The potential of pomegranate extracts and juices to protect against prostate cancer may be due to direct interaction with genes, according to a new study.

07-Jul-2008 - Regular consumption of green tea may improve the function of endothelial cells - cells lining the walls of blood vessels - and boost cardiovascular health, according to new research from Greece.

A study with rabbits indicates that extracts from pomegranate may inhibit inflammation, and positively effect chronic disease risk.

Oral supplements of beta-carotene may protect against sunburn, and the longer the supplementation period the greater the protection, says a new meta-analysis.

Awareness of the benefits of folic acid in preventing birth defects remains low among American women, according to two new reports.

The findings were highlighted this week as part of the Folic Acid Awareness Week, which runs from January 7 to 13, 2008.

Folate, which is found in foods such as green leafy vegetables, chick peas and lentils, has been linked by an overwhelming body of evidence to a reduced rate of a specific birth defect that affected the development of the spinal cord and central nervous system.

This connection led to the 1998 introduction of public health measures in the US and Canada, where all grain products are fortified with folic acid - the synthetic, bioavailable form of folate.

Preliminary evidence indicates that the measure is having an effect with a reported reduction in the incidence of neural tube defects (NTD) in the US of 26 percent.

Gallup: low supplement intake

Nevertheless, when it comes to actually seeking out folic acid supplementation, the majority of women report taking no action.

According to the 2007 Gullup Organization survey, which was funded by the government body Centers for Disease Control and Prevention (CDC), 40 percent of women reported taking daily supplements containing folic acid in 2007.

This percentage is equal to that observed in 2004, and is an increase from 33 percent in 2005 and 32 percent in 2003, said Gullup, which has been conducting the survey annually since 2003.

Based on telephone interviews with around 2,000 women in June last year, the survey results also revealed that folic acid consumption varied greatly according to age.

Approximately 61 percent of women aged 18-24 reported being aware of
folic acid, compared with 87 percent of women aged 25-34 and 89 percent of women aged 35-45 years. 

Additionally, women aged 18-24 years were less knowledgeable about the need for folic acid consumption before pregnancy (6 percent), compared with women aged 35-45 years (16 percent).

“These findings warrant the continued promotion of folic acid consumption among all women of childbearing age and especially among women aged 18-24 years,” said CDC last week.

SRBI: women don’t understand what’s in bread

According to the SRBI survey, which was based on telephone interviews with 600 women in October 2007, most women have misleading perceptions of the folic acid content of bread.

 The survey found that two-thirds of women believe that whole wheat and multigrain breads contain the most folic acid.

Only 12 percent perceive enriched white bread as having high levels of folic acid, despite the fact that it actually has twice as much folic acid as whole grain or whole wheat bread.

According to Judi Adams, president of the Grain Foods Foundation, which commissioned the survey, the results demonstrate the need for women to better understand how to get specific nutrients through their diet.

Supplements of ginkgo biloba may boost the memory and memory function of the elderly, so long as people comply and take them as instructed, according to the results of a new randomised clinical trial (RCT).

On the other hand, in the general study population with differing levels of compliance no overall benefits were observed for gingko. Moreover, there were suggestions that the extract may lead to an increased risk of stroke, report the researchers, led by Hiroko Dodge from Oregon State University.

“To our knowledge, our study is the first to report the results of a dementia prevention RCT among oldest old subjects,” wrote the authors.

“The suggestive results of a protective effect of GBE found in our study needs to be confirmed by ongoing larger prevention studies such as the Ginkgo Evaluation of Memory study in the US and the European GuidAge study.”

Ginkgo is derived from the leaves of the ginkgo tree and has been used for thousands of years by the Chinese as a herbal remedy for a variety of ailments. It contains potent antioxidants called flavoglycosides that have been shown to have neuro-protective effects in animal models of spinal cord injury.

Previous clinical trials in Germany and France reported that gingko biloba produced long-term improvements in cognitive function in older adults with dementia, but, a study by Joseph Carlson and co-workers from Stanford University reported no benefits for the herbal in healthy, non-demented older adults (Journal of the American Dietetic Association, March 2007, Vol. 107, pp. 422-432).

