Saturday, June 30, 2007


The article below is very direct evidence of the benefits of estrogen therapy -- and estrogen is of course at least a major component of HRT. It shows that taking estrogen reduces calcification in your arteries quite a lot. And they've got the pictures to prove it! So does that mean that HRT has been officially rehabilitated as helpful with circulatory problems? It does but it would be too embarrassing to admit it straight out after the scare stories of recent years. So the authors note that estrogen has many other effects -- implying that there are "other risks" (e.g. stroke) with HRT. They caution, in other words that it may do harm as well as good. The evidence for the "other risks" is, however, as far as I can tell, almost wholly epidemiological -- which translates as "speculative". So I think that the direct evidence of improvement in the heart's circulatory system recorded below DOES warrant use of estrogen in women with circulatory or cardiac problems

Estrogen Therapy and Coronary-Artery Calcification

By JoAnn E. Manson et al.


Background: Calcified plaque in the coronary arteries is a marker for atheromatous-plaque burden and is predictive of future risk of cardiovascular events. We examined the relationship between estrogen therapy and coronary-artery calcium in the context of a randomized clinical trial.

Methods: In our ancillary substudy of the Women's Health Initiative trial of conjugated equine estrogens (0.625 mg per day) as compared with placebo in women who had undergone hysterectomy, we performed computed tomography of the heart in 1064 women aged 50 to 59 years at randomization. Imaging was conducted at 28 of 40 centers after a mean of 7.4 years of treatment and 1.3 years after the trial was completed (8.7 years after randomization). Coronary-artery calcium (or Agatston) scores were measured at a central reading center without knowledge of randomization status.

Results: The mean coronary-artery calcium score after trial completion was lower among women receiving estrogen (83.1) than among those receiving placebo (123.1) (P=0.02 by rank test). After adjustment for coronary risk factors, the multivariate odds ratios for coronary-artery calcium scores of more than 0, 10 or more, and 100 or more in the group receiving estrogen as compared with placebo were 0.78 (95% confidence interval, 0.58 to 1.04), 0.74 (0.55 to 0.99), and 0.69 (0.48 to 0.98), respectively. The corresponding odds ratios among women with at least 80% adherence to the study estrogen or placebo were 0.64 (P=0.01), 0.55 (P<0.001), and 0.46 (P=0.001). For coronary-artery calcium scores of more than 300 (vs. <10), the multivariate odds ratio was 0.58 (P=0.03) in an intention-to-treat analysis and 0.39 (P=0.004) among women with at least 80% adherence.

Conclusions: Among women 50 to 59 years old at enrollment, the calcified-plaque burden in the coronary arteries after trial completion was lower in women assigned to estrogen than in those assigned to placebo. However, estrogen has complex biologic effects and may influence the risk of cardiovascular events and other outcomes through multiple pathways.

NEJM, 2007, Volume 356:2591-2602


The article Explaining the Relation Between Birth Order and Intelligence by Petter Kristensen and Tor Bjerkedal (appearing in the journal "Science") seems to have got quite an amazing amount of press so I thought I should say a few words about it. I did not make any comment initially because I thought that it raised no new issues and was not in any way surprising.

To recap briefly, the authors did some very clever statistics on data from Norwegian army recruits which show pretty clearly that being a firstborn raises your IQ by a few points.

I think the reason the article has got such a lot of attention is that the political Left seizes on environmental causes of intelligence like a thirsty man in a desert. All the evidence is of an overwhelming genetic influence on IQ so anything that appears to "undermine" that will be highlighted -- given the traditional but vastly counterfactual Leftist belief in the infinite plasticity of human characteristics.

But the Norwegian findings don't in fact undermine anything. Although IQ is one of the human attributes that is most strongly influenced by genes, nobody has ever claimed that genes alone do the trick. It has always been known and asserted that environmental factors have a subsidiary role -- and stimulation in early childhood has long been agreed to be one of those subsidiary factors.

And firstborns get more attention and hence most stimulation. So a small advantage from being a firstborn was always to be expected.

Perhaps the most amusing part of the coverage given to the findings is the way that old scientific fraud, Frank Sulloway, has managed to insert himself into the discussion. Sulloway is a great advocate of birth order as an influence on human behaviour so I suppose it had to happen but Sulloway's own theory is that birth order determines your politics and, among social scientists, I think it is only the credulous who believe that these days. Sulloway's sustained attempts to block publication of evidence contradicting his theory probably tell you all you need to know about that.

Just a footnote: Did you know that your politics are even more heavily determined by your genetics than is how tall you are? Some people (Leftists) are just born crybabies. See Eaves, L.J., Martin, N.G., Meyer, J.M. & Corey, L.A. (1999) Biological and cultural inheritance of stature and attitudes. In: Cloninger, C.R., Personality and psychopathology. Washington, D.C.: American Psychiatric Press. Pesky things, those genes!


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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