As in, do they actually work?
, tells SELF. “For one, everything we eat is this extremely complex mixture of things.” There are many different nutrients—carbs, fat, protein, vitamins, and minerals—in every food, plus other non-nutritive substances like chemical residues, coloring agents, and additional substances we may not even know about, says Dr. Dus., it’s estimated that humans have between 20,000 and 25,000 genes. Each person has two copies of every gene and most genes are the same in every person.
, a genetic switch flips and triggers a reaction that stops you from producing more of these amino acids for the time being. Nutrigenomics researchers are currently trying to answer very specific questions. For example, Dr. Dus runs a laboratory that studies how sugar consumption affects the expression of certain genes that impact particular cells in the brain. “Other labs might look at how fat consumption or a particular vitamin affects the expression of certain genes,” she says.