Naringin is mainly found in grapefruits. It is the compound that gives grapefruit its typical bitter flavor. Naringin belongs to a group of chemicals called bioflavonoids, which are colorful pigments found in plants. Bioflavonoids also belong to a larger group of phytochemicals called polyphenols. They were discovered by Nobel Prize-winning biochemist Albert Szent-Gyorgi, who labeled them “vitamin P” (though they were subsequently stripped of their vitamin status).
Flavonoids work as powerful antioxidants, protecting the body from free radicals. Flavonoids also strengthen capillary walls, assisting circulation and helping prevent bruising and bleeding. Some flavonoids are strong anti-inflammatory agents, helping control damage to tissues. Citrus bioflavonoids are thought to work by strengthening the walls of blood vessels.
Naringin is a bioflavonoid – arguably one of the most important emerging classes of nutrients. It is mostly promoted for its dramatic effect on the absorption and uptake of supplements – increasing their effectiveness! As such, naringin is most commonly used in the nutrition industry to increase uptake of supplements such as caffeine for added performance. It works by interfering with the activity of enzymes in the intestines and thus the breakdown of nutrients and supplements, which leads to higher levels of these compounds in the body.
Naringin has become most popular for its synergistic effects with other supplements, especially caffeine. However, make no mistake about it; a good reason to be interested in naringin is to increase the effectiveness of the other supplements you may be taking! (It’s quickly gaining ground for its ability to support healing of our tissues after intense, grueling workouts.)
However, we have other reasons for liking naringin…
Naringin has Cholesterol Lowering Abilities!
Studies have shown that naringin has a cholesterol-lowering effect, reduces LDL oxidation and can help to prevent hypercholesterolemia. Hebrew University-Hadassah Medical School found that naringin has plasma lipid lowering and plasma antioxidant activity increasing activity. (Naringin’s properties may explain the popularity and possible benefits of the grapefruit diet during the 1970’s. People used grapefruit juice to reduce appetite for weight loss and enhance taste sensation because the naringin in the juice stimulates the taste buds.
Then studies started to find that naringin in citrus juice may increase levels of good (HDL) cholesterol. Boosting levels of HDL cholesterol slows accumulation of artery-clogging plaque and may support long-term heart health. Even better, the juice isn’t even the best source of naringin: higher levels are found in the peel. (You also get a fair amount of naringin in thegrapefruit pectin we include in our artery products.)
So, we like naringin for 2 reasons:
- The potential for helping cholesterol management.
- Helping the absorption of the other supplements.
(For those who enjoy clinical support for the nutrients they take, we offer the following…)
“The naringin and lovastatin supplementation significantly lowered the plasma total cholesterol level compared to the control group. The hepatic cholesterol content was lowered by both the naringin and lovastatin supplements compared to the control group. The hepatic HMG-CoA reductase activity was significantly lower in the naringin and lovastatin supplemented groups than in the control group, whereas the ACAT activity was unaffected. Accordingly, the current results confirmed that naringin lowers the plasma cholesterol level via the inhibition of hepatic HMG-CoA reductase activity and increases the excretion of fecal sterol. Naringin was also found to improve the activities of hepatic antioxidant enzymes against oxidative stress in a hypercholesterolemic animal model, i.e. cholesterol-fed LDLR-KO mice.”
Naringin alters the cholesterol biosynthesis and antioxidant enzyme activities in LDL receptor-knockout mice under cholesterol fed condition. Kim HJ, Oh GT, Park YB, Lee MK, Seo HJ, Choi MS. Kyungpook National University, 1370 Sank-Yuk Dong Puk-Ku, Daegu, 702-701, South Korea.
“The objective of this study was to compare the influence of hesperidin and naringin on plasma lipid profile and antioxidant activity in rats fed a cholesterol-containing diet. After 30 days of the experiment it was found that the diets supplemented with hesperidin and naringin increased the plasma antioxidant activity. In conclusion, diets supplemented with hesperidin and naringin significantly hindered the increase in plasma lipid levels caused by cholesterol feeding.”
Effect of hesperidin and naringin on the plasma lipid profile and plasma antioxidant activity in rats fed a cholesterol-containing diet Shela Gorinstein, Hanna Leontowicz, Maria Leontowicz, Ryszard Krzeminski, Mikolaj Gralak, Zenon Jastrzebski, Yong-Seo Park, Soon-Teck Jung, Seong-Gook Kang, Simon Trakhtenberg, Mar. 6, 2007
“Among the ethanol-treated groups, naringin supplementation resulted in a significant decrease in the hepatic triglycerides and plasma and hepatic total cholesterol compared to that in the naringin-free group. Naringin supplementation significantly increased the HDL-cholesterol and HDL-C/total-C ratio, while lowering the AI value among the ethanol-treated groups.”
Role of naringin supplement in regulation of lipid and ethanol metabolism in rats. Seo HJ, Jeong KS, Lee MK, Park YB, Jung UJ, Kim HJ, Choi MS. Department of Food Science and Nutrition, Kyungpook National University, 1370 Sankyuk Dong Puk-ku, Daegu 702-701, South Korea.
