Another major resource constraint will arise from the lack of water available for farming. Many nations, such as South Africa, are already ‘water stressed’, and the UN FAO report, which focuses on agriculture and food security, suggests that within 40 years many areas in the world will not have access to water for farming, which forms the backbone of the economies in developing nations, where 75 per cent of the population is poor, rural and dependent on agriculture for both food and income.

Development of a sustainable international  ‘ecosystem framework’, which will include land and water policy and focus on agricultural production, as suggested in the recent FAO issue paper, will help to develop a more holistic approach to nutrition for resource poor nations.

Sources: ‘Energy smart food for people and climate’ issue paper, UN FAO, November 2011 (click here >>); IRIN Global, humanitarian news and analysis, 28 November 2011.

There are now some signs that environmentalists and health professionals are beginning to take note of the synergies available in tackling climate change and human health. The Climate and Health Council (here >>) is a network of health professionals interested in this area (around 5,000 of whom, from over 70 countries, have signed a Pledge to protect health and call for a framework to control carbon emissions). The first ever Global Climate and Health Summit Summit (co-organised by the World Federation of Public Health Associations, the Climate and Health Council, Health Care Without Harm and the Nelson R. Mandela School of Medicine at the University of KwaZulu Natal, in partnership with the World Health Organization, the World Medical Association and the International Council of Nurses, among others) is being held on 4 December to coincide with COP17 (more information will be available here >>).

For tweets on health from COP17, follow Climate Health Connect on Twitter (here >>).

The voice of health professionals has been largely silent in the discussions to date, despite the substantial role that the sector can play in reducing carbon emissions – not only by saving money by reducing the environmental footprint of health facilities, but by promoting the clear win–wins for human health when working to mitigate climate change, with many of these potential gains relating to the major risk factors for NCDs:

• Transport is a major contributor to CO₂ emissions. Reducing the number of miles driven – substituting walking and cycling – is an obvious way in which human health could benefit from what appears to be a primarily environmental intervention. This will reduce air pollution (which contributes to the risk of CVD, COPD and lung cancer) and traffic accidents – each of which cause over 1 million deaths a year: mortality in cities with high levels of pollution exceeds that of relatively cleaner cities by 15–20%. And replacing car use with walking and cycling will also work to reduce levels of overweight and obesity.
• Diet also impacts both on our health and the environment. Meat and dairy production currently accounts for about a fifth of greenhouse gas emissions worldwide – and consumption may double by 2050 if current trends continue. Diets that are high in red meat are also unhealthy – consumption of red meat has been linked to many cancers (including bowel and breast cancer), and meat is high in saturated fats, which can contribute to other NCDs such as heart disease.
• Indoor air pollution, largely caused by open fires or traditional stoves, is not only an environmental hazard: it is responsible for around 2 million deaths annually, mostly in developing countries. It increases the risk of acute lower respiratory infections among young children, and is a major risk factor for COPD and lung cancer in adults, especially women. Finding less environmentally damaging options could also save millions of lives.

COP17 represents a huge opportunity that must not be squandered. ‘What is good for the planet is good for health’ is a message that has the potential to be a powerful political lever for policy-makers, bringing home the real impact that climate change will have on many billions of people.

Published in the New England Journal of Medicine, it assessed women who were in the US government ‘Moving to Opportunity’ programme between 1994 and 1998 in areas including Baltimore, Boston, Chicago, Los Angeles and New York City. The majority of the women were either black or Hispanic. 1,788 of the women were given housing vouchers that were only good in neighborhoods where the poverty level was less than 10 per cent; a further 1,312 were given vouchers that could be used anywhere; both groups also got counselling on moving. The remaining 1,398 women received neither vouchers nor counselling.

The follow-up study in 2008 to 2010 included height and weight measurements and blood-sugar levels over three months. Among obese women (BMI 30+), neighbourhood made no difference, but among those with BMI>35, the voucher to move into a wealthier neighbourhood seems to have had an impact:

• About 31 per cent of women who were offered a voucher (and, therefore, the opportunity to move to a better neighbourhood) had BMI>35, compared to 36 per cent who did not receive a voucher.
• 14.4 percent of the women who received a voucher had BMI>40, compared to 17.7 per cent of those who did not get a voucher.
• 20 per cent of the women who did not get a voucher had diabetes (glycated hemoglobin level of 6.5% or more), compared to 16.3 per cent in the group that were given the chance to move.

There are some caveats to the survey – notably that height/weight/blood sugar were not measured in the 1990s, that only about half of the vouchers for moving into lower-poverty areas were used, and most women in the study ended up moving to better neighbourhoods anyway. The association is described in the article as ‘modest but potentially important’.

Lead author, Jens Ludwig, commented that the results are ‘comparable to what you see from targeted lifestyle interventions or with providing people with medications to prevent the onset of diabetes’. Reasons for the improvements could include safer areas (which can reduce stress and facilitate exercise), easier access to health care, shops with healthier food.

Sources: Reuters, 19 October 2011; USA Today Online, 19 October 2011; New England Journal of Medicine, 20 October 2011: here >>

By putting a financial estimate on the benefit of green space, it is hoped that the benefits will be easier to factor into decisions around planning permission. The report found that the UK’s ecosystems, properly cared for, could add an extra £30 billion pa to the UK’s economy; if neglected, the cost would be more than £20 billion pa. The assessment will be used to inform in the forthcoming White Paper on the natural environment.

