Women who develop dementia start to lose weight a decade earlier

Researchers in the U.S. have discovered that prior to developing dementia, women experience a decline in weight as early as 10 years before they begin to lose their memory.

Researchers at the Mayo Clinic in Minnesota carried out a retrospective study on a group of women by analyzing the medical records of those seen by doctors in Olmsted County, who were diagnosed with the onset of dementia between 1990 and 1994.

Lead study researcher Dr. David Knopman, a Mayo Clinic neurologist says they saw that the weight of those women who developed dementia was drifting downward many years before the onset of symptoms.

He believes this illustrates that changes occur before memory loss and mental decline in dementia and the brain disease begins to interfere with the maintenance of body weight, long before it affects memory and thinking.

The team compared 560 women along with another group of similar age who did not develop dementia.

Weight was identified for the year of dementia diagnosis and then for the 20 to 30 years preceding and the weights of those patients who didn't develop dementia were tracked over the same period.

Knopman says the women who did not go on to develop dementia, were on average 140 pounds at the outset and 142 pounds at the year of their peers' dementia onset.

The women who developed dementia started off at the same weight as those who didn't develop dementia, but then their weight drifted downward to 136 pounds 10 years before symptom began and 128 pounds when symptoms appeared.

Why the women who developed dementia steadily lost weight is unclear but the investigators suspect that they may have less initiative and lose interest in eating, or might have a duller sense of taste and smell, or they might experience an earlier sense of being satiated.

The team say as the weight loss is not evident in men with dementia it may be linked to postmenopausal hormonal changes.

Other experts also say that low oestrogen levels in women have been shown to increase the risk of dementia.

Dr. Knopman says the discovery is unlikely to be useful for the diagnosis of dementia, but hopes the research may lead to a better understanding of dementia and how it develops.

Dementia is a neurological disorder affecting a person's ability to think, speak, reason, remember and move and the most common forms are Alzheimer's disease, vascular dementia and Lewy body dementia.

The research was presented at the Alzheimer's Association International Conference on Alzheimer's Disease and Related Disorders in Madrid, Spain.