A Potential Pathway to High-Fat Induced Obesity Prevention
Over the years, studies have shown potential health benefits associated with the intake of foods high in anthocyanins. Anthocyanins are colored water-soluble pigments belonging to the phenolic group (Khoo et al., 2017). Anthocyanins are responsible for the red, purple, and blue colors in fruits and vegetables. Berries, currants, grapes, and some tropical fruits have high anthocyanins content. Vegetables with high levels of anthocyanins include red to purplish, blue-colored leafy vegetables, and some grains, roots, and tubers (Khoo et al., 2017).
Another vegetable rich in anthocyanins is purple corn. Recently, more research has been done on how anthocyanins affect blood sugar levels and obesity. A study from the University of Oxford examined ferulic acid and anthocyanins in purple corn and how it influences high-fat induced obesity in mice (Luna-Vital et al., 2020).
The objective of this 12-week study was to compare the anti-obesity efficacy of different concentrations of phenolic-rich purple corn extract (PPE). The mice were divided into four groups:
· Standard diet (SD)
· High-fat diet (HFD)
· High-fat diet + 200 mg/kg purple corn extract (200 PPE)
· High-fat diet + 500 mg/kg purple corn extract (500 PPE)
The purple corn extract contained mainly ferulic acid, anthocyanins, and other phenolic compounds. Several measurements were taken throughout the study as well as upon conclusion. Body weight was measured weekly and blood glucose and triglycerides were evaluated biweekly. At the end of the study, liver and adipose tissue were collected, protein expression was performed in blood plasma, a gene array was performed on adipose tissue and liver, and histological analyses were performed in adipose tissue and liver (Luna-Vital et al., 2020).
A number of results were found, many of which suggested potential benefits of adding purple corn to the high-fat diet groups. Here is a summary of the results:
Bodyweight, blood glucose, and blood triglycerides showed the greatest amount of decrease in the 500 PPE group compared to HFD and 200 PPE groups.
Mice from the HFD group became hyperinsulinemic (a condition in which there are excess levels of insulin circulating in the blood relative to the level of glucose), whereas the 200 PE, and 500 PE groups had lower insulin levels.
The 500 PPE group had reduced plasma protein levels of TNF-α, MCP-1, resistin, and leptin compared to the HFD group.
Fatty liver disease scores were highest for the HFD group.
Relative adipose tissue was lower in 200 PPE, 500 PPE, and SD, compared to HFD group.
The diameter of adipocytes was significantly reduced in 200 PPE and 500 PPE groups, compared to the HFD group.
In the 500 PPE group, important genes were modulated related to adipogenesis, inflammation, and glucose metabolism in adipose tissue, compared to the HFD group.
In the liver, the 500 PPE group showed modulation of genes related to gluconeogenesis, lipogenesis, and β-oxidation.
Overall results from the study suggested that phenolic-rich purple corn extract “prevented obesity mainly through the modulation of TLR and AMPK signaling pathways reducing adipogenesis and adipose inflammation and promoting energy expenditure.”
Read the abstract here: https://academic.oup.com/cdn/article/4/Supplement_2/433/5844711
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
Luna-Vital, D., Luzardo, I., Cuellar, L., Loarca, G., Gonzalez de Mejia, E. (2020). Ferulic Acid and Anthocyanin from Colored Maize Correlated with Prevention of High-Fat Induced Obesity in Mice by Modulating Lipid, Glucose and Inflammatory Pathways, Current Developments in Nutrition, 4(433), https://doi.org/10.1093/cdn/nzaa045_066