Alzheimer's Disease Watch
No Effect of Anticholinergic Drugs on AD Patients
There has recently been much debate over anticholinergic medications and whether they have a negative effect on elderly patients with Alzheimer’s disease (AD), either by decreasing cognitive function even further or by causing cholinergic medications used in the treatment of AD to become less effective.
A study published in Age and Ageing in December 2011 studied this effect. Conducted by researchers from the British Geriatric Society, the Laser-AD Study examined a cohort study of 224 participants with AD. Baseline anticholinergic scores that included all prescribed and OTC medication use were calculated, and cognitive function was measured at baseline and at 6- and 18-month followups using the Mini-Mental State Exam (MMSE). After adjusting for baseline cognitive function, age, gender, and use of cholinesterase inhibitors, the study showed no differences in MMSE scores and other cognitive functioning at either 6 or 18 months between those with and those without a high anticholinergic load.
Because of the ubiquity of anticholinergic medications in the elderly population— they are used to treat a variety of conditions, including psychiatric conditions, cardiac disease, bladder illnesses, and insomnia—examining whether they have a negative impact on elderly patients with AD is very important. Although this study does not demonstrate a clear link between cognitive decline and the use of anticholinergic medications, the researchers warn, studies that include different patient populations, such as those who are still cognitively intact, should be performed to further examine a possible link between the use of anticholinergic medications and the development of AD.
Researchers Discover Potential Biomarker for AD
A biomarker has been discovered in serum samples that may predict future development of Alzheimer’s disease, even before symptoms of cognitive impairment are present.
The study, published online on December 13, 2011, in Transitional Psychiatry, followed a cohort of 143 elderly patients with mild cognitive impairment. Blood samples were collected at baseline and during the follow-up period of 27 months. Of the 143 patients with mild cognitive impairment, 52 progressed to AD. Although 3 metabolites in the blood were found to predict who progressed to AD, the one that was statistically significant was 2,4-dihydroxybutanoic acid (P = .0048), a metabolite that predicts potential hypoxia in the brain. Independent studies have shown oxidative stress to be a key characteristic in patients in the beginning stages of AD.
The authors of the study conclude, “Establishment of pathogenic relevance of predictive biomarkers such as ours may not only facilitate early diagnosis, but may also help identify new therapeutic avenues.”
Baked or Broiled Fish May Reduce AD Risk
In an intriguing study presented at the Radiological Society of North America 97th Scientific Assembly and Annual Meeting in Chicago, Illinois, researchers demonstrated that people who eat baked or broiled fish at least once a week may reduce their risk of developing mild cognitive impairment and AD.
The study followed 260 cognitively normal participants 65 years and older from an observational study conducted by the National Heart, Lung, and Blood Institute. Dietary intake of fish at baseline was assessed using a questionnaire. After 10 years, each subject underwent a 3-dimensional volumetric magnetic resonance imaging scan of the brain, and models were created to examine the relation between weekly fish consumption and brain structure at baseline and follow-up.
After adjusting for numerous variables, it was found that participants who ate baked or broiled fish had statistically significant larger volumes in certain areas of the brain, including the hippocampus and frontal lobes, which are the areas responsible for memory and cognition. This difference in size was not statistically significant in participants who ate fried fish.
Although the study is promising in providing more evidence that consumption of fish and omega-3 fatty acids has neuroprotective effects, more studies, including studies that do not solely rely on self-reported questionnaires and that include more participants, are required to solidify this theory.