Science - March 14, 2013

Road map to nowhere?

'Diet replaces medicine,' read the headline in the Dutch daily paper De Volkskrant at the beginning of March. It referred to the publication of a 'road map' of the human metabolism.

'One of the biggest scientific breakthroughs of all time,' said co-author Hans Westerhoff, claiming that it will soon be possible to combat diseases with tailor-made dietary advice. Other experts quickly weighed in with the view that this is a big exaggeration. Yet the study that lies behind it is certainly 'useful', says Michael Müller, professor of Nutrition, Metabolism and Genetics, 'and we shall certainly use it.'
What did you think of the extravagant promises made in the Volkskrant article?
'I don't know which cloud Professor Westerhoff  was on, but I do hope he has come back down to earth by now. The journalist should have picked holes in it. I hope people can see that this is a case of one overenthusiastic scientist who does not understand the complexity of human physiology. They shouldn't dismiss the whole research or academic field out of hand.'
Are you more positive about the road map behind these claims?
'Yes, it is a very important article for the field. The researchers were able, for example, to predict with 77 percent certainty the consequences of congenital digestive tract diseases: conditions caused by just one defective gene. But it will take a long time before the map is of any use in complex diseases such as obesity and type II diabetes. In those cases several different genes are involved. And environmental factors such as suboptimal nutrition are important too.'
You also think the research tells us little about nutrition.
'Indeed, because it leaves out a crucial element for nutrition. The researchers do not look at all at regulation: the switching on and off of genes. Yet this is very important. Digestive processes have massive overcapacities which can be switched on and off. This depends, for instance, on our biorhythms: the capacity varies from the morning to the evening. There are other elements missing too: hormones, the influence of gut flora and the fact that cells are never isolated but are part of an organ.'
Now your field is front-page news, and it is for this. Do you feel that's a pity?
'Oh well, you spend your whole week trying to defuse the situation. But that makes a nice change.' 

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