Flavonoids, Anthocyanins, and Improvement of Insulin Resistance
Updated: Mar 31, 2020
Data has suggested that several flavonoid subclasses are involved in glucose metabolism. What are flavonoids? Live Science defines flavonoids as, “a diverse group of phytonutrients (plant chemicals) found in almost all fruits and vegetables and are responsible for their vivid colors” (1).
Numerous studies have examined links between the intake of flavonoids and subclasses of flavonoids, and potentially positive health outcomes. Notably, purple corn has a high anthocyanin content, one of the flavonoid subclasses.
According to a study from Food & Nutrition Research, anthocyanins are blue, red, or purple pigments found in plants like fruits, vegetables (including some root vegetables), and flowers. Anthocyanins have many uses. The rich pigments extracted from flowers, fruits, and vegetables are traditionally used as dyes and food colorants. However, plant anthocyanins have also been widely studied for their medicinal values and have been used as medicine to treat various diseases. “Anthocyanins possess antidiabetic, anticancer, anti-inflammatory, antimicrobial, and anti-obesity effects, as well as prevention of cardiovascular diseases. Therefore, anthocyanins extracted from edible plants are potential pharmaceutical ingredients” (2).
This particular study, from the Journal of Nutrition, examined the associations between regular intake of flavonoid subclasses (flavanones, anthocyanins, flavan-3-ols, polymeric flavonoids, flavonols, flavones), insulin resistance, and related inflammatory biomarkers in women. According to Jennings, et al., “several flavonoid subclasses have been associated with a reduction in risk of type 2 diabetes, as have foods and drinks rich in flavonoids” (3).
The cross-sectional study included 1,997 females aged 18-76 years old. Their intakes of total flavonoids (and their subclasses) were calculated from food frequency questionnaires using an extended USDA database. During the study, a number of levels were measured including fasting blood sugar, insulin, high sensitivity C-reactive protein (hs-CRP), plasminogen activator inhibitor-1, and adiponectin (a protein hormone involved in regulating glucose levels) (4).
Observations from the study concluded that a higher intake of anthocyanins and flavones was associated with significantly lower peripheral insulin resistance as a result of a decrease in insulin concentrations. Higher anthocyanin intake was also associated with lower hs-CRP levels and those in the highest quintile of flavone intake had improved adiponectin levels. Furthermore, anthocyanin-rich foods were also associated with lower insulin and inflammation levels overall (5).
Read the full study here: https://academic.oup.com/jn/article/144/2/202/4575100.
(1) “What Are Flavonoids?” Live Science, https://www.livescience.com/52524-flavonoids.html. Accessed 24 March 2020.
(2) Khoo, H. E., Azlan, A., Tang, S. T., & Lim, S. M. (2017). Anthocyanidins and anthocyanins: colored pigments as food, pharmaceutical ingredients, and the potential health benefits. Food & nutrition research, 61(1), 1361779. https://doi.org/10.1080/16546628.2017.1361779.
(3-5) Jennings, A., Welch, A., Spector, T., Macgregor, A., Cassidy, A. (2014). Intakes of Anthocyanins and Flavones Are Associated with Biomarkers of Insulin Resistance and Inflammation in Women. The Journal of Nutrition, 144(2), 202-208,https://doi.org/10.3945/jn.113.184358.