The Dollars and Sense of Alzheimer’s

June 19, 2015

By Medical Discovery News

As people age, they begin to worry about developing dementia and its most common cause, Alzheimer’s. Alzheimer’s is a neurodegenerative disease that can affect your cognitive abilities, the ability to function in daily life, and orientation. If that’s not devastating enough, those with Alzheimer’s only live four to eight years on average after diagnosis.

In America, Alzheimer’s is the 6th leading cause of death. Today 5.1 million of those 65 or older are living with this disease, a number that is only expected to grow as the population ages – by 2050 it is projected to affect 13.5 million of those 65 or older. The few drugs readily available only moderate the symptoms, as there is no way to cure, slow, or prevent Alzheimer’s.

Recently, the Alzheimer’s Association published a report called “Changing the Trajectory of Alzheimer’s Disease: How a Treatment by 2025 Saves Lives and Dollars.” It focuses on the costs associated with a theoretical treatment that could delay the onset of Alzheimer’s for five years. If such a thing were discovered, it could have a huge impact on people’s lives and their financial.

Since Alzheimer’s is a disease of older Americans, treatments for it are mostly funded by Medicaid and Medicare. Currently, Medicare covers 80 percent of the total costs of Alzheimer’s care in America, which equates to $153 billion. By 2050, the total costs of caring for those with Alzheimer’s is expected to rise to $1.1 trillion, with Medicare allocating one-third of all its expenses to treating it.

Within the Alzheimer’s population, a higher proportion will be in severe stages of the disease by 2050, as opposed to early or moderate stages. In the early stage of the disease, people can continue everyday functions and may appear symptom-free. They do have deficits in their abilities to think and learn, but the financial impact and burden on family members are low. In the moderate stage, memory lapses, inability to express thoughts, and confusion become apparent. Finally, in the severe stage, people have trouble taking care of themselves and require extensive daily care. In 2050, almost half of those affected will be in the severe stage.

The Alzheimer’s Assocation presents a case for funding biomedical research now, before the human and economic costs can be realized. For the sake of argument, they describe a hypothetical new treatment that would delay the onset of Alzheimer’s symptoms by five years. If such a thing were available by 2025, it would save $220 billion in its first five years. By 2050, 6 million fewer people would be affected by Alzheimer’s, saving families $90 billion in healthcare costs and the federal government $367 billion. Even if such research costs $2 billion a year starting today, a way to delay Alzheimer’s by just five years would pay for itself within three years.

Research from very basic studies on the brain to translational research leading to new therapeutics and early diagnostics are desperately needed. There are many promising studies that suggest a delay in the progression or even cure for Alzheimer’s are possible.

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The Teen Brain on Weed

April 24, 2015

By Medical Discovery News

A brain

It is now legal to use marijuana (recreationally and/or medically) in more than 20 states and the District of Columbia, and as more places debate legalizing the substance, more people are asking about its consequences on human health. There are many myths and misconceptions out there, but this is what science has to say about the subject.

As with all substances, the health effects depend on the potency, amount, and a person’s age. An independent scientific committee in the United Kingdom evaluated how harmful various drugs were based on 16 criteria and ranked heroin, crack cocaine, and methamphetamine as the most harmful drugs to individuals using them, and ranked alcohol, heroin, and crack cocaine as the drugs that cause the most harm to others. Marijuana ranks eighth, with slightly more than one-quarter the harm of alcohol.

Short-term use is associated with impaired short-term memory, making it difficult to learn and retain information while under the influence. Short-term use can also impair motor coordination, interfering with tasks such as driving. The overall risk of an accident doubles if a person drives soon after using marijuana. In comparison, those with blood alcohol levels above the legal limit are five times more likely to have an accident, and the combination of alcohol and marijuana is higher than either one alone.

