KEEPING the brain active and eating a healthy diet are the best ways to protect against dementia in old age, say experts.
Two breakthrough new studies have revealed that being good with words and eating just a handful of walnuts every day can help stave off the ravages of the brain disease.
The simple tips mean that millions of people could protect themselves from Alzheimer's in old age by introducing the easy changes to their daily lives.
There is increasing evidence that the key to beating the disease is to keep the brain active from middle age and to ensure a diet packed with health-boosting vegetables, fruits and nuts is followed.
Proving the old adage "use it or lose it", a new study has shown that being good with words could help stave off ageing conditions including dementia.
Experts have discovered that having a rich and varied vocabulary, just like TV personalities Stephen Fry and Will Self, protects against brain decline.
As people get older, their brain's intelligence is put under strain.
But researchers from the University of Santiago de Compostela in Spain have studied what factors can help to improve this ability and they conclude that having a higher level of vocabulary is one such factor.
"Cognitive reserve" is the name given to the brain's capacity to compensate for the loss of its functions.
With over 830,000 people in the UK living with dementia and that number on the increase, investment in research to find ways to prevent the condition is crucial
This reserve cannot be measured directly; rather, it is calculated through indicators which are believed to increase this capacity.
Cristina Lojo Seoane, co-author of the study published in the journal Annals of Psychology, said: "We focused on level of vocabulary as it is considered an indicator of crystallised intelligence - the use of previously acquired intellectual skills.
"We aimed to deepen our understanding of its relation to cognitive reserve."
The research looked at 222 healthy individuals and 104 with mild cognitive impairment who were over the age of 50.
They measured their vocabulary levels as well as analysing their years of schooling, the complexity of their jobs and their reading habits.
They also analysed the scores they obtained in various established vocabulary tests.
Ms Logo Seoane said: "With a regression analysis we calculated the probability of impairment to the vocabulary levels of the participants."
The results revealed a greater prevalence of mild cognitive impairment in participants who achieved a lower vocabulary level score.
She said: "This led us to the conclusion that a higher level of vocabulary, as a measure of cognitive reserve, can protect against cognitive impairment."
A second study, from experts at New York State Institute for Basic Research in Developmental Disabilities (IBR), revealed that eating a diet packed with a handful of walnuts every day can have a major impact on keeping dementia at bay.
The new research, published in the Journal of Alzheimer's Disease, found that potent ingredients in the popular nuts can have a beneficial effects in reducing the risk, delaying the onset, slowing the progression of, or preventing Alzheimer's.
Led by Dr Abha Chauhan, the study found significant improvement in learning skills, memory, reducing anxiety, and motor development in mice fed a walnut-enriched diet.
The researchers believe that it is the high antioxidant content of walnuts which may protect the brain from the degeneration typically seen in Alzheimer's.
Oxidative stress - the damage caused by molecules that the body naturally produces - and inflammation are both major causes of the disease.
Antioxidants protect the brain and other body cells from the damage caused by chemicals known as free radicals which cause oxidative stress.
This causes damage to DNA, proteins and fat molecules in the brain cells.
The new study shows that walnuts in the diet can help protect against this damage.
Dr Chauhan, said: "These findings are very promising and help lay the groundwork for future human studies on walnuts and Alzheimer's disease - a disease for which there is no known cure.
"Our study adds to the growing body of research that demonstrates the protective effects of walnuts on cognitive functioning."
The researchers examined the effects of dietary supplementation on mice with six per cent or nine per cent walnuts, which are equivalent to one ounce and 1.5 ounces per day - around a handful - of walnuts in humans.
This research came after a previous study by Dr Chauhan that highlighted the protective effects of walnut extract against the oxidative damage caused by the amyloid beta protein.
This protein is the major component of amyloid plaques that form in the brains of those with Alzheimer's disease.
Walnuts are also packed with vitamins and minerals and are the only nut that contains a significant source of alpha-linolenic acid, an omega-3 fatty acid with heart and brain-health benefits.
The researchers also suggest that ALA may have played a role in improving the behavioural symptoms seen in the study.
Dr Laura Phipps of Alzheimer's Research UK, said: "There is evidence to suggest that keeping the brain active may help boost 'cognitive reserve', allowing the brain to resist the early damage from diseases like Alzheimer's for longer.
"Some studies have linked particular diets to a lower dementia risk, and although it's unlikely that any single food will be able to prevent the condition, a healthy, balanced diet may help reduce the risk of dementia as part of a healthy lifestyle.
"With over 830,000 people in the UK living with dementia and that number on the increase, investment in research to find ways to prevent the condition is crucial.
"In the meantime, the best evidence suggests that eating a healthy diet, doing regular exercise, not smoking, and keeping weight and blood pressure in check can all help to lower the risk of dementia."