The overall mental health of older adults does not improve with brain training, say researchers.
The study led by German researchers showed that such items can only improve specific abilities they are aimed at.
In the old age, the ability to think gets slower and it becomes harder to learn new things.
Many people try to stay mentally fit by, for example, learning a new language or doing crossword puzzles.
Computer games that aim to keep the brain active are also becoming increasingly popular.
"Doing exercises like trying to find symbols on a computer screen as fast as possible can actually improve your reaction time," said Professor Peter Sawicki, Director, German Institute for Quality and Efficiency in Health Care.
"But scientific studies have shown that brain training only leads to an improvement in the specific ability that it is aimed at. So if you learn to find symbols quickly, it does not mean that you will be able to remember names better too."
The research team suggests there is no need for people to push themselves to do brain training if they do not enjoy it.
Research has not shown that brain training can keep up or enhance people's overall mental abilities.
"So there is no need to feel bad if you do not enjoy brain training: there are no health reasons for doing it," said Sawicki.
"But if you think brain training exercises are fun, you can try out different things. For example, completing sequences of letters can improve your logic skills. And practising word association techniques can help you to remember things better," he added.