Tuesday July 17 2012
Seaside living leads to sunnier moods, claims study
“People feel ‘healthier’ on the English coast,” BBC News reports. The Daily Telegraph goes on to tell us that the sea air “really is healthy”.
The study on which this news is based aimed to investigate whether self reported ‘good health’ was associated with living closer to the English coastline. The study based its results on data from the 2001 England census, which included asking people to rate their health over the past 12 months. Researchers compared the results with people’s geographical location and found that on average ‘good health’ was more common when a person lived closer to the coast.
Overall, this type of study provides some evidence of a link between reported good health and proximity to the coast. However, it is difficult to unpick all the possible reasons why ‘people do like to be beside the seaside’.
The researchers offer a number of theories, which, in the absence of further research, are currently pure speculation, such as:
- living by the sea may promote feelings of relaxation
- people may feel more encouraged to be physically active due to their environment, such as running along the beach
The findings should not be misinterpreted to mean that living close to the beach or coast automatically leads to ‘good health’. Before considering a ‘sea change’ it is worth noting some of the study limitations, including self-reported data and measurements taken at only one point in time, which both limit the reliability of results.
However, these results do provide a launching pad for discussions around how we can make urban environments more conducive to improved health and wellbeing.
Where did the story come from?
The study was carried out by researchers from the European Centre for Environment & Human Health at the University of Exeter (which is a seaport) and was funded by the European Regional Development Fund and the European Social Fund Convergence Programme for Cornwall and the Isles of Scilly (Cornwall has England’s longest coastline and the Isles of Scilly are, by definition, by the sea). The study was published in the peer-reviewed journal Health & Place.
What kind of research was this?
This was an ecological study investigating whether self-reported rates of ‘good health’ in the UK improve with proximity to the coast. Researchers used data from the 2001 England census and compared this to geographical data.
An ecological study is a study of a population or community rather than a study of individuals. Common types of ecological study include geographical comparisons, time trend analysis or studies of migration. The national census is a cross-sectional type of survey, which measures health, lifestyle and other sociodemographic details at one point in time and therefore cannot imply cause and effect between any of the factors.
What did the research involve?
The researchers analysed data from 48.2 million people from the 2001 England census – a national survey looking at various details of individuals. Using standard geographical methods, census data was broken down into 34,482 smaller areas (known as Lower-layer Super Output Areas or ‘LSOAs’) each of which had an average population of about 1,500 people.
As part of the census, participants were asked ‘over the last 12 months would you say your health has on the whole been: good, fairly good or not good?’ The researchers then investigated the relationship between participants who reported their health as ‘good’ and how close they lived to the coast. To identify proximity to the coast researchers used geographical methods to calculate the direct (linear) distance from the centre point of each population-weighted LSOA to its nearest coastline. As there was confusion between a ‘coastline’ and ‘riverside’, researchers defined the end of a coastline as ‘where an estuary narrowed to less than approximately 1km’. Coastal proximity was then divided into five bands:
- between 1-5km
- between 5-20km
- between 20-50km
- more than 50km
As well as coastal proximity, researchers looked at the percentage of area classified as ‘greenspace’ and five indicators of socioeconomic deprivation:
- education and skills
- environmental deprivation
On the assumption of a link between coastal proximity and good health, researchers also looked to see if this association remained if there was income deprivation.
The researchers adjusted for potential confounders of age, sex and a range of social and economic factors, such as education and income. Statistical methods were used to analyse results, which were broken down into urban, town and fringe, and rural areas.
What were the basic results?
The main finding of this large study was that self-reported good health was on average more common (prevalent) the closer a person lived to the coast. When compared to urban communities living more than 50km from the coastline, the proportion of those reporting ‘good health’ living within 1km of the coast was 1.13 percentage points higher after statistical adjustment (95% confidence interval 0.99 to 1.27). The researchers also found that the positive effects of coastal proximity may be greater among poorer communities.
How did the researchers interpret the results?
The researchers concluded that good health is more prevalent the closer one lives to the coast.
In response to the research findings, lead author Ben Wheeler says: “By analysing data for the whole population, our research suggests that there is a positive effect. We need to carry out more sophisticated studies to try to unravel the reasons that may explain the relationship we're seeing.” Importantly he says that “this type of study cannot prove cause and effect”.
He goes on to say: “If the evidence is there, it might help to provide governments with the guidance necessary to wisely and sustainably use our valuable coasts to help improve the health of the whole UK population.”
Overall, this interesting study provides some evidence of a link between reported ‘good health’ and living close to the coast. Before any hasty decisions are made to up sticks and move to Bournemouth, Brighton or Bognor, there are some limitations to this type of study worth noting:
- ‘Good health’ was self-reported, which can make the results less reliable.
- As participants were asked to rate their health ‘over the last 12 months’, it is possible that they did not accurately report their health, which can also make the results less reliable. For example, people who may have had a short episode of ill health would have had to weigh up how to rate their health overall and potentially rated it as ‘good’.
- A rating of people’s health was only taken at one point in time – in 2001. Measuring people’s health more often would have given a more accurate picture of their actual health status.
- Despite the authors’ efforts to adjust their results for confounders, it is always possible that other factors such as the home environment, stress or other illnesses influenced the results.
- As the results are from a cross-sectional survey, it is not possible to say people have good health because they live by the coast, or whether people with good health choose to live by the coast. It is possible that the results may be caused by what is known as ‘the healthy migrant’ effect, whereby the healthiest and often wealthiest of society may be more able (physically and financially) to live in more desirable environments, including near to the coast. However, the authors suggest that this effect is unlikely given the results that the coast association is strongest in the most deprived areas. In addition, being a cross-sectional study, this cannot take into account migration of people.
To draw further conclusions, more research is needed. However, these results do provide a launching pad for discussions around greener spaces and healthy living.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on twitter.