Eat plenty of broccoli, kale, elderberries, and citrus fruits, and when it's time to replace flooring, choose wood over carpeting.

This year's ragweed could run you ragged, especially if you have pets.

RODALE NEWS, EMMAUS, PA—Pet and dust mite allergies tend to be year-round problems. But new research has found that those allergies actually pre-prime your immune system, setting up hay fever sufferers for a much stronger allergic reaction when ragweed season—the main cause of hay fever—hits in mid-August.

THE DETAILS: In the study, published recently in the Annals of Allergy, Asthma & Immunology, researchers looked at 123 people allergic to ragweed and found that 66 percent of them tested positive for cat allergies, 63 percent tested positive for dog allergies, and 73 percent tested positive for dust mite allergies. To test for symptoms, study participants sat in a controlled room exposed to ragweed for three hours, and answered a symptom questionnaire every 30 minutes. They found that hay fever sufferers who are also allergic to dogs, cats, or dust mites developed symptoms of hay fever faster, earlier, and more severely than those who have been spared pet and dust mite allergies. Researchers conclude that treating the cat, dog, or dust mite allergy year-round may help make the hay fever more manageable.

"People with hay fever react differently when ragweed allergy season arrives. Some start sneezing right away, and others don’t, so we wanted to determine what makes certain people develop symptoms more quickly," says allergist Anne K. Ellis, MD, lead author of the study and a member of The American College of Allergy, Asthma & Immunology (ACAAI).