Archive for June, 2008

Pomegranate extract may stop inflammation

Friday, June 13th, 2008

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

The activity of cyclooxygenase enzymes associated with inflammation, COX-1 and COX-2, was inhibited in animals fed a polyphenol-rich extract of pomegranate fruit, according to results published in the open-access Journal of Inflammation.

If the study can be repeated in humans it offers promise for preventing chronic inflammation, brought about by an over-expression or lack of control of the normal protective mechanism. Chronic inflammation has been linked to range of conditions linked to heart disease, osteoporosis, cognitive decline and Alzheimer’s, type-2 diabetes, and arthritis.

It is in terms of arthritis that the researchers focus their study, and indicate that pomegranate extracts could provide an alternative to use of non-steroidal anti-inflammatory drugs (NSAIDs), especially in light of mounting concerns about the adverse effects of NSAID use. 

Some of these drugs, which are among the most frequently prescribed medications worldwide, have been linked with gastrointestinal toxicity, increased blood pressure, and increased risk of cardiovascular disease.

“Consumption of pomegranate fruit extract may be of value in inhibiting inflammatory stimuli-induced cartilage breakdown and production of inflammatory mediators in arthritis,” wrote the researchers, led by Tariq Haqqi from Case Western Reserve University in Cleveland, Ohio.

Pomegranate, a rich source of antioxidants, has been linked to improved heart health, but a growing body of science indicates the fruit protect against prostate cancer. Studies have also reported a role in joint health by slowing cartilage loss in arthritis.

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

Study details

Haqqi and co-workers fed four rabbits the pomegranate extract, equivalent of 175 ml of pomegranate juice, while two rabbits given water instead acted as the controls. Blood samples were taken to measure inflammatory biomarkers and antioxidant levels.

The data showed that blood antioxidant levels were significantly higher after ingestion of the pomegranate extract, indicating the bioavailability of the antioxidants.

Moreover, COX-1 and COX-2 activity was significantly reduced in the pomegranate-fed animals, compared to control, particularly for COX-2. Indeed, COX-1 activity was reduced by about seven per cent following ingestion of the extract, while COX-2 activity decreased by about 26 per cent.

“Although direct inhibitory effect of plant extracts or components on COX enzyme activity have been reported by several investigators, inhibition of COX enzyme activity by polyphenols that become bioavailable after consumption of pomegranate fruit or extract has not been reported,” wrote the researchers.

While the results are promising for pomegranates, the researchers rightfully stated that additional animal studies are required, “followed by controlled clinical trials.”

Beta-carotene effective as sunburn protector: meta-analysis

Wednesday, June 11th, 2008

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

Ten weeks of supplementation were required to produce a protective effect, according to pooled data from seven studies reported in the journal Photochemistry and Photobiology.

“This meta-analysis indicates that beta-carotene supplementation of humans is effective in providing protection against the development of a sunburn reaction,” wrote Wolfgang Kopcke from Munster University Hospital and Jean Krutmann from the Heinrich-Heine-University in Dusseldorf.

“This observation emphasizes that systemic photoprotection by beta-carotene is quite different from that achieved with a topically applied sunscreen,” they added.

There is a growing body of science focusing on the potential benefits of nutrients to boost skin health from within, with lutein, lycopene and superoxide dismutase (SOD) having been reported to improve skin health.

Kopcke and Krutmann searched the literature for studies on beta-carotene supplementation studies for protecting humans against sunburn. Seven studies were identified that tested the effectiveness of the carotenoid.

The meta-analysis found that the carotenoid did offer protection against sunburn and that at least 10 weeks of supplementation were required to afford this protection.

Moreover, for every additional month of supplementation, the degree of protection increased, added Kopcke and Krutmann.

“This observation emphasizes that systemic photoprotection by beta-carotene is quite different from that achieved with a topically applied sunscreen,” they said. “Whereas proper use of modern sunscreens provides protection against the development of a sunburn reaction within minutes after topical application, beta-carotene-induced photoprotection builds only slowly over several weeks of supplementation.”

Responsibly, they stressed that the carotenoid was not a replacement for sunscreen, particularly under strong sun exposure, but may work in addition to topicals. Beta-carotene’s sun protection factor (SPF) was “at best” about four, they said.

“Topical application of sunscreens and systemic photoprotection with beta-carotene are not competing strategies which are intended to replace each other, but instead they are complementary in nature and should be combined,” wrote Kopcke and Krutmann.

“In this regard, beta-carotene intake would serve to provide a basic, all day protection against sunburn, which would affect all parts of the skin, whereas sunscreens would be used ‘in addition’ in particular to prevent sunburns under conditions where the consumer anticipates increased exposure of selected skin areas to UV radiation.”

Mechanism

The researchers said the exact mechanism or mechanisms behind beta-carotenoid’s sun protection were unknown, but said it was tempting to speculate that the carotenoid’s antioxidant activity may be responsible. On exposure to UV radiation, particularly UV-B, reactive oxygen species (ROS) are produced in the skin that may result in oxidative stress, a known accelerator of the ageing process. Beta-carotene may quench these ROS and thereby offer skin protection.

On the other hand, an alternative mechanism is proposed by Kopcke and Krutmann: beta-carotene may interfere with various signaling pathways that result form UV-B exposure, which start in DNA.

“The efficacy of beta-carotene to prevent sunburn formation may thus alternatively be explained by the capacity of beta-carotene to interfere with one or several of these signaling pathways,” they concluded.

Industrial welcome

The results of the study were welcomed by Manfred Eggersdorfer, head of R&D at DSM Nutritional Products. “These findings demonstrate our ever-growing understanding of the vital link between nutritional intake and health,” he said. Nutritional science is increasingly demonstrating how we can influence our health and well-being by means of the nutritional choices we make.”

Surveys reveal low folic acid awareness

Wednesday, June 4th, 2008

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

Conducted by The Gallup Organization and Schulman, Ronca & Bucuvalas Inc (SRBI), the recent surveys indicate there is still room for education efforts and continued promotion of folic acid consumption.

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.

Gingko may boost memory - if you remember to take it

Wednesday, June 4th, 2008

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).

Researchers report in the journal Neurology that reliably taking the supplement could reduce the risk of developing mild memory problems by 68 per cent in healthy older people with no memory problems.

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). 

Pomegranate juice may boost sperm quality study suggests

Wednesday, June 4th, 2008

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

The link between the antioxidant-rich juice and male fertility could see pomegranate seen as much more than a heart healthy food, if the new results published in Clinical Nutrition can be translated to humans.

“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.