Researchers from the Department of Cell and Molecular Pharmacology and Experimental Therapeutics and Digestive Disease Center, Medical University of South Carolina, completed a unique study of resveratrol in 2004. The study was intended to determine the amount of resveratrol a human could absorb through oral dose.
Oral Doses of Resveratrol
Resveratrol has long been known to have verified positive impact on a variety of health issues, most notably prevention and suppression of various cancers and heart disease.
Scientific studies have dramatically shown the impact resveratrol (a compound naturally occurring in red wine and grapes) has on cancer cells and lipoproteins. However, the question was raised whether it was feasible that human beings could ingest and absorb enough resveratrol orally to generate the same results as produced in the laboratory. This is the question the team from the Medical University of South Carolina set out to answer.
Conclusion: Low bioavailability of resveratrol when ingested orally
It was discovered that while 70% of the resveratrol doses administered orally was absorbed, most of the resveratrol was soon metabolized and eliminated from the body via urine and feces. Only trace amounts of unchanged resveratrol were found in the bloodstream after a short period of time. These trace amounts do not have the capacity to reproduce the beneficial effects observed in laboratory settings.
Buccal delivery provides greater bioavailability
However, according to another study by Asensi M, Medina I, Ortega A, et al (2002), the most efficient way of administering resveratrol in humans appears to be buccal delivery. This group of researchers found that after keeping the trans-resveratrol compound inside the mouth for up to one minute – without swallowing – the levels of unchanged resveratrol in the bloodstream were 250 times higher to those obtained with pills. These findings make alternative delivery methods such as resveratrol melting tablets, lozenges and chewables more likely to produce the beneficial effects of resveratrol found in the laboratory.
Leading up to this 1999 study, there was a great deal of literature surrounding the health benefits of resveratrol, a polyphenol naturally occurring in many foods and beverages. Its cancer preventative and heart disease preventative characteristics have made red wine resveratrol the focus of many studies. However, Calabrese intended to determine if these health benefits would extend themselves beyond cancer and heart disease and might be an influence on menopause.
Calabrese’s Findings Surrounding Resveratrol
The hypothesis of this study is based on the idea that the structure of resveratrol is so much like that of diethylstilbestrol, a drug prescribed to prevent miscarriages, that it might act as a phytoestrogen in humans.
Calabrese’s team conducted a population study, read literature on resveratrol’s effects on female reproduction, osteoporosis, and cancer, and they conducted various trials of their own.
Their findings concluded that moderate wine consumption appeared to act as a phytoestrogen, a compound in plants that simulates estrogen in humans. Resveratrol doses boosted the physiological reactions that typically accompany estrogen increases.
This activity could effectively moderate the effects and symptoms of menopause in women.
Hai-Bo Zhou, Juan-Juan Chen, Wen-Xia Wang, Jian-Ting Cai, and Qin Du of the Department of Gastroenerology in the Second Hospital of Zhejiang University set out to study the effects of resveratrol on stomach cancer. The 2004 study revealed some critical findings about resveratrol.
The researchers transplanted human stomach cancer into the subcutaneous tissue of nude mice to determine resveratrol’s effect on live candidates.
Three different doses of resveratrol were tested (500 mg/kg, 1000 mg/kg, and 1500 mg/kg). The dose was directly injected beside the tumor in each candidate. Changes in tumor size were then monitored.
Effects of Resveratrol on Stomach Cancer Tumors
In all cases, the resveratrol inhibited cell growth significantly. As the dose increased, the inhibition rate also increased. In fact, at 1500 mg/kg inhibition rate reached nearly 40%.
In addition to the growth inhibiting effect, resveratrol also induced cell apoptosis (natural cell death) in the cancer cells. A marked reduction of tumor size was observed.
Resveratrol slowed cell development in the stomach cancer cells at a rate of up to 40% and initiated apoptosis in the gastric carcinoma cells.
Resveratrol has been reported to have cancer prevention capabilities. The structural similarities between red wine resveratrol and a synthetic estrogen prompted Drs. Barry D. Gehm, Joanne M. McAndrews, Pei-Yu Chen, and J. Larry Jameson to study how resveratrol could affect the body’s estrogen receptor. In 1997, the doctors released a study from the Division of Endocrinology at Northwestern University Medical School in Chicago, IL.
The focus of this experiment was to investigate whether resveratro supplements could mimic the body’s estrogenic activity, which is known to produce a heart-protective benefit. Resveratrol did mimic estrogenic activity at concentrations that are needed to produce other benefits of resveratrol. Resveratrol was proven to be a ‘phytoestrogen’, which is a naturally occurring plant compound that has beneficial properties to fight cancers, heart disease and osteoporosis. Overall, resveratrol’s anti-cancer and anti-blood clotting activities show therapeutic promise.
Resveratrol and Red Wine for Heart Disease Prevention
This study shows that a few glasses of red wine may supply a sufficient amount of resveratrol. This also suggests that daily consumption of some red wines might produce significant concentrations of resveratro doses in the bloodstream. Resveratrol occurs naturally in grapes and other medicinal plants. In plants, resveratrol protects against fungal infections. Red wine has large amounts of resveratrol because resveratrol has high concentrations in grape skins. Because of the levels of resveratrol in red wine, moderate consumption of red wine may reduce the risk of heart disease. High concentrations of resveratrol without alcohol or calories may also be found in nutritional supplements.