Similar results in the new study were reported when the researchers looked at the overall population.

New data

The new study involved 118 people age 85 and older with no memory problems. The elderly subjects were randomly assigned to receive either a ginkgo biloba extract (240 mg daily, provided by Thorne Research) or placebo for three years. The extracts were independently verified to contain at least six per cent terpene lactones and 24 per cent flavone glycosides.

Dodge and co-workers report that, during the course of the study, 14 people taking the placebo developed mild memory problems, while only seven people developed such problems after taking the ginkgo extract. Although there was a trend favouring ginkgo, the difference between those who took gingko versus the placebo was not statistically significant.

Interestingly, when the researchers considered only people who followed the directions in taking the study pills, they found that people took at least 84 per cent of the supplements as directed had a 68 per cent lower risk of developing mild memory problems, compared to those taking placebo.

On a cautionary note, a slight increase in the risk of a stroke or mini stroke was observed for those taking the gingko supplements, with seven people taking ginkgo experiencing strokes, compared to none in the placebo group.

“Ginkgo has been reported to cause bleeding-related complications, but the strokes in this case were due to blood clots, not excessive bleeding, and were generally not severe,” said Dodge.

“These results need to be clarified with larger studies, but the findings are interesting because ginkgo biloba is already widely used, readily available, and relatively inexpensive,” said Dodge.

“One of the most pressing public health problems facing our society is the rapidly growing number of people who, due to their age alone, are at high risk of developing dementia. The potential to delay or prevent this is of great importance. Further studies are needed to determine whether gingko biloba has any benefits in preventing cognitive decline and whether it is safe.”

The study was supported by grants from the National Institute on Aging and the National Center for Complementary and Alternative Medicine (NCCAM). 

Regular consumption of pomegranate juice may enhance the quality and mobility of sperm, suggests a new study with male rats.

“The results of this study demonstrated, for the first time, that daily consumption of PJ for seven weeks caused increased spermatogenic cell density, epididymal sperm concentration, sperm motility and decreased abnormal sperm rate related with decreased lipid peroxidation in male rats,” wrote lead Gaffari Turk from Firat University in Turkey.

The health-benefits of pomegranate have focussed almost exclusively on the pulp and juice of the fruit, most notably in fruit form although extracts are also gaining increasing attention. The antioxidant-rich fruit have been linked to improved heart health, and claims that it may offer protection against prostate cancer, Alzheimer’s, and may slow cartilage loss in arthritis.

It is these antioxidants, and particularly compounds like punicalagin, which accounts for about half of the fruit’s antioxidant ability, that are reportedly behind the proposed health benefits.

The new study suggests the health benefits of the fruit may also extend to improving fertility, and comes only months after a pilot study reported that pomegranate juice may help manage erectile dysfunction (International Journal of Impotence Research, doi: 10.1038/sj.ijir.3901570).

Turk and co-workers divided 28 male Wistar rats into four groups, and assigned them to drink one millilitre of distilled water (control group), 0.75 mL water plus 0.25 mL pomegranate juice (PJ), 0.50 mL water plus 0.50 mL PJ, or one mL PJ daily for seven weeks.

At the end of the experiment, the researchers report that levels of malondialdehyde (MDA), a reactive carbonyl compound and a major end product of lipid oxidation, significantly decreased as a result of PJ consumption, with the a 48.5 and 63.5 per cent decrease in the serum and sperm of the animals drinking the concentrated juice, respectively, compared to controls.

“Spermatozoa are especially susceptible to peroxidative damage because of the high concentration of polyunsaturated fatty acids which are involved in regulation of sperm maturation, [and] spermatogenesis,” explained the researchers.

Levels of antioxidant enzyme activities increased as a result of PJ, report Turk and co-workers, with sperms activities of glutathione (GSH), glutathione peroxidase (GSH-Px) and catalase (CAT) increasing by 4.5, 12.5 and 52.9 per cent, respectively.

Moreover, the researchers report: “In the present study it was observed that epididymal sperm concentration and sperm motility of rats that received different doses of PJ were significantly higher than those of the control.”

“Additionally, only a high dose of PJ significantly decreased total abnormality of sperms when compared to the control,” they added.

Significant further research is necessary to investigate if such observations would be reproducible in humans, and the necessary doses required to illicit such improvements. Mechanistic studies would also help identify the active ingredients in the pomegranate and their direct mode of action.

Consumption of pomegranate juice has been on the rise, particularly in the UK where sales have rocketed in the last year thanks to media coverage of the antioxidant-rich fruit that has commonly been linked to improved heart health, as well as claims that pomegranate could protect against prostate cancer and slows cartilage loss in arthritis.

10-Apr-2008 - A dietary supplement of red grape juice may reduce the activity of an enzyme linked to cardiovascular disease, suggests a new study said to be first report of its kind in humans.

Researchers looked at the grape juice supplement’s effects on the activity of NADPH oxidase in white blood cells (neutrophils), the main producer of the superoxide anion that may significantly increase oxidative stress.

Oxidative stress has been linked to an increased risk of various diseases including cancer, Alzheimer’s, and cardiovascular disease.

The effects of the grape juice supplement or a vitamin E supplement were studied in haemodialysis patients since this procedure is “well-recognised” to activate NADPH oxidase in neutrophils, said the researchers from Madrid’s Hospital Ramon y Cajal, the Universidad de Alcala, and CIBER Fisiopatologia Obesidad y Nutricion.

The results are published in this month’s issue of the American Journal of Clinical Nutrition.

Study details

Thirty-two haemodialysis patients were randomly assigned to receive supplements of vitamin E and/or the red grape juice, a placebo, or no supplementation for two weeks.

At the end of the study, lead author Patricia Castilla reports that only the red grape juice supplement was associated with lowed blood levels of total cholesterol and apolipoprotein B (apoB). ApoB is the main apolipoprotein of LDL cholesterol and is responsible for the transport of cholesterol to tissues. In high concentrations it has been linked to plaque formation in the blood vessels, although the mechanism behind this is not clear.

Furthermore, the red grape juice also increased HDL cholesterol levels.

Both active supplements reduced the activity of neutrophil NADPH oxidase ex vivo, as well as reducing blood levels of oxidised LDL-cholesterol. When the supplements were used together the “effects were intensified,” said the researchers.

“Regular ingestion of concentrated RGJ by haemodialysis patients reduces neutrophil NADPH-oxidase activity and plasma concentrations of oxidized LDL and inflammatory biomarkers to a greater extent than does that of vitamin E,” wrote the researchers. “This effect of RGJ consumption may favor a reduction in cardiovascular risk.”

Building on earlier studies

The same researchers report in the same journal in 2006 initial results of their studies with the red grape juice and heart health. Both healthy and hemodialysis patients were used in that earlier study, and the researchers reported that, in addition to reductions in markers of inflammation levels of plasma monocyte chemoattractant protein 1 (MCP-1), an inflammatory biomarker associated with CVD, were reduced by 56 per cent at the end of the supplementation period.

Sports nutrition

Grape juice and grape extracts have previously been linked to improvements in oxidative stress markers after excessive exercise. High intensity exercise can bring on oxidative stress, where free radicals attack tissue and increase ageing.

In 2006 researchers from San Antonio Catholic University in Spain, showed that a drink containing black grape, raspberry and red currant concentrates reduced protein oxidation by 23 per cent following excessive exercise. Similar tests for a placebo crossover showed protein oxidation increased by 12 per cent (Clinical Nutrition, doi: 10.1016/j.clnu.2005.11.007).

Moreover, Berkem - now part of Naturex - reported that supplements of a polyphenol-rich Bordeaux grape extract increased power during exercise by 21 per cent. Their Powergrape ingredient is being marketed to the sports nutrition market.

 An ellagitannin-rich pomegranate extract is safe and effective in enhancing the antioxidant profile in humans, scientists have reported.