There’s an old Indian tale about giving a group of blind men an elephant to describe through feel. As each of them is feeling different parts of the elephant, they end up squabbling as none can agree on how to describe it as a whole. Each sticks fervently to their version of the truth, without communicating effectively and realising that all of their “truths” in harmony describe the total picture.
Lessons from this ancient fable are just as relevant today when we evaluate how various scientific experts approach the totality of scientific evidence. Recently we had a good example of this when one prominent scientist published his professional (and somewhat extreme) opinion on sugar in Nature, resulting in a media storm and “expert” slanging match across the globe. Personally I thought Dr Arya Sharma’s commentary on this was one of the better ones.
The very essence of scientific endeavour is to prove or disprove hypotheses, and since research often raises more questions than it answers, further research is usually justified. So individual researchers passionately chase logic down the path where their research leads them. It’s hardly surprising that when they come up for air and see what other “descriptions of the elephant” exist, debates can get heated. People who “describe the animal in the same way” comfortably reference each other’s material, while desparately trying to disprove the findings of others who might describe the animal differently. Hence many highly esteemed experts fight it out in the media and the general public become more confused and disenchanted than ever.
In the world of nutrition science nothing is black and white, as everything is highly dependent on a complex web of lifestyle variables and genetic make-up. It is therefore difficult to make clear and meaningful recommendations on a population basis, and no wonder really that we usually wind up back at use-your-common-sense messages, such as “eat a variety of foods” and “a balanced diet” which can be waffly and confusing for people.
White hat scientists (and there are a lot of them), tend to take the approach that it won’t do anyone any harm , rather than the evidence-based approach. There is an increasing school of thought that goes; since it takes so long to prove or disprove scientific theories on nutrition, we should just make recommendations which may not be effective but can’t do any harm. The American Heart Association clearly states in its position paper on sugar that “research tools thus far have been insufficient to confirm a direct link” [between added sugar intake and weight gain]. Then they go ahead and make prudent recommendations anyway.
Sadly this well-intended advice often serves to confuse and alienate the public further, as they reach for another chocolate bar and vow never to listen to another expert. Judging by the comments on TVNZ’s Breakfast facebook page (Feb 24th) this is certainly what happened when the NZMJ published a viewpoint article listing 49 foods for obese people to avoid, and the media made a complete meal of it. Yet again, the dietitians among us come out of it looking like the food police.
So, can we win? Is practical, meaningful and evidence-based dietary advice the ever-elusive holy grail? I’d love your views on this.