Tuesday, July 28, 2009

"I've recently read that cranberry juice doesn't help to prevent cystitis after all. Should I stop drinking it now?"

An interesting contrary view to a recent knockback

The answer, in a word, is no. The news story that you are referring to arose when Ocean Spray submitted research to a new EU body, the European Food Safety Authority, in the hope that it would be allowed to make the health claim on its cartons that drinking a certain amount of cranberry juice each day would prevent cystitis. The panel agreed that while research does show this to be the case in laboratory studies, more studies were needed to be sure of the exact “dose” needed in humans.

Professor Stuart Stanton, Emeritus Professor of Urogynaecology at St George’s Hospital in London, who is versed with the EU panel and the research submitted, has been recommending cranberry juice to his patients for more than 20 years. He says that it is necessary for us to appreciate that much of what is recommended in everyday medicine is founded on years of experience and anecdotal findings, as well as clinical research.

In his view, cranberry juice is beneficial in preventing urinary infections and he makes the rather timely point that if women who have read about the panel’s findings suddenly stop drinking it, GPs, who are already overburdened with the demands of swine flu, could see more patients presenting with what had previously been well-controlled urinary infections.

It is also important to remember, however, that cranberry juice is not a medicine. While the latter are man-made and very specific dose-response mechanisms can be determined for them, it is frequently very hard, if not impossible, to achieve the same in food products that contain naturally functional ingredients.

That said, from the work that has already been carried out, scientific thinking suggests that two glasses of cranberry juice, containing 80mg of proanthocyanidins (PACs), is roughly the amount needed for it to “do its job” — ie, to stop cystitis-causing E. coli bacteria from attaching to the walls of the urinary tract and setting up infections.

It is thought that the PACs may work by wrapping themselves directly around the E. coli so that the bacteria cannot grab on to receptors in the lining of the bladder and urethra, or that they may block the receptors themselves so that there is no room for the E. coli to dock.

Either way, the result is that the bacteria leave the body without the opportunity to set up infections. This prevents patients from needing constantly to take antibiotics, which is good news, because you do not get the risk of building up antibiotic resistance.

The important point to bear in mind is that PACs in cranberry juice work in helping to prevent infections taking hold, which is why if you are prone to them, it is a good idea to drink some of the juice each day. If the E. coli do get their little “claws” into the lining of your tracts, they bind securely and at this point antibiotics are the only real option.

Test-tube experiments suggest that cranberry juice extracts may also be able to fight salmonella infections. Test-tube work also has found that they appear to prevent the ulcer-causing Helicobacter pylori from attaching itself to the stomach lining.

The red antioxidant pigments in cranberry juice also seem, again in laboratory tests, to help to stop platelets in blood from clumping together. If this happened in our bodies, this would assist in keeping blood thin and potentially lower the chances of clots forming that can trigger heart attacks and strokes.

Other interesting super nutrients present in cranberries include EGCG found also in green tea and linked with possible disease-fighting properties including cancer.

The tart taste of cranberries is down to the PACs, which give them their potential health benefits and are present in nature to stop insects feasting on them. For us to be able to tolerate the taste, sugar or sweeteners need to be added to cranberry juice drinks.


Women are getting more beautiful

FOR the female half of the population, it may bring a satisfied smile. Scientists have found that evolution is driving women to become ever more beautiful, while men remain as aesthetically unappealing as their caveman ancestors. The researchers have found beautiful women have more children than their plainer counterparts and that a higher proportion of those children are female. Those daughters, once adult, also tend to be attractive and so repeat the pattern.

Over generations, the scientists argue, this has led to women becoming steadily more aesthetically pleasing, a “beauty race” that is still on. The findings have emerged from a series of studies of physical attractiveness and its links to reproductive success in humans.

In a study released last week, Markus Jokela, a researcher at the University of Helsinki, found beautiful women had up to 16% more children than their plainer counterparts. He used data gathered in America, in which 1,244 women and 997 men were followed through four decades of life. Their attractiveness was assessed from photographs taken during the study, which also collected data on the number of children they had.

This builds on previous work by Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics, who found that good-looking parents were far more likely to conceive daughters. He suggested this was an evolutionary strategy subtly programmed into human DNA. He cited two findings from the Longitudinal Study of Adolescent Health, a US government-backed study that is monitoring more than 15,000 Americans. The measurements include objective assessments of physical attractiveness.

One finding was that women were generally regarded by both sexes as more aesthetically appealing than men. The other was that the most attractive parents were 26% less likely to have sons. Kanazawa said: “Physical attractiveness is a highly heritable trait, which disproportionately increases the reproductive success of daughters much more than that of sons. “If more attractive parents have more daughters and if physical attractiveness is heritable, it logically follows that women over many generations gradually become more physically attractive on average than men.”

In men, by contrast, good looks appear to count for little, with handsome men being no more successful than others in terms of numbers of children. This means there has been little pressure for men’s appearance to evolve.

The findings coincide with the bicentenary of the birth of Charles Darwin, whose theory of evolution first described the forces that shape all species. Even he, however, might have been surprised by the subtlety of the effects now being detected by researchers looking into human mating. The heritability of attractiveness is widely accepted. When Elizabeth Jagger became a model, her mother, the former model Jerry Hall, said: “It’s in her genes.”

Women may take consolation in the finding that men are subject to other types of evolutionary pressure. Gayle Brewer, a psychology lecturer at the University of Central Lancashire, said: “Men and women seek different things in their partners. “For women, looks are much less important in a man than his ability to look after her when she is pregnant and nursing, periods when women are vulnerable to predators. Historically this has meant rich men tend to have more wives and many children. So the pressure is on men to be successful.”


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