THAT MAGICAL VITAMIN D AGAIN

The popular report immediately below is much less cautious than the original journal article, also reproduced. It would appear that the effects are small and the type of data weak

Note that Vitamin D has also recently been shown to be bad for you. Note also here, where antioxidants generally were found to be bad for you.

Children given vitamin D supplements have a lower risk of developing type 1 diabetes, says a study in the Archives of Disease in Childhood. Type 1 diabetes is when the body's immune system attacks and destroys cells in the pancreas that produce insulin. Without insulin, cells are unable to take up sugar from the blood that they need to function properly. The authors combined information from five studies looking at the effect of vitamin D supplements on the risk of type 1 diabetes. Overall, children given extra vitamin D in the form of tablets or cod liver oil were 29 per cent less likely to develop type 1 diabetes compared to children who were not given supplements. The higher and more regular the dose, the lower the chances of developing the disease. Clinical trials are now needed, say the authors, to find out which form and dose of vitamin D gives the best protection, and at what age it should be given to children.

Source

Vitamin D Supplementation in Early Childhood and Risk of Type 1 Diabetes: a Systematic Review and Meta-analysis

By Christos S. Zipitis et al.

Objectives: To assess whether vitamin D supplementation in infancy reduces risk of type 1 diabetes in later life.

Design: Systematic review and meta-analysis. Data sources: Medline, Embase, Cinahl, Cochrane Central Register of Controlled Trials and reference lists of retrieved articles.

Main outcome measure: Development of type 1 diabetes.

Inclusion criteria: Controlled trials and observational studies which had assessed the effect of vitamin D supplementation on risk of developing type 1 diabetes.

Results: Five observational studies met the inclusion criteria; no randomised controlled trials were found. 4 of the 5 included studies were case control studies and the fifth study was a cohort study. Meta-analysis of data from the case control studies showed that the risk of type 1 diabetes was significantly reduced in infants who were supplemented with vitamin D compared to those who were not supplemented (pooled odds ratio 0.71, 95% CI 0.60 to 0.84). The result of the cohort study was in agreement with that of the meta-analysis. There was also some evidence of a dose-response effect, with those using higher amounts of vitamin D being at lower risk of developing type 1 diabetes. Finally, there was a suggestion that the timing of supplementation might also be important for the subsequent development of type 1 diabetes.

Conclusion: Vitamin D supplementation in early childhood may offer protection against the development of type 1 diabetes. The evidence for this is based on observational studies. Adequately powered, randomised controlled trials with long periods of follow-up are needed to establish causality and the best formulation, dose, duration and period of supplementation.

Arch Dis Child. 13 March 2008







Passive smoking

I personally detest having the air I breathe polluted by tobacco smoke. It once used to happen a lot but is now rare because of the various prohibitions on smoking that have gradually been legislated throughout the Western world. I am extremely grateful about that.

The prohibitions were gradually put in place on the back of a claim that exposure to smoke from others is bad for your health. I think there is now a widespread recognition that such a claim is rubbish. I believe that the bans were justifiable as just another curb on offensive behaviour but they are not justifiable on medical grounds. We now see a similar dishonest attack on obesity. Obesity is aethetically offensive but to curb it you have to pretend that it is medically harmful. It is not.

So just for the record I reproduce below a background article on the passive smoking plus the abstract of what is probably the most solid of the research on passive smoking. It involved a very large number of people over a very long period of time and found no significant effect of passive smoking. I understand that the authors encountered difficulty in getting the paper published, due to its unpopular conclusions.

All done with passive smoke and mirrors

Anti-smoking activists can celebrate today one of the most remarkable lobbying campaigns in modern politics. The statutory no-smoking signs outside every "enclosed public space", including churches, synagogues, mosques and Buckingham Palace, will always remind us how they find the smell of other people's smoke offensive. One thing they cannot claim, though, is that protecting people from others' smoke will save thousands of lives.

The scientific evidence to support their belief that inhaling other people's smoke causes cancer simply does not exist. In the course of writing a book on "scares", I recently trawled through all the scientific literature on the health risks of tobacco, ever since Richard Doll's seminal paper in 1950 alerted the world to the link between smoking and lung cancer (when 82 per cent of British men were smokers). Over the next 30 years, the realisation that smokers risked serious damage to their health led to a 50 per cent drop in the habit. But this divided people into three groups: more or less addicted smokers, generally tolerant non-smokers and fiercely intolerant anti-smokers.

At the end of the Seventies, the anti-smokers first seriously turned their attention to what they called "passive smoking". Over the next decade, it is fascinating to follow how, try as they might, they could not come up with the evidence they wanted to prove that "environmental tobacco smoke" was directly harming non-smokers' health. They became greatly excited by a series of studies which purported to show a link between smoking and cot deaths. But these somehow managed to ignore the fact that, in the very years when cot deaths were rising by 500 per cent, the incidence of smoking had halved.

