Saturday, December 24, 2011

How the Mediterranean diet can add 3 years to your life... even if you don't start until you're 70 (?)

A load of old cobblers in the article below. Difficult to know where to start but I was amused to read in the journal abstract (also below) that they got their results by using "a refined version of the modified Mediterranean diet index". First you modify your index then you refine it to get the results you want, apparently.

I was however impressed that they went to great trouble to validate their diet questionnaire. Validation is routine in psychology but rare in medicine. None of the validation methods used would have distinguished Mediterranean from non-Mediterranean diets, however. The authors themselves admit the fallibility of their methods by excluding some "implausible" diet claims from their analysis. One wonders if some bias might have crept into that process.

Anyway, as usual, the results are explicable by social class. Middle class Swedes are more likely to say they eat the "correct" foods (whether they do or not) than working class ones are. And middle class people have better health anyway.

I note also that the failed but indestructible antioxidant theory is invoked.

And finally, how do they explain the fact that a traditional Australian diet is about as "incorrect" as you can get yet Australians live longer than Greeks? There are an amazing number of nonageneraians tottering around Australia who grew up on very fatty food accompanied by a few vegetables that had been boiled to death.

The traditional diet favoured in Greece, Spain and Italy provides a great health boost no matter when you switch. No one doubts that following a Mediterranean diet is the healthy option.

But researchers have calculated the regime could add an extra three years to your life. They say it is a rich source of chemicals called anti-oxidants that fight cancer, heart disease and can slow the ageing process.

Scientists who studied the eating habits of 1,200 over-70s found that those following a Mediterranean-style diet tended to live for two or three years longer. They examined surveys which had been carried out by all the adults on their eating habits.

This contained details of how much fruit, vegetables, cereals, meat and fish they ate as well as how much alcohol they drank.

Elderly men and women have been recruited for the rolling research programme since the 1970s. Those taking part were contacted by researchers every few years to find out about their general health.

The team from Sweden’s University of Gothenburg found participants whose eating habits followed a Mediterranean style diet were 20 per cent more likely to be alive eight years later. They calculated that on average these individuals lived for between two and three years longer than those who had a different eating regime.

The diet was inspired by traditional eating habits of Greece and Southern Italy, hence its name.

Does the Mediterranean diet predict longevity in the elderly? A Swedish perspective

By Gianluca Tognon et al.


Dietary pattern analysis represents a useful improvement in the investigation of diet and health relationships. Particularly, the Mediterranean diet pattern has been associated with reduced mortality risk in several studies involving both younger and elderly population groups. In this research, relationships between dietary macronutrient composition, as well as the Mediterranean diet, and total mortality were assessed in 1,037 seventy-year-old subjects (540 females) information. Diet macronutrient composition was not associated with mortality, while a refined version of the modified Mediterranean diet index showed a significant inverse association (HR=0.93, 95% CI: 0.89; 0.98). As expected, inactive subjects, smokers and those with a higher waist circumference had a higher mortality, while a reduced risk characterized married and more educated people. Sensitivity analyses (which confirmed our results) consisted of: exclusion of one food group at a time in the Mediterranean diet index, exclusion of early deaths, censoring at fixed follow-up time, adjusting for activities of daily living and main cardiovascular risk factors including weight/waist circumference changes at follow up. In conclusion, we can reasonably state that a higher adherence to a Mediterranean diet pattern, especially by consuming wholegrain cereals, foods rich in polyunsaturated fatty acids, and a limited amount of alcohol, predicts increased longevity in the elderly.

Age (Dordr). 2011 September; 33(3): 439–450.

Thursday, December 22, 2011

Debunking Myths about Gender and Mathematics Performance?

There is an amusing paper in the forthcoming JANUARY 2012 NOTICES OF THE AMS (American Mathematical Society) which purports to show that it is only oppression of women by society which causes females not to do well in mathematics.

The paper was of course zealous to rule out genetic differences but that does rather leave them without an explanation for Chinese excellence in mathematics. Regardless of the country in which they reside, Chinese tend to be prominent among leading mathematicians -- and China itself is a major centre of mathematical excellence. Yet China is still in many ways a very traditional society in which the very notion of gender equality would normally be scoffed at. The way they abort girl babies is surely enough evidence of that.

Anyway, the paper more or less assumes what it has to prove. In a rather self-contradictory way, the authors seem to assume that educational performance fully indexes innate ability. The paper draws its "evidence" not from IQ tests but from various international measures of educational attainment. And educational attainment is the product of many things other than IQ. Hard work anyone? Social pressures anyone? So I partially agree with the first line of their "Conclusions":
In summary, we conclude that gender equity and other sociocultural factors, not national income, school type, or religion per se, are the primary determinants of mathematics performance at all levels for both boys and girls

You note that they skate entirely over IQ.

They go on to argue that eliminating gender "inequities" is needed to lift female mathematical achievements. After decades of feminism and affirmative action it is hard to imagine how more might be done on that front in the USA other than by procrustean quota systems so the recommendation is as vacuous as it is irrelevant.

Women will always be up against their lower level of mathematical ability that IQ tests reveal so clearly. In recent years women have been pushed into mathematics to satisfy feminist dogma but few will rise to the heights.