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June 30, 2009

Even obesity paradoxes can't "excuse" fatness

Junkfood Science's latest instalment in its series on the obesity paradox, that is, the disconnect between what we believe about being overweight and what the actual scientific evidence shows.
 
It also manifests itself in the knots researchers tie themselves into when trying to spin their own results so they give the "right message."
 
This study into the links between excess weight and increased risks of mortality was a null study. That means it found no such link. In fact, it found the opposite. So it was fun to see how this "inconvenient message" was spun in the associated press release and the media coverage of it.
Reporting research finding anything positive about fat is accompanied by disclaimers, caveats and every effort to minimize its significance. It’s even called an obesity paradox, perhaps hoping we’ll think it an anomaly, rather than where the strength of the evidence lies. You’ve probably caught the news stories about a Canadian study reportedly showing that people with “a few pounds,” who are “slightly overweight,” are carrying “a little extra weight,” have “excess pounds, but not too many,” and are “overweight but not obese” will “actually live longer than those of normal weight.” But that isn’t what this latest study found. It’s what the press release said it found.
So, what did the study actually find?

The results of this epidemiological study were published in Obesity, the journal of the Obesity Society. This study found that none of the relative risks associated with mortality they examined were tenable [explained here], except for one. Age. At age 65, the relative risks of dying rose to 44.35 times compared to age 25; and by age 75, relative risks are 119-fold. We should stop right there, as tenable correlations are the only ones that deserve our focus. But that wouldn’t have made a news story, so what followed was splitting hairs among the rest.

Looking at corrected BMIs, according to the breakdowns adopted by the world’s governments, the authors found that compared to ‘normal’ BMIs (18.5 up to 25):

● being overweight (BMI 25 up to 30) was associated with a 25% lower risk of dying

● being obese (BMI 30 up to 35, which includes about 80% of all obese people) was associated with a 12% lower risk of dying.

● And the risks associated with the most ‘morbidly obese’ (BMIs 35+) — the uppermost 3% of this Canadian cohort— were statistically the same as those with ‘normal’ BMIs. [RR=1.09 (0.86-1.39, 95% CI) versus RR=1.0.]

Go to Junkfood Science to read the full post. Unsurprisingly, (I would have thought), it is age that is the most tenable risk factor it seems!

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June 30, 2009

Does it really matter how your body measures up?

June 27, 2009

The Figure-Flaw Paradox: Does it really matter how your body measures up? Part 2

The “figure flaw paradox” is really a retake on the obesity paradox. As obesity has proven to be a poor measure of health or mortality risk, new renditions are being proposed. But the fallacies are the same.

We’ve encountered all sorts of spins trying to preserve the myths of the deadliness of fat — from claims that the studies only show a paradox with really old people to that being overweight might be okay but not obese — hoping we won’t actually read the studies to see that that’s not what they found. It’s unpopular to spread the news that most fat — most overweight, as well as most obese — people have lower risks for mortality than those with “healthy” weights; or that thin people, regardless of their age, fair the worst. Some discount the better outcomes among obese people by saying they get better healthcare than thinner people — something completely opposite of decades of documented discrimination against obese people in healthcare.

Full post at Junkfood Science

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June 22, 2009

And hands off my Turkey Twizzlers!

Bernard Matthews' Turkey Twizzlers frozen foods.

Truth be told, I had never heard of Turkey Twizzlers before or that tiresome bore Jamie Oliver's campaign against them. Sadly I don't think they are on sale in Australia.

But going by this photo all I can think at the moment is "yum, yum, I wish they were."

This comes from the Food & Health Skeptic:

Some wide ranging food skepticism from Britain

Extracted from "Global Warming And Other Bollocks: The Truth About All Those Science Scare Stories" by Professor Stanley Feldman and Professor Vincent Marks. It reprises most of what I have been saying on this blog

THERE ARE FEW 'BAD' FOODS

Received wisdom, repeated by many doctors and public health professionals, says we can remain fit and avoid disease by cutting out certain 'bad foods' from our diets. Indeed, it is variously claimed that 35-50 per cent of all cancers are caused by the food we eat.

But while they are despised by the culinary elite, readily available hamburgers, sausages and pizzas have provided good nutritional value for many low-income families, who in previous days could afford only low-protein, high-carbohydrate, high-fat meals such as bread and dripping, and chip butties.

In fact, fears about hamburgers and sausages in Britain are especially irrational. Most countries have a national dish based on minced or processed meat - and none is suffering from an epidemic of junk food-inspired illness. For example, meatballs are used in many guises in the Middle East, chopped meat on a bed of onions is a national dish in the Balkans, and mince is also used in countless Italian sauces.

The terrines and pâtés of France and Belgium also contain processed chopped meat. Obesity is not caused by these foods, but by those who choose to gorge on them. Studies claiming to show the negative impact of a 'junk food' diet usually have little scientific validity.

ORGANIC FOOD IS NO BETTER FOR YOU

A widespread belief has emerged that organic foods are better for you than others because they do not contain 'chemicals' used in large- scale conventional farming.

This dogma is wrong. All plant nutriment comes from the air, in the form of CO2, and from water-soluble chemicals in the soil. The composition of these chemicals is the same, whether they come from a plastic bag or from 'natural' manure or compost. They are certainly the same by the time they are on your plate.

THERE'S NO NEED TO CUT BACK ON SALT

Salt is an essential food. Without it, we would die. Land-based mammals-such as humans control their body temperature by sweating and panting. Sweating is impossible without sufficient salt. In fact, strenuous exercise in a person depleted of salt causes overheating and death.

The Government has caved in to the anti-salt zealots in its advice to reduce salt intake. However, there is, in fact, very little, if any, truly scientific evidence that cutting back on it will do you any good.

TURKEY TWIZZLERS ARE FINE

The much-disparaged Turkey Twizzler, bugbear of TV chef Jamie Oliver, is made of recovered turkey meat and provides the same amino acids as normal turkey breast.

Corned beef, now an unfashionable meat product, is also no less nutritious than any other beef, although, like Turkey Twizzlers, it is also a reclaimed meat product.

Turkey Twizzlers are fine: The recovered meat provides the same amino acids as regular turkey breast meat

WE DON'T KNOW WHAT CAUSES HEART DISEASE

The medical (and social) consensus is that cardiovascular disease is caused by being overweight, by having a high-fat, high-cholesterol diet and by unhealthy activities such as smoking.

While being morbidly obese, eating nothing but lard and smoking 60 a day will probably lead to an early grave, there is nevertheless a lot of confusion about the precise link between lifestyle and this, the biggest killer of all.

Many people with high cholesterol levels in their blood do not get heart disease. Many people with very low levels do.

The very low levels of heart disease recorded in some populations, notably the Japanese, may have more to do with cultural variation and prejudice than with medical reality (in many societies, what are, in fact, heart attacks are often listed on death certificates as 'strokes').

Furthermore, some of the lowest levels of cholesterol and arterial sclerosis are to be found in populations such as the Inuit and Siberian hunter-gatherers, who live on a diet which is incredibly high in saturated fat.

TAKE HEALTH ADVICE WITH A PINCH OF SALT

Everything seems to be bad for you these days, but there is also plenty of scientific evidence to the contrary. Eggs seldom contain salmonella, even if some chickens do. Cholesterol in the diet does not cause fatty deposits in your arteries. There is probably little difference between the effect of saturated and unsaturated fats.

In those with normal kidney function, salt does not cause high blood pressure. Those with a body-mass index of between 25 and 32 live as long as or longer than those with a lower BMI. And avoiding the sun causes vitamin D deficiency; a suntan is nature's natural sun block, although sunburn is to be avoided.

MERCURY FILLINGS ARE PROBABLY HARMLESS

Anti-mercury campaigners believe that the mercury used in dental fillings will make you ill (mercury is a potent poison).

But a single amalgam filling provides just 0.03 micrograms/day of mercury, which is almost 3,000 times less than the safety level permitted for persons with occupational exposure to mercury, and is too small to be responsible for any symptoms.

SOURCE

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Filed under  //   diet   fat   health   health panics   heart disease   mercury fillings   obesity   organic food   salt  

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June 20, 2009

Can fat be good for you? Part 2

Continuing Junkfood Science's series on peer-reviewed research into fat, diet and health that has produced some surprising and counter intuitive results.
 
Though for those who keep an eye on the results of the good quality science, and not the pseudo-scientific epidemiological rubbish to underpins so much of the scare campaigns and hysteria surrounding our food, this will not come as a surprise at all.
 
The series is called Paradoxes compel us to think.
 
It's a long post, but worth a read. Here are the concluding paragraphs:

The adult years are characterized by a gradual and persistent physiologic increase in body weight, leading researchers to suggest that this age-related natural phenomenon may be protective and a major force in human longevity. The typical American adult gains 3–5 kg per decade beyond the age of 20 years, which translates into about 10–15 kg [22-33 pounds] between the third to fifth decades. The clinical research of Dr. Andres found that the fewest deaths occurred in those whose weights increased as they aged. Given the protective, fertility, immunological and nurturing benefits of fat stores, it is not surprising that the preponderance of medical research has failed to support beliefs that midlife weight gain is harmful to healthy women and men. With age, fat cells have also been shown to become less metabolically active, lessening their role in diseases associated with aging like diabetes.

“It’s acceptable, possibly even highly beneficial, for normal, healthy adults to gain gradually about a pound a year beginning around age 40,” said Dr. Andres in Food & Nutrition Digest, “so that by the time they’re in their 60s they weigh about 20 pounds more than the Met Life tables would suggest.”

The possible healthfulness of natural weight gain with aging, however, is a paradoxical idea in popular media. People may never think to question their beliefs about the deadliness of fat and benefits of weight loss when they never hear anything different.

The importance of research finding seeming paradoxes is that it make us think, question and not be afraid to learn where the evidence might really take us.

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June 13, 2009

Can fat be good for you?

Interesting research that went largely ignored by the media.
 
Sandy at Junkfood Science begins a four part series looking at recently published research that challenges the fashionable notions about fat and obesity.
 
In a nutshell, the research found that amongst its study group, it was men of so-called "normal" weight that had higher mortality rates.
Researchers, led by Dr. Paul McAuley with the Department of Human Performance and Sport Sciences at Winston-Salem State University in North Carolina, set to test the hypothesis that high cardiovascular fitness and high BMI were associated with a lower risk for death among healthy older men. As they noted, most studies, and the strongest ones, point to an inverse relationship between BMI among mature adults and mortality, with obesity having a protective role. Obesity’s survival advantage among patients with a wide range of diseases and health problems has also been especially well documented in the medical literature. Could being fat be associated with lower risk for premature death among healthy adults, and is fitness an independent risk factor?
Given the hysterical moralising about fat and obesity that we are subjected to these days, the findings may surprise you:
Among 981 healthy older men, 208 died during 6.9 years of follow-up. Compared to the reference ideal of a “healthy” BMI (20-24.9), men who were overweight were associated with a 34% lower risk for all-cause mortality, while the obese men (regardless of the degree of obesity) were associated with a 44% lower risk. In contrast, men with BMIs under 20 had more than a two-fold higher risk for premature death. When cardiovascular fitness was controlled for (as measured by MET = 3.5 mL/kg/min oxygen uptake on exercise tests), the slim men with BMIs below 20 were associated with an even higher 2.5 fold higher risk for premature death. Meanwhile, the most obese men had the lowest risk for all-cause mortality of all, at less than half (HR= 0.44) the “normal” weight men. As the authors noted, none of these correlations were significant. However, they do help to dispell popular beliefs about the deadliness of being fat as we age.
You can read the full post here.
 

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May 14, 2009

Does this kid look fat to you?

 
Dr John Ray asks the pertinent question here - when "will this totally unscientific mania ever fade?"
 
He reproduces an article from The Telegraph (see at the end of this post) that perfectly highlights the madness that wellness and healthy lifestyle programs are producing.
 
Let's be clear about this. These programs are often not based upon sound science.
 
They now form the basis for government advertising, both here and in Great Britain, that can only be described as a largely pointless waste of tax dollars that could have been spent productively elsewhere.
 
There is no credible evidence to support the claim that even if he were overweight he would be at greater risk of cancer later in life.
 
None at all. The high quality properly randomised double-blind trials have found no such linkage between diet, overweight and cancer.
 
The false claim that there is a link rests solely on a number of poor quality epidemiological studies with weak findings.
 
But the problem is that matters of health have been taken over by a collection of "moral puritans" and "moral entrepreneurs" who have been conducting a crusade against fat. I'm not saying that fat and diet is completely irrelevant to health, rather that this debate has become decoupled from the actual evidence and is not being driven by the evidence.
 
So it is interesting to see that The Australian and the Weekend Australian Magazine have now blown the lid on the fake childhood obesity epidemic here in Australia.
 

It’s easy to lie with statistics, graphs and scary marketing, and even to get people to believe the opposite of reality, such as in an epidemic of obese, unhealthy and sedentary children. As alarming claims are repeated and the most extreme examples are depicted as representative of the crisis, few people stop to question how a statistic is being defined.

With today’s new definition of “overweight” (children ≥95th percentile on new BMI growth curves, also called “obese” depending on the author), a mere 5 pounds makes the difference between a first grader being labeled as “normal” or “obese.” Even doctors are unable to recognize the children who meet the definition and few people understand what most “obese” and “overweight” children really look like. If they did, of course, they’d realize how incredible the claims of a crisis really are.

 

 
(It'll be worth your while following the embedded links in that quote.)
 
There are going to have to be some hard questions asked of health academics and government health agencies who have actively promoted this myth, even when any sober consideration of the evidence should have made it clear that there was something terribly wrong with it.
 
The crucial question here is how is it possible for bad ideas, poorly supported by hard evidence, to take over whole areas of science and public policy and become moral crusades, not carefully thought through and considered policy decisions?
 
For this I would yet again refer people back to the article by John Tierney, the science writer for The New York Times, entitled Diet and Fat: A Severe Case of Mistaken Consensus, and its notion of informational cascades.
 
Briefly, this is the process where the loudest voices and not the evidence take over a topic. These voices, because they seem authoritative and most of us don't have the time or the ability to do our own research, accept what others think about an issue and everybody proceeds on that assumption.
 
Then this becomes entrenched as an orthodoxy and to speak against it carries the threat of being denounced as a "heretic."
 
This is what happened with our understanding of diet, fat and health.
 
The loud voices convinced other academics who didn't bother to look very deeply at the claims being made, and then the bureaucracy and politicians came on board, deciding that "something had to be done" and it was their responsibility to do it.
 
So it got to the point where other scientists would appear before Congressional committees in the US to try and explain why the concern about fat may not in fact be supported by good evidence, only to be ridiculed and derided as enemies of the public good.
 
And woe unto them if they had ever done any work of any kind for the food industry at any time. Then they were pilloried as the paid stooges of big business, putting the interests of money ahead of people's health and well being.
 
A kind of McCarthyism prevailed.
 
It is now dawning on some people that they were probably also right.
 
The Telegraph's article:
 
 

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