You can read about the investigation Drs Jo Barton and Professor Jules Pretty from the University of Essex conducted into how a walk a day might keep the doctor away, in Environmental Science and Technology, where it appeared online on 25 March and will appear in print later this month.

Pretty, who is Professor of Environment and Society at Essex, told the media that:

“For the first time in the scientific literature, we have been able to show dose-response relationships for the positive effects of nature on human mental health.”

Barton, a Senior Researcher and Lecturer at Essex, said encouraging people to take a walk a day would help keep the doctor away and save the country money.

“There is a large potential benefit to individuals, society and to the costs of the health service if all groups of people were to ’self -medicate’ more with green exercise,” she added.

Barton and Pretty had alread established in earlier studies that links existed between green exercise, which they defined as activity in the presence of nature, and long term health benefits, but this meta-analytical study (a study that pools and re-analyzes results from other studies as if they came from one large one) is the first to measure what the best exposure “dose” might be.

For their research they pooled data covering 1,252 participants of varying ages, gender, and mental health status, drawn from 10 UK studies covering outdoor activities like gardening, walking, cycling, boating, fishing, horse riding and farming that showed green exercise was linked to improved mental and physical health.

In their calculations they looked at the links between two types of dose response: intensity and duration of activity, and two types of mental health indicators: scores on mood and self-esteem.

The biggest effect was seen in just 5 minutes of activity:

“The overall effect size for improved self-esteem was d = 0.46 (CI 0.34-0.59, p < 0.00001) and for mood d = 0.54 (CI 0.38-0.69, p < 0.00001).”

“Dose responses for both intensity and duration showed large benefits from short engagements in green exercise, and then diminishing but still positive returns,” they wrote.

It appears the effect was even greater in the presence of water, such as a lake, stream or pond, so perhaps it would be more accurate to say that the most beneficial environment is a blue and green one.

When they looked at age, the authors found the greatest improvement in self-esteem was in the youngest participants, and diminished with age, while for mood the smallest change was in the young and old.

The biggest change in self-esteem occurred in the mentally ill, and while both men and women showed similar boosts in self-esteem after green exercise, men showed a difference for mood.

Barton and Pretty concluded that:

“This study confirms that the environment provides an important health service.”

They recommended that green exercise should be considered for therapy (green care), planning authorities give more thought to creation and design of green space, and educators should give children more opportunity to learn outdoors.

Pretty said that we often make recommendations like these to public policymakers but they rarely adopt them. To make a significant impact in whole populations, the shift needs to be in areas as diverse as urban design, transport, social care, parenting and what we expect from our doctors, he said.

The authors said the UK population has a “natural health service” that complements the National Health Service and is there for everyone.

“What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis.”
Jo Barton and Jules Pretty.
Environ. Sci. Technol., Published online ahead of print 25 March 2010.
DOI: 10.1021/es903183r

Source: University of Essex.

Written by: Catharine Paddock, PhD

The new survey*, conducted for Siemens in conjunction with The Stroke Association to launch the annual Stroke for Stroke campaign, found that less than half of those questioned (43%) believe they adhere to the GDA (Guideline daily amount) for salt of 6g per day. Also the vast majority (85%) of those questioned failed to take the government recommended 30 minutes of exercise five days a week. This lack of regular exercise, combined with a high salt intake, could lead to high blood pressure and an increased risk of stroke.

The research revealed a general lack of awareness about overall salt consumption and the level of salt found in foods. While 92% of those surveyed believe that too much salt is bad for their health, 40% were unable to correctly identify six grams or one teaspoon as the maximum recommended daily salt allowance for an adult and, worryingly, 64% of those questioned are not concerned about their salt intake.

Perhaps surprisingly, those aged under 18 are most conscientious about always looking at the salt content of foods before buying (21% compared to the national average of less than 10%), but this doesn’t appear to lead to a reduction in the amount of ready-made and takeaway meals consumed by this age group. On average under-18s consume more than three of these types of meal per week, the highest of any age group, with 16% consuming seven or more every week.

The under 18s are also the least aware (53%, compared with 76% for all other age groups) that salt present in the food they buy is likely to constitute their main source of salt intake. In common with all other age groups, over three-quarters (78%) of under 18s regularly add more salt to their food during cooking or consumption, leading to a potentially very high weekly salt intake. This, coupled with the fact that 84% of young people exercise fewer than five times per week, means that this group could be increasingly at risk of serious health problems in later life.

Siemens carried out the research as part of the launch of their third annual Stroke for Stroke campaign, which seeks to raise awareness of stroke and highlight the benefits of a healthy diet and regular exercise as an effective means of stroke prevention.

Andreas J. Goss, chief executive, Siemens in the UK, said: “Stroke is the UK’s third biggest killer and contrary to popular belief it can affect people of any age. It is imperative that people take regular exercise and modify their lifestyle habits and diet if they are to reduce the risk of suffering from serious health conditions such as stroke.”

Wendy Martinson, Registered Dietician and Sports Nutritionist to the Great Britain Rowing Team, said: “A combination of poor dietary choices and habits, along with lack of regular exercise, could result in serious future health problems. A campaign such as Stroke for Stroke can raise awareness of the importance of taking positive action in your diet and lifestyle to improve your health. The risk of stroke is patently real and these warnings need to be acknowledged.”

Joe Korner, Director of Communications for The Stroke Association comments: “Each year an estimated 150,000 people in the UK will suffer a stroke. High blood pressure is the single biggest risk factor for stroke, eating too much salt on a regular basis as well as not exercising can contribute to this. Stroke for Stroke is now in its third year and a campaign like this is integral to raising awareness of how regular exercise and lifestyle choices can help prevent a stroke, which is clearly a message the UK still needs to hear.”

The Stroke for Stroke campaign will run between 25 – 31 January 2010 and will challenge members of the public to row 10km (or more), helping to raise vital funds for the charity. Not having access to a rowing machine is no excuse, as Stroke for Stroke has teamed up with Nuffield Health to offer a free five day pass to their nationwide network of Fitness & Wellbeing Centres for everyone taking part in Stroke for Stroke. The campaign is open to everyone across the UK. The campaign website contains useful information on stroke prevention, including limiting salt intake and taking regular exercise.

Notes

*The research was carried out by One Poll in September 2009 and questioned 3,000 participants. Siemens Stroke for Stroke Week is supported by The Stroke Association. Full details and a link to the justgiving website can be found at http://www.strokeforstroke.co.uk

Source
Nuffield Health
Siemens in the UK
The Stroke Association