Dementia experts from 24 worldwide institutions have produced a study that reviews research that has already been produced on dementia, and used them to put a set of recommendations together that will target prevention as well as treatment. The report was presented at the Alzheimer’s Association International Conference, in London, 2017 and published in The Lancet.
The latest estimates suggest that nearly 50 million people worldwide suffer from a form of dementia, and scientists suggest that basic lifestyle changes could prevent up to a third of these cases. Some estimates have suggested that there could be up to 132 million sufferers by 2050.
The scientists came to the conclusion that possible risk factors for dementia should be reduced where possible through every phase of life, from childhood to old age. One of the risk factors identified was where a person stopped their education before the age of 11 or 12. The scientists noted that for maximum benefit, people needed to stay in education until they were at least 15. Middle-aged people should take good care of their hearing and try to minimise hearing loss, watch out for hypertension and manage their weight carefully to avoid becoming obese. The scientists calculated that a person could reduce their risk of dementia by up to 20% by watching their health for these factors.
The scientists also recommended that as people get older that they should avoid smoking, make sure that depression did not get too much of a hold, manage diabetes, be physically active and have an active social life. These factors could reduce their risk of dementia by about 15%. They also noted that maintaining good health and a good diet as well as increasing physical activity was important in all stages of life.
The researchers acknowledged that not all cases of dementia will be prevented by paying attention to lifestyle changes, but that onset of dementia could be delayed by a number of years, delaying some of the costs involved in caring for people with the disease. The scientists acknowledged some of the limitations of the study which included not taking other risk factors into account such as consumption of alcohol, diet, living near major roads or sleep patterns. Studies have also identified these as possible risk factors for the disease. They suggested that the estimates of the number of people who could delay onset of the disease could increase if these factors were taken into account. The nine factors included were:
The scientists found 3 studies on dementia and hearing loss, and each felt that hearing was a significant risk factor for dementia, when followed up over a number of years. It is a relatively new connection with the disease, but studies have shown it to be fairly important as even mild hearing loss could increase the risk. More research is needed as it is not yet understood why hearing loss can have this effect nor whether intervention through the use of hearing aids, could help delay the disease.
Obesity, diabetes and hypertension
These three can be linked, offering vascular risk factors for dementia. Reducing body weight can reduce the risk of developing diabetes as well as dementia.
Smoking offers a high risk factor. The researchers suggested that although there are interventions to reduce smoking, the habit may be increasing in eastern Mediterranean and African countries.
Studies suggest that although part of dementia can appear to be depression symptoms, studies have found that it is mostly in the 10 years before dementia symptoms appear that depression can be a risk factor.
People who take part in regular physical activity are more likely to keep their cognitive function in good working order than those who do not. Observational studies have found links between exercise and a lower risk of developing dementia. Physical activity can also help improve mood, balance, reduce falls and mortality.
Identified by both NICE (National Institute for Health and Care Excellence - UK) and NIH (National Institutes of Health - US) as a possible dementia risk factor which could be modified. The study looked into social contact, including phone calls or face-to-face contact with family and friends, social participation or taking part in community activities or organisations, and loneliness.
Studies show that education at least to the age of 11 and preferably up to 15 can lower the risk of dementia.
Prof. G.Livingston MD, et al., Dementia prevention, intervention and care, July 2017, The Lancet,