Laugh loud, laugh often. At Western New England College in Springfield, Massachusetts, psychologist Kathleen Dillon, Ph.D., noticed that people who seemed cheerful and used humor to deal with adversity had higher IgA levels than those who seemed dour. Dr. Dillon wondered if she could boost IgA levels by encouraging mirth. To find out, she had five students watch the comedy video Richard Pryor Live, followed by an education video about the health hazards of anxiety. Another five students watched the same videos, only in the opposite order. After each viewing, the students had their IgA levels tested. IgA rose significantly after the comedy video but dropped after the anxiety video.

Embrace life’s highs. Just as minor daily hassles undermine your immune system, everyday pleasures boost immunity. In fact, according to Arthur Stone, Ph.D., a psychologist at the State University of New York at Stony Brook, the positive impact of uplifting events seems to outweigh the negative impact of upsetting events.

In a study of 100 men, Dr. Stone found that on days when the joys outnumbered the stresses, the men’s immune function rose and stayed elevated for 2 days afterward. On bad days, the men’s IgA levels fell but remained low for only a day.

Watch the alcohol. An occasional beer or glass of wine probably won’t your risk of catching a cold. But if you drink on a daily basis, your neutrophil activity can become impaired, says Joseph Pizzorno Jr., N.D. That means you’re more susceptible to infection.

Other Good Choices

Homeopathy

Take a constitutional medicine. “Homeopaths offer two types of treatment,” explains homeopath Dana Ullman. “They can treat specific symptoms, and they can prescribe constitutional medicines, preparations matched to your own unique health characteristics that help keep you healthy. Constitutional medicines are individualized immune boosters.” To find out which of these medicines would work best for you, consult a homeopath.

Home Remedies - Get some quality snooze time. Many studies show that lack of sleep impairs immune function. Studies by the National Commission on Sleep Disorders Research show that many, if not most, Americans are at least somewhat sleep-deprived. “If you feel rundown, try getting at least 8 to 9 hours every night for a week;’ says William Dement, M.D., Ph.D., director of the Stanford University Sleep Disorders Clinic and chairperson of the National Commission on Sleep Disorders Research. “You’ll probably feel better.”