Long-term or heavy use is associated with diminished life satisfaction and achievement overall. At high doses, marijuana can cause paranoia and psychosis, and long-term marijuana use increases the risk of developing schizophrenia or other chronic psychotic illnesses. Nine percent of all marijuana users, or 2.7 million people, develop an addiction to it. That figure jumps to 25-50 percent for those who use marijuana daily, and 17 percent of people who begin using marijuana as adolescents become addicted. Cannabis withdrawal syndrome is real and includes symptoms of irritability, sleep disturbance, dysphoria, craving, and anxiety.

Adults who occasionally use marijuana do so with little to no risk, but adolescent brains are not fully developed, making them more vulnerable to the adverse effects of marijuana. Using marijuana during adolescence can alter brain development, causing impaired cognition and lower IQs. This is probably because the active ingredient in marijuana, tetrahydrocannabinol, affects the brain’s ability to make connections between neurons in certain regions of the brain. Adolescent marijuana users also have a smaller hippocampus, which is important in learning and memory, and a less active prefrontal cortex, which is important in cognitive tasks such as planning and problem-solving.

Since acute marijuana intoxication can impair cognitive functions for days, students who use marijuana may function well below their natural abilities, causing academic difficulties. High school dropouts do report higher marijuana usage than their peers. Some evidence suggests that these cognitive impairments could be long-lasting or permanent in long-term users who started at younger ages, which can impact their abilities to succeed academically and professionally.

There is no clear association between long-term marijuana use and any deadly disease, although chronic marijuana smokers have increased rates of respiratory infections and pneumonia and an increased risk of heart attack and stroke. The effects of marijuana on a developing embryo and the effects of second-hand or third-hand marijuana smoke have not been well-studied, but as marijuana legalization continues to be an issue the science behind it will as well.

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Chocolate on My Mind

April 10, 2015

By Medical Discovery News

Chocolate

Peanuts creator Charles Schulz once said, “All you need is love. But a little chocolate now and then doesn’t hurt.” New research shows he might be right. In one study, certain compounds in cocoa called flavanols reversed age-related memory problems.

Flavanols, found in a variety of plants, are potent antioxidants that help cells in the body deal with free radicals. Free radicals arise from normal cellular processes as well as from exposure to environmental contaminants, especially cigarette smoke. Unless your body gets rid of free radicals, they can damage proteins, lipids, and even your genetic information. You can get flavanols from tea, red wine, berries, cocoa, and chocolate. Flavanols are what give cocoa that strong, bitter, and pungent taste. Cocoa is processed through fermentation, alkalization, and roasting among other methods, which can influence how much of the good flavanols are lost. Among the products made from cocoa, those with the highest levels of flavanol are cocoa powders not processed by the Dutch method, followed by unsweetened baking chocolate, dark chocolate and semi-sweet chips, then milk chocolate, and finally chocolate syrup contained the least.

In the latest study, a cocoa drink specially formulated by the Mars food company to retain flavanols was compared with another drink that contained very little flavanols. The study asked 37 randomly selected adults aged 50 to 69 to take one of the drinks. One group consumed 900 milligrams per day of flavanols and the others consumed only 10 milligrams per day for three months. Brain imaging and memory tests were administered before and after the trial.

Those who consumed the high levels of cocoa flavanols had better brain function and improved memories. Before the study, the subjects on average demonstrated the memory of a typical 60-year-old person. At the end, those who consumed more flavanols exhibited the memory capabilities more closely resembling a 30- to 40-year-old. Unfortunately, the average candy bar contains only about 40 milligrams of flavanol, so you would have to eat 23 of them a day to equal the amount of flavanol used in the study, which would lead to other health problems like obesity and diabetes.

Other studies have similarly revealed that high-flavanol cocoa beverages cause regional changes in the brain’s blood flow, suggesting that it could be used to treat vascular impairments within the brain. Flavanols have also been reported to reduce blood pressure and other factors that lead to cardiovascular disease, improve insulin sensitivity, modulate platelet activity thereby reducing the risk of blood clots, and improve the activities of the endothelial cells that line our blood vessels. The Kuna indians living on the San Blas Islands near Panama, who consume a type of cocoa rich in flavanol on a daily basis, have unusually low rates of hypertension, cardiovascular disease, cancer, and diabetes.

