Should We ‘Eat a Rainbow’? An Umbrella Review of the Health Effects of Colorful Bioactive Pigments in Fruits and Vegetables

Abstract

Health promotion campaigns have advocated for individuals to ‘eat a rainbow’ of fruits and vegetables (FV). However, the literature has only focused on individual color pigments or individual health outcomes. This umbrella review synthesized the evidence on the health effects of a variety of color-associated bioactive pigments found in FV (carotenoids, flavonoids, betalains and chlorophylls), compared to placebo or low intakes. A systematic search of PubMed, EMBASE, CINAHL and CENTRAL was conducted on 20 October 2021, without date limits. Meta-analyzed outcomes were evaluated for certainty via the GRADE system. Risk of bias was assessed using the Centre for Evidence-Based Medicine critical appraisal tools. A total of 86 studies were included, 449 meta-analyzed health outcomes, and data from over 37 million participants were identified. A total of 42% of health outcomes were improved by color-associated pigments (91% GRADE rating very low to low). Unique health effects were identified: n = 6 red, n = 10 orange, n = 3 yellow, n = 6 pale yellow, n = 3 white, n = 8 purple/blue and n = 1 green. Health outcomes associated with multiple color pigments were body weight, lipid profile, inflammation, cardiovascular disease, mortality, type 2 diabetes and cancer. Findings show that color-associated FV variety may confer additional benefits to population health beyond total FV intake.

Association of pre-diagnosis specific color groups of fruit and vegetable intake with ovarian cancer survival: results from the ovarian cancer follow-up study (OOPS)

“…Our findings provided support that color-associated FV varieties intake may provide additional health benefits beyond the total FV intake. 18,19 This study based on OOPS showed that high green and red/purple FV intake before diagnosis elevated the survival of OC, which provided a theoretical basis for improved health outcomes by pre-diagnosis intake of color-associated FV variety for OC patients. This is consistent with several national dietary guidelines, which specifically have recommended FV should be consumed in a variety of colors.…”

“…These pigments can be classified into different categories based on their color, such as chlorophyll for green, lycopene for red, anthocyanins for purple and blue, alpha-carotene for yellow, beta-carotene for orange, and flavones for white. 18,19 Phytonutrients have the potential to prevent and manage diseases by performing various biological functions, including antioxidant, anticarcinogenic, anti-inflammatory, and chemoprotective properties. [20][21][22][23] Previous studies have investigated the association between the pre-diagnosis intake of FV intake and its particular color group with OC survival.…”

Myoprotective whole foods, muscle health and sarcopenia in older adults

“…Fruit and vegetables are a perfect example of whole foods low in energy but dense in nutrients (vitamins, minerals, protein, dietary fiber) and nonnutrients known as phytonutrients [32]. Phytonutrients are biologically active compounds that have several beneficial properties, including antioxidant, anti-inflammatory, and antibacterial properties [32] within a healthy, balanced diet. Higher habitual consumption of fruit and vegetables may exert beneficial effects by increasing the antioxidative capacity of the diet and counteracting the inflammatory response in ageing muscle [5 && ].…”

“…The health benefits of antioxidant-rich foods (e.g., fruit, vegetables, legumes, nuts, seeds, soy, olive oil) have been well documented. As a crucial part of a healthy, balanced diet, a higher consumption of a variety of these foods have been linked to positive health outcomes, including longevity and reduced risk of chronic diseases [17 ▪▪ ,32]. Fruit and vegetables are a perfect example of whole foods low in energy but dense in nutrients (vitamins, minerals, protein, dietary fiber) and nonnutrients known as phytonutrients [32].…”

“…As a crucial part of a healthy, balanced diet, a higher consumption of a variety of these foods have been linked to positive health outcomes, including longevity and reduced risk of chronic diseases [17 ▪▪ ,32]. Fruit and vegetables are a perfect example of whole foods low in energy but dense in nutrients (vitamins, minerals, protein, dietary fiber) and nonnutrients known as phytonutrients [32]. Phytonutrients are biologically active compounds that have several beneficial properties, including antioxidant, anti-inflammatory, and antibacterial properties [32] within a healthy, balanced diet.…”