Do you ever walk purposefully into a room only to wonder what it is you came in for? Are you always losing your car keys or grappling for the right word? The chances are that you will put such memory lapses down to the passing of the years. But forget the stereotype - memory loss doesn't have to be an inevitable part of getting older.

Scientists used to think brain cells could not be regenerated, but new research suggests it may be possible to stop them dying - as well as build up new connections between them. In fact, evidence is stacking up to show it's possible to boost your memory powers through a variety of lifestyle measures. One US study found that volunteers who did just ten hours of sessions to improve their memory, problem-solving abilities and reaction times had mental skills equivalent to people between seven and 14 years younger than those who did not have the training.

Your memory can, experts now agree, be largely what you make it. "The average person's memory deteriorates as they get older, but that's not due to the ageing process - it's because they are unwittingly training their memories to become worse," explains world-renowned memory expert Tony Buzan. "The decline of memory with age is not inevitable - it's just that we tend to neglect it, as we do our bodies. We feed it the wrong foods and don't exercise it, then wonder why it's going wrong. We have to learn to expand our memory powers."

Ian Robertson, professor of psychology at the University of Dublin Trinity College, says that giving the brain new challenges helps build better connections between brain cells and improve function." ‘Use it or lose it' is a fact," he says.

Read on to see how you can help your memory... 

A diet that's good for the heart is good for the mind, too. That's because having high blood levels of homocysteine - an amino acid that's linked to cardiovascular disease - has also been implicated in dementia. To reduce your homocysteine level, increase your intake of folates (found in leafy green vegetables and pulses) and cut down on fatty, processed foods.

There's evidence galore to show that omega-3 fatty acids, found in cod-liver oil and in oily fish (such as trout and mackerel), help prevent damage to brain cells and keep your memory sharp. Aim to eat three portions of oily fish a week, and a variety of different types, says Natalie Savona, nutritionist and author of 'Wonderfoods' (Quadrille).

Researchers believe it's possible to increase your memory power by playing mentally stimulating games such as bridge, in which you have to retain information to work out who holds which cards; chess, which forces you to think ahead as many spaces as possible; or crosswords. "Any such mind game is good for keeping your memory sharp as you progress through life," Tony Buzan says

Give your brain a taxing work-out by doing Sudoku number puzzles. "Sudoku requires complex reasoning skills, a bit like code-breaking, which means you'll be using more than one part of your brain and so building up networks between different areas," explains Dr Celeste de Jager, senior neuropsychologist at OPTIMA (Oxford Project to Investigate Memory and Ageing).

Taking a newspaper every day is good mental exercise - but only if you pay attention to what you're reading. Professor Robertson advises making a mental image of the main points of each paragraph as you read it, then repeating the gist of the story to yourself from memory. Skim it again to check that you have got it right.

Taking a supplement of the ancient herb ginkgo biloba is thought to boost memory powers by thinning the blood and so improving oxygen circulation to the brain. Research is so positive that it's routinely prescribed in Germany and France for patients with dementia. (If you take any existing medication, check with your doctor first.)

Prompt your memory by giving your mind images to work with, says memory expert and former World Memory Champion Jonathan Hancock. To remember people's names, he suggests choosing an image suggested by their name. "While you're talking to Mr Baker, for instance, visualise him baking a loaf of bread. And Annabel is ringing a large church bell."

Back in the 16th century, herbalists used lemon balm to ‘quicken the senses', and now laboratory tests at Northumbria University have shown that, taken in dried form, this common herb helps people learn, store and retrieve information. Grow it in the garden and brew it as a tea.

You will never need to worry about leaving your shopping list at home if you get your brain to do the work instead. "Memorise your list by mentally placing each item you need along a route you know well, such as your walk to the shops," Jonathan Hancock advises. "So, for instance, you might visualise tomatoes squashed into the hall carpet; bananas planted in the garden, wine trickling down the garden path, and so on. To recall the list, simply retrace your mental journey and find all the reminders that you have left for yourself." For a free memory test, visit Jonathan Hancock's website (www.memorypower.org) which has details of his memory improvement courses.

It's no coincidence that the word ‘sage' derives from the Latin savere (‘to be sensible'). In research at Northumbria University and the University of Newcastle upon Tyne, volunteers who took a capsule of sage oil beforehand performed better in memory tests than those given a placebo. Add the herb to your cooking in good measure or make a tea brewed from the fresh leaves (always preferable to dried).

Protect brain cells from the damage age brings by eating a diet rich in antioxidants - found in fruit, vegetables, nuts and seeds. "Berries are a particularly rich source," Natalie Savona says, "and so is fresh thyme - use it when roasting vegetables or making soups and casseroles."

Sharpen your wits with a piece of chewing gum. UK psychologists found that people who chewed during tests for both long- and short-term memory scored much higher than those who hadn't been chewing. The reasoning is that chewing increases heart rate, so boosting the oxygen supply to the brain.

Get tramping through the countryside, or take up any exercise that will get your heart pumping faster for 30 minutes at least twice a week.  "Aerobic exercise generates brain-nourishing chemicals that act like fertiliser, helping to grow new brain cell connections," Professor Robertson says. "If you only do one thing to improve your memory, make it exercise."

The ‘spaced retrieval' system makes sure you never forget important information, Professor Robertson says. "This means learning something, recalling it after a few seconds, then after a few minutes, a few hours, and so on. This is a powerful way of firmly storing information."

Exercising the brain by constantly giving it new things to learn will help it stay in shape, whether that means going to museums or attending WI talks. "Choose something you're interested in to gain the full benefits," Dr Celeste de Jager says.

Taking up a second language works your frontal lobes - the part of the brain most likely to diminish with age. "Learning a language is good brain training, because it involves all your senses and requires constant concentration," Tony Buzan says.

Regularly drinking green or black tea could help prevent age-related memory loss, according to scientists at the Medicinal Plant Research Centre at the University of Newcastle upon Tyne. Chemicals in tea are thought to block enzymes that destroy acetylcholine, a neurotransmitter that carries messages between brain cells.

People who have plenty of social contact with others are less likely to develop serious memory problems, evidence suggests. Researchers at the University of Michigan found that socialising stimulates the mind, keeping memory and mental ability sharp.

Iron helps carry oxygen around the body, including to the brain, so if iron levels drop, you may start to feel your memory fogging. Maintain healthy levels by eating iron-rich foods such as chicken, fish and dried apricots - washed down with a glass of fruit juice, as vitamin C aids iron absorption. Don't start taking an iron supplement without getting your iron levels checked by a doctor, Natalie Savona advises.

"Forgetting takes up more time than remembering," Tony Buzan says, so help yourself out by having a place where you always put things like your car keys. "Think of the amount of time you spend looking for things and the tiny amount of time you would need if things were always in the same place."