Category Archives: Polyphenols

Strawberry polyphenols mitigate very high dietary fructose-induced metabolic dysfunction in rats

This was an interesting paper that has been sitting in my drafts for awhile, so here is a quick post on it. By Jaroslawska et al., it directly examines the ability of strawberry pomace (leftover from industrial processing of strawberries) to mitigate the adverse metabolic effects of a high fructose intake in rats in the blood and in the gut (unabsorbed fructose seems to alter gut physiology). Dried strawberry pomace is made by removing the seeds of pressed strawberries (juice is removed) and Read more [...]

Dietary sulforaphane reduces oxidative stress in diabetes

Type 2 diabetes is characterized by increased oxidative stress, which may result in vascular pathologies (Bekyarova, Ivanova, and Madjova, 2007). Certain dietary phytochemicals may ameliorate oxidative stress and restore a more normal metabolic milieu. As reviewed by Angeloni, Leoncini, Malaguti, Angelini, Hrelia, and Hrelia (2009), one such phytochemical found in cruciferous vegetables such as broccoli sprouts, sulforaphane (SFN), induces phase-II enzymes and increases endogenous antioxidant activity, Read more [...]

“Antioxidants” in chocolate (and fruit): don’t buy the hype

Last week, just in time for Valentine's day (clever science marketing or lucky peer review speed?), Hershey announced that cocoa is a "super fruit" with a paper in the Chemistry Central Journal (open access). Here is a random sampling of just a few of many media takes on the press release: From WebMD (and a great review of this by HealthNewsReview.org) Researchers found the antioxidant activity of dark chocolate and cocoa powder was equivalent to or higher than that found in some other so-called Read more [...]

Quercetin paradox in a complex antioxidant network

This is sort of a random post, but I remember coming across this paper from 2007 awhile back titled "The quercetin paradox" that shows how quercetin protects against some oxidative damage in a lung cell line but the oxidation product reacts with glutathione (GSH), lowering its concentration, which leads to an increase in LDH leakage and cytosolic free calcium (an apparent indication of cytotoxicity).  So it was a neat example of a redirection of oxidative stress onto another antioxidant in the complex Read more [...]

Uric acid, not flavonoids increases antioxidant capacity from (apple) juice

In my article on "super"fruits I noted that many flavonoids have poor bioavailability, necessitating in vivo studies when assessing health effects- we cannot extrapolate the antioxidant capacity results of in vitro studies of flavonoid extracts to suggest that they are the reason fruits/vegetables are healthy.  This 2006 review by Lotito and Frei concluded that uric acid may be the major reason antioxidant capacity increases in the in vivo studies, consequent to the metabolism of fructose.  I also Read more [...]

Bioavailability & pharmacokinetics of anthocyanins from cranberry juice

Recently, I wrote why "super" fruits are no better than regular fruit.  Among those reasons, is because constituents in fruit have other discovered roles beside functioning as antioxidants, and in vitro antioxidant activity does not measure these.  I do not think antioxidant activity is a major reason why fruits are good for us. A recent study with cranberry juice by Milbury et al. (1) may further support this. Cranberries, and especially anthocyanins, which make up a significant portion of Read more [...]

Super fruits, super marketing.

Last year was the year of the acai berry.  Mangosteen, noni, goji, and others also proliferate on the juice and supplement market.  Some are predicting what will be next.  Are these so called "superfruits"  any better than "regular" fruit? Let's look at a few lines of evidence. What makes a fruit "super"? First of all, we have to define what characteristics a fruit has to have to be labeled "super."  The superfruit craze seems to have hit a tipping point in 2004, however there appear to be Read more [...]