Plagued by changing consumer preferences and growing foreign competition, U.S. cranberry growers are betting the bog ... on urinary tract infections.

Juice sales have fallen flat. Producers grow more berries than Americans consume. Against that backdrop, cranberry behemoth Ocean Spray has invested millions of dollars into research on the link between cranberries and UTIs — and is requesting regulators’ permission to advertise that women get fewer UTIs when they drink cranberry juice.

The move has precipitated a showdown between industry-funded science and independent critics. Many experts dispute Ocean Spray’s claim that cranberries reduce urinary tract infections.

The labels could help beleaguered growers, they say, but would do little for UTI patients — or for consumer trust in America's food-label system.

“These health claims are marketing ploys that mislead consumers,” said Bonnie Liebman, the nutrition director at the consumer group Center for Science in the Public Interest. “All they do is sell products. That’s why companies use them.”

Ocean Spray insists that motivation doesn’t invalidate the company’s research.

A massive agricultural cooperative composed of 700 farms across five states, Canada and Chile, Ocean Spray has long dominated the production and processing of U.S. cranberries, turning the niche, seasonal enterprise into a multibillion-dollar industry.

To do that, Ocean Spray has invented an array of cranberry products that include canned cranberry sauce, cranberry juice cocktail and the now-ubiquitous Craisin.

The cooperative has also invested heavily in health research on cranberries, with a particular focus on the age-old claim that cranberry juice can prevent or treat urinary tract infections. Roughly half of all U.S. women will contract a UTI at some point in their lifetime, according to the American Urological Association.

Clark Reinhard, Ocean Spray’s vice president of global innovation, says the cooperative’s research has consistently shown that daily cranberry consumption reduces the risk that a woman who has had a UTI will contract others in the future. (There is no evidence that cranberries treat UTIs, and Ocean Spray does not claim they do.) The preventive effect has been attributed to a compound called proanthocyanidins, which prevent bacteria from adhering to the urinary tract and occur naturally in the fruit.

In September 2017, Ocean Spray applied for permission to make that claim on its products, including a juice that will be specifically marketed as a health beverage.

“We’ve got evidence over a long period of time that there’s a solution [to UTIs],” Reinhard said. “And so we applied for [the label claim] because it was important for us to have that connection validated, and to show customers it was legitimate.”

But some leading researchers say the science on cranberries and UTIs is still unsettled. A 2012 Cochrane review of the available literature, conducted by a team of highly regarded independent researchers, concluded that “cranberry juice cannot currently be recommended for the prevention of UTIs.”

“I think the evidence is mixed and small at best,” said Ruth Jepson, the lead author of that paper. Asked by The Post to review Ocean Spray’s petition, Jepson added that she was “not convinced by the research.”

The confusion lies in the definition of a UTI, Jepson and other researchers said. Ocean Spray has studied the preventive effects of cranberries largely in people with common UTI symptoms, such as painful or frequent urination. Independent researchers studied cranberries in people with both those symptoms and confirmed, bacterial infections, a higher standard.

Independent studies have not found that cranberries prevent confirmed bacterial infections, said Betsy Foxman, who directs an infectious disease research center at the University of Michigan and has conducted large-scale studies on cranberries and UTIs. And industry-sponsored studies have technically found that cranberry consumption prevents some future UTI symptoms — which can be caused by a variety of other conditions, including things as ordinary as nervousness.

“I love the idea of having an intervention that would really make a difference for people,” Foxman said. “But I’m not convinced cranberry juice is it.”

Already, FDA appears to be siding with critics. In a February letter to Ocean Spray, the agency declined to consider cranberries for an “authorized health claim,” which requires a high standard of scientific evidence, but said it would be considered for a “qualified health claim,” which comes with a lower standard, instead.

Under a qualified health claim, Ocean Spray would not be allowed to claim that cranberry consumption “may help prevent” UTIs. Instead, it would have to use much more circumspect language, noting that the evidence is inconclusive.

But even this has riled food industry watchdogs, who say consumers don’t understand the difference between the two types of labels. Multiple studies, including one conducted by FDA, show that people confuse the labels and misinterpret words such as “inconclusive.” In a 2011 report, the Government Accountability Office criticized the system on the basis that it “might encourage consumption of foods with few or no health benefits.”

If science isn’t strong enough for an authorized health claim, then they should not be allowed, CSPI’s Liebman said.

“FDA has tried to distinguish between claims backed by strong evidence and weak evidence,” she said. “But many consumers don’t pick up the difference.”

Ocean Spray disagrees: Christina Khoo, the cooperative’s science lead, said she had confidence in her team's research. Ocean Spray moved forward with the lower health claim, she added, because it believes that even the qualified information is valuable to consumers.

Cranberries could certainly use the sales boost. Growers are producing too many of them, dropping prices at a time when demand has also flattened out. To further complicate things, cranberries are a probable target of any trade dispute with Europe.

Even now, the industry is looking for new ways to stabilize prices and expand its market.

In addition to seeking production caps to stabilize prices, and leeway in added sugar labeling to counter consumer health concerns, cranberry growers are looking beyond UTI research for other bankable health and wellness claims.

Just last week, an industry-funded study concluded that cranberries are good for heart health.

“We're just painting a full picture of what the cranberry can do,” said Kellyanne Dignan, the cooperative's director of corporate communications. “This isn't coming out of nowhere: It's how cranberries have always been marketed.”

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