Diet may regulate obesity health risks, but genes decide, says new research

Dec 1 2008

The risk of obese people developing the metabolic syndrome that leads to diabetes, hypertension, and heart disease, can not be solved by a one-size-fits-all diet programme, according to new scientific findings.

The results of Lipgene, a five year EU research programme, show that personalised nutrition diets based on peoples genetic make-up will be the way of the future when tackling obesity and its associated health risks.

Currently, obesity costs the EU an estimated €32.8 billion each year. And, at current rates, it is estimated that 50% of Europeans will be obese by 2050.

Obesity results when excess calories are consumed and insufficient energy is spent (physical inactivity). Obesity is a major health hazard worldwide, it is directly linked to several common diseases such as diabetes, hypertension, heart disease, and some cancers.

"We analysed the findings from 500 volunteers across Europe who took part in a dietary programme to measure the effects of different diets on the development of the metabolic syndrome associated with obesity," says Professor Helen Roche from the Institute of Food and Health at University College Dublin, one of the principal scientists on the Lipgene programme.

"The volunteers, each of whom were previously identified as obese and at risk from developing associated health complications, were placed on one of four specific diets," Professor Roche explains.

One was high fat, high in saturated fats, like the average Irish diet. One was high fat, high in monounsaturated fats, like the average Mediterranean diet. And two were low fat diets one of which had a fish oil supplement.

"After the dietary programme was complete the volunteers were tested for reductions in any of the five main factors associated with the metabolic syndrome - high blood glucose; high levels of fats in the blood; high blood pressure; a waist circumference greater than 100cm; and low levels of good cholesterol (HDL)."

"The findings show that different fats have different health effects. A high saturated fat diet dis-improved the metabolic profile of subjects whilst the fish oils had positive effects. But certain clusters of genes determined a volunteer's responsiveness to dietary interventions. Some of the volunteers experienced obvious positive effects while others experienced little or no changes to the metabolic syndrome indicators," says Professor Roche.

As the common genetic variations, or polymorphisms, identified in the volunteer group are carried in 25% - 30% of the general population, the sample is clinically relevant, according to the scientists. The findings will now be tested against different population cohorts in Ireland and elsewhere in Europe.

If the results are confirmed by further studies, we will see the creation of more effective dietary treatments and nutritional therapies for obesity. Into the future, a GP is likely to take a blood sample from a patient to compare their genotype against genes active in common diseases and related this to the person's lifestyle and environmental factors to gauge whether physical activity as opposed to nutritional regulation might work better for each individual patient.

It may be like visiting a GP to be measured for a certain health fitting which has been proven to work for your genetic type - just as we visit tailors and dress makers for fitted suits and dresses that make us feel and look better.

Professor Michael Gibney from University College Dublin, the coordinator of the Lipgene project has called on EU policy makers to evaluate the evidence presented by the EU Lipgene project with a view to improving the health of the EU population.