A team of researchers at Georgetown University, Washington DC, have discovered the world’s first blood test to predict Alzheimer’s. By determining the presence of certain chemicals in a blood sample, the test can be used to identify whether someone will contract the condition. The current range for detection is between 2 to 3 years before symptoms start to show, though it is hoped that development could lead to predictions more than a decade in advance. There are already several types of blood test that can detect the condition once symptoms have shown, however this is the first of its kind with the sensitivity to flag Alzheimer’s before its onset.
Alzheimer’s is currently incurable, though it is believed that lifestyle changes may be able to delay the onset of dementia. The vascular effects caused by Alzheimer’s and dementia can potentially be slowed by eating a healthy diet, making sure to exercise regularly, avoiding overconsumption of alcohol and refraining from smoking. As well as taking care of one’s body physically, there is also some evidence to suggest that increased mental activity can help prolong the life of a healthy brain. The NHS recommends learning new languages, musical instruments or sports as ways of keeping socially and mentally active.
Typically, a brain affected by Alzheimer’s shows a build up of amyloid and tau proteins. The research conducted at Georgetown University showed that Alzheimer’s affected brains would also have depleted levels of certain metabolites before build up of other proteins.”We think the decrease in these chemicals reflects the breakdown of neural populations in the brain,” says team member Mark Mapstone. He also believes that the test could be used to predict Alzheimer’s much earlier, maybe even by several decades: “These metabolic changes might occur 10 or 20 years earlier – that would give us a real head start”.
During the same research period, the team also catalogued the genome sequences of patients. Supposedly, the changes in the participants’ genes could offer even better predictions than metabolite levels. Federoff said: “The gene changes are linked to the metabolite changes, so we’re hoping to put all this together to provide a more complete description of the underlying pathology. What’s most exciting is that we know the function of all the affected genes so if we can intercept these changes, they might make good candidates for new drugs.”
In the absence of a cure, would people be willing to take a test for Alzheimer’s? According to Mapstone, they would: “In my experience, the majority of people are very interested to know whether they will get Alzheimer’s. They believe that knowledge is power – particularly when it comes to your own health. We may not have any therapy yet but there are things we can do – we can get our financial and legal affairs in order, plan for future care, and inform family members.” Regarding the potential for decades worth of notice, he commented: “Imagine what you would do in your early 40s to slow the onset […] You could eat the right foods, avoid head trauma or do more exercise.”
Tracy Young-Pearse (Harvard Medical School) also has faith in the test. “In the short term, I think some people would want to know” she said. If some way of preventing neurons from ceasing to function correctly, then the test would obviously become more appealing to most people.
Should a treatment for Alzheimer’s eventually be found, how might this blood test affect future generations of potential dementia patients?