Wednesday, March 26, 2008


The old "wonders of fish" story again! Popular summary followed by journal abstract below. There is a lot of scorn that I could pour on this study (control for education and income etc.?) but I will content myself with noting that IQ at age 3 cannot reliably be assessed

Pregnant women who regularly eat fish can give their children a head start in life by boosting their intelligence, a study has found. The children of mothers who ate fish more than twice a week during their second trimester were better in language and motor skill tests, research at Harvard University found

But it also showed the effects may depend on the type of fish eaten. The study, which monitored more than 300 children at three stages of development, counters advice that pregnant women should avoid fish because it can contain toxic chemicals.

"Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake," the report, which will be published in the American Journal of Epidemiology this week, concluded.


Maternal Fish Intake during Pregnancy, Blood Mercury Levels, and Child Cognition at Age 3 Years in a US Cohort

By Emily Oken et al

The balance of contaminant risk and nutritional benefit from maternal prenatal fish consumption for child cognitive development is not known. Using data from a prospective cohort study of 341 mother-child pairs in Massachusetts enrolled in 1999-2002, the authors studied associations of maternal second-trimester fish intake and erythrocyte mercury levels with children's scores on the Peabody Picture Vocabulary Test (PPVT) and Wide Range Assessment of Visual Motor Abilities (WRAVMA) at age 3 years. Mean maternal total fish intake was 1.5 (standard deviation, 1.4) servings/month, and 40 (12%) mothers consumed >2 servings/week. Mean maternal mercury level was 3.8 (standard deviation, 3.8) ng/g. After adjustment using multivariable linear regression, higher fish intake was associated with better child cognitive test performance, and higher mercury levels with poorer test scores. Associations strengthened with inclusion of both fish and mercury: effect estimates for fish intake of >2 servings/week versus never were 2.2 (95% confidence interval (CI): -2.6, 7.0) for the PPVT and 6.4 (95% CI: 2.0, 10.8) for the WRAVMA; for mercury in the top decile, they were -4.5 (95% CI: -8.5, -0.4) for the PPVT and -4.6 (95% CI: -8.3, -0.9) for the WRAVMA. Fish consumption of ~2 servings/week was not associated with a benefit. Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake.


Breast cancer risk test on the way

GENETIC research is moving so fast that a Brisbane scientist believes a blood test may be available to calculate a woman's breast cancer risk within five years. Georgia Chenevix-Trench, of the Queensland Institute of Medical Research, is part of a global team of scientists involved in searching for breast cancer susceptibility genes. "What you could do is give women a risk assessment at different ages," she said. "That might be a reality within a few years."

Dr Chenevix-Trench said no test was likely to be able to tell women categorically whether they would develop breast cancer. Lifestyle factors and environment are also believed to play a role. But a blood test should be able to tell women whether they were at high or low risk - or somewhere in-between - at varying stages of their lives based on their genetic profile. "Maybe women who are lining up for mammograms would have a blood test and they would be told: 'You're at a very high risk, you should have additional screening'," Dr Chenevix-Trench said. "If you're at very low risk, you possibly could reduce your frequency. It's a political hot potato to suggest that some people could have less screening but I think you could probably do that."

Australian women have a one-in-eight chance of developing breast cancer in their lifetime. Scientists have known for years that defects in two genes, BRCA1 and BRCA2, give women a much higher risk of breast cancer. Some women found with defects in those genes opt for mastectomies and ovary removal to dramatically cut their odds of cancer.

A paper published recently in the American Journal of Human Genetics, co-written by Dr Chenevix-Trench, found variations in two genes, known as FGFR2 and TNRC9, amplified a woman's breast cancer risk if she also carried the BRCA2 defect. The research found BRCA2 defect carriers with the highest risk combination of FGFR2 and TNRC9 genes had a 70 per cent likelihood of developing breast cancer.


Cod liver oil lubricates your bones! "A regular dose of cod liver oil reduces the quantity of painkilling drugs needed by people with rheumatoid arthritis (RA), a study in Scotland has found. The finding, published in Rheumatology magazine, is significant because cod liver oil is benign, whereas nonsteroidal antiinflammatory drugs, such as ibuprofen or naproxen, which are commonly taken by RA patients, can have serious side-effects. The study was carried out over five years by researchers from rheumatology units in Dundee and Edinburgh.


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].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

Even statistical correlations far stronger than anything found in medical research may disappear if more data is used. A remarkable example from Sociology:
"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."
So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

"What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!


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