Drinking coffee with sugar increases your diabetes risk, especially type 2 diabetes. Some studies have found that people who drink black coffee without sugar have a 23 to 50 per cent lower risk of getting this disease  ,  ,  . Diabetic people should also avoid sugar-laden coffee as they cannot secrete enough insulin, and drinking coffee with sugar causes the sugar to accumulate in the blood.
Women who drank more than 4 cups of coffee per day, had a 20 per cent lower risk of becoming depressed. The reason being the caffeine, a natural stimulant which stimulates the central nervous system and increases dopamine levels  . An increase in dopamine levels removes the symptoms of depression and anxiety  . And due to this people are less likely to commit suicide .
So, how if you feel bored with the original black coffee? If you really want add something to your coffee, you can add the low calorie sweetener and low fat milk. You can also add soya milk instead of fatty dairy milk. In addition, you better choose the light or medium roasted coffee bean, since the dark roasted coffee bean may not give enough substance needed to burn fats. The chlorogenic acid may damage during the heating process of dark roasted beans.
The National Cancer Institute has reported that men who drink coffee regularly are less likely to develop prostate cancer. A 60 percent reduction in the risk of developing lethal prostate cancer was found in men who drank 6 or more cups of coffee per day. Even 1 to 3 cups of coffee reduced the risk. Four or more cups of coffee per day have also been shown to reduce the incidence of colon cancer. Furthermore, researchers discovered that people who drink coffee are 50 percent less likely to develop liver cancer than their non-drinking counterparts. Additional studies have linked coffee consumption to lower rates of breast and rectal cancer.
Again, it's the caffeine working here. Your recommended maximum amount of caffeine is 400 milligrams, roughly the amount that you’ll get from 4 cups of coffee. If you’re caffeine-sensitive, be careful with coffee. You are probably already aware what amount and what kind of coffee suits, or doesn't suit you. The amount of caffeine that is safe for human consumption is actually written in our DNA.
A 28-year study, eventually published in 2017 in Alzheimer's and Dementia, the journal of the Alzheimer's Association, determined that four to five cups of a coffee a day – a level deemed "moderate" – led to a decreased risk of dementia during that time period. Those who drank coffee in moderate levels had less medial temporal atrophy, which is linked to Alzheimer's disease, compared to those who drank three or fewer cups a day, including those who didn't drink any.