The Kokum fruit is a natural source of Hydroxycitric Acid (HCA), which has gained much attention in recent years for its pivotal role in fat/lipid metabolism. Normally, excess glucose in the body is converted to lipids and stored as fat, contributing to weight gain. ATP-citrate lyase is an enzyme that cleaves citrate, produces oxaloacetate and acetyl-coA (a key molecule used in fat storage). Watson, et al. discovered that HCA inhibits this crucial catalytic reaction, thus preventing glucose conversion to fat.
Watson, J.A., Fang, M., Lowenstein, J.M., 1969. Tricarballyate and hydroxycitrate: Substrate and Inhibition of ATP:citrate oxaloacetate lyase. Arch. Biochem. Biophys. 135: 209-217.
Research has shown that purple corn potentially has a significant role in controlling weight and hyperglycemia. Adipocytokines, such as adiponectin and leptin, are intricate proteins in the plasma that are valuable markers in glucose homeostasis. Researchers in Japan have shown in animal models that adipocytokine production increased when cyanidin-3-glucoside from purple corn was administered. Weight gain was apparent in over-fed mice; however, when over-fed mice consumed the purple corn cyanidin-3-glucoside, they were unable to gain weight.
Tsuda, T., Horio, F., Uchida, K., Aoki, H., Osawa, T. 2003. Dietary 3-O-ß-D-Glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in mice. J. Nutr. 133(7): 2125-2130.
It was also established by researchers in Maryland that adiponectin levels are substantially low in obese or diabetic human subjects. When weight loss occurs, adiponectin levels are increased and restored to normalcy. Hyperglycemia usually leads to diabetes and obesity. When weight gain occurs, it is generally followed by excessive glucose levels in the plasma leading to hyperglycemia. Due to excessive glucose levels, glucose is converted to fats/triglycerides and stored in adipose tissue. Tsuda et al. investigated purple corn’s role in fat metabolism and found in mice that weight gain was suppressed, triglyceride (LDL, fatty acids) accumulation in adipocytes (fat cells) was reduced, and hyperglycemia (excessive glucose in the plasma) was reversed as well.
Ryan, A.S., Berman, D.M., Nicklas, B.J., Sinha, M., Gingerich, R.L., Meneilly, G.S., Egan, J.M., Elaihi, D. 2003. Plasma adiponectin and leptin levels, body composition, and glucose utilization in adult women with wide ranges of age and obesity. Diabetes Care. 26: 2383-2388.
A very interesting study by Dr. Prior and his collegues compared whole berries versus berry anthocyanins in a mouse model of obesity (measuring weight gain, final weights, body fat, epididymal fat weights, and body protein). Anthocyanins fed as the whole blueberry did not prevent obesity, whereas feeding purified anthocyanins from blueberries or strawberries reduced obesity.
Prior, R.L., Wu, X., Gu, L., Hager, T.J., Hager, A., Howard, L. 2008. Whole berries versus berry anthocyanins: Interactions with dietary fat levels in the C57BL/6J mouse model of obesity. J. Agric. Food Chem. 56: 647-653