From Eight Simple Ways To Reduce Stress from Better Homes And Gardens Magazine
Drinking four or five cups of coffee every 
morning does more than open your eyes. The caffeine raises your blood pressure and increases secretion of adrenaline, a stress hormone. While your brain is pumping out more adrenaline, your heart is also working harder, causing a three-point increase in blood pressure. A five-point increase in blood pressure has been associated with a 21 percent increased risk of heart disease and a 34 percent increased risk of stroke.
When all is working as it should, our nervous systems have mechanisms that keep us from overreacting to stress. But caffeine seems to inhibit that natural function and leave the body in an agitated state for longer than normal. Because the effects of caffeine last for hours after intake - it takes 4 to 5 hours to eliminate half the caffeine present - the body never really gets a chance to function without caffeine.
The long-lasting effects of caffeine are greater for women taking birth control pills because estrogen and caffeine are broken down by the liver. It may take 10 to 12 hours for women on birth control pills to lower their caffeine levels by half, so by the time yesterday's caffeine is gone, many people have already started with this morning's coffee.
Slowly taper off caffeine by drinking a cup of decaf or herbal tea to substitute for your affricated cup. Or, try mixing regular with decaf beans at the grocery store. If you take it slowly, your body will hardly notice the difference.
