Friday, December 22, 2006


Long known as part of the "Mediterranean diet" mythology

People who use plenty of olive oil in their diets may be helping to prevent damage to body cells that can eventually lead to cancer, new research suggests. In a study of 182 European men, researchers found evidence that olive oil can reduce oxidative damage to cells' genetic material, a process that can initiate cancer development. They say the findings may help explain why rates of several cancers are higher in Northern Europe than in Southern Europe, where olive oil is a dietary staple.

They also support advice to replace saturated fats from foods like meat and butter with vegetable fats, particularly olive oil, said study co-author Dr. Henrik E. Poulsen, of Copenhagen University Hospital in Denmark. He and his colleagues report the findings in The FASEB Journal, a publication of the Federation of American Societies for Experimental Biology.

The study included healthy men between the ages of 20 and 60 from five European countries. For two weeks [The wonders of long-term research!], the men consumed a quarter cup of olive oil throughout each day. At the end of the study, they showed an average 13 percent reduction in a substance called 8oxodG, which is a marker of oxidative damage to cells' DNA. Such damage occurs when byproducts of metabolism called reactive oxygen species overwhelm the body's antioxidant defenses. Olive oil contains a number of compounds, called phenols, believed to act as powerful antioxidants. However, those compounds didn't seem to account for the drop in DNA oxidative damage, according to Poulsen's team. The men in the study used three different olive oils with varying levels of antioxidant phenols, and oxidative damage declined regardless of the phenol content.

Instead, the researchers suspect that the monounsaturated fats in olive oil are behind the effect. The findings, they say, suggest that olive oil may be part of the reason that certain cancers, including breast, colon, ovarian and prostate cancers, are less common in Mediterranean countries than in Northern Europe. At the beginning of the study, men from Northern Europe had higher levels of 8oxodG than those from Southern Europe. This is consistent, according to Poulsen's team, with the expected effects of the olive-oil-rich "Mediterranean diet."

However, Poulsen told Reuters Health, the diet is more than just olive oil. Ideally, it's also rich in fruits, vegetables, whole grains and fish. Moreover, regardless of its benefits, he added, olive oil is no substitute for calorie control and regular exercise. [He got that right]


The journal abstract is as under:

Effect of olive oils on biomarkers of oxidative DNA stress in Northern and Southern Europeans

Anja Machowetz, Henrik E. Poulsen et al.

High consumption of olive oil in the Mediterranean diet has been suggested to protect DNA against oxidative damage and to reduce cancer incidence. We investigated the impact of the phenolic compounds in olive oil, and the oil proper, on DNA and RNA oxidation in North, Central, and South European populations. In a multicenter, double-blind, randomized, controlled crossover intervention trial, the effect of olive oil phenolic content on urinary oxidation products of guanine (8-oxo-guanine, 8-oxo-guanosine and 8-oxo-deoxyguanosine) was investigated. Twenty-five mililiters of three olive oils with low, medium, and high phenolic content were administered to healthy males (n=182) daily for 2 wk. At study baseline the urinary excretion of 8-oxo-guanosine (RNA oxidation) and 8-oxo-deoxyguanosine (DNA oxidation) was higher in the Northern regions of Europe compared with Central and Southern European regions (P=0.035). Urinary excretion of the 8 hydroxylated forms of guanine, guanosine, deoxyguanosine and their nonoxidized forms were not different when comparing olive oils with low, medium, and high phenolic content given for 2 wk. Testing the effect of oil from urinary 8-oxo-deoxyguanosine changes from baseline to post-treatment showed a reduction of DNA oxidation by 13% (P=0.008). These findings support the idea that ingestion of olive oil is beneficial and can reduce the rate of oxidation of DNA. This effect is not due to the phenolic content in the olive oil. The higher DNA and RNA oxidation in Northern European regions compared with that in Central and Southern regions supports the contention that olive oil consumption may explain some of the North-South differences in cancer incidences in Europe.

Maybe I am missing something here but it seems to me that the different physiological response to olive oil observed in Northern and Southern Europeans indicates relevant genetic differences between the two populations and it may be the genetic differences that account for the different disease patterns in Northern and Southern Europe


They may be as much neurological as psychological

Scientists at the Melbourne Neuropsychiatry Centre studying the development of the teenage brain have learned that the frontal lobe gradually matures during adolescence until the age of 25, when it reaches maturity. Over those years, the frontal lobe is "pruned" of excess nerve cells to create more efficient information processing that is useful to adulthood. This "pruning" results in a temporary loss of grey matter. The findings help provide a scientific explanation for the difficult teenage years, when the combination of hormones and brain "pruning" causes adolescents to make reckless decisions and suffer emotional problems. And when parents scream at their teenagers to "start acting like an adult" they are asking for the impossible.

Steve Rankin, 16, of St Andrews in outer Sydney, "stupidly" dropped out of school three months ago. He is yet to find a job and has been fined for drinking on a train. His relationship with his parents is strained. The result of the study "totally makes sense to me", Steve said. "When I was younger I was the golden child and then when I was 15 I felt like a neglected child. Then, not long ago, I just started hating my parents and started getting kind of emo-ish," he says, using teen slang for emotional. "I was like a little kid and then I turned 15 and my parents expected me to be like Albert Einstein or something."

In the past five years, the teenage brain has become the focus of intense scientific study throughout the world. The current issue of the American Journal of Physiology carries a report by University of California psychiatrists who also found that the "pruning" removed useless "white noise" from the brain.

The University of Melbourne's Christos Pantelis began making neuropsychological assessments of teenagers in 2002. His team is brain-scanning 200 10-year-olds to get a closer look at how the brain works. Funding permitting, he will brain-scan the children routinely until they reach full maturity at 25. "The frontal lobes are responsible for the higher-level mental abilities," Professor Pantelis said. "These abilities include problem solving, planning, thinking flexibly. Working memory and the frontal lobes are also important in terms of behavioural and mental control - that is, the ability to stop yourself doing anything inappropriate." Professor Pantelis said the new information might provide useful insights for parents, teachers and legislators. "It is very helpful when you think of some of the problems adolescents are having, either in terms of their behaviour, control of their emotions and their interaction skills. "If we understand that their brains are still maturing in particular ways then it might lead us to teach them in different ways too. "There has also been interest in our studies from the legal world, because you have to ask whether it is OK to put an adolescent or young adult into the same prison as a hardened criminal," he said.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter? It is just about pure fat. Surely it should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The use of extreme quintiles to examine effects is in fact so common as to be almost universal but suggests to the experienced observer that the differences between the mean scores of the experimental and control groups were not statistically significant -- thus making the article concerned little more than an exercise in deception


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