Sunday, September 30, 2007



SOME SOPHISTICATED EPIDEMIOLOGY AT LAST

Medical research normally ignores the role of social class -- even though it is known to have important and complex effects on health. In the case below, however, the original research appeared in a Sociology journal, and sociologists are acutely aware of the importance of social class. So if we read the original article (Abstract given) we find that an effect which could easily be attributed to social class was not wholly so caused. Women who have babies early tend to be of lower social class and so it could be class which predisposes them to illness in later life. The authors in this case, however controlled statistically for social class and found an effect that went beyond class. But the study is after all an epidemiological one so WHY women who have babies earlier tend to die young we simply do not know. Any number of possibilities spring to mind, however. That women who have babies young tend to be risk-takers and risk-taking has many hazards would be one possible explanation

Early childbirth risky for women

Women who have their first child before the age of 20 are at a higher risk of chronic diseases and death when they reach middle age, a new study shows. The study, which appears in the September issue of the Journal of Health and Social Behavior , said that women who are single at the time they have their first baby could also be at risk of earlier death - an outcome that probably relates to socio-economic status later in life after having a child as a young, single woman. "Being unmarried at the time of first birth is associated with lower midlife income and a lower probability of being married in midlife," said study author John Henretta at the University of Florida. "It's not so much the characteristic of being unmarried at first birth that's important; it's what being unmarried at first birth tells us about the midlife status of these women."

Henretta evaluated data from the Health and Retirement Study, focusing on 4,335 women born in the United States between 1931 and 1941. These women were first interviewed in 1992 (at ages 51 to 61) and then followed until 2002. Interviewers were asked about their health, level of education, marital status, wealth, how many children they had and the age of each living child

Source

Journal Abstract:

Early Childbearing, Marital Status, and Women's Health and Mortality after Age 50

Author: Henretta, John C.

This article examines the relationship between a woman's childbearing history and her later health and mortality, with primary focus on whether the association between them is due to early and later socioeconomic status. Data are drawn from the Health and Retirement Study birth cohort of 1931-1941. Results indicate that, conditional on reaching midlife and controlling for early and later socioeconomic status, a first birth before age 20 is associated with a higher hazard of dying. In addition, having an early birth is associated with a higher prevalence of reported heart disease, lung disease, and cancer in 1994. Being unmarried at the time of the first birth is associated with earlier mortality, but this association disappears when midlife socioeconomic status is controlled. The number of children ever born does not significantly affect mortality but is associated with prevalence of diabetes.

Journal of Health and Social Behavior, Volume 48, Number 3, September 2007 , pp. 254-266(13)





Amusing: How is "junk food" defined?

Is salt better than sugar? Nonsensical though that enquiry is

A billion-dollar battle over selling sports drinks and "enhanced" water in public schools has spilled into Congress and threatens to derail a major attempt to cut back the sale of junk food from school vending machines and snack bars. Sen. Tom Harkin (D-Iowa) has introduced a bill that would have the government set new nutritional standards for the foods and drinks that schools sell to students outside cafeterias. But just what those standards should be is the issue, the Washington Post reports.

Public health advocates want the standards to ban the sale of Gatorade and Powerade, which typically contain as much as two-thirds the sugar of sodas and more sodium, as well as sweetened waters such as VitaminWater and SoBe Life Water. Excessive sodium intake by young people could fuel a surge in high blood pressure, which until recently was considered a health threat only in later life, they said, reports Post writer Jane Black.

The trade group representing Coca-Cola, Pepsi and other bottlers, whose annual sales of sports drinks reached $7.5 billion last year, counters that sports drinks and sweetened waters are lower in calories, "appropriate" for high school students and "essential" to young athletes. In 2006, sports drinks were the third fastest growing beverage category in the United States, after energy drinks, such as Red Bull, and bottled water, according to the trade journal Beverage Digest.

The current version of the legislation requires the Agriculture Department to begin developing the rules behind the standards, but industry and public health advocates both favor speeding things up by writing the standards into the legislation itself. Having agreed voluntarily to phase out full-calorie sodas from schools by 2009, bottlers are heavily promoting the sports drinks, and not just to athletes.

Harkin's bill, which he hopes to incorporate into this fall's farm bill, has been co-sponsored by 25 senators. More than 100 organizations, from the American Federation of Teachers to the Yale Prevention Research Center, support the plan. Eager to avoid bad publicity, even the Grocery Manufacturers Association and the American Beverage Association, which have historically resisted any regulation, say they are "open to discussing" federal standards to avoid a patchwork of state and county rules.

But the bottlers do not want the standards to prohibit sports drinks and enhanced waters. Without bottler support, it will be difficult to sign up members of the Senate Agriculture, Nutrition and Forestry Committee, which is chaired by Harkin but includes beverage industry supporters such as ranking Republican Saxby Chambliss, who represents Coke's home state of Georgia.

Nutrition experts contend that sports drinks are not as healthful as manufacturers claim. A 12-ounce bottle of Gatorade Rain contains 75 calories, 21 grams of sugar and 165 milligrams of sodium, compared with 150 calories, 40.5 grams of sugar and 52 milligrams of sodium in a can of Coke. [So it is saltier but less sweet]

Source

****************

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.


*********************

No comments: