Friday, April 8, 2016

Another Settled Science Bites the Dust

Full-fat milk 'may drastically reduce risk of diabetes' - study

"The 15-year study, in which researchers analysed the blood of 3,333 adults aged between 30 and 75, found that people with higher levels of dairy fat in their systems had as much as a 46 percent lower risk of diabetes than those who regularly consumed only low-fat foods.

The research team at Tufts Friedman School of Nutrition Science & Policy looked at data from the Nurses’ Health Study of Health Professionals.

“There is no prospective human evidence that people who eat low-fat dairy do better than people who eat whole-fat dairy,” said researcher Dr. Dariush Mozaffarian.

However, he cautioned that the research results were preliminary and shouldn't be taken as official guidance on diet: “The implications aren’t yet to tell people definitely to drink only whole milk and avoid skim milk,” he said.

However, speaking to Time he said: “In the absence of any evidence for the superior effects of low fat dairy, and some evidence that there may be better benefits of whole fat dairy products for diabetes, why are we recommending only low fat diary? We should be telling people to eat a variety of dairy and remove the recommendation about fat content.”

Dr. Susan Spratt, a diabetes specialist and assistant professor of medicine at Duke University School of Medicine, told CBS: "I think we now understand there are healthy fats and unhealthy fats; healthy carbohydrates and less healthy carbohydrates. And fat can improve satiety and that could reduce total calorie intake."
Dietary science is noticeably non-replicable. Plus, the guidelines are heavily lobbied by food industries. It's a wonder that sugar is not at the top of the official food pyramid, since it is in nearly everything.
The sugar conspiracy
In 1972, a British scientist sounded the alarm that sugar – and not fat – was the greatest danger to our health. But his findings were ridiculed and his reputation ruined. How did the world’s top nutrition scientists get it so wrong for so long?


"In 1980, after long consultation with some of America’s most senior nutrition scientists, the US government issued its first Dietary Guidelines. The guidelines shaped the diets of hundreds of millions of people. Doctors base their advice on them, food companies develop products to comply with them. Their influence extends beyond the US. In 1983, the UK government issued advice that closely followed the American example.

The most prominent recommendation of both governments was to cut back on saturated fats and cholesterol (this was the first time that the public had been advised to eat less of something, rather than enough of everything). Consumers dutifully obeyed. We replaced steak and sausages with pasta and rice, butter with margarine and vegetable oils, eggs with muesli, and milk with low-fat milk or orange juice. But instead of becoming healthier, we grew fatter and sicker.

Look at a graph of postwar obesity rates and it becomes clear that something changed after 1980. In the US, the line rises very gradually until, in the early 1980s, it takes off like an aeroplane. Just 12% of Americans were obese in 1950, 15% in 1980, 35% by 2000. In the UK, the line is flat for decades until the mid-1980s, at which point it also turns towards the sky. Only 6% of Britons were obese in 1980. In the next 20 years that figure more than trebled. Today, two thirds of Britons are either obese or overweight, making this the fattest country in the EU. Type 2 diabetes, closely related to obesity, has risen in tandem in both countries.

At best, we can conclude that the official guidelines did not achieve their objective; at worst, they led to a decades-long health catastrophe. Naturally, then, a search for culprits has ensued. Scientists are conventionally apolitical figures, but these days, nutrition researchers write editorials and books that resemble liberal activist tracts, fizzing with righteous denunciations of “big sugar” and fast food. Nobody could have predicted, it is said, how the food manufacturers would respond to the injunction against fat – selling us low-fat yoghurts bulked up with sugar, and cakes infused with liver-corroding transfats.

Nutrition scientists are angry with the press for distorting their findings, politicians for failing to heed them, and the rest of us for overeating and under-exercising. In short, everyone – business, media, politicians, consumers – is to blame. Everyone, that is, except scientists.

But it was not impossible to foresee that the vilification of fat might be an error. Energy from food comes to us in three forms: fat, carbohydrate, and protein. Since the proportion of energy we get from protein tends to stay stable, whatever our diet, a low-fat diet effectively means a high-carbohydrate diet. The most versatile and palatable carbohydrate is sugar, which John Yudkin had already circled in red. In 1974, the UK medical journal, the Lancet, sounded a warning about the possible consequences of recommending reductions in dietary fat: “The cure should not be worse than the disease.”

ADDENDUM:
The Science of Bad Science
"In a 2015 paper titled Does Science Advance One Funeral at a Time?, a team of scholars at the National Bureau of Economic Research sought an empirical basis for a remark made by the physicist Max Planck: “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.”

The researchers identified more than 12,000 “elite” scientists from different fields. The criteria for elite status included funding, number of publications, and whether they were members of the National Academies of Science or the Institute of Medicine. Searching obituaries, the team found 452 who had died before retirement. They then looked to see what happened to the fields from which these celebrated scientists had unexpectedly departed, by analysing publishing patterns.

What they found confirmed the truth of Planck’s maxim. Junior researchers who had worked closely with the elite scientists, authoring papers with them, published less. At the same time, there was a marked increase in papers by newcomers to the field, who were less likely to cite the work of the deceased eminence. The articles by these newcomers were substantive and influential, attracting a high number of citations. They moved the whole field along.

A scientist is part of what the Polish philosopher of science Ludwik Fleck called a “thought collective”: a group of people exchanging ideas in a mutually comprehensible idiom. The group, suggested Fleck, inevitably develops a mind of its own, as the individuals in it converge on a way of communicating, thinking and feeling.

This makes scientific inquiry prone to the eternal rules of human social life: deference to the charismatic, herding towards majority opinion, punishment for deviance, and intense discomfort with admitting to error. Of course, such tendencies are precisely what the scientific method was invented to correct for, and over the long run, it does a good job of it. In the long run, however, we’re all dead, quite possibly sooner than we would be if we hadn’t been following a diet based on poor advice."

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