How do you ask someone at risk of dementia to participate in a study in which they might receive a placebo and miss out on a therapy that could prevent them from slipping into a prolonged and very challenging end of life?
This is the ethical dilemma that that prevents clinical researchers from mounting such a study. So in lieu of clinical trials, research into the prevention of Alzheimer’s disease (AD) is mostly confined to laboratory animals. It’s far short of the double-blind, placebo-controlled gold standard, but this sort of research is still very useful in revealing promising therapies.
A new trial does just that, and also confirms the results of previous trials, giving hope to those diagnosed with the early symptoms of dementia.
Yesterday’s e-Alert, “Good Catch” (4/25/07), had good news about a new technique that may revolutionize the way doctors diagnose Alzheimer’s. As promised, today I’ll look at two ways that patients in the earliest stages of Alzheimer’s may be able to help delay the onset of the disease.
A 2002 Canadian study found that Alzheimer’s patients and elderly patients with various types of dementia all had lower levels of docosahexaenoic acid (DHA; an omega-3 fatty acid) than subjects with normal cognitive function. And in a follow up study, researchers analyzed ten years of data taken from more than 1,100 elderly men and women. Results showed that those with high levels of DHA had nearly 50 percent reduced risk of developing AD.
In the current issue of The Journal of Neuroscience, researchers from the University of California, Irvine, report on a study that sheds new light on the use of omega-3 fatty acids in AD treatment.
Researchers used mice that were genetically altered so they would develop the waxy amyloid brain plaques that are common in AD
When DHA was added to mouse food, accumulation of amyloid plaques was reduced, as was another protein that contributes to plaque formation
When omega-6 fatty acids were added to food, the positive benefits of DHA intake were diminished over the course of a year
As I’ve noted in previous e-Alerts, omega-6 fatty acids are far more common in the average western diet than omega-3s. The ideal ratio of omega-3 to omega-6 intake is 1:1 – a ratio that’s hard for most of us to reach without making a special effort to reduce omega-6 intake and increase omega-3.
Walnuts and flaxseed contain omega-3 fatty acids, but only fish contains both DHA and eicosapentaenoic acid (EPA). When combined, these two essential fatty acids have been shown to help prevent depression, as well as heart disease, arthritis, influenza, hyperactivity, and even some forms of cancer.
The UCI study provides a good follow up to a similar study conducted at UCLA, and also reported in The Journal of Neuroscience.
Researchers divided older mice into three groups to receive different diets: a low-DHA diet, a high-DHA diet and a DHA-free diet. After three months, the UCLA team analyzed tissue samples from different sections of the mouse brains. They found that amyloid plaque was significantly reduced in mice on the high-DHA diet, while total amyloid accumulation was more than 70 percent less in mice that received a high-DHA diet when compared to those in the DHA-free group.
Sage is another natural agent that has been shown to help control the advance of Alzheimer’s. Researchers at the Medical Plant Research Centre (MPRC) in the UK have shown that sage inhibits an enzyme called acetylcholinesterase (AChE), which breaks down acetylcholine, a neurotransmitter chemical that’s typically deficient in Alzheimer’s patients.
Elaine Perry is the director of the MPRC and a professor the University of Newcastle upon Tyne. She and her colleagues have studied a variety of botanicals in the treatment of Alzheimer’s. In 2004, Professor Perry presented data that showed sage to have a significant effect on behavior and attention. And when lemon balm was added to sage, the combination improved memory and mood.
Professor Perry told Reuters Health: “Lemon balm reduced agitation and improved quality of life in people with Alzheimer’s disease.”
Talk to your doctor before using sage, lemon balm, or omega-3 supplements to address Alzheimer’s symptoms.
“Dietary Docosahexaenoic Acid and Docosapentaenoic Acid Ameliorate Amyloid- and Tau Pathology via a Mechanism Involving Presenilin 1 Levels” The Journal of Neuroscience, Vol. 27, No. 16, 4/18/07, jneurosci.org
“A Diet Enriched with the Omega-3 Fatty Acid Docosahexaenoic Acid Reduces Amyloid Burden in an Aged Alzheimer Mouse Model” The Journal of Neuroscience, Vol. 25, No. 12, 3/23/05, jneurosci.org
“Plant Extracts May Ease Dementia Symptoms” Reuters Health, 3/5/04, reutershealth.com