Author: Brandon Tavshanjian

New Technologies: Can New “Slippery” Brain Drugs Better Treat Neurodegenerative Disease?

Treating neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, among others) is a challenging project from the start. Not only do scientists have to counteract multiple problems, they also have to deal with the fact that the brain is a complex organ with: 1) different areas that perform different functions and have different cell types and 2) defense mechanisms not present in other organs to protect it from toxins. This blog examines one potential way in which scientists are addressing these challenges.

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The Adult Stem Cell Revolution: How Regenerative Medicine Rediscovered Old Science

If you’ve read this blog on a regular basis, you’ll note that we have brought up the topic of “adult stem cells” when discussing aging or regeneration (see our blog on how stem cells age). This is because a lot of current research focuses on how adult stem cells maintain health and proper functioning of our tissues and organs. But knowledge of adult stem cells and their importance to aging wasn’t appreciated until fairly recently. So why the current interest in stem cells? After all, stem cells have been well known to developmental biologists and medical scientists for over 100 years, since early embryos are basically made entirely of stem cells. The notion of stem cells playing an important role in adults is slightly more recent. As early as the 1850s, German physician Rudolf Virchow proposed that cancer arises from embryonic-like cells, and further work by Julius Cohnheim showed that these “embryonic remnants” were still present in adult tissue. By the 1930s, medical pathologists began to understand that adult stem cells (bone marrow “hematopoietic stem cells”, HSCs) formed the basis for our continually regenerating blood supply and immune system. By the 1960s, scientists had discovered that these stem cells had a wider use than expected, even being able to produce skin and bone cell types. But for a long time, stem cells were really only discussed among hematologists and...

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Why “selection bias” should affect the way you view alcohol consumption

Previously, we talked about one reason why studies of Alzheimer’s disease (and other aging diseases) can be hugely complicated: scientists have to rely on observational evidence and are only able to experiment on humans in narrow circumstances. This means that it’s sometimes difficult to tell the difference between cause and effect. In the case of Alzheimer’s, it meant it was difficult to tell the difference between “side effects” of a disease process and the actual cause, meaning scientists can spend a lot of time developing treatments for something that may not be causing the actual disease. Another problem with clinical studies arises when we try to study the impact of so-called lifestyle factors (exercise activity level, diet) on aging and disease. Since we usually can’t control peoples’ daily lives, we have to use metrics to group people into categories…and those categories can mean something completely different than what you might expect. The best example of this is in studies of alcohol consumption on aging health. Depending on the study, alcohol consumption either has a U-shaped effect (worse in no or heavy drinkers) or a linear effect (better with more alcohol) on a wide variety of health outcomes, including cognition, cardiovascular disease, and overall protection from death. This has led to a small number of physicians to recommend that mild alcohol consumption is beneficial. But a new study done on...

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SAGE Review: Focus on the Liver as a Regulator of Metabolism

While everyone’s familiar with the liver’s detoxifying functions (especially after a night of friendly drinking), most people are less familiar with the role of the liver as a regulator of “fuel” molecules in the blood: the liver stores and synthesizes glucose as needed, as well as being responsible for clearing excess cholesterol/fats from the body which are received as HDL (“good cholesterol”) and excreted into the intestines as bile. While the liver is generally considered one of the more resistant organs to aging, there are important changes in its structure during aging that result in overall declined function in the elderly, and because of the organ’s central role in controlling blood metabolism, these changes can have whole-body effects. Accordingly, dysfunctions in the liver have been investigated in aging-related metabolic diseases (type II diabetes, for example), cardiovascular disease, and chronic kidney disease. Below are two studies that focus on understanding the role of the liver in metabolic diseases as well as interventions aimed at improving liver function in disease. Insulin lowers levels of a diabetes risk factor in blood by signaling in the hypothalamus Recent research in obesity has focused on levels of branched-chain amino acids (BCAAs: leucine, isoleucine, and valine) as both a marker for people at risk for obesity/diabetes and as a contributor to disease; obese patients and those at risk of diabetes have elevated concentrations of BCAAs...

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Why Vitamin Supplements Aren’t Doomed—At Least When it Comes to your Old-Age Brain Health

If you follow health reporting by outlets like Salon or the New York Times, you might know that the last several years have been dark times for vitamin manufacturers. Despite about half of Americans using vitamin supplements and even the Harvard School of Public Health recommending a daily multivitamin as a “nutrition insurance policy”—the data just hasn’t seemed to hold up. In both pooled analyses of clinical trials and direct intervention with multivitamins with clinical trials, researchers have largely failed to see any large health benefit to your daily multivitamin. Some outlets have even gone so far as to call the entire vitamin industry a scam. But this isn’t the end of the road for vitamin supplements in general. Supplementation with individual vitamins still shows promise for reducing the threat of aging related diseases, as a groundbreaking study showing that normal vitamin D levels significantly reduce the risk of Alzheimer’s and general dementias now demonstrates. Re-analyzing data: Double the bang for your buck! Using a remarkably frugal approach, researchers primarily based at the University of Exeter Medical School re-analyzed samples from the 1992-1999 Cardiovascular Health Study for vitamin D levels and followed up with patients from the study to see which ones developed symptoms of dementia (the clinical term for age-related cognitive impairment, both Alzheimer’s and not). Because the people in this study weren’t specifically selected to be at...

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