Losing weight could be a warning sign for dementia which will strike more than a decade later.
A study of almost 5,400 older people tracked their health for up to 11 years, during which time 1,078 people developed dementia.
Researchers found those with dementia, compared to dementia-free people of a similar age, tended to lose more weight in the years before they were diagnosed.
People with dementia in the study had a lower body mass index (BMI) from approximately seven years before they were diagnosed with the memory-robbing condition.
Their waist circumference was smaller from about a decade before they received a dementia diagnosis.
Experts believe the condition actually begins years before it causes memory loss – involving changes in regions of the brain which control the appetite and those which control how fast the body burns off food.
This is why someone could lose weight, and why that weight loss could be a red flag that they are in the very early stages of dementia.
However, this knowledge means someone with unexplained weight loss in later life could seek help from their doctor earlier, getting treatment faster, which could slow down how fast their dementia progresses, giving them extra months or years with better quality of life.
Unintentional weight loss could be a warning sign of dementia in later life, experts say
Dr Zimu Wu, who led the study from Monash University in Australia, said: ‘Our findings suggest that unintentional weight loss, especially over several years, could be a warning sign of dementia.
‘Recognising these changes may help identify individuals at higher dementia risk earlier, for earlier intervention and better support.’
The research, published in the journal JAMA Network Open, looked at people over the age of 65, free from dementia and major cognitive problems, who also did not have cardiovascular disease or physical disabilities, and who had signed up to a large health study which began in 2010 across the US and Australia.
For every person in the study who later developed dementia, a comparison was done with four people who did not get dementia, who were no more than a year older or younger, with the same gender, race, ethnicity and education level.
All of their health readings over time were compared.
Men and women with dementia had a significantly higher rate of weight loss, judged using BMI and waist circumference.
The weight dropped off these people faster than it did for people who were not later diagnosed with dementia.
Dementia is the memory-robbing condition plaguing nearly 1million Brits and 7million Americans
Weight loss may also occur if people in the very early stages of dementia are having problems with their brain which make it harder to plan to buy groceries and to prepare and cook meals.
People with dementia in the study had higher levels of the so-called ‘good’ cholesterol called HDL, approximately five years before their diagnosis, although it levelled off in the four years before they were diagnosed.
This cholesterol may be increased because the brain uses it to clear away a protein called amyloid which sometimes builds up in the brain in old age, and can be part of dementia.
The results showed people who got dementia did not have significantly different levels of blood pressure, a type of fat in the blood called triglycerides, or higher total cholesterol.
Dementia in the study was diagnosed by an expert panel of geriatricians and neurologists, based on many measures, including people’s ability to carry out daily tasks and their memory, after people were asked about their use of dementia drugs and if they had reported concerns they might have dementia to their doctor.
The study notes that people who had dementia tended to live alone, which can mean less support when it comes to preparing meals, and less encouragement to sit down and eat them, so that they may lose weight.
Dr Wu said: ‘Weight loss alone doesn’t mean someone will develop dementia, but maintaining a balanced diet, regular physical activity, and cognitive engagement could help support brain health.
‘If unexpected weight loss occurs, it’s worth discussing with a doctor.’
