A large cup of warm coffee is a morning ritual for millions of people to begin a day. But for those who count sheep to fall asleep, coffee probably isn’t an option. Why does caffeine affect people’s preference for coffee so dramatically? A substantial factor is our genes.Coffee is known for its ability to improve attention, raise alertness and increase energy due to its high caffeine content. It also contains several beneficial nutrients, including vitamins B2, B3, B5, manganese, potassium, magnesium and various phenolic compounds or antioxidants. Many studies show that caffeine can improve brain functions, including memory, vigilance, reaction time and mental performance. It is possibly protective against the development of cognitive decline that may be caused by such conditions as Alzheimer’s and Parkinson’s disease.Coffee’s high antioxidant content helps to protect the body from free radicals, which can damage important molecules, including proteins and DNA. Because antioxidants can effectively neutralize free radicals, coffee can potentially offer protection against many diseases that are partly caused by oxidative stress, including cancer.According to a new study led by researchers from the US-based Harvard School of Public Health, people who increased daily coffee intake by more than one cup over a four-year period had an 11% lower risk of developing type 2 diabetes than those who did not increase their coffee intake. A study that included more than 490,000 people, tracked for an average of 10.7 years, showed that drinking coffee significantly lowers the risk of chronic liver disease and death from it, fatty liver disease, and liver cancer.Although caffeine may boost your mood, metabolism, and mental and physical performance, overconsumption of it may lead to unpleasant consequences, such as insomnia, nervousness, restlessness, nausea and increased heart rate. Doctors recommend curbing coffee consumption after 2 pm to ensure that most caffeine can be metabolized before bedtime and allow adenosine to kick back in for a good night sleep.