Scientists at Georgetown University in Washington DC, US, have managed to accurately predict the onset of Alzheimer’s disease after years of study on a small sample involving 525 people aged over 70 years.
“This research is significant in the quest for a promising therapy for Alzheimer’s dementia especially in Africa. Alzheimer’s dementia is an irreversible disease, and therapies previously tested have been on patients who are already symptomatic,” said Linnet Ongeri, a researcher specialising in mental health at the Kenya Medical Research Institute (Kemri).
The research results published in Nature Medicine, will be a major step forward in treating Alzheimer, which shows symptoms only at a stage when it is too late to treat effectively.
Alzheimer’s disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. It is a neuro-degenerative type of dementia, since the disease starts mild and gets progressively worse. There is no cure for the disease.
Dr Ongeri said the disease is a major problem in people aged 65 and above in Kenya and Africa in general.
“We do not have epidemiological survey data for Kenya to know the exact number though studies in Africa found that the overall prevalence of dementia in adults older than 50 in Africa was estimated to be about 2.4 per cent, which translates to 2.76 million people living with the disease in 2010, “ said Ms Ongeri.
The US scientists showed that testing the levels of 10 different types of fats in the blood could predict, with almost 90 per cent accuracy, whether a person risks being affected by the disease in the next two or three years.
The latest study was led by neurologist Howard Federoff of Georgetown University Medical Centre in Washington DC. The team tested the participants’ cognitive and memory skills, using blood samples taken from individuals at least once a year for five years.
The scientists analysed the blood plasma of 53 participants with mild cognitive impairment or Alzheimer’s disease, including 18 who developed symptoms during the study, and 53 who remained cognitively healthy.
Dr Federoff and his team found the 10 fats (lipid metabolites) were present at consistently lower levels in the blood of most people who had, or went on to develop, cognitive impairment. The team confirmed the results in a set of 41 further participants.
However, scientists caution the study will have to be conducted on large scale, to further validate its accuracy and it might take years.
“The laboratory tests would have to be carried out in much larger populations in order to assess their sensitivity and specificity as well as their predictive value , before they could be recommended for public health problems,” says Dr Ongeri.
The problem with the disease is that it can silently attack the brain for more than 10 years before symptoms appear. Scientists believe drug trials that have been conducted in the past have failed because patients are treated when it is too late to make a difference.
“This is why discovering a test that predicts the risk of dementia is a major priority for the field. The research will hopefully help in the discovery of a treatment that stops the progression of the symptoms of Alzheimer,” adds the Kemri scientist.
There are currently two categories of drugs for Alzheimer’s available in Kenya and other African countries.
Cholinergic treatment approved for mild to moderate Alzheimer’s and Memantine-based treatment for moderate to severe treatment. These medications only offer some relief from the symptoms for a limited time.