"Send a saliva sample... and we'll tell you what you should eat for the rest of your life!".

An enticing phrase, repeated in advertisements of centers and companies offering what is called genetic dietary analysis, to the point that some people think the human genetic code contains a ready-made food list that only needs someone to read it! But is this true? The scientific answer: it is not that simple.

There is no dispute that genetics has revolutionized medicine, and that the field of nutrigenomics is one of the most promising medical specialties. There are indeed genes that influence how our bodies handle certain foods, explain differences in lactose tolerance, gluten sensitivity, or caffeine metabolism, and may even help understand predisposition to some diseases. However, the problem begins when science becomes a commodity, probabilities become promises, and preliminary results become absolute truths. Some advertisements suggest that a single genetic report can design the ideal diet, guarantee weight loss, or prevent diseases. These are claims not supported by scientific evidence—so far.

The truth is that human health is not determined by genes alone; it is also influenced by lifestyle, physical activity, sleep quality, mental state, dietary habits, and the surrounding environment. Genes may pave the way, but they do not alone decide the journey's destination.

Therefore, it is wise not to be swept away by marketing glitter, and not to spend large sums waiting for a report that may provide limited information that does not change much of the basics of healthy nutrition that everyone knows.

Science is advancing, and perhaps the day will come when genetically tailored nutrition becomes part of routine medical practice. But for now, the best healthy prescription remains the least costly and most proven: a balanced diet, daily physical activity, adequate sleep, and avoidance of excess... A prescription that does not require a saliva analysis, but rather willpower and commitment. "Genes may pave the way... but they do not alone decide the journey's destination. Stay well."