Wednesday, June 26, 2013

The Nutrition Debate #120: Nutrigenomics – an emerging new science

When I showed my step-daughter this Wikipedia piece on Nutrigenomics recently, she was curious. She had just earned her master’s in Forensic Biology at UConn, where she has worked in the Medical Center’s research labs for 20 years (after getting her Bachelor’s in Biology there), and she had never heard of it. This subject is ‘cutting edge’ and certainly not ‘mainstream,’ yet. But I think it’s time has come because we are now entering an age where the juncture of technologies will enable its rapid development. It is an exciting concept, and I will try to describe it to you here, briefly.

Cribbing almost entirely from various entries in Wikipedia, “In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information.”  “The study of the global properties of genomes of related organisms is usually referred to as genomics, which distinguishes it from genetics which generally studies the properties of single genes or groups of genes.” “Nutrigenomics,” then, “is the study of the effects of foods and food constituents on gene expression.” “By doing so, nutrigenomics aims to develop rational means to optimize nutrition with respect to the subject's genotype, which in the case of humans is the “genetic make-up,” colloquially speaking, of an individual.

As an individual then, I could look at this from a purely personal perspective.  I was diagnosed a Type 2 diabetic 27 years ago. I probably “presented” with all the symptoms of Metabolic Syndrome some 35 years ago – half a lifetime. But now this cohort includes roughly half of the human race who are overweight or obese and have all the indications of Metabolic Syndrome: central obesity, hypertension, dyslipidemia, and dysfunctional glucose regulation (pre-diabetes or “frank” Type 2 diabetes). This is the cohort of the earth’s population that now eats a Western diet.

“It is hoped that by building up knowledge in this area, nutrigenomics will promote an increased understanding of how nutrition influences metabolic pathways and homeostatic control, which will then be used to prevent the development of chronic diet related diseases such as obesity and type two diabetes. Part of the approach of nutrigenomics involves finding markers of the early phase of diet related diseases; this is the phase at which intervention with nutrition can return the patient to health. As nutrigenomics seeks to understand the effect of different genetic predispositions in the development of such diseases, once a marker has been found and measured in an individual, the extent to which they are susceptible to the development of that disease will be quantified, and personalized dietary recommendation(s) can be given for that person.”

The prospect that, as this new science develops, “personalized dietary recommendation(s) can be given for that person” is appealing. It would be nice to have some scientific proof that if one changed one’s diet it “would return the patient to health.” It would be nice to know the particulars of the gene and protein expression, and the metabolite production and genetic sequencing, that half of the human race has that gives it a “genetic predisposition in the development of such diseases” and is therefore “susceptible to the development of that disease” (obesity and/or type two diabetes). Such “personalized dietary recommendations” could then be given to half the world’s population who have this genotype that predisposes them and makes them susceptible to such diseases as obesity and type two diabetes.” 

Wait a minute! Am I missing something? Am I being dense? We already have the “markers” – okay, they’re admittedly crude markers compared to a DNA microarray, but they are the indications of Metabolic Syndrome: 1) central “truncal” obesity with associated hypertension, 2) dyslipidemia, particularly low HDL and elevated triglycerides, 3) and a broken glucose metabolism. Your waist-hip ratio can tell you almost everything you need to know.  And we already know what “intervention with nutrition can return the patient to health”: a low-carb, high-fat diet. This is my “prescription,” and I aver it would work for half the human race, if they would just try it.

If I sound frustrated, it is only that I know that science needs to prove the self-evident truth by the scientific process: In science you start with a hypothesis, demonstrate it, test it, test it again to attempt to disprove it, obtain grant money from an unbiased source to pay salaries, and then patent your discovery and get rich. That’s how science works today.

But I digress. Nutrigenomics has a laudatory goal. It will be helpful for the more specialized and increasingly common disorders related to diet, such as Celiac disease,  the inflammatory bowel diseases (autoimmune conditions such as Crohn’s and various forms of colitis, including ulcerative colitis), and Irritable Bowel Syndrome which can be caused or exacerbated by fiber and food intolerances (FODMAP, fructose, gluten and casein, for example). To find “markers” in the early phase of such “chronic diet related diseases” would be a boon for the sufferers. That will be especially true if in this phase “intervention with nutrition (could) return the patient to health.” These sufferers will anxiously await developments in this new science. Of course, when fully developed the symptoms of these diseases are manifest, and the sufferers already know what they have to do to avoid them. Just as some of us Type 2s have learned.
If you want to help advance the cause of science (and for just $99 fund some research), you could participate in a small way through an ongoing “study”: 23andme. From a saliva sample, they will analyze your DNA and send you a report.

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