These studies need to be repeated with larger groups to confirm the benefits of consuming flavanols and to ensure that there are no negative effects. Still, if a cocoa beverage high in flavanols could be mass produced and marketed, we could improve human health in a very tasty way.

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We Are Out-Smelling Ourselves

Jan. 16, 2015

By Medical Discovery News

We Are Out Smelling Ourselves

Dogs are commonly known for their strong sense of smell. Their noses can detect when someone is pregnant, has cancer, even blood glucose levels. But the human nose is pretty amazing too. You may already know that smell is the strongest sense tied to memory – it can provoke intense responses and can seemingly bring back memories from long ago. Recently, a study has determined that our noses are capable of distinguishing between at least a trillion different scents, much more than previously believed.

The common theory was that we could only discern about 10,000 different odors, so this new estimate is a huge jump. Compare that with our ability to discriminate between 2.3 and 7.5 million different colors, which vary in wavelength and intensity, and about 340,000 different tones, which vary in frequency and loudness.

Back in 1927, a study proposed that there were four elementary odor sensations with sufficient resolution for humans to rate each elementary odor sensation on a nine-point scale. Doing the math, they estimated the number of discernable odors to be nine to the fourth power or 6,561, which was later rounded up to 10,000. Since then, that number has been accepted in both popular and scientific literature. But some scientists suspected that this number was too low. After all, we have just three receptors for light yet we can see millions of colors. Since human noses have about 400 different smell receptors that work in concert, the number of smells we can perceive is likely to be much higher the original estimation.

Natural odors are usually mixtures of large numbers of diverse components. The scent of a rose is produced by a mixture of 275 components, only some of which are chiefly responsible for the aroma. Researchers tested human ability to smell using 128 different molecules that are odorants, mixing them in many unique combinations. They then asked how much (or how little) two mixtures had to differ before the human nose could detect two separate smells.

Although they used many familiar smells like orange and spearmint, they intentionally mixed them to produce unfamiliar odors. Since this equals thousand to millions of odors, the study used methods similar to those used by political polls that use a sample to represent the general population. Each person was given three vials at a time, each consisting of 10, 20, or 30 different compounds. Two contained the same mix of odors while the third was different. Each subject was asked to smell about 500 different odorants in all.

Two vials of odorants had to differ by at least 49 percent to be distinguished. That means two vials of odorants could be 51 percent identical and humans could still tell them apart! Overall, scientists estimated that the human nose can distinguish at least 1 trillion scent combinations. Keep in mind, however, that this estimation is based on only 128 different odors. In the real world, many more odors exist in varying combinations so the number of smells discernible by the human nose could actually be much higher.  Of course, there was large variability in the abilities of different people to discern different smells.

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Does Grey Matter?

Aug. 8, 2014

By Medical Discovery News

The brain

What do brain scientists and fans of E. L. James have in common? They are both passionate about shades of grey. Results from a recent study in the scientific journal “Molecular Psychiatry” indicate that grey matter really does, well, matter. This study shows that the thickness of grey matter in the brain may be linked to intelligence and may also explain why some people have learning difficulties.

Grey matter is the outermost region of the brain, a layer of tissue two to four millimeters thick covering the brain on both sides with a wrinkled surface. Underneath the grey matter, also called the cerebral cortex, is the white matter of the brain, the cerebrum.

Grey matter is responsible for some major human functions including awareness, attention, consciousness, language, thought, and memory. Previous studies have shown that animals with bigger brains generally have thicker cortexes, but there has not been a strict link between intelligence and the thickness of the grey matter until now. 

