Opinion – Suzana Herculano-Houzel: The pros and cons of supplementation

Oh my, the same 16 billion cortical neurons that make us flexible and capable beings, full of cognitive resources and ingenuity to see problems and invent solutions, make us lazy.

By definition, the technologies we invent with so many neurons – the systems, objects, processes, methods that solve problems the fastest – leave us with downtime. And what do we do with idle time? Some stop to enjoy the day; others use the opportunity to find even more problems to solve; and others… want to turn to technology so they can do nothing, including not having to deal with the problems caused by their inactivity. For these, science serves to create pills that replace the effects of exercise.

Holy laziness.

Here’s two news for the lazy, then. Two studies, published right next to each other in the March journal Cell Metabolism, show that dietary supplementation has effects on brain metabolism and neuron production in the adult hippocampus, two topics of special interest for healthy aging, which requires efforts.

The first study, carried out by researchers in Norway, was carried out with patients with Parkinson’s, a degenerative disease caused by the loss of dopaminergic neurons in the midbrain, possibly through problems with the cellular respiration of these neurons. Because cellular respiration depends on small molecules called nicotinamide adenine dinucleotides, or NAD, the researchers tested supplementing patients’ diets for a month with a molecule that the body turns into NAD. The treatment changed brain activity and improved the patients’ motor performance.

In the following pages, the study by researchers in Australia, Germany and China found that one of the proteins produced by mice in response to physical exercise in the rodent version of the treadmill, one of the proven ways to increase the production of new neurons in the hippocampus and health of the brain in general, is a transporter of the element selenium, which makes up some brain enzymes. In fact, the group found that supplementing the animals’ diet with selenium mimics the effects of exercise on neurogenesis in the adult hippocampus.

As levels of both selenium and NAD decline in the brain with age, and the deficiency is exacerbated in degenerative diseases like Parkinson’s and Alzheimer’s, dietary supplementation in these cases makes perfect sense.

But it’s not a universal panacea, I’m sorry. First, because it is not necessary for those with a varied diet: the other name for NAD is… vitamin B3, present in meats, and Brazil nuts are an excellent source of selenium. Second, because supplementation has risks: anyone who has watched “House” knows that excess selenium in the body is as toxic as radioactivity.

More importantly, however, is that the core of physical and mental health is the feeling of ability and control, and for that there is no pill that will help: satisfaction really comes as a result of our efforts.