Tuesday, May 8, 2012

Modernity and Health

I wrote about this only a few posts ago, but some interesting studies have just come out in the past few days.

Study predicts 42 percent of Americans will be obese in 2030 (Washington Post)
In 2030, 42 percent of American adults will be obese, and about one-quarter of that group will be severely obese, a condition that shortens life and incurs large medical expenses, a new study predicts.

This view into the future is less ominous than one published four years ago that predicted that 51 percent of the population would be obese in 2030. Nevertheless, the trend fortells a huge drag on the health and economic welfare of the United States.
For men, obesity prevalence doubled but has changed little in the past eight years, with no difference between blacks, whites and Mexican Americans (which are the three groups for which there are good data). For white women, the obesity prevalence has not changed in 12 years. It has risen slightly in black women and Mexican American women, although that increase mostly occurred early in that 12-year period.

There are some exceptions to this general picture of stability.

Obesity is rising in higher-income men. Severe obesity is increasing in both sexes. It was 6.2 percent in women in 1999 and 8.1 percent in 2010. For men, it was 3.1 percent in 1999 and 4.4 percent in 2010.

Eric A. Finkelstein, a researcher at Duke University who led the new study, said that just in the past 50 years has it been possible for millions of people to be both sufficiently inactive and to have access to enough food to become severely obese.

“The world has changed in ways that allow people to be that overweight,” he said.
Only 42 percent?

Lack of contact with nature 'increasing allergies' (BBC)
A lack of exposure to a "natural environment" could be resulting in more urban dwellers developing allergies and asthma, research has suggested. Finnish scientists say certain bacteria, shown to be beneficial for human health, are found in greater abundance in non-urban surroundings. The microbiota play an important role in the development and maintenance of the immune system, they add.

"There are microbes everywhere, including in the built environment, but the composition is different between natural environments and human-built areas," explained co-author Ilkka Hanski from the University of Helsinki. "The microbiota in natural environments is more beneficial for us," he told BBC News.

"Urbanisation is a relatively recent phenomenon, and for most of our time we have been interacting in an area that resembles what we now call the natural environment," he said. "Urbanisation can be seen as a lost opportunity for many people to interact with the natural environment and its biodiversity, including the microbial communities."

While it was not possible to reverse the global trend of urbanisation, he said that there were a number of options. "Apart from reserving natural areas outside of urban areas, I think it is important to develop city planning that includes green spaces, green belts and green infrastructure," Dr Hanski suggested.

Another recent study also illustrated a link between the lack of green spaces and higher stress levels among people living in urban areas described as deprived. The study published in the journal Landscape and Urban Planning measured levels of cortisol, a hormone released in response to stress, found in residents' saliva.

"The stress patterns revealed by these cortisol samples were related to the amount of green space around people's homes," explained co-author Catharine Ward Thompson, director of the OPENspace Research Centre, based in Scotland. "We were actually surprised by the strong relationship between the two," she told BBC News.

Prof Ward Thompson said that the study provided an objective measure of stress associated by the lack of green spaces in urban areas. "We know that if you live near more green spaces, and you are from a deprived urban population, you are more likely to be healthier," she observed.

Researchers from OPENspace have also been involved in another study that looks at the wellbeing of people over the age of 65 and their ability to get out and about. The Inclusive Design for Getting Outdoors consortium (I'dgo) - involving scientists from the universities of Edinburgh, Heriot-Watt, Salford and Warwick - identified a direct link between the ease of getting outdoors and health and quality of life.

The study, involving 4,350 older people across the UK, found that good walkable access to local shops, services and green spaces doubled the chances of an older person achieving the minimum recommended amount of walking - 2.5 hours each week. "If you lived within 10 minutes of a park, then you were twice as likely to achieve the recommended minimum amount of physical activity."
Amish children are nearly immune to asthma and allergies (Daily Mail)
Researchers have long observed the so-called 'farm effect' -- the low allergy and asthma rates found among kids raised on farms -- in central Europe, but less is known about the influence of growing up on North American farms.

Holbreich, an allergist in Indianapolis, has been treating Amish communities in Indiana for two decades, but he noticed that very few Amish actually had any allergies. As studies on the farm effect in Europe began to emerge several years ago, Holbreich wondered if the same phenomenon might be found in the United States. He teamed up with European colleagues to compare Swiss farming children and non-farming children to Amish kids in Indiana.

Amish families, who can trace their roots back to Switzerland, typically farm using methods from the 1800s and they don't own cars or televisions.

The researchers surveyed 157 Amish families, about 3,000 Swiss farming families, and close to 11,000 Swiss families who did not live on a farm -- all with children between the ages of six and 12. They found that just five percent of Amish kids had been diagnosed with asthma, compared to 6.8 percent of Swiss farm kids and 11.2 percent of the other Swiss children.

Similarly, among 138 Amish kids given a skin-prick test to determine whether they were predisposed to having allergies, only 10 kids -- or seven percent -- had a positive response. In comparison, 25 percent of the farm-raised Swiss kids and 44 percent of the other Swiss children had a positive test, the researchers report in the Journal of Allergy and Clinical Immunology.

The study did not determine why the kids who grew up on farms were less likely to develop asthma and allergies, but other research has pointed to exposure to microbes and contact with cows, in particular, to partially explain the farm effect.

Drinking raw cow's milk also seems to be involved, Holbreich said.

The going theory is this early exposure to the diverse potential allergens and pathogens on a farm trains the immune system to recognize them, but not overreact to the harmless ones. As for why the Amish kids have even lower allergy and asthma rates than the other farming kids, 'that piece of the puzzle we really haven't explained,' Holbreich told Reuters Health.
Good thing the government is protecting us from raw milk. It might harm sales of Claritin.


  1. No lack of contact with microbes in India:


  2. Yikes! I've said before if you wanted to intentionally set up an experiment to breed antibiotic resistant bacteria, you couldn't do better than we're already doing.


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