Evidence suggests that if key risk factors for dementia - such as poor nutrition, lack of exercise and unhealthy lifestyles - were addressed, fewer people would have it. We talk to Professor William O'Connor about ways to stave off this condition
1 Wear a helmet
Head injury has been linked to early onset of Alzheimer's later in life, says Professor O'Connor. Some boxers, as well as people who otherwise suffer a head injury, can have a higher risk of contracting Alzheimer's disease, which constitutes about 70pc of dementia cases.
"It's therefore wise to make a point of wearing a helmet if you play sports which can result in a head injury. For the same reason, it's also a very good idea to always wear your seat-belt in the car," he adds.
2 Eat Fish
"A diet rich in fish is a diet low in cholesterol," says O'Connor, who advises that it's sensible to eat oily fish because of the proven link between high cholesterol and dementia.
"When the medical profession started to treat high cholesterol with cholesterol-lowering medication called statins, they discovered they could also delay the onset of dementia for about seven years.
"There is evidence that the only drug known to temporarily reverse the onset of Alzheimer's or dementia is a statin," O'Connor adds.
"Statins may be helpful to people who show signs of early-onset dementia. There is a link between a high-cholesterol diet and dementia," he says, adding that a diet high in animal fats has also been linked to early onset of the condition.
3 Use It or Lose It
"Keep your brain active," says O'Connor. "It's a case of use it or lose it.
"The more you challenge the brain, as you do in education, the fitter and healthier it becomes, which means it can withstand attack in older age from problems such as stress, depression or trauma.
"The more educated you are and the more effective you've been in using your brain during your life, the stronger its ability to resist attack," he says.
Interestingly, adds O'Connor, people who are by nature curious tend, on average, to develop Alzheimer's much later in life than people who are not.
4 Eat less sugar
We all know what sugar can do to the teeth and to the figure - but did you know that it's now being linked to dementia?
"Most people with type two diabetes develop the diabetes because they eat so much sugary food and take so little exercise that the body cannot handle the sugar," O'Connor explains.
New research has shown that diabetes, and the rebound hypoglycaemia (low blood sugar) it causes, may exacerbate the risk of developing dementia and Alzheimer's disease.
Scientists now believe there is an association between hypoglycaemia and dementia.
The brain uses glucose (sugar) as a primary source of energy, and cognitive function becomes impaired when blood glucose drops to low levels.
Basically, diabetes impairs the production and regulation of insulin which helps blood cells take up glucose.
This means that for diabetics, getting a regular supply of glucose to the brain is more difficult. Scientists now believe that when the brain is starved of energy, neurological problems like dementia and Alzheimer's are more likely to develop.
5 Lose weight
Scientists now believe there is a link between midlife obesity and a higher risk of developing dementia. "Once the body is extremely overweight or obese, the deposits of fat can become unstable," O'Connor explains. "The fat becomes metabolically or chemically unstable and can become inflamed.
"That inflammation may then spread around the body - including to the brain. Inflammation in the brain is believed to be linked to dementia," he says.
During a study in the US with the anti-inflammatory drug ibuprofen, he explains, researchers noticed that of the patients who later went on to develop dementia, those who took the drug had a more delayed onset of dementia than people who didn't.
"The anti-inflammatory effect of ibuprofen helped to temporarily protect them from dementia.
"This led to the theory that dementia, including Alzheimer's, may actually be a form of brain inflammation. Obesity is a source of inflammation," he says, adding that the process of inflammation which can trigger Alzheimer's can begin in a person who is obese in their 20s or 30s.
"If it not treated, and is left there for decades, it can suddenly start to have an adverse effect elsewhere in the body, including the brain."
6 Don't smoke
Smoking causes lung inflammation, says O'Connor. "It obstructs the lungs, and can cause chronic obstructive pulmonary disease.
"This means the lungs are not able to get as much oxygen as they need and you end up damaging the lungs, and the lung tissue."
Insufficient oxygen supplies to the brain lowers the brain's energy levels, thereby impairing its ability to protect itself.
Meanwhile, the nicotine damages blood vessels everywhere in the body, including in the brain.
By damaging the blood vessels, nicotine can help cause high blood pressure and damage the nerves in the brain. When we smoke, says O'Connor, "we are essentially compromising the ability of our nervous system to fight infection and protect itself."
7 Treat your depression
It's now believed that depression can be a factor in the onset of dementia. "There is evidence now that depression may be a brain inflammation in the frontal part of the brain - while Alzheimer's is an inflammation in the hippocampus," says O'Connor.
If you're suffering from depression, get it treated, he says, because inflammation weakens the ability of the brain to fight infection.
"Depression is also about withdrawal from society so being depressed means you're less open to doing things and that means you aren't challenging your brain."
When we are depressed, we also don't always eat well and often don't feel like exercising.
Therefore, warns O'Connor, depression can affect the brain both on a physical and psychological level.
"However, studies have shown that a 90-minute walk in nature can help to get rid of repetitive negative thoughts and worries.
"That's because you take notice of what's around you and observe beautiful things in nature. You're not just exercising your body by walking, but also exercising the brain."
We tend not to be as aware of our surroundings in an urban setting, he says. "In an urban setting we tend to go into our own heads more," he adds.
