A study that upended medical practice by recommending feeding babies peanut products early to prevent allergies has had a big effect in the real world.

Encouraging parents to introduce peanuts to their infants early has led to a significant drop in new allergy diagnoses, researchers said in a new study.

Peanut allergy rates in young children plummeted since guidelines were introduced that advised parents to feed the common allergen to babies — reversing decades of medical practice.

New research found that feeding peanut products to babies has helped about 60,000 kids grow up without developing peanut allergies.

Doctors have long recommended that infants avoid peanuts. But in 2017, experts officially reversed that guidance, and food allergies decreased sharply.

Peanut allergies in children under 3 have dropped by more than a quarter since 2015 when experts began recommending early peanut introduction, a new study finds.

The research, known as the LEAP trial and published in the New England Journal of Medicine, found that early introduction decreases the likelihood of an allergy developing.

The researchers analyzed health data on almost 125,000 children born before and after the latest guidelines were introduced. Peanut IgE-mediated allergies dropped from 0.79 percent to 0.45 percent of the study group, while any IgE-mediated food allergy fell from 1.46 percent to 0.93 percent

New data suggest that early peanut exposure may cut the risk of allergic reactions. Newsweek asked experts what parents should do.

The effect was even greater after the full 2017 Prevention of Peanut Allergy Guidelines from the National Institute of Allergy and Infectious Diseases (NIAID), which recommended introduction of peanut products by 11 months for low-risk infants, and by 6 months for those at high risk.