A Mineral for Mental Energy

Life can be so dizzyingly dynamic that our moods ride it like a roller coaster. We all know that there are factors from within that influence our state of mind as well as those coming at us from everyday experience. What is more, there are minute-by-minute events that can take our mood hostage as well as deeper experiences that impact more enduring mood states.

But it may be that despite all that impinges on us from every direction, there is a simple way to balance mood by what we eat. Evidence is accumulating that an essential mineral found in whole grains, mushrooms, liver and brewer's yeast—chromium—may play an important role in helping to regulate mood.

Chromium, it turns out, is a key player influencing levels of sugar in the blood. You may remember from biology 101 that glucose is the brain's primary fuel. Brains that don't get a steady supply of energy tend to be cranky. You feel mentally fatigued and down.

Scientists have begun testing chromium by itself or in combination with standard antidepressants as a treatment for mood disorders ranging from mild to more severe and treatment resistant. The mineral has proved effective, sometimes dramatically so, in small-scale trials, and larger studies are now underway in several medical centers.

Take the form of depression known in the mental health world as atypical depression, actually something of a misnomer because it is hardly atypical. It afflicts more than a third of those with the mood disorder. What's atypical is that sufferers crave carbohydrates, binge eat and sleep excessively and gain weight, in contrast to garden-variety depression, marked by obvious anxiety, loss of appetite, insomnia and weight loss. Persons with atypical depression also are exquisitely sensitive to rejection and experience overwhelming, sometimes paralyzing, fatigue.

Researchers at Duke University have found that a daily dose of 600 mcg of chromium picolinate led to a significant decrease in symptoms among those with atypical depression. The mineral was most effective in curbing their tendency to overeat. The dose was considerably higher than that which most people get through a normal diet

It's not entirely clear how chromium works against depression. It's known to affect important neurotransmitters in the brain, such as release of norepinephrine. It also influences the supply of serotonin.

But the action of chromium on mood may be directly and indirectly an effect of the mineral's influence on insulin, the hormone that controls blood sugar. Lack of mental and physical energy seems to be a critical facet of the disorder.

Depression is known to make the body resistant to insulin, although it's not clear which comes first—insulin resistance or depression. It may also be that the stress hormone cortisol, known to be elevated in depression, leads to insulin resistance.

Scientists also know that diabetics are especially susceptible to depression, twice as vulnerable than the rest of the population. Diabetic women are even more susceptible to depression. In the vast majority of diabetics, their condition results not from a lack of insulin but from the body's increasing resistance to it.

Studies have long shown that chromium picolinate increases the body's sensitivity to insulin and helps cells extract glucose from the blood stream. Once in cells it is used as energy.

A study by researchers at Louisiana State University sheds light on how chromium enhances insulin sensitivity. It seems to turn on a switch inside muscle cells, the primary site for glucose action, stimulating their uptake of glucose.

Chromium supplements are widely available in health food stores. But that doesn't mean they are entirely safe. Studies suggest that large doses of chromium picolinate could cause kidney problems or genetic mutations of the kind known to give rise to cancer. The supplements have been touted as a possible aid to weight loss, though there's no credible evidence to support that claim.

In the meantime, the Institute of Medicine has put chromium on its short list of supplements about which safety information is urgently needed.