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Providing perspectives on recent research into vitamins and nutritionals


If Stephen Colbert doesn’t see Color, Could it be a Lack of Fruit and Vegetables?

By Michael McBurney

Everyone knows we should eat more fruit and vegetables. Higher intakes are associated with lower risk of chronic disease. But we don’t consume the recommended number of servings. Among US women, 90% don’t consume the recommended amount of servings. Fewer than 5% of Australian women consume 2 servings of fruit and 5 servings of vegetables.

Fruit and vegetables contain many carotenoids. These colored compounds can be measured in skin. Pezdirc and associates measured skin reflectance at 9 sites on 91 Caucasian women. Overall skin yellowness was associated with higher fruit and vegetable intake.

The most commonly consumed carotenoids from the diet are α- and β-carotene, lycopene, and lutein-zeaxanthin.

Beta-carotene, a precursor for vitamin A, is essential for vision and immune function. Milk, eggs and liver provide retinol (vitamin A). The amount of vitamin A obtained from provitamin A carotenoid forms, e.g. β-carotene, found in green leafy vegetables, red and orange fruit, and red palm oil varies widely. When people consume most of their vitamin A from fruits and vegetables, there is increased risk of deficiency. Vitamin A deficiency is the leading cause of preventable blindness in children. Emerging evidence from animal models  also suggests that beta-carotenoid may affect body fat deposition via the activity of peroxisome proliferator receptors (PPAR).

Lycopene is primarily consumed in many countries as ketchup and tomato paste. Consuming the equivalent of half a bowl of tomato soup (7 mg lycopene daily) for 8 weeks increases serum lycopene concentrations and positively affects blood vessel function. Dietary or supplemental lycopene also has a beneficial effect on biomarkers of inflammation and blood cholesterol.

Lutein and zeaxanthin are highly concentrated in the eye where they protect against blue light. For most of us, we do not consume enough to maintain healthy macular pigment optical density (MPOD). MPOD is positively correlated with serum lutein and zeaxanthin concentrations. As intake increases, blood concentrations increase and MPOD of the eye normalizes.

Stephen Colbert famously said, “I don’t see color”. That’s because recommended amounts of fruit and vegetables containing carotenoids aren’t being consumed.

Main Citation

Pezdirc K, Hutchesson MJ, Whitehead R, Ozakinci G, Perrett D, Collins CE. Fruit, vegetable and dietary carotenoid intakes explain skin-color in young Caucasian women: A cross-sectional study. 2015 Nutrients doi: 10.3390/nu7075251

Other Citations

Krebs-Smith S, Guenther P, Subar A, Kirkpatrick S, Dodd K. Americans do not meet federal dietary recommendations. 2010 J Nutr doi: 10.3945/jn.110.124826

Australian Bureau of Statistics (ABS). 4364.0.55.011-Australian Health Survey: First Results, 2011-2012.

Parag R, Gajendragadkar, Kaisa AH, Maki-Petaja M, Serg M, Wilkinson IB, Cheriyan J. Effects of oral lycopene supplementation on vascular function in patients with cardiovascular disease and healthy volunteers: A randomised controlled trial. 2014 PLoSONE doi: 10.1371/journal.pone.0099070

McEneny J, Wade L, Young IS, Masson L, Duthie G, McGinty A, McMaster C, Thies F. Lycopene intervention reduces inflammation and improves HDL functionality in moderately overweight middle-aged individuals. 2013 J Nutr Biochem doi: 10.1016/j.jnutbio.2012.03.015