Squeezable pouches of organic baby food are as omnipresent on some American playgrounds as runny noses, diaper bags and overpriced strollers. Organic baby food can cost up to twice as much as conventionally grown baby food, and it comes in such gourmet blends as "blueberry, oats and quinoa" and " spinach, apple and rutabaga."

Parents go organic for a variety of reasons, including environmental concerns and a desire to avoid pesticide residue. And in some cases, they just want a status symbol. According to the consumer market research firm Mintel, organic baby food made up about 10 percent of the $1.4 billion U.S. baby food and snacks market in 2011.

But studies show that parents who are aiming to buy the best food for their infants may not need to spring for the expensive organics.

"The variety of foods and nutrients that babies take in will have a much larger impact on their health than whether they're fed organic or not," says Tiffani Hays, the director of pediatric nutrition at the Johns Hopkins Children's Center. "Vitamins, minerals and fiber have much better research and documented health benefits than does choosing organic."

A 2012 study in the Annals of Internal Medicine considered the question "Are Organic Foods Safer or Healthier Than Conventional Alternatives?" After analyzing hundreds of previous studies, including some that involved pregnant women and children, the authors found no strong evidence in favor of the organics.

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Stanford University physician Crystal Smith-Spangler and her co-authors did not find consistent differences in nutrient levels between the two options. There was a 30 percent lower risk of pesticide contamination in organic than in conventional food, but it was rare for food from either group to exceed limits set by the Environmental Protection Agency, she said.

"Despite the widespread perception that organically produced foods are more nutritious than conventional alternatives, we did not find robust evidence supporting this perception," the authors noted.

"The purpose of the study was not to tell people what to buy and eat, but to give people the information about the difference," Smith-Spangler says. "I can see smart, rational people making different decisions. It's a complex decision."

A 2000 study, meanwhile, compared pesticide levels in three brands of baby food, two of them conventional and one organic. The authors didn't detect pesticide residues in any of the samples.

Additives in food, such as dyes and preservatives, have been studied and found to be safe, though some parents still worry that there are negative effects, especially for infants and young children, Hays says. Cancer, immune diseases, gastrointestinal symptoms and even behavioral problems such as attention-deficit hyperactivity disorder have all been blamed on food additives, she says, adding that there are no data behind these suspicions.

"These only remain concerns in theory, not something that has been documented and supported by controlled research studies or anything like that," she says.

The squeezable pouches of organic baby food hit the market about five years ago and have exploded in popularity since, according to organic baby food manufacturer Happy Family.

Parents love the pouches for the convenience: They can squirt the puree onto a spoon for the baby; when the child gets older, he or she can suck the food straight out of the pouch. There is very little mess. In the last few years, Gerber and other power players in the baby food market added pouches to their product lines, and not just for organics, according to Mintel. And just as conventional baby foods come in pouches these days, some organics are sold in jars. (While the pouches are parent-friendly, they are not so planet-friendly. The plastic cap is the only part that's recyclable. The pouch is made of foil and plastic and is therefore headed for the landfill, according to Shazi Visram, the founder and chief executive of Happy Family.)

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Parents opting for organics pay a premium. At a Wegmans grocery in Virginia recently, for example, a four-ounce jar of Gerber non-organic sweet potatoes cost 65 cents while the organic version, made by Earth's Best, was 85 cents. A 4.2-ounce pouch of Earth's Best sweet potato and apple puree cost $1.49. Yet Mintel reports that four in 10 mothers are willing to pay the premium for organics.

Jarred baby food is typically considered the domain of infants, but it's common to see toddlers eating from pouches, and some companies have introduced squeeze pouches for adults.

Most babies need to eat super-smooth baby food for the first few weeks after introducing solids, Hays says. After that, she says, their oral motor skills advance quickly and parents should watch to see when their kids are ready to move from simple purees to more complex mixtures and eventually finger foods and table foods.

"Having a positive eating experience with a variety of foods, testing for allergic reactions and advancing textures are the most important parts of early feeding, not whether they're getting organic or not," Hays says.

How popular are the organic pouches? Visram started the company in 2006 with $115,000 in sales; by 2011, she said, she was up to $35 million. ("I pinch myself a lot," she says.) The company's top pouch is the spinach, mango and pear flavor. At 3.5 ounces and 60 calories, parents are smitten with the idea of getting their kids to eat spinach, "one of the holy-grail, top-10 foods you want your baby to develop a taste for," Visram says. While spinach is listed first on the front of the pouch, it's actually the third ingredient listed in the official "Nutrition Facts" label on the back, behind pear and mango.

"Parents are looking for ways to get more vegetables into their children," Visram says. "Our philosophy is: You do all you can, and it's about repetition."

Jessica Wolff, a Leesburg, Va., mother who works for a nonprofit medical society, feeds her 1-year-old daughter only organic food, though she and her husband eat conventional food. She's hoping to keep pesticides and hormones out of her daughter's diet.

"Across the board, everything for the baby has to be pure and good and better. I'm a little neurotic about it," she says.

When her daughter started eating solids, Wolff bought organic foods at the farmers market and spent an entire day cooking them, pureeing it all and freezing some of the bounty in one-ounce portions. Once, when she tried to puree a free-range chicken, the baby food processor started to smoke. That was the end of "the whole horrible Sunday situation," she says.

Now, her daughter eats prepackaged organic purees and meals from brands such as Ella's, Plum Organics and Happy Family, sometimes mixed with organic yogurt, plus finger foods and fresh produce such as avocado.

"She has a really advanced palate, and I hope it sticks," Wolff says. "It looks like we have a food snob living in the house."

The organic craze has gotten so intense that even parents of very sick children have been asking Hays and doctors at Johns Hopkins Children's Center about replacing the hospital-provided liquids delivered by feeding tube with organic and homemade mixtures. "They couldn't believe a liquid formula was as nutritious," Hays says.

Paul Weiner, a Maryland pediatrician, does not recommend organic baby food to patients because "there's no definitive data that it's better," he says. He has gotten a lot of questions about arsenic in rice ever since last fall, when Consumer Reports found "worrisome levels" of the element in a variety of products, including infant rice cereal. The report led the Food and Drug Administration to test about 200 food samples. That produced similar results, but the agency did not recommend that consumers change their rice-eating habits. "We are not aware of any acute health risks linked with the consumption of infant rice in the U.S.," the agency said in a message to consumers.

Weiner encourages parents to rotate rice cereal with barley cereal and oatmeal so that children don't consume too much of it.

"If an adult were to eat that amount of arsenic, it wouldn't necessarily be a problem, but for a baby's small body size, it adds up," he says.

Hays hopes that parents will refocus their good intentions for children's nutrition.

"My hope is that any parent that is going to be diligent to make sure their child doesn't get pesticides and hormones would be diligent that their child avoided obesity, because that effort would trump anything that we could do to avoid the side effects of additives," Hays says.

Saslow is a former Post staff writer.