Fluoridation of drinking water supplies: tapping into the debate

This article originally appeared on the OUPblog on 6 March 2014: http://blog.oup.com/2014/03/fluoridation-drinking-water-supplies/

Karen Blakey and Richard J.Q. McNally

Since their introduction in the United States in the 1940s, artificial fluoridation programmes have been credited with reducing tooth decay, particularly in deprived areas. They are acknowledged by the US Centers for Disease Control and Prevention as one of the ten great public health achievements of the 20th century (alongside vaccination and the recognition of tobacco use as a health hazard). Such plaudits however, have only gone on to fuel what is an extremely polarised ‘water fight’. Those opposed to artificial fluoridation continue to claim it causes a range of health conditions and diseases such as reduced IQ in children, reduced thyroid function, and increased risk of bone cancer. Regardless of the controversy, the one thing that everyone agrees upon is that little or no high quality research is available to confirm or refute any public concerns. Continue reading “Fluoridation of drinking water supplies: tapping into the debate”

Metabolomic markers of aging

This article originally appeared on the OUPblog on 26 October 2013: http://blog.oup.com/2013/10/metabolomic-markers-of-aging/

Ana M. Valdes

Aging is a complex process of accumulation of molecular, cellular, and organ damage, leading to loss of function and increased vulnerability to disease and death. Lifestyle choices such as smoking and physical fitness can hasten or delay the aging process. This has led to the search for molecular markers of age that can be used to predict, monitor, and provide insight into age-associated decline and disease.

Metabolomics is a novel technology that entails the simultaneous study of numerous low-molecular weight compounds, called metabolites. The aim is to profile all low-molecular weight metabolites that are present in biological samples. Metabolites represent intermediate and end products of metabolic pathways that rapidly reflect physiological dysfunctions and may mirror early stages of a pathological process. Continue reading “Metabolomic markers of aging”

John Snow and cholera: how myth helped secure his place in history

Sandra Hempel

This article originally appeared on the OUPblog on 6 May 2013: http://blog.oup.com/2013/05/john-snow-bicentenary-cholera/

The high-profile marking of John Snow’s bicentenary on the fifteenth of March would have surprised the great man. The London School of Hygiene and Tropical Medicine, the WellcomeTrust, and The Lancet were among the august UK organisations to honour him with events including an exhibition, three days of seminars, and a gala dinner. The physician was also celebrated in the United States where he has a large fan base.

By the time of his death, on 16 June 1858 at the age of 45, Snow was convinced beyond doubt that his theory on the mode of transmission of epidemic cholera was correct but had little expectation that any credit would accrue to him. His friend, the Soho curate Henry Whitehead, said Snow predicted that he might not live to see the day when great cholera outbreaks were in the past — which was true — and also that his name would be forgotten when that day came, which was not. On the contrary, he is now widely regarded as the father of the science of epidemiology, with his life and work the subject of countless books, articles and web pages, while 200 years after his birth his legacy remains the focus of lively academic debate.

M0009238 John Snow, 1856.
John Snow, 1856. Credit: Wellcome Library, London. Wellcome Images Copyrighted work available under Creative Commons by-nc 2.0 UK.

Continue reading “John Snow and cholera: how myth helped secure his place in history”

Parents: does size matter?

Linsay Gray

This article originally appeared on the OUPblog on 31 October 2012: http://blog.oup.com/2012/10/parental-height-children-health/

What can the height of a person tell us about them and their children? Although determined to an extent by genes, the height of a fully grown man or woman can be considered as a ‘marker’ of the circumstances they experienced early in life. These childhood circumstances include illness, living conditions, diet, and maybe even stress. Such early life circumstances have been shown to be linked to health risks later in life. In fact, the height of an individual is also linked with their chance of developing chronic health conditions. Taller people are at lower risk of heart disease, for example.

But what about the height of their parents? One may wonder if that could have an effect? Evidence from studies of animals indicates that poor health which is caused by challenging circumstances during development early in life may be transmitted from generation to generation. Continue reading “Parents: does size matter?”

The demographic landscape, part II: The bad news

Jonathan Minton

This article originally appeared on the OUPblog on 19 September 2013: http://blog.oup.com/2013/09/demographic-landscape-bad-news/. It is reproduced here with updated figures and captions.

In the first part of this post, I showed how we used a classic mapping technique — contour plots — to explore the demographic landscape, examining the texture of the lives and deaths of billions of people from more than forty countries. Our maps showed how a third variable, mortality rates, varied against two others: age and time. Just as the coordinates of physical terrain are latitude and longitude, so the coordinates of mortality terrain are age and year, or age-time.

Previously, we saw how these contour maps highlighted the good news we found in demographic changes. Today we explore the bad news.

Period effects: The dinosaurs of the twentieth century

Our demography has been scarred by the two World Wars. In our maps these appear as two thin clusters of ovals, like onions that have been flattened then cut open. Topographically, these oval clusters show mortality risk jutting shard-like out of the lowlands of early adulthood like the kite-shaped plates of a stegosaurus. These are period effects, disruptions to the usual order. The bathtub-shaped age-specific mortality risks for the cohorts of men who had come of age by the onset of these wars had spikes in them. Women of the same age, though protected by patriarchal gender inequality from the front line, were still exposed to much of this additional risk, especially if they had the misfortune of having one’s home located in what turned into a battlefield. Continue reading “The demographic landscape, part II: The bad news”

The demographic landscape, part I: the good news

Jonathan Minton

This article originally appeared on the OUPblog on 18 September 2013: http://blog.oup.com/2013/09/demographic-landscape-good-news/. It is reproduced here with some updated figures and captions.

If demography were a landscape, what would it look like? Every country has a different geographical shape and texture, visible at high relief, like an extra-terrestrial fingerprint. But what about the shape and texture revealed by the demographic records of the people who live and die on these tracts of land?

Maps show the fingerprints of the physical landscape on a human scale, letting us see the forests for the trees, the regions for the forests, and the countries for the regions. They are powerful visualisation techniques, knowledge tools for comprehending enormity.

Our visualisations use a classic mapping technique, contour plots, to explore the texture of life and death of billions of people from more than forty countries. Continue reading “The demographic landscape, part I: the good news”

Trends in European life expectancy: a salutary view

David A. Leon

This article originally appeared on the OUPblog on 14 April 2011: http://blog.oup.com/2011/04/life-expectancy/

Making a difference to the health of populations, however small, is what most people in public health hope they are doing. Epidemiologists are no exception. But often caught up in the minutiae of our day-to-day work, it is easy to lose sight of the bigger picture. Is health improving, mortality declining, are things moving in a positive direction? Getting out and taking in the view (metaphorically as well as literally) can have a salutary effect. It broadens our perspectives and challenges our assumptions. Looking at recent trends in European life expectancy is a case in point.

Since 1950 estimated life expectancy at birth of the world’s population has been increasing. Initially, this was accompanied by a convergence in mortality experience across the globe—with gains in all regions. However, in the final 15 years of the 20th century, convergence was replaced with divergence, in part due to declines in life expectancy in sub-Saharan Africa. However, this global divergence was also the result of declining life expectancy in Europe. Home to 1 in 10 of the world’s population, and mainly comprised of industrialized, high-income countries, Europe has over 50 states. These include Sweden and Iceland that have consistently been ranked among the countries with the highest life expectancies in the world. But while for the past 60 years all Western European countries have shown increases in life expectancy, the countries of Central and Eastern Europe (CEE), Russia and other parts of the former Soviet Union have had a very different, and altogether more negative experience. Continue reading “Trends in European life expectancy: a salutary view”