Red Wine Grapes - a major source of anti-oxidant polyphenols

 

General Health and Longevity

In one of the earliest studies conducted on the longevity effects of trans-resveratrol, the life span of yeast cells was increased in a similar fashion to the proven calorie restriction method¹. Recent studies by Dr. David Sinclair have demonstrated the calorie restriction mimicking effects of trans-resveratrol intake on mice². The results showed that trans-resveratrol delays age related deterioration. Elderly mice fed trans-resveratrol showed signs of reversal of age-related conditions including cataracts, bone density decreases, decrease inflammation, cardiovascular conditions and motor coordination. In perhaps the most famous study conducted by Sinclair et al trans-resveratrol was found to alter the physiology of middle-aged mice fed a high calorie diet to that of mice on a standard diet and to significantly enhance their life span³. The observed changes related to increased insulin sensitivity, an increase in the number of chemical messengers blocking hunger and importantly increased mitochondrial number resulting in improved energy efficiency and motor function. These aspects are thought to be responsible for the observed effects of trans-resveratrol. The authors concluded that this data showed an overall improvement in the general health of the subjects and may be the foundation for new treatments for obesity-related disorders and diseases of aging.

A 2005 study by Juan et al showed that trans-resveratrol fed mice displayed significantly increased sperm counts than the control group⁴. An increase in the levels of testosterone and gonadotrophins was also observed in the trans-resveratrol group.

 

Reduce stroke risk

Anti-oxidants may reduce stroke risk

Increased intake of anti-oxidants may contribute to a lowering of the risk of stroke, say researchers from the Karolinksa Institutet in Sweden.

A new study published in the journal Stroke suggests a high anti-oxidant intake may reduce the risk of stroke by “inhibiting oxidative stress and inflammation”.

The study set out to determine if there was a relationship between Total Anti-oxidant Content (TAC), a measure of the body’s anti-oxidant capacity, and stroke risk in patients with and without a history of cardiovascular disease. The study recruited more than 31,000 participants without heart disease and more than 5,000 with pre-existing heart disease.

The researchers then measured anti-oxidant capacity of the participants through the TAC measurement, a known measure to reduce disease-causing free-radicals in the system.

Researchers found that the group with the highest anti-oxidant intake and no pre-existing heart disease had a 17% lower risk of stroke compared to those in the lowest anti-oxidant intake group. The researchers also reported that participants with a history of heart disease and a moderately high anti-oxidant intake had up to 57% lower stroke risk.

While further studies are required to assess the association between anti-oxidant intake and the proposed health benefits, the researchers said their “findings suggest that dietary TAC is invcersely associated with total stroke…” Simply put, this means that increased intake of anti-oxidants is associated with a decrease in stroke in all trial participants.

Glucose Sensitivity

Resveratrol may enhance glucose sensitivity

Resveratrol may improve insulin sensitivity and reduce post meal blood glucose levels in adults with impaired glucose tolerance, according to a new study. The study, conducted at the Albert Einstein College of Medicine in New York is one of the first human studieson the impact of Resveratrol on blood glucose levels. It follows several animal studies which demonstrated promising results where insulin sensitivity was enhanced and ‘spikes’ in blood glucose after a meal were significantly reduced.

In this human trial, subjects were given Resveratrol once daily for 4-weeks. Baseline levels of fasting blood glucose, peak post meal glucose and 3-hour after meal glucose were determined. The researchers determined that fasting blood glucose levels remained unchanged, however, post meal and 3-hour post meal glucose levels were all significantly reduced. These findings were consistent with previous animal trials which showed enhanced insulin sensitivity and reduced blood glucose levels with Resveratrol administration.

The researchers concluded that “these findings support the conduct of larger studies to further investigate the effects of resveratrol on metabolism and vascular function”.

Reduce breast cancer risk?

Studies suggest red wine compounds may reduce breast cancer risk

A new study published in the Journal of Women’s Health investigated the possibility that red wine – or more accurately, compounds present in red wine – may reduce breast cancer risk. The study investigated the potential association between red wine intake and decreased levels of certain hormones implicated in breast cancer.

The study recruited 36 women split into two groups and assigned to the ‘red wine’ or ‘white wine’ group. Each subject consumed a moderate amount of the wine daily for one month before being switched to the other type of wine. Blood tests to measure hormone levels were conducted on two occasions in each month.

The researchers observed that there was an association between consumption of red wine and hormonal changes such as increased circulating testosterone levels and lowering female sex hormones. One of the key researchers involved in the study, Dr Glenn Braunstein suggested that a possible mechanism was by Aromatase inhibition, (Aromatase is the enzyme responsible for conversion of hormones). A high level of the female sex hormone estrogen is associated with an increased risk of breast cancer.

Dr Braunstein, said that “there are chemicals in red grape skin and red grape seeds that are not found in white grapes that may decrease breast cancer risk”.

The researchers also suggested that the presence of various molecules in red wine may serve some protective role in the body. Other molecules also present in red wine and grape skins such as resveratrol, rutin, quercetin are suggested to inhibit aromatase, but further studies are required to confirm this relationship.

Cancer Promise

Grape Polyphenol Extracts Shows Cancer Promise

New research suggests that grape polyphenol extracts (anti-oxidants) may help fight cancers of the head and neck whilst maintaining the integrity of the surrounding healthy cells.

The study, conducted at the University of Colorado Cancer Centre, showed that in both cell cultures and in mouse models addition of grape polyphenol extracts hindered the growth of cancer cells. The researchers reported that grape extract reduced growth of cancer cells by up to 67% and initiated DNA damage and programmed cell death of cancer cell lines.

According to the researchers, the beneficial results of grape polyphenols seem to be two-pronged. The extract creates conditions which are unfavourable to cell growth and thus cause damage to the DNA of cancer cells and also block the mechanisms of DNA repair. The surrounding healthy cells are able to withstand the stresses exerted by the polyphenol extracts to a greater extent than cancer cells. In the mouse model, the research team observed that cancer cells were killed with “absolutely no toxicity to the mice themselves”.

Previous studies conducted on cancer cell lines have been consistent with hindering the growth of cancer cells, however, the mechanism was unknown. Due to the difficulty in treating head and neck cancers, the researchers suggest that further investigation is required to determine the potential of grape extract supplementation as a therapeutic intervention

Resveratrol and Metabolism

Resveratrol Supports Metabolic Benefits

A recent clinical trial has indicated that daily supplementation with resveratrol may improve insulin sensitivity and reduce sudden rises in blood sugar levels after eating.

The study, conducted at the Albert Einstein College of Medicine, New York, tested the affect of resveratrol supplementation on insulin sensitivity in the older population with age-related glucose intolerance.

The preliminary nature of the study should be taken into account and the results be interpreted with caution, the researchers suggest.

In the study, patients were given a daily dose of resveratrol for a period of four weeks. The results showed a significant reduction in blood glucose levels for patients after a meal when compared to data taken prior to resveratrol supplementation. The researchers also observed an increase in insulin sensitivity following the four week resveratrol supplementation.

No adverse reactions to the resveratrol dose were observed, which suggests that resveratrol is well tolerated. However, the researchers suggested that larger and longer trials are required to adequately assess this outcome.

The researchers concluded that “resveratrol shows promise as a new therapeutic strategy for an important and highly prevalent age-related metabolic disorder”.