Sunday, August 19, 2007

Regionally defined healthful diets?


There is no proof beyond reasonable doubt that consumption of ecologically produced foods is more healthful than eating their non-ecological counterparts. Similarly, foods that are produced locally are probably fresher than foods that need to travel over long distances, but there is no convincing evidence that eating such locally produced foods lead to lower disease risk or longer lives.
However, ecological and preferably locally produced foods are to be preferred for environmental protection and sustainability. Protecting the environment is, as professor Johan Mackenbach so clearly describes in a recent paper in International Journal of Epidemiology (see http://jech.bmj.com/cgi/content/extract/61/2/92), of great importance for public health. Eating locally may also contribute to the protection of nutritional diversity and local food cultures as argued by the slow food movement (see http://www.slowfood.com/).

So should health promoters start to promote locally produced products as part of their nutrition education efforts to improve population health?
In promotion of healthful eating, basically two different avenues are explored. The first is the nutrients way, with a focus on identification of key nutrients and other food compounds that help to prevent disease and promote health, leading to nutrients specific recommendations and to, for example, use of dietary supplements, nutrient enrichment or fortification of foods, and the development of functional foods. This avenue has been fruitful in the past to help get rid of a number of deficiency diseases in large parts of the world.
However, this nutrient-oriented avenue in general appears to be less effective in addressing the most important present-day nutrition-related health problems that are related to over-consumption rather than deficiencies and stronger related to foods and eating patterns then to nutrients. For example, there is ample evidence that nutrition is directly or indirectly related to CVD, cancer risk and obesity (see for example http://www.hopeproject.eu/), there is only very little evidence that specific nutrients contribute to prevention of such conditions.

The second avenue is therefore food and food patterns oriented. This avenue is more closely linked to what people actually eat: foods and meals. Different food guide pyramids, food plates and other nutrition education tools build on this food-oriented avenue (see for example http://www.mypyramid.gov/; or http://www.voedingscentrum.nl/voedingscentrum/Public/Dynamisch/hoe+eet+ik+gezond/).

Some attempts have been made to take this food-oriented avenue a few steps further, by describing meal patterns or diets that incorporate the foods for which the strongest evidence has been found for a health enhancing effect such as the famous ‘Mediterranean Diet’(http://en.wikipedia.org/wiki/Mediterranean_diet), which is supposed to include olive oil, fruits, vegetables, grains (mostly unrefined), fish, diary in moderate amounts, low quantities of meat and meat products, and a regular but moderate intake of alcohol.

Several of the ingredients of the Mediterranean Diet do not grow well in many areas of the world and other ingredients are not available in large enough quantities to be included in diets across the world. Furthermore, most regions have other culturally and regionally appropriate foods that might be as health enhancing as the ingredients for the Mediterranean diet.

It is a challenge to define such alternative regionally defined diets that may contribute to health promotion and disease prevention, as well as to protection of the environment. Local food production and diversity in food cultures. Together with my Norwegian colleague Dr. Elling Bere of Agder University College, Norway, we have been working on exploring the ‘Nordic Diet’. A paper on our explorations will soon be ready to be submitted for publication! Geit Ost (Norwegian goat cheese) may not be part of such a health enhancing Nordic Diet, but it does taste great!

No comments: