By Katie Sweeney
Research investigator Michael Goran, PhD in his lab
Research investigator Michael Goran, PhD in his lab
How the tastiest of treats—sugar—may be wreaking havoc on children’s growth and development, as early as in the womb

There’s a simple reason why kids love sugar so much, says Michael Goran, PhD. They were literally born that way.

“It’s protective,” he explains. “It was designed to encourage consumption of breast milk, which is sweet, and prevent the eating of poisonous berries from the forest floor.”

Today, though, that evolutionary advantage has been turned upside down. Most children don’t frequent forests, let alone crawl around in one. Instead of bitter berries, the threat to their health is deceptively sweet: sugar.

Infographic showing statistics of sugar consumption and the amount of sugar contained in drink types

“Sugar is everywhere. We’re basically being bombarded,” says Dr. Goran, Program Director for Diabetes and Obesity at The Saban Research Institute of Children’s Hospital Los Angeles. “The types of sugars we’re consuming are also different than in past generations. It’s a perfect storm.”

That storm may be hitting children the hardest. In their research at CHLA, Dr. Goran and his team are finding that excess sugars can disrupt a child’s growth and development, including cognitive development.

And those disruptions can start early in life—even before a baby is born.


Not all sugars are created equal. One type is particularly troublesome: fructose.

Research investigator Michael Goran, PhD in his lab
Dr. Goran in front of a cabinet full of beverages he uses to show the sugar content of popular drinks

Unlike other sugars, fructose is metabolized entirely in the liver, where it’s converted to fat. Give the body too much fructose, and over time that fat can build up in the liver and even lead to nonalcoholic fatty liver disease—a life-threatening condition. Other times, extra fat is pushed back into the bloodstream, where it can wreak havoc on metabolism.

“The problem is not so much the calories,” says Dr. Goran. “Fructose is just not as well-regulated in the body.”

And yet, it’s found in abundance in processed foods—everything from cereal to bread to yogurt—and in beverages like sodas and fruit juices. Often, it takes the form of high-fructose corn syrup or “fruit sugar.”

Fructose is found in fruit, too. But when you eat an apple, the amount of fructose is too small to do any harm. Each glass of apple juice, meanwhile, delivers a much more concentrated dose.

“It’s the higher doses and rapid consumption in liquid form that become problematic,” Dr. Goran says.

He and his team have already identified sugar-sweetened beverages as the main nutritional factor explaining obesity in 2-year-olds and diabetes in teens. Now evidence is also mounting that sugar impacts the developing brain.

“Several studies have found that maternal consumption of sugars or artificial sweeteners during pregnancy contributes to disruptions in a child’s cognitive development, including lowering of memory,” he adds. “The same goes for sugar consumption in infancy and early childhood.”

In addition, Dr. Goran’s collaborators at USC found that high fructose consumption caused memory problems and brain inflammation in rats—but only when fructose was consumed during adolescence. Most alarming of all: Even after switching to a normal diet, the rats’ brain damage was irreversible.

“What we’re learning is that sugars may have an effect during critical windows of development,” he says. “That’s another part of the perfect storm.”

Infographic showing statistics of growing sugar consumption from 200 years ago to today
Amount of sugar consumed in one year - 200 years ago vs. today

One of those critical windows Dr. Goran is studying is early life. Currently, his team is following 200 babies and their moms from birth to age 2 in a clinical study called “Mother’s Milk.”

Researchers conduct detailed surveys on what moms and babies are eating and drinking. They also collect breast milk and stool samples. The goal: See how early nutrition affects the development of a baby’s microbiome (healthy gut bacteria), as well as body fat composition and cognitive health, by age 2.

The group is looking not only at a baby’s direct intake of sugar, but also a phenomenon Dr. Goran has coined “secondhand sugars.”

The team has found that when moms drink a large sugary beverage, some of the fructose from that drink is transmitted into their breast milk—where it can remain for up to five hours. In other words, many babies are getting their first taste of fructose, which is not part of the usual sugars in breast milk, when they’re just days old.

The group’s newest study, called Sweet PEA, is tracing the effects of secondhand sugars back even further, to early pregnancy. Researchers are examining how nutrition during pregnancy impacts infant growth and development, including a baby’s body fat and brain structure.

Investigators are paying particular attention to pregnant moms’ consumption of sugars and low-calorie sweeteners. And yes, artificial sweeteners appear to be just as damaging as sugar— if not more so.

“Evidence shows that consuming sugars in pregnancy contributes to obesity development in newborns. But when pregnant women consume diet sodas, the effect may be more pronounced and at an earlier age,” Dr. Goran notes. “We’re trying to verify those findings and, most importantly, understand why this happens.”

Both studies are also focused on the potential protective power of breastfeeding. In earlier research, Dr. Goran’s team found that breastfeeding for longer than 12 months “obliterated” the obesity risk from sugar-sweetened beverages. “We know that breastfeeding can be protective, but we don’t really know why,” he adds. “The idea is to identify specific components in breast milk that protect the baby.”


A father of two teenagers, Dr. Goran understands that eliminating all sugar is unrealistic—and probably not necessary.

“You don’t have to be the parent who puts out celery sticks from the Easter Bunny,” he says. “It’s important to find a balance.”

His advice to families? Keep sugars out of the house as much as possible, reserve sweets for special treats, avoid sugary beverages (including fruit juices) and reduce processed foods. For pregnant women, he recommends limiting sugars and avoiding “fake sugars” altogether.

Educating parents is a key part of his efforts. His team’s research includes an intervention program designed to get new moms off of sugar and avoid introducing it to their children during the first two years of life. Dr. Goran is the author of a forthcoming book called “Sugarproof,” which aims to spread the word about the dangers of too much sugar during childhood and provide families with strategies to reduce it from their diet.

“We need to translate our scientific data into practical tools and information,” he says. “We’re doing all this research, but it won’t have much impact until we get major shifts in diet in the population. That’s what I want to see.” CHLA butterfly icon graphic

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