Skin is fed from within. The foods we eat are broken down into nutrients and waste. The nutrients are absorbed by bloodstream which transports them around body to various organs, largest of which is skin. Oxygen is also transported and delivered in same way. The cells absorb oxygen and this is vital for health of organs and life process itself. This whole process takes place automatically when we breathe........Except when we are breathing in smoke!
When we inhale smoke from a cigarette carbon monoxide from smoke is absorbed by hemoglobin in blood. Carbon monoxide is a colorless odorless highly toxic gas also found in smoke from car exhausts. The blood can absorb carbon monoxide 200 times as fast as oxygen so a lot of oxygen is displaced by carbon monoxide. The organs including skin are starved of life giving oxygen and slowly poisoned by carbon monoxide.
But that's not end of it. Cigarette smoke also contains following deadly cocktails of chemicals. Ammonia, hydrogen cyanide, butane, nicotine, carbolic acid, collidine, formic aldehyde, lutidine, parvoline, prussic acid, pyridine, arsenic and cadmium. This list is by no means complete.