There is a lot of research on both

There is a lot of research on both humans and animals on the effects of caffeine, and there is often thoughts that too much is bad for us. There is no conclusive evidence to implicate caffeine consumption as being significantly harmful to health, but there still is controversy with this, as there is still some negative effects associated with caffeine consumption. Having some caffeine daily is ok, but using food and exercise strategies listed below, will certainly help in reducing fatigue and avoiding caffeine addiction.
Caffeine is a central nervous stimulant and can have some positive effects on the human body. Caffeine in low doses is thought to be associated with an improvement in sporting performance, increased alertness and reduction in fatigue potentially lifting a person’s mood. Coffee and tea also contain some antioxidants which have positive effects on heart health.
However, increased amounts of caffeine lead to dependency due to increased tolerance and hence the need for greater amounts to gain the same stimulatory benefits. Heavy users who have to go without can experience withdrawal symptoms such as headaches and fatigue. Too much caffeine can produce restlessness, nausea, , and cardiac.