Thursday, November 4, 2010

Nutrigenetics–a little bit of history, but no miracles

Reading The $1,000 Genome by Kevin Davies, as expected it’s a fascinating story and right at the beginning in Chapter 1 there was something that I liked. The first personal genome to be sequenced and interpreted was that of Jim Watson (Craig Venter was first but no interpretation). Davies describes the presentation of Watson’s genome to the man himself and reports that the sequencing was performed by 454 and the interpretation was handled by the team directed by Richard Gibbs of the Baylor Genome Center.

Watson’s genome inventory, for example, revealed 310 genes with likely mutations and 23 with known disease causing mutations, increasing his risk for cancer and heart disease. The Baylor team recommended that he should take folic acid and other vitamins and minimize his exposure to sunlight, particularly during his daily tennis matches. p19

So there you have it, the first advice based on the first interpretation of a human genome sequence was nutrigenetic!

But then I read later in the book about Davies’ experiences with Sciona (actually I read this first, I started reading from the index expecting to see Sciona there, remembering that several years previously the author had contacted me about trying out our test - his review is here http://www.bio-itworld.com/BioIT_Content.aspx?id=43364) and in the book (p. 141):

The report soberly recommended that I should cut back on alcohol and caffeine, eat more cruciferous vegetables, and exercise more. "Brilliant, I thought, I've known that for years!"

 

Still the ensuing dietary recommendations – increase my intake of folic acid and omega-3 fatty acids – would be standard medical advice from any family physician. In a few cases, specific gene variants prompted more personalized dietary advice in the form of recommended vitamin and antioxidant supplements. This couldn’t hurt, but would they actually do a body good? A Newsweek cover story on the nutrigenomics fad said it best: “Some people will be advised to eat broccoli, while others will be told to eat…even more broccoli”.

Later in the book on page 204 Davies quotes John Sulston

British HGP leader and Nobel prize winner Sir John Sulston said “Nutrigenomics is a very easy scam. Not only is the advice useless…worse, some companies are associated with the companies that will sell you the dietary supplements”. Sulston’s advice was simply to grow your own vegetables.

So Baylor what did you tell Jim???

Well it’s easy to understand the contrasting reactions, from Baylor actually giving Jim Watson nutrigenetic advice, through Kevin Davies’ reasonable but slightly sceptical review to the outright condemnation of Sulston. In my opinion Sulston is right, wrong and impractical all in one go. It is unfortunately an easy scam and there have been many scammers, many still exist, many more are on the way. I would estimate that about 90% of the offerings then and now are rubbish, either scams or just through ignorance. Genetic based nutritional advice is not necessarily useless though, not all of it, the Baylor group presumably would agree with that. Grow your own vegetables is good advice but maybe not so practical for many…

Nutrition has a big problem – it’s the home of many scams, false promises, snake oil, disreputable companies, poisonous ingredients, no standardisation, poor research, overblown claims, and on and on and on. It’s a problem for us all though because inside all the mess of exploitation there is the serious side, the only key we really have for preventative healthcare. There is constant talk about how we need to change the current situation from curing disease to prevention otherwise society will collapse under the burden of obesity and diabetes, heart disease, cancer, etc. But what is preventative healthcare? Is it prescribing statins, aspirin, metformin? No, of course not, it’s boring nutrition and lifestyle where personal genetics really do have a role to play

The Kevin Davies reaction to nutrigenetics is quite common, the advice seems the same as normal healthy eating advice, and it’s broccoli or more broccoli, etc, etc, etc,. But what do you expect? Really, what do you expect? Of course it’s going to be similar to the usual advice – it’s not going to tell you that you should live on a diet of beetroot juice and walnuts while another person needs to eat rabbit and pears. It’s going to say a bit more of this and a bit less of that – there is no magic. It’s looks very similar to what your doctor would say. Yes it does, similar, not the same. Little differences make big differences in the long term. A size 8.5 shoe looks very similar to a size 9 and may feel OK in the morning, but will be hurting by the afternoon. A few calories too many per day will not make a difference except that 30 years later 14 kg have appeared.

That’s nutrition for you and you need to accept it. It’s boring but it’s the best tool we have for preventative healthcare. If you expect more from nutrigenetics, if you expect a load of zing in the advice unfortunately there are many companies out there who will satisfy your need. Why are there so many scammers? Because there are so many miracle addicts desperate for a fix.

Unfortunately the hype around genetics, the great promises made in 2000 around the human genome (although I must say that these were mainly from the politicians) lead to great expectations, so some unexciting nutritional advice is seen as worthless and a waste of money. Ironically this is the sort of expectation that drives the sales of the genetic tests which offer nutritional miracles in a bag of pills and herbs – it’s not a surprise that the company which was labelled fraudulent by the GAO earlier this year, the one selling the bag of herbal panacea, is the company that is making the most money. Boring nutritional advice is not enough is it, surely there must be more than that… yes there is, but don’t rely on it to really work…

Maybe one day there will be harmless pills for preventing all known diseases whatever we do to ourselves, for now though all that nutrigenetics can offer you is a slightly better fitting shoe – anyone offering more is not to be trusted.

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