Risky science metaphor: BDNF as ‘Miracle-Gro for the brain’

bdnf-miracle-gro-for-brainI appreciate fun linguistic approaches to explaining science such as a good science metaphor and I use them myself at times, but sometimes these end up risking doing much more harm than good. The best or should I say worst example I’ve heard recently is referring to a growth factor called BDNF as “Miracle-Gro for the brain”.

What the heck?

BDNF is the acronym for brain-derived neurotrophic factor. It is a growth and trophic factor that has the exciting potential to induce helpful changes in the brain therapeutically. There are tons of translational or clinical experiments going on related to using BDNF as a tool to help patients. There is real promise there.

However, I believe that calling it “Miracle-Gro” for the brain is a mistake for a number of reasons. First of all, referring to anything biomedical using the word “miracle” is dangerous as it implies miraculous, proven clinical results, which is hype.

Then of course the plant fertilizer Miracle-Gro is supposed to make plants vigorously grow and so the use of “Miracle-Gro for the brain” implies that it can stimulate major brain growth. BDNF may hypothetically be able to stimulate some kinds of neuron growth or changes in humans, but we just don’t know and to call it “Miracle-Gro” is way over the top.

Furthermore, anything that stimulates growth can also make weeds grow. To use an analogy here, in the brain “weeds” would be unhelpful neuron growth or taken to its extreme, tumors. Even if non-cancerous, more neurons or more brain tissue is not necessarily a good thing. For instance, having too large of specific brain regions is associated with some forms of autism spectrum disorder.

Apparently psychiatrist John J. Ratey, author of Spark, The Revolutionary New Science of Exercise and the Brain, first coined the metaphor for BDNF of “Miracle-Gro for the brain”.

I hope that this phrase is phased out as it is counterproductive and even harmful when used in certain ways.

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