Flight passengers may want to think twice before ordering drinks or washing their hands on the plane, a new analysis suggests.

The Center for Food as Medicine and Longevity, based in New York City, recently reviewed airline water systems over a three-year period, analyzing over 35,000 samples collected between 2022 and 2025.

The study evaluated both major and regional carriers, grading them based on contamination violations, E. coli findings, maintenance practices and how frequently water systems were cleaned, according to a press release.

THE HIDDEN REASON SCIENTISTS SAY BOTTLED WATER MAY NOT BE THE CLEANER CHOICE

A score of 3.5 or higher was considered indicative of relatively safe water, while lower scores reflected potentially unhealthy onboard water.

The analysis found 32 E. coli violations across 21 airlines during the study window.

Delta Air Lines received the highest scores for water safety, with Alaska Airlines also ranking well. Spirit Airlines, JetBlue and American Airlines placed at the bottom of the rankings.

NOT DRINKING ENOUGH WATER FLOODS YOUR BODY WITH HARMFUL STRESS HORMONES

Charles Platkin, the researcher behind the study, told Fox News Digital that airlines often cite compliance with federal guidelines, though much of the data is self-reported.

“Compliance should be the floor, not the ceiling,” he said.

The study examined whether airlines are doing enough beyond minimum requirements to protect passengers, according to Platkin.

He noted that travelers should not have to worry about the safety of onboard water when ordering drinks or washing their hands while flying. “These aren’t luxuries; they’re basic expectations,” he said.

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Nicolette M. Pace, a registered dietitian and founder of NutriSource in New York, said the findings reinforce the importance of taking simple precautions when flying.

Passengers can reduce risk by filling reusable water bottles after clearing security or purchasing bottled water, Pace recommended, adding that hand sanitizer is preferable to washing hands with airplane tap water.

“Compliance should be the floor, not the ceiling.”

Consuming contaminated water, even at low levels, can disrupt digestion and weaken immune defenses, she warned.

It’s especially important for children, older adults and people with weakened immune systems to take extra precautions, Pace cautioned.

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Fox News Digital reached out to airlines that ranked at the top and bottom of the study requesting comment.

Spirit Airlines said it maintains an extensive testing and maintenance program for onboard water systems that complies with the Environmental Protection Agency’s Aircraft Drinking Water Rule.

“The well-being and comfort of our guests is very important to us,” the airline said, adding that its data shows progress in recent years and that it continues to review and refine procedures as needed.

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American Airlines told Fox News Digital that its potable water program is fully compliant with EPA requirements and that a recent EPA audit found no significant issues.

The airline said it is reviewing the Center for Food as Medicine & Longevity’s analysis, including its methodology, to determine whether any changes could further enhance passenger safety.

Delta Air Lines said ranking highest in water safety reflects its commitment to providing clean, safe, potable water for customers and employees.

“Safety and quality in all aspects of our global service and operation are paramount at Delta,” the airline said.

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JetBlue also commented, stating that safety is “their first responsibility” and that they serve bottled purified drinking water on all flights.

“For coffee and tea preparation, JetBlue follows processes outlined by the EPA, the FDA and the FAA to ensure our water supply is safe,” the spokesperson told Fox News Digital, adding that they perform routine water system sampling and cleaning procedures in accordance with regulatory guidelines to ensure that water used on planes is safe and reliable.

A substance the body makes from vitamin A can make the immune system less effective at fighting cancer, a new study reveals.

Vitamin A itself is an essential nutrient, but one of its byproducts can accidentally “turn off” parts of the immune response against cancer, according to new research published in Nature Immunology.

Blocking that byproduct’s effects can restore immune activity and may improve cancer immunotherapy, the findings suggest.

FAST-GROWING CANCER COULD BE SLOWED BY COMMON BLOOD PRESSURE DRUG, RESEARCH SHOWS

Researchers at the Princeton University Branch of the Ludwig Institute for Cancer Research made this discovery by growing dendritic cells — key immune cells that activate the body’s defenses — in the lab. 

