Oily fish such as salmon and mackerel are rich in Omega 3 fatty acids, which reduce the tendency to dryness. Fish are also full of protein, which is vital for continually making and repairing skin cells.
You need some fat in your diet to build and maintain every cell in the body, especially those in the skin.
Without fat, skin cell walls break down so their fluids leak out, leading to dehydration and dryness. But don’t overdo it – a drizzle of good-quality olive oil on salad will do.