Comprehensive Library Of Resveratrol News

A news report is making resveratrol pill users wonder whether they are using the best form of this molecule for their health.  Scientific debate continues over whether a form of resveratrol that is advertised to be more bioavailable (pterostilbene) is superior to plain resveratrol.

As background information, resveratrol is a molecule that human body perceives as a toxin and seeks to detoxify it as it passes through the liver.   Resveratrol is an antioxidant when given in modest doses (100-350 mg) but promotes oxidation when given in mega-doses (2800 mg).

For example, a human equivalent dose of 2800 mg was shown to increase the size of a heart attack (area of damaged heart muscle) whereas a modest dose decreases the area of damage.  In fact, 2800 mg resveratrol actually “kills” a pumping rodent heart.   However, when resveratrol is complexed with quercetin and rice bran IP6 (Longevinex®) there is no cardiac toxicity whatsoever (see chart below), making Longevinex® the safest resveratrol pill available should mega-doses be mistakenly consumed.

After resveratrol is absorbed in the digestive tract it traverses to the liver where it is attached to detoxification molecules (sulfate and glucuronate).  Unmetabolized resveratrol makes a few passes through the liver so a small amount is immediately bioavailable.  But eventually all resveratrol is detoxified (metabolized).

The provision of bioperine, a back pepper extract, or quercetin, a polyphenol found naturally in red apple peel or onion, allows more resveratrol to pass through the liver before it is metabolized (attached to sulfate or glucuronate).

Methylated resveratrol (pterostilbene, pronounded trr-oh-still-bean) does the same thing as bioperine/quercetin.  Pterostilbene is said to be 80% bioavailable versus 20% for resveratrol.  However, by definition, high-dose pterostilbene would potentially be more toxic as it is not attached to detox molecules.  However, nothing is said about this by purveyors of pterostilbene (methylated resveratrol).

So now we get to the recently published animal study in the journal of Evidence Based Complementary Alternative Medicine that is making news headlines around the globe.

In this study laboratory mice were chemically induced to develop diabetes.  The red wine molecule resveratrol was pitted against its methylated cousin, pterostilbene, widely panned as being superior to resveratrol.  Blood sugar and insulin levels were compared following the 5-week study.  Muscle mass would also be tested as diabetes induces muscle degeneration, a real problem for heart muscle among diabetics.

Pterostilbene and resveratrol were instilled into the lab mice by body weight: 10 milligrams, 20 milligrams and 40 milligrams per kilogram (2.2 lbs.) of body weight.  To convert this dose to humans we have to multiply 10, 20 and 40 by 70 kilograms (154 lbs.), which is the typical weight of humans used in experiments like this one.

The pterostilbene-fed lab rats were given three different daily doses – in human equivalent doses of 700, 1400 and 2800 milligrams per day.  Resveratrol-treated rats received 700 and 1400 milligrams human equivalent doses daily.  No 2800 mg dose of resveratrol was employed, for unexplained reasons.  A mix of resveratrol and pterostilbene at 700 mg per day was also tested.  All doses were injected into the stomach and intestines to ensure the animals consumed the molecules.

The news headlines said pterostilbene was far superior to resveratrol in terms of blood sugar reduction.  But examination of the data doesn’t quite correlate with the news headlines.

For unexplained reasons, no 2800 mg dose of resveratrol was put to the test for a same-dose comparison.  Here is the chart comparing the ability of resveratrol and pterostilbene to reduce blood sugar (glucose) levels:

C = healthy control group
D = chemically-induced diabetic group
PTS = pterostilbene
RSV = resveratrol

The study authors stated that “the treatment with 40 mg/kilograms per day pterostilbene produced a −52.8% reduction in blood sugar (glucose) levels” and was superior to resveratrol, but no equivalent dose of resveratrol was used.

Amount per kilogram (2.2 lbs.) body weight	10 mg/kilogram	20 mg/kilogram	40 mg/kilogram
Human equivalent dose (X70 kilograms/ 154 lbs)	700 mg	1400 mg	2800 mg
Resveratrol	X	X	—
Pterostilbene	X	X	X

As the chart shows, there was “no significant difference in blood sugar (glucose) levels” between the two doses (700 and 1400 mg human equivalent dose) of pterostilbene and resveratrol employed.   But news reports focused on the purported superiority of pterostilbene at 2800 milligrams human equivalent dose when there was no comparison performed with an equal dose of resveratrol.

Pterostilbene did show greater ability to retain muscle contraction than plain resveratrol but this is explained by its early and temporary greater bioavailability.  Presumably, any resveratrol + quercetin/bioperine combination would have achieved the same result as pterostilbene.

It took 2800 mg human equivalent dose of pterostilbene to reduce a marker of oxidation (malondialdehyde) -66.6% whereas just half as much resveratrol (1400 mg) reduced MDA by -50.4%.

Here is wording directly from the report: “While the administration of 20 mg/kilogram pterostilbene was more effective than the same amount of resveratrol, 10 mg/kilogram resveratrol, a lower dose (of resveratrol), was more effective than pterostilbene for all parameters measured at the end of this experiment.”  So the results depended upon the point in time examined.

The report went on to say “the biomechanical and biochemical effects of the 10 mg/kilogram pterostilbene/resveratrol combination therapy were observed to be almost similar to the corresponding effects of the 20 mg/kilogram dose of RSV treatment.”

Conclusion: don’t heed the news headlines.  Rigged scientific studies like this one abound.  The best tested and safest resveratrol pill, in fact the only resveratrol pill tested for toxicity, is still Longevinex®.