Plentiful and Powerful: The Benefits of Purple Foods

The Benefits of Purple Foods

The food industry predicts purple foods will populate our plates over the next twelve months. While there’s a wide range of purple food to choose from, you may be wondering if they contain any kind of specific nutritional benefits. After all, purple foods are pretty to look at, and they certainly make interesting additions to our meals, but what else do they offer?

Purple Pigments in Food

Purple Pigments in Food

What Are Anthocyanins and Flavonoids?

There are thought to be over 550 types of anthocyanins – a flavonoid. Test tube studies show that these chemicals have a strong antioxidant activity which helps protect plants against free radical damage. However, recent research suggests that as the human body rapidly metabolizes anthocyanins, these chemicals have little direct antioxidant activity outside of the test tube [1].

But there’s good news too! By prompting the body to increase levels of phase II enzymes needed to metabolize them, anthocyanins may inadvertently increase the body’s capacity to metabolize and safely eliminate other, less desirable substances that can cause unwanted cellular changes [1].*

Flavonoids such as anthocyanins also increase the activation of an enzyme called nitric oxide synthase. This enzyme supports the relaxation and health of blood vessels [2]*. Anthocyanins may also support healthy blood lipids and blood glucose levels already within the normal range [3].* And if you’re consuming anthocyanins in fruits and vegetables, you’re also consuming beneficial fiber that helps support digestion, lipid levels, and blood glucose levels already within the normal range.*

Other Benefits of Purple Foods

More Robust

In addition to simply making food more fun, the purple hue may also make food more robust. In one study, green and white cauliflower varieties lost 24% of their ascorbic acid (vitamin C) content after being blanched and frozen for a year. Interestingly, purple cauliflower retained its vitamin C, suggesting that it’s better suited for longer-term storage [4].

Immune Boosting

Some studies have also found an association between immune function and the consumption of purple foods, such as grapes and elderberries. Concord grapes appear to support the function of immune system cells, including T-cells [5], while elderberries have been associated with immune support [6].*

Purple Power for Overall Health

As with many aspects of health, moderation is key. Purple produce may contain higher levels of anthocyanins than white, green, or orange counterparts, but these less florid fruits and vegetables provide higher levels of lutein and beta-carotene, as well as other nutrients that have benefits for health.*

*This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

References

[1] Lotito, S.B. & Frei, B. (2006). Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomenon? Free Radic Biol Med, 41(12):1727-1746.

[2] Edirisinghe, I., Banaszewski, K., Cappozzo, J., et al. (2011). Effect of black currant anthocyanins on the activation of endothelial nitric oxide synthase (eNOS) in vitro in human endothelial cells. J Agric Food Chem, 59(16):8616-8624.

[3] Li, D., Zhang, Y., Liu, Y., et al. (2015). Purified anthocyanin supplementation reduces dyslipidemia, enhances antioxidant capacity, and prevents insulin resistance in diabetic patients. J Nutr, 145(4):742-748.

[4] Volden, J., Bengtsson, G.B. & Wicklund, T. (2009). Glucosinolates, l-ascorbic acid, total phenols, anthocyanins, antioxidant capacities and colour in cauliflower (Brassica oleracea L. ssp. botrytis); effects of long-term freezer storage. Food Chemistry, 112(4): 967-976.

[5] Rowe, C.A., Nantz, M.P., Nieves, C. Jr., et al. (2011). Regular consumption of concord grape juice benefits human immunity. J Med Food, Jan-Feb;14(1-2):69-78.

[6] Tiralongo, E., Wee, S. S. & Lea, R. A. (2016). Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial. Nutrients, 8(4):182.


About the Author

Leigh Matthews, BA Hons, H.Dip. NT, is a health and wellness writer specialising in plant-based nutrition. A long-time vegan, Leigh is interested in diet as preventative medicine, as well as the politics of food justice. She also enjoys baking (and eating) delicious cupcakes.