Omega-3 fatty acids, gingko and vitamin B6 are touted as memory boosters, but a recent study suggests otherwise.
Oily, cold-water fish that are rich in omega-3 such as salmon, trout, sardines and tuna are often described as "brain food". Canadian researchers found that laboratory mice that were fed a diet high in docosahexaenoic acid (DHA), a type of omega-3, had 30 per cent higher levels of DHA in their hippocampus, which helped memory cells better communicate with each other.
However, a recent review of published research conducted at St Michael's Hospital in Toronto has found no evidence to support the claims.
There is also no strong evidence for pharmaceutical treatments such as cholinesterase inhibitors, which are used for Alzheimer's patients, and there is a weak link between physical exercise and better memory, according to the review.
The study, published in the Canadian Medical Association Journal, suggests mental exercises - such as computerised memory training programmes or intensive one-on-one cognitive training in memory, reasoning or processing speed - are the best memory boosters.
But it seems that views are divided among experts.
Hong Kong University Professor Eric Chen says aerobic exercise has been shown to have a direct effect on strengthening the brain's memory capacity and facilitating growth in the hippocampus among patients with illnesses such as psychosis.
Jordan Poppenk, of Princeton University, believes "brain exercise games" may improve one's memory within the context of the game, but not memory in general.
He suggests using mnemonics, such as the 2,000-year-old Greek memory place method where one imagines certain items housed in a different place, then walks among them and recalls their locations.
A study by German scientists published this month in Neuron demonstrates an easy and non-invasive way to enhance memory: playing sounds synchronised with the brain's slow oscillation rhythm when people are sleeping. This way the study participants were better able to remember word associations they learned the night before.
But just getting enough quality sleep could help. A study in The Journal of Neuroscience shows that sleep deprivation can cause memory impairment by increasing adenosine levels - a compound believed to cause memory loss and attention deficit - in the hippocampus.