Seasonal changes, temperature and humidity can all impact the amount oil that is created in our skin.  During colder months, it takes a bit more effort to combat dehydration, dullness and dryness. As we age, natural moisture barriers break down making it difficult for our skin to stay hydrated, causing pores to look bigger, wrinkles to appear deeper, and general lack of luster and plumpness.  All cell membranes are made of fats and are essential to the function of our cells while collagen helps improve our skin's ability to store water.   For youthful and glowing skin we'll need to look for ways to continuously preserve and boost collagen production while preserving lipids in the skin.