It is possible to 'slow down' the accumulation of aging caused by unhealthiness. If you want to slow down the damage caused by unhealthiness - the answer is to improve your health. It is possible to make your body healthier, so that it can heal and reverse damage caused by unhealthiness. The healthier you are, the less you will suffer permanent damage, or 'aging', and the more likely your body can recover from prior damage. The less healthy you are, the more you will suffer the permanent damage that is aging.
Many nuts (especially almonds) are a great source of vitamin E, which may help repair skin tissue, retain skin moisture, and protect skin from damaging UV rays. Walnuts even contain anti-inflammatory omega-3 fatty acids that may help:
strengthen skin cell membranes
protect against sun damage
give skin a beautiful glow by preserving its natural oil barrier