— Findings support guidance limiting such beverages in young children, researcher says
by Jennifer Henderson, Enterprise & Investigative Writer, MedPage Today
Daily consumption of 100% fruit juice was associated with a small increase in body mass index (BMI) in children, while an association between consumption and weight gain among adults appeared mixed, a systematic review and meta-analysis found.
In prospective cohort studies involving kids, each 8-oz serving of 100% fruit juice was associated with a 0.03 increase in BMI (95% CI 0.01-0.05), a link that appeared to be driven by younger children, reported Vasanti Malik, MSc, ScD, of the University of Toronto, and colleagues.
Cohort studies in adults found no significant association between each serving of 100% fruit juice and increased weight (0.07 kg, 95% CI -0.06 to 0.20), however. Furthermore, randomized clinical trials (RCTs) in adults found no association, with a mean difference of -0.53 kg (95% CI -1.55 to 0.48) for individuals assigned to drink juice versus controls, the researchers detailed in JAMA Pediatrics.
The findings “support public health guidance to limit the consumption of 100% fruit juice, especially for young children,” said co-author Michelle Nguyen, HBSc, also of the University of Toronto, adding that whole fruit rather than fruit juices should be recommended, with water as the drink of choice.
“Whether 100% fruit juice is a healthy beverage is a question of great interest from clinicians, the general public, parents and caregivers, and policymakers,” Nguyen told MedPage Today in an email. “The evidence on 100% fruit juice and weight gain has yielded mixed findings from both observational studies (prospective cohort studies) and clinical trials. Our findings indicate that 100% fruit juice consumption was associated with weight gain in children, with younger children showing greater weight gain.”
No RCTs addressing this question have been conducted in kids, but subgroup analyses of the cohort studies showed the association to be driven by kids age 10 and younger (BMI increase of 0.15, 95% CI 0.05-0.24), with no association in those age 11 and older (-0.001, 95% CI -0.01 to 0.01).
The findings in children are in line with American Academy of Pediatrics guidelines that suggest children younger than 6 years of age consume less than one glass of fruit juice per day, Malik and colleagues noted.
“Concerns have been raised that the early age of fruit juice introduction may lead to an increased risk for overweight and obesity in later childhood due to increased preference for sweet foods,” they wrote. “Thus, delaying the introduction of 100% fruit juice in young children, moderating serving sizes, and favoring whole fruit is recommended. Although the effect sizes are modest, small gains in BMI over time may substantiate over the life course; therefore, limiting intake of fruit juice among children is an important strategy for them to develop healthy weight trajectories.”
In adults, cohort studies that did not adjust for total energy intake showed a positive association between 100% fruit juice and increasing body weight (0.21 kg, 95% CI 0.15-0.27 kg), whereas studies that adjusted for energy intake found an inverse association (-0.08 kg, 95% CI -0.11 to -0.05).
This suggests that “excess calories play a role in this association,” Nguyen said.
Significant associations between juice consumption and weight gain among adults also appeared dependent on study location:
North America: 0.14 kg (95% CI 0.02-0.26)
Europe: -0.15 kg (95% CI -0.37 to 0.08)
For their systematic review and meta-analysis, the researchers searched MEDLINE, Embase, and Cochrane databases for studies through May 18, 2023. Prospective cohort studies of at least 6 months and RCTs of at least 2 weeks that assessed the association of 100% fruit juice with body weight change in children and adults were included.
The final review included 45,851 children (median age 8 years) from 17 prospective cohort studies along with 268,095 adults (median age 42) from six prospective cohort studies and 19 RCTs.
Most of the cohort studies in children were conducted in North America, and the median study duration was 4 years. Cohort studies in adults were conducted in North America or Europe, with a median duration of 3 years.
The majority of RCTs in adults were conducted in Europe or Asia, with a median duration of 6 weeks. All studies were feeding trials, with participants provided 100% fruit juice in the form of pomegranate, berries, tart cherry, apple, citrus, or grape juice.
Limitations included the lack of RCTs in children, and that only five of the 17 cohorts in children and five of the six cohorts in adults used a change-versus-change analysis. “This would be the optimal analysis to assess longitudinal changes in 100% fruit juice intake and concomitant body weight change,” the researchers wrote.
Jennifer Henderson joined MedPage Today as an enterprise and investigative writer in Jan. 2021. She has covered the healthcare industry in NYC, life sciences and the business of law, among other areas.