Consuming fructose, a sweetener used in processed foods and sodas, is an established risk factor for obesity and related metabolic diseases like Type 2 diabetes, cardiovascular disease, and non-alcoholic fatty liver disease.
Researchers have found now that fructose can be passed from mother to child during breastfeeding, putting children in contact with this high-risk sugar very early in life, with severe consequences on the infant’s body composition, and likely influencing their risk of developing debilitating diseases.
The study, “Fructose in Breast Milk Is Positively Associated with Infant Body Composition at 6 Months of Age,” was published in Nutrients.
“Early life is a period of rapid development and early nutrition is strongly linked to long-term health outcomes,” Tanya Alderete, co-author of the study and a postdoctoral research scholar at the Keck School of Medicine, said in a press release. “We know that the decision to breastfeed or bottle feed may have impacts on later health. Results from this work suggest that the composition of breast milk may be another important factor to consider in regard to infant health,” she said.
Researchers examined data from 25 mothers and their infants. When babies were one month old, a breast milk sample was collected from each mother and scanned for sugars like lactose, glucose and fructose. At the same time, researchers measured the infants’ body composition, including their fat mass, lean mass, and bone mass. The same procedure was repeated when the babies were six months old.
Looking at the data, the team found that a one-month-old infant would consume just 10 milligrams of fructose from breast milk a day — the equivalent weight of a grain of rice. But even though this was 1,000 times lower than the amount of lactose found in the milk, consuming this little fructose was associated with a 5-10% increase in body weight and body fat at six months.
Indeed, each microgram of fructose per milliliter of breast milk was associated with a 257 g higher body weight, 170 g higher lean mass, 131 g higher fat mass, and 5 g higher bone mineral content.
“We know very little about why some children eventually become overweight or obese,” said Michael Goran, lead author of the study. “It’s important that we study what may be taking place in the earliest times of their development to determine whether anything could be done just after birth to lower their risks.”
The first year of life is critical for building brain networks and establishing the metabolic system. Thus, even small amounts of fructose at this age may have detrimental effects in the metabolism. The team believes that fructose in this early age may be instructing pre-fat storage cells to become actual fat cells, increasing the infant’s risk of becoming overweight or obese.
Nevertheless, they say that maternal-intake of fructose-containing products is a targetable intervention for reducing exposure to fructose in early life.
“New moms can prevent passing secondhand sugars to their children by eating and drinking less sugars while pregnant or breastfeeding,” Goran said. “Caregivers can shield babies and children from harmful effects of sugars by carefully choosing infant formula, baby foods and snacks without added sugars or sweeteners.”