed by cooking, but is most abundant in leafy green vegetables- an often underconsumed food group. As we age, vitamin B12 may not be absorbed as readily, even if the recommended daily requirement is met through the diet.Minerals that play a role in the development or prevention of depression, irritability, and mood swings include calcium, iron, magnesium, selenium, and zinc.

The bottom line is that food plays a key role in maintaining mental health. Foods to eliminate or eat in moderation include sugar and sugary foods, and caffeine. Get into the habit of eating at least three times a day, including breakfast, replace sweets with fruit and whole grain carbohydrates, eat lean sources of protein several times a day, and drink plenty of water. Focus on a well-balanced diet, including plenty of leafy greens for folic acid, and bananas, avocado, chicken, greens, and whole grains for B6. If you're concerned about getting enough of some of the key nutrients, consult your physician or dietitian before supplementing.

© Bonnie Beardsley

Bonnie Beardsley, MPH, LDN, RD is a Licensed Dietitian/Nutritionist in private practice.