Drinking grape juice to prevent stomach flu is unproven

The claim: Drinking grape juice daily prevents the stomach flu

With the ongoing coronavirus pandemic and the arrival of flu season, some people have turned to unproven, at-home remedies to stay healthy.

One Facebook user claims drinking grape juice will prevent or treat norovirus, also known as the “stomach flu” – a contagious illness that causes vomiting and diarrhea.

“It’s that time of year… I make my family drink grape juice daily from now until March,” reads a Sept. 13 Facebook post that accumulated 6,900 shares within two weeks. “Just a few sips each day. It keeps the stomach bug from attaching to your digestive system if you’re exposed to the virus.”

The claim that grape juice can treat or prevent stomach flu has circulated on different parenting blogs for years and typically resurfaces in the fall and winter.

However, there’s no evidence drinking grape juice can prevent or cure norovirus, according to experts who spoke with USA TODAY. Numerous fact-checkers, news sites and health experts have debunked the claim. To avoid getting sick, the Centers for Disease Control and Prevention encourages hand-washing, disinfecting contaminated surfaces and washing food and laundry thoroughly.

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USA TODAY reached out to the social media user who shared the post for comment.

No evidence to support grape juice remedy

Experts and research dating back to the 1970s indicate drinking grape juice is not a proven way to treat or prevent stomach flu.

Bethany Doerfler, clinical research dietitian in the division of gastroenterology and hepatology at Northwestern University’s School of Medicine, said while the phenolic compounds in fruit juices have natural antiviral properties, most studies have been done with animals or cell cultures, not humans.

“To date, no studies in humans have been done so we completely lack (the) ability to recommend dose or frequency,” Doerfler said via email. “There is no danger to having people drink grape juice preventatively, and it is part of a healthy diet, but the claim that just a few sips a day is protective is not evidence-based.”

Doerfler pointed to a 2014 study, which found “no norovirus-specific antiviral drugs or vaccines” are available for the norovirus. Researchers found that while foods containing flavonoids and polyphenols have anti-norovirus activity, “future studies will be necessary to confirm the effectiveness of such compounds against human norovirus.”

Another study published in 1978 in the Journal of Food Protection looked specifically at the antiviral properties of grape juice and found it “has not been shown likely to prevent or modify human enterovirus infections.” More recently, a 2010 paper in Nutrition Reviews found compounds in grapes can positively affect risk factors associated with cardiovascular health, cancer, Alzheimer’s, diabetes and neurodegenerative diseases.

However, no human clinical trials have been conducted on antiviral activity and grape juice.

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Linda Van Horn, a professor of preventive medicine in epidemiology at Northwestern University, said in an email that while 100% fruit juices offer many beneficial nutrients, “prevention of stomach flu or anything else is unproven.”

Similarly, Dr. Richard Martinello, an infectious diseases specialist and associate professor of medicine and pediatrics at Yale Medicine, said it is “improper for anyone to conclude that either drinking grape juice, eating grapes, drinking wine, or eating any grape product will provide any benefit whatsoever.”

“In no way (would) any competent clinician suggest the use of grape juice to prevent or treat influenza, or any other grape product for that matter,” Martinello said.

Health officials recommend food safety, hand-washing

There is no vaccine for noroviruses, but health officials recommend hand-washing and other preventative measures to avoid getting sick.

Practicing proper hand hygiene, preparing food safely, thoroughly cleaning surfaces, utensils and counters, and washing laundry can prevent a norovirus infection, per the CDC.

The Mayo Clinic recommends avoiding contaminated food and water, avoiding travel, staying home from work and cooking seafood thoroughly.

The best beverages to drink for stomach flu are clear liquids, decaffeinated herbal tea, electrolyte replacements and ice chips, according to the Cleveland Clinic.

Our rating: False

Based on our research, we rate FALSE the claim that drinking grape juice daily prevents the stomach flu. Health experts say that, while grape juice does contain beneficial nutrients, using it to treat or prevent stomach flu is unproven. There is no scientific evidence to support the claim. Hand-washing, cleaning surfaces and preparing food safely are recommended to prevent the norovirus.