As these cells developed, the scientists noticed that they naturally turned on an enzyme that makes retinoic acid, a molecule that comes from vitamin A.

Retinoic acid can weaken dendritic cells’ ability to stimulate immune responses. This reduces the effectiveness of dendritic cell vaccines, an immunotherapy that trains the immune system to attack cancer, according to the study.

The researchers also found that when dendritic cells made a lot of the retinoic acid, they were less able to send strong danger signals to the immune system.

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When they removed the retinoic acid, the dendritic cells became stronger and better at activating T cells, which are the immune system’s cancer-killing cells.

A second study, published in iScience by collaborators from the same research group, looked at how to develop drugs to block this process.

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Using computer modeling and large drug screens, the team designed and identified small molecules that blocked the enzymes that produce retinoic acid. 

This led to the creation of a promising inhibitor that shuts down retinoic acid production in a controlled way — the same tool used in the first study’s experiments, the researchers noted.

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“Taken together, our findings reveal the broad influence retinoic acid has in attenuating vitally important immune responses to cancer,” lead researcher Yibin Kang said in a press release.

“In exploring this phenomenon, we also solved a long-standing challenge in pharmacology by developing safe and selective inhibitors of retinoic acid signaling and established preclinical proof of concept for their use in cancer immunotherapy.”

Study limitations

As these findings are based on laboratory and animal models, they may not fully reflect how retinoic acid functions in humans.

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Also, the studies examined a specific vitamin A-derived molecule (retinoic acid) acting in immune cells, not dietary vitamin A intake or overall vitamin A status.

Vitamin A remains an essential nutrient for normal immune function, growth and vision, according to the National Institute of Health, and extensive human studies have found no evidence that vitamin A causes cancer.

The South Carolina measles outbreak has spread to Clemson University.

The state’s Department of Public Health informed Clemson staff of a “confirmed case of measles” in an individual associated with the university, according to an update from the school published Saturday.

“The individual has isolated, per DPH requirements, and DPH is conducting contact tracing with individuals who may have been exposed and outlining isolation and quarantine protocols,” the school stated.

MEASLES CASES CONFIRMED AT FOUR MAJOR US AIRPORTS ACROSS COUNTRY AMID PEAK HOLIDAY TRAVEL

Individuals thought to be exposed to the virus will be contacted via email about quarantining.

Officials are reporting 558 cases of measles centered around Spartanburg County in the current outbreak.

Some cases are travel-related exposures or close contacts with known cases, according to the DPH.

Other cases have no identified source, suggesting that measles is circulating in the community and could spread further.

LARGEST MEASLES OUTBREAK IN US IS OFFICIALLY OVER, HEALTH OFFICIALS SAY

“Over the last seven to nine days, we’ve had upwards of over 200 new cases. That’s doubled just in the last week,” said Dr. Johnathon Elkes, an emergency medicine physician at Prisma Health in Greenville, South Carolina, during a media briefing Friday.

“We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse.”

Nearly 98% of main campus Clemson students have provided proof of immunity, according to the most recent data from Student Health Services.

“The health, safety and well-being of Clemson’s campus community remains our highest priority,” the school noted.

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Measles is highly contagious, according to the Centers for Disease Control and Prevention. If one person has it, up to nine out of 10 people will become infected if not protected.

“We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse.”

A person infected with measles is contagious for four days before and after a rash begins. Isolation of an actively infectious case lasts until four full days have passed after the onset of the rash. 

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Dates of isolation are determined by DPH, according to the university press release.

Quarantine for measles is reserved for exposed individuals without documented immunity, and lasts for 21 days after the last exposure, per DPH guidelines.

If a person without documented immunity receives a dose of the MMR vaccine within 72 hours after the last exposure, that person does not have to quarantine.

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The university also claims to have previously provided guidance to students, faculty and staff regarding measles preparedness. 

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More information is available on the Student Health Services website and through the South Carolina Department of Public Health’s measles updates.