text: No matter how young or old we are, most of us experience the odd memory lapse. Perhaps it will be forgetting where you put the car keys, or what you went to get from upstairs. Thankfully, these moments pass. But for those with dementia there is no such relief. Imagine what it's like being unable to recall what you'd done an hour before. Or not remembering how to navigate around your own house or the names of your nearest and dearest. Or knowing what everyday things are for, such as a fridge. Today, in the third part of our major Good Health series on dementia, we look at ways to help minimise the impact of these memory problems, to prolong independence and help those with dementia live as full a life as possible. Scroll down for video . Older people find it harder to reach a deeper sleep - but they still need just as much . THINGS THAT SABOTAGE YOUR MEMORY . Getting overtired: If the brain is tired, it affects the memory even for those without dementia. Recently, scientists have found out why. During deep sleep, brain waves move memories from the hippocampus - the area of the brain that is involved in short-term memory - to the prefrontal cortex at the front of the brain, where long-term memories are stored. If this doesn't happen, short-term memories get overwritten with new ones and the consequence is forgetfulness, according to researchers at the University of California, Berkeley. It is a common misconception that we need less sleep as we get older - in fact we need just as much, the problem is that older people find it harder to reach a deeper sleep. Getting a good night's sleep can be especially difficult for those with dementia, especially those with Alzheimer's disease who may experience changes to their sleeping patterns. Quite why this happens is not understood, but it may be related to the impact the condition has on the brain. But there are steps that can make it easier. One of the most important measures is to avoid catnapping during the day (this becomes harder to avoid as dementia becomes more advanced). Catnapping makes it both harder to fall asleep at night and more likely you'll wake up earlier than desired. Other steps include avoiding caffeine - coffee or tea - in the evening. A regular bedtime is also important as this gives the body the cues it needs to feel sleepy at set times, making it easier to fall asleep. Although many people believe a nightcap will help them sleep, alcohol is counter-productive and tends to make you wake in the night. It is a diuretic and, therefore, you are likely to wake up needing to go to the loo. It is also known to reduce the amount of the night you spend in deep, restorative sleep. Regularly eating food high in fat and sugar leads to inflammation in the hippocampus . Eating too much junk food: Cakes, chips and biscuits won't just impact on the waistline - they can adversely affect your memory, too. Recent research has found that regularly eating food high in fat and sugar leads to inflammation in the hippocampus. Scientists at the University of New South Wales, Australia, found that eating these foods every day caused inflammation in the brain after just one week. The work was done on rats, but it is thought the principle could extend to humans. Smoking: Many studies have found that even occasional smoking can impact on the brain. One study, from King's College London, analysed 8,000 over-50s and found that smokers performed worst in memory tests, learning ability and reasoning. Why this happens is thought to be linked to the fact that smoking reduces the amount of oxygen that reaches the brain. Those who have smoked have also been shown to have greater overall shrinkage of the brain. Not 'using it': When someone is diagnosed with dementia, they often start to withdraw from their normal hobbies and activities. Yet to retain your mental ability and memory skills for as long as possible you need to keep the brain stimulated. Think of it this way: just as our bodies need physical exercise in order to stay as strong as possible so, too, do our brains. It's a tried-and-tested principle: for example, a review of 15 studies by the respected Cochrane Library looked at the benefits of a variety of activities designed to stimulate the brain and promote memory such as word games, puzzles, listening to music and practical activities such as baking and indoor gardening. The studies involved 718 participants with dementia - some took part in these activities and others did not. After between one and three months those who'd taken part in the brain stimulating and practical activities did better on cognitive function tests than those who did not. TIPS TO HELP WITH A FAILING MEMORY . A failing short-term memory is a characteristic of dementia and can make it difficult to cope with day-to-day life. The following strategies may help: . One of the most important measures is to avoid catnapping during the day . Have set meal times, as these are easier to remember - and write them down on a whiteboard to help recall what time is meal time. The Mediterranean type of diet may be most beneficial as it's been shown to maintain the health of the blood vessels, and keeping a healthy circulation is key for people with dementia as it ensures a healthy flow of blood to the brain. Try to include oily fish such as trout, salmon or mackerel three times a week: the latest research suggests this is a good way to stop brain shrinkage. These fish contain omega-3 fatty acids and research has found that people with the highest level of these have less shrinkage in the hippocampus, the area associated with memory. To confirm a diagnosis of dementia or to access specialist services, a GP can refer a patient to a memory clinic. Normally, these are based either at a community clinic or at a hospital. They will have a team of psychologist nurses and doctors. As well as running tests that can help provide a diagnosis, they co-ordinate a range of services to help the dementia patient. For example, all clinics will offer cognitive stimulation therapy. This takes the form of group activities and exercises the patient is invited to attend twice a week for seven weeks. These activities could involve word games or even singing and have been found to help improve language skills and comprehension. Each session lasts for about 45 minutes. You cannot simply attend a clinic - you need to be referred. Typically, there is a four-to-six week wait after referral for an appointment. If the patient is too infirm or incapacitated to attend, most clinics can offer a home assessment by one of the community mental health team. Do it in chronological order. Having a history of their life can help them remember and, as the condition progresses this book may also be useful to bring out to show them if they seem distressed. Asking the person with dementia to reminisce and recall stories about the people or events shown in the pictures can also be a good way to 'use it'. Dr Souter is a retired GP and fellow of the Royal College of General Practitioners. Adapted by LUCY ELKINS from Your Guide To Understanding And Dealing with Dementia by Dr Keith Souter, published by Summersdale, £8.99. Order at www.mailbookshop.co.uk, or call 0808 2720808, p&p is free for a limited time only.
target: This is the third part of our major Good Health series on dementia .
  We look at ways to help minimise the impact of memory problems .
  For example, we need just as much sleep as we get older .
  The problem is that older people find it harder to reach a deeper sleep .
  When the short-term memory starts to go, it can make it hard for someone to recall what they have already done that day, such as whether they've had breakfast, or showered, or spoken to someone.
  It can help to keep a diary - a record of what has been done through the day. Writing also helps encourage the cognitive processes, which can help slow down future decline.
  Create a memory hub - that is, a central place in the home, perhaps the dining room table or a desk, where important notes, car keys, house keys and drugs that need to be taken are kept. Put things here that you want to be able to find quickly. Get into the habit of having everything in this one place rather than having things scattered about the home.
  Get a whiteboard or blackboard - that can be used to record a timetable of what needs to be done each day that week. Things that get done can be ticked off. It is another way to show what has been done, but also shows what remains to be done.
  Label doors, drawers, cupboards and cabinets to avoid confusion about what goes where.
  Have a list of the numbers of key people by the phone - your GP and other care professionals, carers, family and reliable friends.
  Have a daily newspaper delivered - it is a simple way of keeping aware of what is happening in the world and is a useful reminder of that day's date.
  When showering or having a bath, establish a routine as a reminder of whether your hair has been washed. For example, move the conditioner and shampoo from one side of the bath to the other once you've used them.
  Eat regular meals. While other body cells can take fuel from elsewhere, the brain relies on a good supply of glucose from the blood. That's why skipping a meal can affect reasoning, cognition and memory.
  In the early stages of dementia, begin a reminiscence book to act as a reminder of key events in that person's life and who people are. It's a nice thing for the person with dementia and a loved one to do together. Include pictures and snippets of information and date and label every entry.