Tuesday, May 29, 2007

Scientists find more genes linked to breast cancer

I was rather pleased personally to read the report below. QIMR is located about 15 minutes drive from where I live and I did in fact meet Georgia Chenevix-Trench socially some years ago -- a very pleasant lady despite her frightening surname. My congratulations to her on her research. I write without fear or favour, however. I was quite dismissive of research by another QIMR group on May 21st

AUSTRALIAN scientists have helped to uncover four new genes involved in breast cancer and believe they hold the magic key to exposing all others behind the deadly disease. The breakthrough is being heralded as the most significant in the field of breast cancer genetics for more than a decade. "This is huge, absolutely huge, because now we know how to find them all," said Queensland researcher Georgia Chenevix-Trench, who was involved in the landmark international study of more than 40,000 women.

In research released yesterday, the collaborators revealed four genes that slightly increase a woman's chance of developing breast cancer. Everyone carries these genes but those who carry specific abnormal variants will have a 10 to 30 per cent increased risk of disease. The find sharply boosts the number of known low-risk genes to five, after the group publicised the discovery of another gene, Caspase 8, earlier this year.

Although the latest developments are promising, scientists say there is no point screening women for these dangerous variants until 30 or 40 more have been uncovered. A woman would need to carry multiple bad variants to really increase their cancer risk, said Dr Chenevix-Trench, of the Queensland Institute of Medical Research. Dr Chevenix-Trench said the most exciting aspect of the research, published in the international journal Nature, was that researchers now understood how to find these genes.



The American Journal of Epidemiology is usually at the top of my list for amusing absurdities but I think I am going to have to add "Archives of Internal Medicine" to my list of guffaw-provoking reading. One of their latest articles is a real lulu. I will reproduce below first the Abstract and then a media summary. See if you can spot the absurdity:

Calcium Plus Vitamin D Supplementation and the Risk of Postmenopausal Weight Gain

By: Bette Caan et al


Background: Obesity in the United States has increased significantly during the past several decades. The role of calcium in the maintenance of a healthy body weight remains controversial.

Methods: A randomized, double-blinded, placebo-controlled trial was performed with 36 282 postmenopausal women, aged 50 to 79 years, who were already enrolled in the dietary modification and/or hormone therapy arms of the Women's Health Initiative clinical trial. Women were randomized at their first or second annual visit to receive a dose of 1000 mg of elemental calcium plus 400 IU of cholecalciferol (vitamin D) or placebo daily. Change in body weight was ascertained annually for an average of 7 years.

Results: Women receiving calcium plus cholecalciferol supplements vs women receiving placebo had a minimal but consistent favorable difference in weight change (mean difference, -0.13 kg; 95% confidence interval, -0.21 to -0.05; P = .001). After 3 years of follow-up, women with daily calcium intakes less than 1200 mg at baseline who were randomized to supplements were 11% less likely to experience small weight gains (1-3 kg) and 11% less likely to gain more moderate amounts of weight (>3 kg) (P for interaction for baseline calcium intake = .008).

Conclusion: Calcium plus cholecalciferol supplementation has a small effect on the prevention of weight gain, which was observed primarily in women who reported inadequate calcium intakes.

A Media summary below:

CALCIUM and vitamin D supplements could help postmenopausal women to control their weight, according to research in the latest issue of the Archives of Internal Medicine . The study included 36,282 women aged 50 to 79 who were randomly assigned to receive either 1000 milligrams of calcium plus 400 international units of vitamin D each day, or an inactive placebo. Participants were weighed each year for approximately seven years. At the end of the study, women who took the supplements weighed an average of 130 grams less than those who did not. The benefits were greatest in women who were not previously getting their recommended daily intake of calcium, with those in the supplement group weighing an average of 190 grams less than those in the placebo group by the end of the study. The authors suggest that calcium and vitamin D may help to break down existing fat cells and prevent the development of new fat.

Dja geddit? Popping all those pills over all those years helped the ladies lose all of one quarter of one pound! Wotta laugh!

A more honest conclusion to the study would have been something like: "Calcium and vitamin D supplements were found to be unimportant to weight control in this study".


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 and margarine? They are just about pure fat. Surely they 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.


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