A recent study at Nanjing university found that genetic information in the foods a person eats can affect his or her physiology. This occurs through the interaction between microRNA (miRNA) in the food and Messenger RNA (mRNA) in the target.
Messenger RNA is a molecule in the body that is used as a blueprint for synthesizing proteins. MicroRNA is another molecule present in the body that can attach itself to Messenger RNA and stop it from being able to generate those proteins. MicroRNAs have the effect of silencing or regulating certain physiological functions.
This study shows that not only are humans affected by their own microRNA molecules, but the microRNA molecules of the species of plants and animals that we eat can also regulate our physiology. This implies that the species of foods that we eat has more of an effect on us than simply the nutrients that they contain.
An article on physorg.com explains:
The finding is obviously very thought-provoking; for instance, it would indicate that in addition to eating "materials" (in the form of carbohydrates, proteins, etc), you are also eating "information" (as different miRNAs from distinct food sources could well bear different consequences on the regulation of host physiology once taken by the host due to potential regulation of different target genes as determined by the "information" contained within the miRNA sequence), thus providing a whole new dimension to "You are what you eat".
From the perspective of kashrut, this finding is interesting because it highlights how little we know about how foods affect us. And yet, it is important to understand that health and science are not the foundation of kosher laws in the Bible. While it is good and even biblical to make healthy choices in all aspects of our lives, the dietary laws have a primarily spiritual function.