Really? Outside India coffee is more popular than tea . Might have some effect . But there are other good things than cofee which increases brain power.
Too much of coffee results in danger and also too much of sugar leads to danger. Only in India we drink coffee however the rest of the world prefer tea rather than coffee and especially without sugar.
In a study published in Human Psychopharmacology: Clinical and Experimental, researchers found that taken together, caffeine and sugar have a synergistic effect on each other, meaning that it is this enhanced effect on each other (rather than taking either alone) that can help in the areas of attention span and verbal memory.