A one-two punch for two or winter's side effects. (Food for Thought).

WINTER, DEPRESSION AND CARDIOVASCULAR HEALTH

Winter can be a tough time to stay motivated and combat negative mood. Seasonal Affective Disorder (SAD) emerges in those who don't receive enough sunlight, a bout of the flu can put a damper on anyone's spirits, and even the holidays make many people feel depressed or lonely. Winter can be equally trying on physical health. Even if you don't suffer from SAD, the shorter, darker days make rising early more difficult and offer less time for outdoor activity, which is tempting to avoid altogether when it's cold outside. And by the beginning of the year, the over-eating associated with the holiday season has taken its toll on the body. Compounding everything, depression often leads to less exercise, which in turn leads to negative self-image, and the cycle spirals ever downward.

To make matters worse, the risk of heart disease has been reported to be as much as double in people with clinical depression. The latest link between cardiovascular risk and depression emerged in October when researchers at the University of Wales found that people being treated for depression had impaired artery function. Many health-care professionals are unsure whether heart disease is a cause or a result of depression. Some believe depression causes stress-related responses in the body that lead to blood-clotting problems, irregular heart rate and organ damage. Other studies suggest hardening of the arteries in the brain may cause depression, while still other researchers think that some heart medications may contribute. The speculation that antidepressant medications can cause cardiovascular problems persists, though one study detected heart impairment in people with untreated depression, suggesting it was not a side effect of the drugs.

FISH OIL, DEPRESSION AND CARDIOVASCULAR HEALTH

Fish oil may be one answer for depression sufferers, especially if there does turn out to be a health risk associated with some antidepressant medications. In a recent UK study, 70 depressed patients who did not respond to selective serotonin reuptake inhibitors (SSRIs) were given one gram of omega-3 fatty acid daily. After 12 weeks, 69% of the patients experienced a 50% reduction in all aspects of depression, including anxiety, low libido and suicidal tendencies. The reduction was assessed equally by patients and physicians alike, and seen in only 25% of the patients who received a placebo. Doses higher than a gram, however, produced no significant improvement in patients. Because these higher-dose groups were smaller, larger studies are warranted to determine potential efficacy of 2- and 4-gram doses.

Moreover, the link between lower cardiovascular risk and the omega-3 fatty acids found in fish has been well established. Among more than 22,000 initially healthy men followed for 17 years, the chance of dying suddenly was 80% lower for those men with the highest blood levels of omega-3 fatty acids, as compared to those with the lowest levels. Among nearly 85,000 women initially free of heart disease and followed for 16 years, those who reported consuming fish at least once a week were 30% less likely to have had a heart attack as compared to those who ate fish less than twice a month.

The American Heart Association recommends eating fish twice a week, though they do not recommend taking fish oil supplements until further evidence presents itself as to their effectiveness. The highest concentrations of omega-3 fatty acids are found in fresh (not canned) albacore tuna, with 4.2 grams per 100 grams of fish. Next is mackerel, followed by herring, then salmon. There is increased mercury contamination in both fish and fish oil, therefore reputable suppliers should always be sought.

EXERCISE, DEPRESSION AND CARDIOVASCULAR HEALTH

Phenylacetic acid concentration in urine reflects blood levels of phenylethylamine, a hormone known to raise serotonin levels, thereby possessing an antidepressant effect. In one study, 20 men who ran on a treadmill for 30 minutes were found to have a 77% increase in urinary concentration of phenylacetic acid from levels measured on a day without exercise. In another study, 46 outpatients suffering from panic disorder found that regular aerobic exercise produced significant clinical improvement of their condition, though it was not as effective as treatment with clomipramine, a drug of proven efficacy against the disorder.

SSRIs have also been shown to help treat SAD, which is ordinarily battled with lightbox therapy. Exercising outside in the winter may then be doubly effective. You'll be exposed to sunlight (the absence of which is considered the major cause of SAD) and raise your serotonin levels. In addition to helping you dodge the side effects of antidepressants, regular exercise can increase your self-esteem level through weight loss and improved muscle tone. But if winter proves too daunting a time to jump out there and begin an exercise regimen, know that you can achieve benefit by gradually easing into it. The most recent study concluded that three 10-minute bouts of brisk walking each day are as effective as one long bout of 30 minutes in reducing cardiovascular risk and improving mood in previously sedentary individuals. See New Year's Resolutions for tips on winter running, as well as The Crosstraining Report for indoor fitness options.

(Am. J. Physiol. Heart Cire. Physiol, 2002, Vol. 283, No. 4, pp. Hl 688-1694; Archives of General Psychiatry, 2002, Vol 59, pp. 913-919; Heart, 2002, Vol. 88, pp. 441-443, 521-524; Medicine & Science in Sports and Exercise, 2002, Vol 34, No. 9, pp. 1468-1474; Harvard Heart Letter, 2002, No. 7; British Journal of Sports Medicine, 2001, Vol. 35, No. 5, pp. 342-343; Am. J. Psychiatry, 1998, Vol. 155, No. 5, pp. 603-609)