“Morin, genistein, apigenin and biochanin A, naringin and quercetin were used at different concentration. These flavonoids significantly inhibit in vitro LDL oxidation, genistein, morin andnaringin have stronger inhibitory activity against LDL oxidation than biochanin A or apigenin. This study show that flavonoids prevent in vitro LDL oxidation and probably would be important to prevent atherosclerosis.”
Anti-oxidant effect of flavonoids on the susceptibility of LDL oxidation. Naderi GA, Asgary S, Sarraf-Zadegan N, Shirvany H. Department of Biochemistry, Isfahan Cardiovascular Research Center, Amin Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
“This work had as objective evaluates the effect of the flavonoids naringin and rutin on the metabolism lipidic of chicks hypercholesterolemic. In agreement with the results it can be observed that naringin and rutin reduced the levels of total cholesterol significantly, cholesterol-LDL, cholesterol-VLDL and triglycerols, not presenting, however, reductions in the levels of cholesterol-HDL.”
Hypocholesterolemic effect of naringin and rutin flavonoids] da Silva RR, de Oliveira TT, Nagem TJ, Pinto AS, Albino LF, de Almeida MR, de Moraes GH, Pinto JG. Universidade Federal de Vicosa, Minas Gerais, Brazil.
“This study evaluated the effect of naringin on blood lipid levels and aortic fatty streaks, and its action mechanism in hypercholesterolemic rabbits. Cholesterol level in rabbits fed the 0.25% cholesterol diet reached 17 times normal and decreased in the rabbits fed naringin and lovastatin, whose effects were not statistically significant (p > 0.05). Naringin significantly reduced fatty streak formation and neointimal macrophage infiltration and also inhibited the expression of ICAM-1 in endothelial cells, suggesting that suppression of ICAM-1 contributed to the antiatherogenic effect. Naringin, unlike lovastatin, has a hepatoprotective action.”
Naringin has an antiatherogenic effect with the inhibition of intercellular adhesion molecule-1 in hypercholesterolemic rabbits. Choe SC, Kim HS, Jeong TS, Bok SH, Park YB. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
“The effects of the citrus bioflavonoid naringin were tested by using it as a supplement in a high-cholesterol diet. Naringin did not significantly alter the levels of plasma triglycerides, however, the levels of plasma cholesterol (3.80 +/- 0.31 mmol/L vs. 2.61 +/- 0.30 mmol/L, mean +/- SE; p < 0.05) and hepatic cholesterol (70.3 +/- 4.3 mg/g vs. 54.3 +/- 3.8 mg/g, mean +/- SD; p < 0.05) were significantly lowered compared to those of the control. HMG-CoA reductase (2487.0 +/- 210.0 pmole/min/mg vs. 1879.0 +/- 236.0 pmole/min/mg, mean +/- SE; p < 0.05) and ACAT (806.0 +/- 105.0 pmole/min/mg vs. 643.0 +/- 80.0 pmole/min/mg, mean +/- SE; p < 0.05) activities were both substantially lower in the naringin-supplemented group than in the control.”
Hypocholesterolemic effect of naringin associated with hepatic cholesterol regulating enzyme changes in rats. Shin YW, Bok SH, Jeong TS, Bae KH, Jeoung NH, Choi MS, Lee SH, Park YB. Korea Research Institute of Bioscience & Biotechnology, KIST, Yusong, Taejon, Korea.
A-Z Index, – under “Artery Plaque Reduction”, and “Cholesterol – High Cholesterol Formula“, or:
Artery Plaque Reduction – to help dissolve and remove artery cholesterol.
High Cholesterol Formula – how to lower and maintain cholesterol balance
Bear, W.L., and Teel, R.W., “Effects of Citrus Flavonoids on the Mutagenicity of Heterocyclic Amines and on Cytochrome P450 1A2 Activity,” Anticancer Res 20.5B (2000) : 3609-14.
Choi, M.S., et al., “Effect of Naringin Supplementation on Cholesterol Metabolism and Antioxidant Status in Rats Fed High Cholesterol with Different Levels of Vitamin E,” Ann Nutr Metab 45.5 (2001) : 193-201.
da Silva, R.R., et al., “Hypocholesterolemic Effect of Naringin and Rutin Flavonoids,” Arch Latinoam Nutr 51.3 (2001) : 258-64.
Fuhr, U., et al., “Inhibitory Effect of Grapefruit Juice and Its Bitter Principal, Naringenin, on CYP1A2 Dependent Metabolism of Caffeine in Man,” Br J Clin Pharmacol 35.4 (1993) : 431-6.
Fuhr, U., and Kummert, A.L., “The Fate of Naringin in Humans: A Key to Grapefruit Juice-Drug Interactions?” Clin Pharmacol Ther 58.4 (1995) : 365-73.
Nijveldt, R.J., et al., “Flavonoids: A Review of Probable Mechanisms of Action and Potential Applications,” Am J Clin Nutr 74.4 (2001): 418-25.