For this new study, researchers at King’s College London’s Institute of Psychiatry obtained brain scans and DNA samples from 1,583 14-year-olds. They also tested the verbal and nonverbal intelligence of these subjects. Using DNA analysis, scientists looked for gene variants that could be responsible for the intelligence differences of this group. This proved to be a daunting task as they discovered more than 50,000 gene variants associated with brain development. However, with the help of computation biology, researchers uncovered some astounding results. Those with one particular gene variant caused by a single nucleotide polymorphism (or change) had thinner grey matter on the left side of their brains. And, these same individuals tested lower on the intelligence tests. 

Called NPTN, this gene encodes a protein that works in brain cells called neurons. The variant of NPTN affects communication between neurons in the brain, thereby explaining its impact on important functions of grey matter. Additional experiments suggest the NPTN variant may have more of an effect in the left side of the brain than the right side. This may correlate to lower intelligence due to the function of this important gene and its encoded protein in the left brain. 

While important, NPTN is not the only thing that determines intelligence – a multitude of other genes and environmental influences are clearly involved as well. However, this gene may provide new clues as to how intelligence is built in humans. Also, it will be interesting to see if this gene variant is associated with cognitive diseases like autism or psychological disorders like schizophrenia. 

Thanks to the new B.R.A.I.N. initiative that funds basic and translational research, we look forward to better understanding the human brain, arguably one of the most important human organs we know the least about. 

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Altering Memories

March 21, 2014

By Medical Discovery News

Altering Memories

In the film “Eternal Sunshine of the Spotless Mind,” people can request a medical procedure that targets memories pertaining to a specific subject or person and change or delete them. Several characters choose to have their memories of unrequited love and failed relationships erased. While the plot is purely fictional, new research does provide intriguing new details on how memories are stored, and how they might be manipulated.

Memories are stored in the temporal lobe and the hippocampus of the brain. Experiences produce physical and chemical changes in specific brain cells. Connections between brain cells that help with memory storage can also change. Scientists can identify the precise cells in a network involved with a specific experience. These are called memory traces or engrams.

Nobel Prize winner Susumu Tonegawa and his team wanted to explore how these memory traces are stored in cells. They used cells from the hippocampus that contained a light-sensitive protein called channelrhodopsin. When a memory pertaining to these cells is accessed within the brain, the light-sensitive protein activates. To discover which cells are associated with which memories, a memory is triggered and the cells respond with the light-sensitive protein. 

To do this experiment with mice, researchers assessed an easily observed behavior – the fear response. They first placed mice a chamber to allow memories of that environment to be formed. While this memory formed, channelrhodopsin was being produced in specific cells to record this memory. The next day the mice were placed in a completely different chamber and received a mild electric shock to their feet and a pulse of light simultaneously, prompting a fear response. But the pulse of light activated the memory of the chamber from the first day. And the following day when the mice were placed back in the first chamber, they displayed fear even though there was no electric shock associated with that chamber.

This means that activation of memory cells while receiving a shock in a different chamber produced fear associated with the first chamber. Now the mice connected the shock with the first chamber even though nothing bad happened there. This means scientist were able to implant a false memory by activating the trace of the original memory. This experiment identified the location of specific memories and showed that they could be manipulated. 

Not to sound too much like a sci-fi thriller, but this means in the future human memory may be able to be altered. There are positive, therapeutic applications, such as altering stress-inducing memories for war veterans with post-traumatic stress disorder. But in the wrong hands, this could be used for more sinister purposes, like mind control in “The Matrix.” Is it wise to alter any memories at all – does that change the person as a whole? Scientists and society will need to consider these questions if such experiments progress.  

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Do We Smell the Same Thing?

Feb. 7, 2014

By Medical Discovery News

Do We Smell the Same Thing?

Have you ever wondered if we all sense the world in the same way? Evidence suggests that the sense of smell is highly individualized, based on genetic differences. This could revolutionize scents and food flavors into custom-designed creations for individuals.