Caroline Spelman, the secretary of state for the environment, noted, ‘The assessment is a vital step forward in our ability to understand the true value of nature and how to sustain the benefits it gives us.’

Source: The Guardian, 2 June 2011.

While this does suggest that efforts such as ‘green gyms’ have particular value, there is still a lack of high-quality evidence, with a need for long-term large trials. Lead author of the study, Professor Michael Depledge, commented that the research ‘adds significant weight to the case for spending more time in the ntarual environment as members of the public and their clinicians fight to counteract the negative outcomes of modern living, such as obesity and depression. We look forward to conducting the further research and trials required to establish the evidence base for introduction of outdoor activity into general lifestyle to complement therapeutic intervention.’

Source: Science Daily, 5 February 2011.

Domestic indoor temperatures in the winter have been rising over the years in the UK, USA and other developed countries. Easy options give people more opportunity to work indoors, such as working from home and shopping online. Often, too, there are carefully regulated air-conditioning units in cars and public transport, as well as in workplaces.

It was explained in the study that reduced exposure to seasonal cold may have an effect on the human body’s energy expenditure – by minimising the need for the body to generate heat through natural mechanisms, energy expenditure is reduced. Cold temperatures make the body produce brown fat known as adipose tissue, which burns energy to create heat. Evidence from the study indicates that there was a significant lack of adipose tissue in those that spent most of their time in artificially heated surroundings.

The lead author of the study, Dr Fiona Johnson, said that health strategies that are looking at environmental factors such as diet and exercise should also look at heating as an aspect that influences weight gain. The authors did note, however, that direct evidence linking heating to weight gain needs to be directly tested in humans. It is also important that further research be conducted in realistic as well as experimental settings to establish more accurate connections. This could raise further possibilities for strategies to address obesity.

Source: Obesity Reviews, 24 January 2011; The Telegraph, 26 January 2011

The study found a consistent and compelling link between diabetes prevalence and concentrations of fine particulates of 0.1–2.5 nanometers (PM2.5), commonly found in exhaust fumes, haze and smoke. Diabetes prevalence increased by 1 per cent for every 10 microgram per m³ rise in PM2.5 exposure. This occurred in all areas in both years of the study (2004 and 2005).

Even in areas whose PM2.5 levels were well within the recommended EPA limits had diabetes prevalence rates varying by 20 per cent – i.e. counties with the highest exposure (though still within the EPA limits) had diabetes prevalence 20% higher than those with the lowest PM2.5 exposure. Coauthor Dr John Brownstein commented: ‘From a policy perspective, the findings suggest that the current EPA limits on exposure may not be adequate to prevent negative public health outcomes from particulate matter exposure.’

The researchers also noted that further study is needed, particularly into the inflammatory mechanisms in diabetes and the impact of PM2.5.

Source: Medical News Today, 2 October 2010.

Researchers at the London School of Hygiene and Tropical Medicine investigated the relationship between urbanisation and ethnicity with CVD risk markers in Kenya by conducting a cross-sectional population-based survey. The socio-demographic and lifestyle information gathered in the study revealed that there was a high prevalence of hypertension, obesity, diabetes and high cholesterol, particularly in urban areas. Other studies conducted in Africa confirm these findings, and urbanisation is therefore seen as being a major contributing factor in the rise of CVD.

The urban-rural differences in CVD risk markers could be explained by the differences in lifestyle factors such as diet and physical activity, as well as different ethnicities in Africa. Differences in ethnicity explain variations in body composition that influence important metabolic effects.

As the rise of non-communicable diseases are likely to exert more pressure on an already burdened primary health-care system, it is necessary to prevent the rise of CVD risk factors by improving health behaviour. Researchers stress on the need to explore the differences in CVD risk markers between ethnic groups, as it may help to clarify the epidemiology of these conditions.

Source: BMC Public Health 2010, 22 September 2010.

In order to reduce widening inequalities in this way, an alternative approach is population-wide CVD prevention – and there is increasing evidence that the population-wide approach can reduce inequalities. Actions taken include: legislating for smoke-free public spaces, banning dietary transfats, or halving daily dietary salt intake. Such strategies are generally effective and cost-saving. The authors of the study in PLoS Medicine, Capewell and Graham, conclude that screening and treating high-risk individuals represents a relatively ineffective CVD prevention approach – and one that typically widens social inequalities.

Source: PLOS Medicine, 24 August 2010.

In terms of preventing the continuation of this pattern, it is important to note that there was negligible difference in obesity and diabetes levels between recent migrants and older migrants who had moved to urban areas 10 years previously, suggesting an immediate adjusting period to urban lifestyles that should be targeted in prevention programmes. The study has proved very useful because, as Anoop Misra, director and head of the department of diabetes and metabolic diseases at the Fortis Hospitals in New Delhi, explained: ‘We have known earlier that migration has a profound impact on obesity and diabetes. But what is relatively new is risk imparted by migration from rural to urban areas.’

Source: SciDev.Net, 12 May 2010.