In fact a 90-minute walk in nature can be significantly more therapeutic than a walk on a treadmill in a gym.
"Recent studies have shown that with depression it is the quality of your exercise that matters," he adds.
8 Be physically active
"If you're physically inactive, you're not introducing oxygen to the body - and the brain needs huge amounts of oxygen because it's so active, even during the night.
"The brain can use more oxygen in some phases of sleep than when we're awake during the day," he says. Depriving the brain of oxygen prevents it from learning, ie making new connections and repairing itself - let alone getting on with the normal processes of growth and development, he warns.
9 Watch Your Blood Pressure
High blood pressure is a major cause of stroke, which deprives the brain of life-giving oxygen.
"You can end up with dementia through a series of mini-strokes," says O'Connor.
These can gradually lead to a change in the person's character, which eventually, without appropriate treatment, may develop into full-blown dementia. So avoid a lifestyle which can contribute to high blood pressure - reduce your stress levels, make sure you get sufficient, good quality sleep and avoid drugs linked to high blood pressure such as nicotine, advises O'Connor.
"Imagine an oil heater in a house. If the pipes become clogged, the pump has to work harder and harder to push water through the radiators," he says. Under all this pressure, the system may eventually spring a leak.
In terms of the body and the need to pump blood and oxygen into the brain, the 'clogged pipes' and the 'leak' translate into a stroke - which can cause extensive damage to the brain. "If there's no blood supply coming through, that means there's no oxygen coming to the brain," he adds.
10 Get that ingrown toenail treated!
Seriously - never allow an infection in the body to persist, advises O'Connor.
If you do, he says, it may spread and, over a series of decades, can result in an inflammation which spreads to the brain and may result in dementia.
When we develop an infection, the body responds with a series of chemicals which are supposed to fight it. However, if the infection persists, and goes untreated, these 'warrior' chemicals can spread throughout the body. "They can eventually become indiscriminate in what they fight, so instead of fighting infection, they start to fight the body including the brain," he explains.
Make sure your diet includes lots of vegetables, particularly green leafy ones, and fruit, herbs like rosemary and sage and plenty of fish oil. Vegetables and fruit are packed with health-giving antioxidants which stop inflammation, O'Connor explains.
"Antioxidants are like a fire-blanket on inflammation," he declares.
Eat the rosemary and sage which are cognitively enhancing because they contain chemicals which replace the main neurotransmitter damaged in dementia - acetycholine - which is involved in high-level thought.
Make sure your diet also includes good-quality fish oil - try having sardines on toast once a week, for example, O'Connor suggests. Fish oil is used by the body to make the chemicals to fight inflammation. And drink coffee. "People who drink it are less predisposed to Alzheimer's," says O'Connor. "It's a psychological stimulant and a cognitive-enhancing drug."
12 Watch TG4!
Brush up on your Irish - there's evidence to show that having a second language can help protect you from the onset of dementia.
"It has been discovered that learning a second language exercises the brain so much that it strengthens it and makes it more resistant to fighting the injuries and infection which often result in dementia," says O'Connor. "A Swiss study carried out in the last few years has showed that bilingualism and multilingualism seems to offer protection again the onset of dementia."
13 Buy a Smartphone and play video games
Embrace new technology and experiment with it, he advises. "Get a smartphone because it's good for your brain to work out how to use it properly, especially if you're older," says O'Connor.
He also advises spending time working out how to use the various facilities built into other smart- technology devices.
Play video games with your grandchildren - it will help to keep you mentally on your toes, he believes, while playing bridge either with your friends or online is a great way to wake up the brain.
"Bridge is a game of memory and strategy. It's very challenging for the brain and is also a highly sociable activity."
14 Try some brain-teasers
Use your non-preferred hand once in a while for activities such as brushing your teeth or hair.
This challenges your brain because you are carrying out an unfamiliar activity.
Try wearing your wristwatch upside down - this also forces your brain to do some work.
"It requires the hippocampus to do a mental rotation in order to work out the correct time from the dial," says O'Connor, who points out that the hippocampus is the area of the brain which is the most vulnerable to dementia.
And try learning to juggle - this is a great exercise in hand-eye coordination, says O'Connor, because it involves both physical and concentration. Go buy three oranges now and get on with it, he says. "It's part of a brain-building process which helps your brain fight the injury and infection that may lead to dementia."
15 Get creative! Doodle!
Instead of just looking at art or just listening to music, make your own, O'Connor counsels. Write songs, paint a picture, learn to play an instrument, sing or dance.
"First of all, it's physically active, and secondly you're thinking about what you are doing. Your brain is planning and working instead of simply receiving information."
Make a point of regularly reading challenging material, he suggests, and do 30-minute word searches on Google, picking a word, for example 'starling', and finding out everything there is to know about these birds.
"This is about focused attention," explains O'Connor. It's also good to doodle, he believes.
"Doodling is a healthy mental exercise because it is a creative act. It's a sign that what you're currently doing is not sufficiently challenging. Doodling is positive because it's a creative and focused activity."
* For more information visit inside-the-brain.com. Professor William O'Connor is head of teaching and research in physiology at the Graduate Entry Medical School, University of Limerick