Humans have specialized neuronal cells within the lining the nasal cavities, part of what’s called the olfactory epithelium. The surface of these cells, like much of the nasal cavity, is covered with mucus. Odor molecules dissolve into this layer and are detected when they bind to receptors on the neurons. This sets off a string of biochemical events that produces a signal, which travels along the olfactory nerve to the olfactory bulb of the brain. Then that signal is transferred to different regions of the brain’s cerebrum. Here odors can be distinguished and characterized. These signals are stored in long-term memory, which is linked to emotional memory. That’s why particular smells can evoke memories. This process is quite complex due to the highly evolved sense of smell in humans.

The genes that are involved in olfactory or smell sensations are not well understood. People do perceive odors differently, but researchers have only identified genes for certain odors. For example, human perception of cilantro has been linked to the olfactory receptor OR6A2 and grassy odors have been linked to receptor OR2J3.

New Zealand scientist Dr. Richard Newcomb tested the ability of almost 200 people to smell 10 different chemicals associated with the key odors of things like apples and blue cheese. Then these individuals’ genomes were completely sequenced, and genetic variances that could account for these olfactory differences were determined. For four of the chemicals tested, clusters of genes were identified as being able to detect these odors. Interestingly, these genes were located on different chromosomes. Newcomb’s work almost doubled the number of genes known to be connected with the sense of smell. For beta-ionone, a chemical associated with the smell of violets, a single gene was shown to allow people to sense that fragrant flower’s scent. Overall, the result of this study was that people are capable of experiencing chemical smells in different ways.

This opens the door for scientists to define an individual’s olfactory profile. If it’s understood how an individual perceives smells, a chef could personalize food just for their senses. Imagine walking into a restaurant and handing your server a card with your olfactory profile based on your genes. And violá! A dinner prepared with the seasonings and flavors you find most pleasing. With continued research, our sense of smell may be able to experience this scenario and more. 

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Staving Off Dementia

Nov. 8, 2013

By Medical Discovery News

“When I was younger, I could remember anything, whether it had happened or not; but my faculties are decaying now and soon I shall be so I cannot remember any but the things that never happened.”

While American novelist Mark Twain can invariably add his iconic sense of humor to any situation, it is no laughing matter when patients lose their memories and cognitive function to dementia. And for their family members, there is hardly anything harder than caring for a loved one who can no longer remember them or any shared experiences. But lowering a person’s risk of dementia may be as simple as changing their lifestyle.

The incidence of dementia increases with age. As the average age of Americans increase, the number of people with dementia also increases. In 2010, more than 30 million people worldwide had dementia, and this figure is estimated to more than triple by 2050.

Despite the many medical advances over the past 20 years, there are no effective pharmacological therapies for dementia yet. Some drugs are being evaluated and still others are in development, but it could be some time before there is a truly successful treatment for this disease. 

However, studies have uncovered risk factors that can lead to dementia, such as low physical and mental activity, obesity, hypertension, and hyperlipidemia. The good news is that all these risk factors can be controlled by changes in a person’s lifestyle and behavior.

A group of scientists at the Karolinska Institute in Stockholm examined the effects of lifestyle modification on dementia risks. One of the strongest correlations to reducing the risk of dementia is increasing physical activity. Changing from a sedentary lifestyle to one with at least moderate physical activity will also improve cognitive performance. Both aerobic exercise and strength training may delay of the onset of dementia. 

For those with nutritional deficiencies, taking vitamin supplements did help prevent dementia onset, but those with normal levels did not affect their dementia risk by taking supplements. 

Computer games have become a popular way to enhance mental abilities in older people. There are some positive effects of gaming on cognitive performance, but these effects decline with age.  A recent study showed that improvements in language skills and reasoning abilities lasted for a full year after computerized training. While encouraging, more clinical trials are needed to establish the benefits of these activities on cognitive functions and the delay of dementia.

For now, the best advice to delay or prevent dementia is to engage in physical exercise and maintain a healthy weight and nutrition.

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