What Is Epigenetics?

While genetics studies the DNA sequence, epigenetics examines the molecular "tags" that control whether genes are active or silent. The main mechanisms include DNA methylation (adding methyl groups to cytosine bases, typically silencing genes), histone modification (chemical changes to the protein spools around which DNA is wrapped, affecting how tightly it is packed), and non-coding RNA regulation. Every cell in your body has the same DNA, yet a liver cell behaves differently from a neuron because of epigenetic programming. Epigenetic marks can be influenced by diet, stress, toxins, and aging, and some can be passed to offspring. The Dutch Hunger Winter study showed that children of mothers who experienced famine during pregnancy had higher rates of cardiovascular disease and obesity decades later — traced to epigenetic changes. The field has revolutionised understanding of cancer, development, and inheritance.