Nutrition Awareness Month–The Science Behind Eating the Rainbow

By Julia D’Isabella, Alexandra Fekete, Abigail Joy Garcia, Deonte Jefferson and Bridgette Kielhack

Childhood obesity has become a global public health crisis that poses many physical, emotional, and financial burdens on those affected.1 In an effort to reduce the health impact of childhood obesity, the American Academy of Pediatrics (AAP) recommends that pediatricians should offer weight loss pharmacotherapy and bariatric surgery to treat obesity.2 While these may be considered effective methods for treatment, maintenance of long-term, healthy weight is not guaranteed.

Although obesity is complex, it is reversible and preventable. In this article, we will address prevention through dietary changes by discussing the nutritional aspect of whole foods, using example colors from a teaching tool called “Eat the Rainbow.” This tool can be used in pediatric care settings to encourage healthy eating from a young age and to create long-term healthy habits throughout adulthood to prevent obesity and associated comorbidities such as hypertension, cardiovascular disease and cancer.3

Eat the Rainbow Red - Orange - Yellow

Lycopene is a non-provitamin A carotenoid that is responsible for the red hue seen in foods such as tomatoes and strawberries.4 Lycopene’s benefits include antibiotic, anti-inflammatory, antioxidative, cardiovascular, and immunostimulating effects in cells.5 Red beets have also been found to improve endothelial function by increasing nitric oxide precursors which reduce arterial stiffness and lowers blood pressure.6,7 Red fruits have a two-fold effect at mealtime due to the vibrant color adding flare to the plate as well as lowering the risk of cardiovascular disease and preventing comorbidities later in life.

Orange and yellow foods such as carrots, oranges, and bell peppers contain similar antioxidant properties as red-pigmented foods, but are also highly nutritious in various carotenoids such as α-carotene, βcarotene, β-cryptoxanthin, lutein and zeaxanthin.11 Carotenoids’ effects on adipose tissue include inhibiting adipogenesis via down-regulating adipogenic transcription factors, and thus deficiencies in carotenoids have been linked as a risk factor for obesity.12,13 Higher pro-vitamin A carotenoids, especially α and β-carotene serum levels have been associated with lower risk of obesity in children.14

Green

Green cruciferous vegetables are packed with fiber which helps lower one’s risk for cardiovascular disease by reducing LDL levels, and also helps regulate satiety levels.8 Inflammation is implicated in many disease states including obesity, hypertension, cardiovascular disease, autoimmune disorders and cancer. Cruciferous vegetables contain a phytochemical called sulforaphane which has powerful antioxidant, anti-inflammatory and anti-cancer properties.9 For children who do not like the texture or bitterness of cruciferous vegetables, broccoli sprouts are 20-50x more potent than broccoli and may be more palatable for children.10 Also, steaming kale, broccoli, or bok choy for 1-3 minutes, and then having children create their own dressing is an engaging and empowering way for children to get creative and curious in the kitchen.

Blue - Purple

Foods of blue-purple color such as blueberries, blackberries, eggplant, and purple carrots contain important polyphenols called anthocyanins which have been found to have antioxidant, glucoregulatory, anti-inflammatory, cardioprotective and neuroprotective effects.15,16,17 Multiple studies have found that anthocyanins also help lower serum triglyceride and cholesterol levels, increase serum HDL levels, decrease blood pressure and prevent obesity.15,18 Anthocyanins and other beneficial nutrients are mostly found in the colorful blue-purple part of the fruit or vegetable, so be sure to encourage pediatric patients to eat every bite of these vibrant blue-purple foods.

Brown

Whole grains such as oat, quinoa, and barley are associated with a 21% lower risk of cardiovascular events.19,20 Additionally, consuming almonds can decrease cholesterol levels.21 Because the process of atherosclerosis begins in the first decade of life, whole grains and almonds may decrease pediatric patients’ risk of cardiovascular events later in life.22 Furthermore, beans contain a natural source of magnesium.20 Low dietary magnesium intake has been shown to correlate strongly with high blood pressure.23,20,24 Because pediatric hypertension is a leading determinant of cardiovascular disease in adults, increasing intake of steamed or boiled beans with no additional salt or fat may reduce incidence of pediatric hypertension.22,24,25

Additionally, pinto beans, lentils, and black beans provide a better source of protein than animal sources because they do not include the saturated fats, cholesterol and higher calorie count.26 Patients who consume these plant proteins would also gain the added benefits of fiber, phytonutrients, vitamins and minerals.27 Therefore, consuming more plant sources of protein than animal sources in childhood may help prevent cardiovascular diseases and dyslipidemia.

Conclusion

Children learn by example. Helping children establish healthy eating patterns that continue into adulthood should begin with simpli- fied approaches, like the “Eating the Rainbow” color categorization, that focuses on nutrient-dense whole foods with benefits for the entire family.

References

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24. Song, Y., Sesso, H.D., Manson, J.E., Cook, N.R., Buring, J.E., & Liu, S. (2006) Dietary magnesium intake and risk of incident hypertension among middle-aged and older US women in a 10-year follow-up study. American Journal of Cardiology, 98(12), 1616-1621. https://doi.org/ 10.1016/j.amjcard.2006.07.040

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26. American College of Lifestyle Medicine. (n.d.) Plant Protein vs. Animal Protein. https://embeelifestyledocs.com/wp-content/uploads/2020/ 01/ACLM-PlantVAnimal-Protein-043019.pdf

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Julia D’Isabella, MPH is a medical student at the University of the Incarnate Word School of Osteopathic Medicine, class of 2025.

Alexandra Fekete, MS is a medical student at the University of the Incarnate Word School of Osteopathic Medicine, class of 2025.

Abigail Joy Garcia is a predoctoral fellow and medical student at the University of the Incarnate Word School of Osteopathic Medicine, class of 2025.

Deonte Jefferson, MBA is a medical student at the University of the Incarnate Word School of Osteopathic Medicine, class of 2025.

Bridgette Kielhack is a medical student at the University of the Incarnate Word School of Osteopathic Medicine, class of 2025.