A further series of studies in the Nineties, mainly in the US, claimed to have found that passive smoking was causing thousands of deaths a year. But however much the researchers tried to manipulate the evidence, none could come up with an increased risk of cancer that, by the strict rules of epidemiology, was "statistically significant".

In 1998 and 2003 came the results of by far the biggest studies of passive smoking ever carried out. One was conducted by the International Agency for Research on Cancer, part of the World Health Organisation. The other, run by Prof James Enstrom and Geoffrey Kabat for the American Cancer Society, was a mammoth 40-year-long study of 35,000 non-smokers living with smokers. In each case, when the sponsors saw the results they were horrified. The evidence inescapably showed that passive smoking posed no significant risk. This confirmed Sir Richard Doll's own comment in 2001: "The effects of other people's smoking in my presence is so small it doesn't worry me".

In each case, the sponsors tried to suppress the results, which were only with difficulty made public (the fact that Enstrom and Kabat, both non-smokers, could only get their results published with help from the tobacco industry was inevitably used to discredit them, even though all their research had been financed by the anti-tobacco cancer charity).

In the early years of this decade, the anti-smokers had become so carried away by the rightness of their cause that they no longer worried about finding disciplined evidence for their statistical claims. One notorious but widely-quoted study commissioned by 33 councils campaigning for a "smoke-free London" came up with the wonderfully precise claim that 617 Britons die each year from passive smoking in the workplace. No longer was there any pretence at serious debate. This was a propaganda war, in which statistics could be manufactured at will. (The European Commission's 2006 figure for annual deaths from passive smoking in the UK was around 12,000, some 20 times higher than the figure quoted by the British Government itself.)

By the time the Commons pushed through the smoking ban in February 2006, a kind of collective hysteria had taken over. MPs fell over themselves in boasting how many lives they were about to save. One Department of Health official was quoted as equating its significance to the Act setting up the National Health Service in 1948.

As clouds of self-righteousness billow out over England this weekend, the anti-smokers may be entitled to give us their view that smoking is a thoroughly noxious and nasty habit, even that it can exacerbate respiratory conditions such as asthma or bronchitis arising from other causes. They can even claim that the ban will save lives by persuading smokers to give up. But the one thing they cannot claim is any reliable evidence for their belief that passive smoking is responsible for killing people. Sir Richard Doll was right. It is merely a sanctimonious act of faith.

Source

And the most significant scientific report:

Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98.

By Enstrom JE & Kabat GC.

School of Public Health, University of California, Los Angeles, CA 90095-1772, USA. jenstrom@ucla.edu

OBJECTIVE: To measure the relation between environmental tobacco smoke, as estimated by smoking in spouses, and long term mortality from tobacco related disease.

DESIGN: Prospective cohort study covering 39 years.

SETTING: Adult population of California, United States.

PARTICIPANTS: 118 094 adults enrolled in late 1959 in the American Cancer Society cancer prevention study (CPS I), who were followed until 1998. Particular focus is on the 35 561 never smokers who had a spouse in the study with known smoking habits.

MAIN OUTCOME MEASURES: Relative risks and 95% confidence intervals for deaths from coronary heart disease, lung cancer, and chronic obstructive pulmonary disease related to smoking in spouses and active cigarette smoking.

RESULTS: For participants followed from 1960 until 1998 the age adjusted relative risk (95% confidence interval) for never smokers married to ever smokers compared with never smokers married to never smokers was 0.94 (0.85 to 1.05) for coronary heart disease, 0.75 (0.42 to 1.35) for lung cancer, and 1.27 (0.78 to 2.08) for chronic obstructive pulmonary disease among 9619 men, and 1.01 (0.94 to 1.08), 0.99 (0.72 to 1.37), and 1.13 (0.80 to 1.58), respectively, among 25 942 women. No significant associations were found for current or former exposure to environmental tobacco smoke before or after adjusting for seven confounders and before or after excluding participants with pre-existing disease. No significant associations were found during the shorter follow up periods of 1960-5, 1966-72, 1973-85, and 1973-98.

CONCLUSIONS: The results do not support a causal relation between environmental tobacco smoke and tobacco related mortality, although they do not rule out a small effect. The association between exposure to environmental tobacco smoke and coronary heart disease and lung cancer may be considerably weaker than generally believed.

Originally in The British Medical Journal, 2003;326:1057 (17 May). Also here

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

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].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

Even statistical correlations far stronger than anything found in medical research may disappear if more data is used. A remarkable example from Sociology:

"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."

So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

"What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!

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