Blueberries May Help Liver Health

by | Aug 6, 2010 | 2010, Antioxidants, Fruits and Vegetables, Liver Health

Written by Greg Arnold, DC, CSCS. In a study with 45 rats, those with the highest berry intake had 37% less liver damage.

Blueberries are perhaps best known because of their high levels of an antioxidant called resveratrol which has been found to help with heart health (1) and breast cell health (2). But blueberries contain many more antioxidants that include anthocyanins, polyphenols and flavonoids, and appear to have a higher antioxidant capacity than most fruits and vegetables (3, 4). Now a new study in rats (5) has suggested that blueberries may also help maintain liver health.

In the study, 45 rats were divided into 5 groups for 8 weeks:

  • Control group
  • No supplementation with induced hepatic fibrosis (a form of liver scarring common with chronic liver problems (6)).
  • Blueberry group prevention group with induced hepatic fibrosis
  • Dan-shao-hua-xian capsule (DSHX) prevention group with induced hepatic fibrosis
  • Blueberry + DSHX prevention group with induced hepatic fibrosis

Hepatic fibrosis, awas induced in the four groups with injections of a solution of carbon tetrachloride (CCL4) twice per week for the 8 weeks while beginning supplementation on the same day and every day for 8 weeks. The blueberry group was given 1.5 grams of blueberry juice per 100 grams of food while the DSHX group was a mixture of 5 different Chinese herbs given in doses of 1 gram per kg of bodyweight and which has been found in earlier research to benefit liver health (7).

By the end of the 8 weeks, researchers obtained both blood and liver samples and found that all three treatment groups (blueberry, DSHX, and blueberry + DSHX) had levels of liver damage (measured by an enzyme called ALT) that were 26% (149.44 units/Liter), 33% (136.88), and 37% (127.38) lower, respectively, compared to the fibrosis-induced group with no supplementation (203.25). Another marker of cell damage called MDA (8) was also lower in all 3 groups compared to the fibrosis-induced group (0.335 nanomoles/milligram) in amounts of 12% (0.294), 15% (0.285), and 16% (0.284), respectively.

Finally, level of an antioxidant enzyme called SOD (9) were 21% (1.36 micromoles/milligram), 24% (1.42), and 28% (1.50) higher compared to the fibrosis-induced group (1.08). Attributing these results to the ability of blueberries to limit oxidative stress (10), the researchers concluded that “blueberries possessed a therapeutic effect on CCl4-induced hepatic fibrosis in rats through inhibiting liver inflammation and lipid [damage].” This study is complicated by the inclusion of the unidentified Chinese herbs which would be at a dose of about 3 ounces in humans. However the blueberry alone group gave results indicating a significant benefit. All animal trials should be verified in clinical trials in humans.

Source: Wang, Yu-Ping, et al. “Effects of blueberry on hepatic fibrosis and transcription factor Nrf2 in rats.” World J Gastroenterol 16.21 (2010): 2657-2663.

Copyright © 2010 Massachusetts Medical Society.

Posted August 6, 2010.

References:

  1. Barger JL.  A low dose of dietary resveratrol partially mimics caloric restriction and retards aging parameters in mice.  PLoS ONE2008 Jun 4;3(6):e2264.
  2. Lu F.  Resveratrol Prevents Estrogen-DNA Adduct Formation and Neoplastic Transformation in MCF-10F Cells.  Cancer Prev Res 2008 1: 135-145. doi: 10.1158/1940-6207.CAPR-08-0037.
  3. Wu X, Beecher GR, Holden JM, Haytowitz DB, Gebhardt SE, Prior RL. Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. J Agric Food Chem. 2004;52:4026-4037.
  4. Prior RL, Cao G, Prior RL, Cao G. Analysis of botanicals and dietary supplements for antioxidant capacity: a review. J AOAC Int. 2000;83:950-956.
  5. Wang YP, Cheng ML, Zhang BF, Mu M, Wu J. Effects of blueberry on hepatic fibrosis and transcription factor Nrf2 in rats. World J Gastroenterol, 2010; 16 (21): 2657-2663.
  6. Ming LC, Chang QY. Hepatic fibrosis. First published. Beijing: Beijing People’s Medical Publishing House; 2008.pp.3-4.
  7. Wang HY. Effects of Dan-shao-hua-xian on expression of PPAR-gamma and NF-kappa B in rat liver fibrosis. Hepatobiliary Pancreat Dis Int 2008 Apr;7(2):179-84.
  8. Marnett LJ.  Lipid peroxidation-DNA damage by malondialdehyde. Mut Res 1999 Mar 8;424(1-2):83-95
  9. “Superoxide Dismutase” – posted on the Memorial Sloan Kettering Cancer Center website.
  10. Wolfe KL, Kang X, He X, Dong M, Zhang Q, Liu RH. Cellular antioxidant activity of common fruits. J Agric Food Chem. 2008;56:8418-8426