Holistic approach that downplays RCTs best path to optimal nutrition, paper says

This integrative approach will incorporate the lessons learned from many decades of reductionist research to understand the functions and modes of action of individual nutrients.  The views contained in the paper were delivered at the seventh annual meeting of the Council for Responsible Nutrition — International which took place in Hamburg, Germany in early December.  The paper was published online on May 5 by the European Journal of Nutrition​, and includes contributions from 10 co-authors. The report examines trends and data in global public health and offers insights into systems approaches, tracking and analyzing “big data,” use of key nutritional and dietary supplements, personalized interventions, dealing with obesity (visible and invisible), use of dynamic biomarkers, and other perspectives.

Optimal nutrition is a hard concept to pin down. What’s optimal for one individual is less so for another.  The paper’s authors concluded that the best catch-all definition might go like this: “​the most desirable or satisfactory, most favorable, most effective act or process of nourishing or being nourished.​”​

Co-author Jim Griffiths PhD, vice president of scientific & international affairs for CRN, said the goal of the meeting was to cast as wide a net as possible in looking at how modern research perspectives could  help tackle the modern world’s issues with calorie-rich yet nutrient-poor diets.  As such the paper, taken as a whole, does more to stimulate new avenues of research than it might in coming to a definitive conclusion about what to do to best nourish the world.

“​We had 10 speakers each of whom pretty much had a blank piece of paper,​” ​Griffiths told NutraIngredients-USA.

Reductionism yielded early wins

On the subject of the underlying research itself, the paper noted that there has been an evolution from a reductionist mode to a more holistic approach.  The initial move toward reductionism was based on three premises:

• A simple cause–effect relationship exists between a particular nutrient and a specific effect or disease.
• Symptoms of a specific nutrient deficiency can be physiologically explained in terms of the role played by the respective nutrient.
• Providing the nutrient in the diet can prevent, and in many cases reverse, the deficiency disease.

This relatively simple model was appropriate to understand the initial challenges of outright deficiency, the authors noted.  This narrow focus has also yielded important discoveries including advances in understanding the role of diet and nutrition in the etiology of chronic diseases, a greater appreciation of the cellular modes of actions of nutrients, and the role of individual nutrients such as vitamin D, folate, dietary fiber and omega-3 fatty acids. Other advances along these lines have included a better understanding of the role of the microbiome and advances in the various ‘omics’ technologies such as proteomics and metabolomics.

But these successes led researchers down a rabbit hole to some degree, the paper’s authors argue.  The success of the reductionist approach in all of the above advances then held out the promise that a ‘silver bullet’ awaited discovery, the one thing to do, or the one thing to avoid, that would solve most of society’s diet-related problems.

“​Perpetuated by a reductionist approach on single macro- and micronutrients, scientists have similarly spent countless resources satisfying the demand for the nutrition ​‘​villain​’ ​and ​‘​hero.​’ ​Heroes include substances such as anti-oxidants, fiber, protein and probiotics, while the maligned villains include saturated fat, refined carbohydrates, trans-fat, salt and sugar,​” ​the authors wrote.

Less and less support for role of RCTs

This reductionist approach is characteristic of drug trials, but is being seen as less and less appropriate for nutrition research, despite what some regulatory bodies in the United States have had to say on the subject.

“​The role, or the lack of a role, for a randomized controlled trial in nutrition research, all of this is coming to a head now,​” ​Griffiths said. “​There is a reaction against the idea of one disease, one regimen, one target.​”​

“​In an effort to uncover the magic bullet, scientists inappropriately studied nutrients in a drug-like context. Unlike drugs, nutrients do not function in isolation and have beneficial effects on multiple tissues and organ systems; a narrow focus on a single or ​‘​primary​’ ​outcome measure is not practical and does not fit the nutritional context,​” ​the paper’s authors wrote.

Among other aspects of modern research covered in the paper were the applications of ‘big data’ type statistical approaches and the potential application of wearable technologies. 

In addition In addition to Dr. Griffiths, the coauthors of the report are: Andrew Shao, PhD, Herbalife Nutrition; Adam Drewnowski, PhD, University of Washington; D. Craig Willcox, PhD, Okinawa International University; Lisa Krämer, MSc; Technische Universität Braunschweig; Christopher Lausted, Institute for Systems Biology; Mannfred Eggersdorfer, PhD, DSM Nutritional Products; John Mathers, PhD, Newcastle University; Jimmy Bell, PhD, University of Westminster; R. Keith Randolph, PhD, Amway Global Discovery; and Renger Witkamp, PhD, Wageningen University.

Source:​ European Journal of Nutrition​
DOI:10.1007/s00394-017-1460-9 
Optimal nutrition and the ever-changing dietary landscape: a conference report​​
Authors: Shao, A., Drewnowski, A., Willcox, D.C. et al.