Tuesday, August 17, 2010

Another irresponsible epidemiological speculation: Eating red meat increases risk of heart disease

Retrospective self-reports! How weak can data get? And in any case have they ever heard that correlation is not causation? All that the findings most likely show is that middle class women report more "correct" diets. What they actually do is another thing

Eating red meat twice a day can increase a woman's risk of heart disease by nearly a third, a study has shown. The study found those who ate two servings of fresh or processed red meat daily were 30 per cent more likely to suffer heart disease than women who ate just half a portion.

Substituting red meat for a serving of nuts cut the risk of heart disease by 30 per cent, eating fish instead lowered the risk by 24 per cent, while swapping red meat for poultry slashed the risk by 19 per cent, the survey also found.

Researchers at the Harvard School of Public Health in Boston, in the U.S., studied the diets of 84,136 women aged 30 to 55 between 1980 and 2006. Participants were asked to complete a questionnaire saying how often they ate 116 different food items.

During the research period 2,210 suffered non-fatal heart-attacks, while 952 others died from coronary heart disease.

Study author Adam Bernstein said: 'Our study shows that making substitutes for red meat or minimising the amount of red meat in the diet has important health benefits.'


The chocolate merrygoround again: Good for you. Bad for you and so on ad infinitem

The finding makes no sense. Why do small variations in the amount eaten make a big difference? The finding looks like data dredging. They just picked out of a whole lot of data one small bit that tended to justify their nine years of work

It is the news millions of sweet-toothed women have been waiting to hear - a small chocolate treat helps lower the risk of heart failure. A study of middle-aged and elderly women who ate a small amount of chocolate no more than twice a week found they had a lower risk of heart failure.

Unfortunately, however, eating even a little chocolate every day did not have the same health benefits.

The nine-year study, involving 31,823 Swedish women, looked at the relationship between the amount of high-quality chocolate the women ate and their risk of heart failure. The quality of chocolate eaten by the women had a higher density cocoa content.

The researchers found that women who ate an average of one to two servings of the high-quality chocolate per week had a 32 per cent lower risk of developing heart failure.

Those who had one to three servings per month had a 26 per cent lower risk, but those who ate at least one serving daily or more did not appear to benefit from the protective effect against heart failure.

Lead researcher Dr Murray Mittleman said the lack of a positive effect among women eating chocolate every day was probably due to the additional calories consumed.

Dr Mittleman, director of the Cardiovascular Epidemiology Research Unit at Harvard Medical School's Beth Israel Deaconess Medical Centre in Boston, said: 'You can't ignore that chocolate is a relatively calorie-dense food and large amounts of habitual consumption is going to raise your risks for weight gain. 'But if you're going to have a treat, dark chocolate is probably a good choice, as long as it's in moderation.'

High concentration of compounds called 'flavonoids' in chocolate may lower blood pressure, among other benefits, according to mostly short-term studies. However, this is the first research to show long-term outcomes related specifically to heart failure, which can result from ongoing untreated high blood pressure.

In the observational study, researchers analysed self-reported food-frequency questionnaire responses from participants aged between 48 and 83.

Combining the results with data from national Swedish hospitalisation and death registries between 1998 and 2006, the researchers used multiple forms of statistical modelling to reach their conclusions.

Dr Mittleman said differences in chocolate quality affect the study's findings - higher cocoa content is associated with greater heart benefits. He added: 'Anything that helps to decrease heart failure is an important issue worth examining.'

However, Dr Linda Van Horn, former chair of the American Heart Association Nutrition Committee and professor in the Department of Preventive Medicine at Northwestern University's Feinberg School of Medicine in Chicago, said: 'Those tempted to use these data as their rationale for eating large amounts of chocolate or engaging in more frequent chocolate consumption are not interpreting this study appropriately.

'This is not an "eat all you want" take-home message, rather it's that eating a little dark chocolate can be healthful, as long as other adverse behaviours do not occur, such as weight gain.'


1 comment:

Anonymous said...

Weight gain is not a behaviour it is the consequence of one or more behaviours. If these people have as much trouble interpreting their findings as they do using the English language then ignoring them is probably the best strategy. I am also concerned that they appear unaware of the entire concept of dose. Just what exactly do these people have degrees in?