Researchers in New Zealand discovered that children who eat more fruit and come from wealthier families tend to have higher levels of natural color-producing substances in their skin called carotenoids. These substances come from eating colorful fruits and vegetables. The study looked at 75 children aged 8-13 and used a special device to measure the carotenoid levels in their skin. Interestingly, most children weren’t eating enough vegetables, and those from lower-income families had noticeably lower carotenoid levels. This suggests that family income and access to fruit might be important factors in whether kids get enough nutrients from colorful foods.

The Quick Take

  • What they studied: Whether a special skin measurement could show how much fruit and vegetables children eat, and what factors affect this measurement
  • Who participated: 75 children (ages 8-13) from five New Zealand schools, with 69 completing all measurements. About 39% were girls and 49% were boys
  • Key finding: Children from lower-income families and those eating less fruit had lower carotenoid skin measurements. Only 8% of kids met vegetable eating recommendations
  • What it means for you: This suggests that family income affects whether kids can access enough fruits and vegetables. If your family has limited resources, being intentional about affordable colorful foods may help. However, this is just one study, so more research is needed

The Research Details

This was a cross-sectional study, which means researchers looked at a group of children at one point in time rather than following them over months or years. The researchers asked parents and children questions about how often they ate fruits and vegetables using a validated questionnaire (a form that scientists have tested and proven works well). They then used a special device called a reflection spectrometer to measure the amount of carotenoids in the children’s skin—this is like taking a non-invasive photo that shows natural pigment levels. They also collected 24-hour urine samples from most children to measure potassium levels. The researchers then used statistical tests to see which factors (like age, gender, income, and fruit intake) were connected to the carotenoid measurements.

This approach is important because it provides an objective way to measure whether kids are eating enough colorful foods without relying only on what people remember eating. The skin measurement is more accurate than asking kids to recall their diet. By measuring multiple factors at once, researchers could identify which ones were most strongly connected to carotenoid levels, helping identify which children might need more nutritional support

This study has some strengths: it used a validated measurement tool and collected actual urine samples. However, it’s relatively small (69 children) and only looked at children in New Zealand, so results may not apply everywhere. The study was a snapshot in time, not following kids over time, so we can’t say that low income causes low carotenoids—only that they’re connected. The researchers couldn’t explain why 83% of the variation in carotenoid levels occurred (R² = 0.17), meaning other important factors weren’t measured

What the Results Show

The average carotenoid reflection score was 236, with over half the children (51%) having low scores below 250. This suggests that many New Zealand children may not be eating enough colorful fruits and vegetables. When researchers looked at what predicted these scores, they found that annual household income and the number of fruit servings children ate per day were the strongest predictors. Children from higher-income families tended to have higher carotenoid levels, as did those eating more fruit servings daily. Interestingly, younger boys (under 10 years old) had significantly higher carotenoid scores than younger girls of the same age—about 74 points higher on average. This gender difference disappeared in older children.

Only 8% of children (6 out of 75) met the recommended daily vegetable intake, which is concerning for overall nutrition. The researchers also measured 24-hour urinary potassium levels, expecting it might relate to carotenoid levels since both come from fruits and vegetables. Surprisingly, there was no connection between potassium levels and carotenoid scores, suggesting these may be influenced by different factors or that the relationship is more complex than expected

Previous research has shown that carotenoid skin measurements can reflect fruit and vegetable intake, and this study confirms that relationship. The finding that low household income is connected to lower carotenoid status aligns with other nutrition research showing that wealthier families often have better access to fresh produce. However, the lack of connection between carotenoid levels and potassium excretion is somewhat unexpected and suggests future research should explore why these don’t align as predicted

The study was relatively small with only 69 children completing all measurements, making it harder to apply findings to all children. It only included children from New Zealand, so results may differ in other countries with different food systems and income levels. The study was a one-time snapshot, so we can’t determine if low income causes low carotenoids or if other factors are involved. The researchers could only explain 17% of why carotenoid levels varied between children, meaning 83% of the variation came from unmeasured factors. Additionally, the study relied on parents’ and children’s reports of food intake, which can be inaccurate

The Bottom Line

Families with limited budgets should prioritize affordable colorful fruits and vegetables like carrots, sweet potatoes, oranges, and bananas. Schools and communities should consider programs to improve fruit and vegetable access for lower-income families. However, treat these findings as suggestive rather than definitive—more research is needed. Confidence level: Moderate (this is one small study, though it aligns with other nutrition research)

Parents and caregivers of children aged 8-13 should pay attention, especially those with limited food budgets. School nutrition programs, policymakers, and public health officials should care about these findings as they suggest income inequality affects children’s nutrition. Children with very restricted diets or medical conditions should consult healthcare providers before making changes

If children increase fruit intake, carotenoid levels in skin would likely increase over weeks to months as the body accumulates these pigments. However, this study doesn’t tell us exactly how long improvements take

Want to Apply This Research?

  • Track daily fruit and vegetable servings with specific counts (e.g., ‘ate 2 apple slices, 1 carrot, 1 orange’). Set a goal of 2-3 fruit servings daily and monitor weekly totals
  • Use the app to create a weekly shopping list of affordable colorful produce. Set reminders to include one fruit or vegetable at each meal. Track which affordable options your family enjoys most
  • Monitor weekly fruit servings over 8-12 weeks. Track which affordable produce options are most accessible in your area. Note any changes in energy levels or overall health as fruit intake increases

This research is observational and cannot prove that low income causes low carotenoid levels—only that they’re associated. Individual results may vary based on genetics, overall diet, and other factors. This study involved a small group of New Zealand children and may not apply to all populations. Before making significant dietary changes for your child, especially if they have medical conditions or dietary restrictions, consult with a pediatrician or registered dietitian. This information is educational and should not replace professional medical advice.