“Just as your body was designed to extract oxygen from the Earth’s atmosphere, and nutrients from the foods you ingest, your body was designed to love. Love — like taking a deep breath, or eating an orange when you’re depleted and thirsty — not only feels great but is also life-giving, an indispensable source of energy, sustenance, and health. In describing love like this, I’m not just taking poetic licence, but drawing on science: new science that illuminates for the first time how love, and its absence, fundamentally alters the biochemicals in which your body is steeped. They, in turn, can alter the very ways your DNA gets expressed within your cells.”