Sunday, March 11, 2007


Conception harder if father overweight? See if you can see the old familiar omission in the report below

Women are not the only ones who need to watch their weight if they want to get pregnant. New research in Human Reproduction this week shows that if both partners in a couple are overweight or obese, they are likely to have a longer wait before successfully conceiving a child.

Researchers studied 47,835 Danish couples who had a child between 1996 and 2002, calculating their body mass index (BMI) as weight in kilograms divided by squared height in metres. In this group, 6.8 per cent of men and 8.2 per cent of women were obese (BMI of 30 or more), and there were 1.4 per cent of couples where both partners were obese. Fifty-three per cent of men and 68 per cent of women were of normal weight. If both partners were obese the couple was nearly three times more likely to wait more than a year for pregnancy to occur than a normal weight couple. If both partners were merely overweight (BMI between 25 and 29.9), they were 1.4 times more likely than a normal weight couple to wait longer than a year.


Journal abstract:

Subfecundity in overweight and obese couples

By C.H. Ramlau-Hansen et al.

BACKGROUND: Recent studies indicate that not only women's but also men's obesity has adverse effects on fecundity and since fecundity is a couple concept, we examined fecundity in relation to overweight and obesity of the couple. We also examined the association between weight changes and fecundity over time.

METHODS: Between 1996 and 2002, 64,167 pregnant women enrolled in the Danish National Birth Cohort were interviewed during and 18 months after pregnancy. Information on body mass index (BMI) and waiting time to pregnancy (TTP) was available for 47,835 couples.

RESULTS: Among men and women with a BMI of 18.5 kg/m-2 or more, we found a dose-response relationship between increasing BMI group and subfecundity (a TTP of more than 12 months): Odds ratio (OR) = 1.32 (95% CI: 1.26-1.37) for women and OR = 1.19 (95% CI: 1.14-1.24) for men. Among 2374 women with an initial BMI of 18.5 kg/m-2 or more, who participated more than once in the Danish National Birth Cohort, each kilogram increment in weight between the two pregnancies was associated with a 2.84 (95% CI: 1.33-4.35) days longer TTP.

CONCLUSIONS: Couples have a high risk of being subfecund if they are both obese.

So WHY do fat fathers take longer to father children? Do they have fatter sperm? Only Trofim Lysenko would think so. What the study overlooks is, as usual, social class. Working class people tend to be fatter and have more health problems. So a study that lacks an apparent causative mechanism acquires a very obvious one once we realize that. The study is yet another demonstration that working class (fatter) people have poorer health -- and so they also have lower sperm counts, more aspermia, more azoospermia, lower libido etc, etc. And the fatter women became over time (again likely to be class related and hence health related), the more trouble they had in getting pregnant. Yawn!

Vitamins 'reduce infant cancers'

Within 5 years we will of course hear that some of the vitamins concerned are harmful to babies or their mothers. The all-singing, all dancing folate story is already beginning to unwind

Women have been advised to take multivitamin supplements during pregnancy, after a new study found those who do so slash the risk that their babies will develop any of the three main types of cancer affecting young children.

Folic acid supplements - a Bgroup vitamin - are already recommended before and during early pregnancy, to reduce the risk of the baby being born with spina bifida, a defect in the development of the spinal cord. But a meta-analysis by Canadian researchers of seven previous studies, published online by the journal Clinical Pharmacology & Therapeutics, found taking multivitamins including folic acid during pregnancy also cut the risk of leukemia by 36 per cent. In addition, the risk of the baby developing neuroblastoma, a cancer of the adrenal gland or spinal nerves, was slashed by 47 per cent, and the risk of paediatric brain tumours was cut by 18 per cent.

The three types of cancer are the most common malignancies to affect children. In Australia, one child in 600 develops cancer, with leukemia the most common, at 30 per cent of cases. Brain tumours account for a further 20 per cent of childhood cancers, and neuroblastoma 7 per cent.

The study's authors said the findings suggested that if women took multivitamin supplements, 900 cases of child leukemia and 300 to 400 cases of pediatric brain tumours could be prevented every year in the US alone. "Given that women who are considering pregnancy are generally advised to supplement with folic acid, the results from this study suggest that supplementation with a folic-acid-containing multivitamin may be a preferred method," the study concluded.

The authors said they could not be sure which vitamins or minerals in the supplements were responsible for the lower cancer rates. Geoffrey McCowage, a pediatric oncologist at the Children's Hospital at Westmead in Sydney, said the findings would have "very significant implications" if confirmed by further research. While neuroblastoma accounted for only 7 per cent of childhood cancers, in 70 per cent of cases the disease was very difficult to treat - so an effective prevention method would have a huge impact, Dr McCowage said. "If this study were confirmed in further studies, it would have very significant implications for efforts to decrease the risk of childhood cancer," he said. The latest findings "would support taking a multivitamin that contained folate" during pregnancy.



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.