Biological Fountain of Youth

March 27, 2015

By Medical Discovery News

The Biological Fountain of Youth

Over 500 years ago, Ponce de Leon landed in Florida as part of his search for the fountain of youth – magical waters that reverse aging, prevent illness, and grant immortality. He never found it, and neither has anyone else. While immortality is still impossible, we have come a long way in understanding the aging process.

We do not know the precise mechanism of aging, but there are some fundamental processes in our bodies that begin to change and this can drive aging. There are several theories of aging under intense scientific investigation.

A widely accepted theory of aging today is called evolutionary senescence, which mainly hinges on the concept of mutation accumulation. As we age, our cells accumulate mutations in our genetic material or DNA, which affects the ability of our cells to replicate and our tissues to regenerate. Also, some of our genes are designed to enhance reproduction early in life, but can cause problems later. Since genes can only be passed on during reproduction, which generally occurs earlier in life, genes that have negative effects later in life are not removed from the population – we are stuck with them! A good example is a gene called p53, which controls the fate of damaged cells by preventing their replication or directing them to die. This is important in preventing cancer in young people, but it may negatively impact our ability to replace aging cells in tissues as we grow older.

Another widely discussed theory centers on the maintenance of our genomes. As we get older, we accumulate damage to our DNA, which affects cellular function and our ability to renew tissues in the body. In a sense, this is a high mileage effect. Take for example the production of free radical molecules. These highly reactive molecules are normally produced in mitochondria, which use oxygen to produce cellular energy, a process that creates free radical molecules as a by-product. These free radical molecules lead to oxidative damage of DNA and other cellular components.

There is also evidence the neuroendocrine system (hormones that affect neurological function) influences aging. For example, a reduction in hormone levels can lead to a lengthening of life, at least in experimental animals. We are beginning to suspect that the insulin-related hormonal pathway may play a significant role in aging, at least in mice. Mutations that reduce the amount of this circulating hormone extend life.

A relatively new model of aging involves the replication of chromosomes as cells divide. When cells replicate, specialized structures at the ends of chromosomes called telomeres are shortened. Shortened telomeres are linked to decreased viability and increased cancer risk. Cells whose telomeres reach a critical length can no longer divide and are described as senescent.

We are expanding our understanding of how aging occurs. The search for a modern-day fountain of youth will require a great deal of dedicated work by biomedical scientists to safely improve and extend human life.

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Aging and Our Biological Clock

May 9, 2014

By Medical Discovery News

Unlike a mechanical clock our biological clocks do not run at a constant speed

The questions of how we age and how our bodies know what to do during that process have puzzled scientists for years. The answers lay in our biological clocks, which aren’t fully understood. Some scientists think that if we can learn how our biological clocks work, we would hold the key to slowing down or even reversing aging.

A group from the University of California, Los Angeles (UCLA) achieved astounding results that offer insight into the mechanisms of aging. They used existing sets of data to compare DNA patterns in normal and cancerous tissue samples from humans. They examined almost 8,000 samples from more than 50 different people that were taken from various places in or on the body. This allowed them to take a comprehensive look at the changes that occur throughout the body during the aging process and how tissues of the body keep time. 

Most, but not all, tissues had a biological age that matched their chronological age. The biological age of a tissue is the age it appears to be or behaves at. Chronological age is just a person’s overall age.

For example, women’s breast tissues age much faster than the rest of their bodies. In a healthy woman, breast tissues had a biological age two to three years older than the woman’s age. In a woman who had breast cancer, the cancer cells were an astounding 36 years older than the rest of her body! And even the healthy tissues surrounding those cancer cells were affected – they were up to 12 years older than the rest of the body. Maybe this age difference explains why breast cancer is so prevalent in women.

The results also show that biological clocks do not run at a constant rate. The clock advances much faster from birth through adolescence. When we reach our 20s the clock slows to a steadier rate.

Stem cells, cells that are basically clean slates and can develop into any type of cell in the body, are age zero according to the biological clock. This makes sense since embryos and umbilical cords have stem cells. So, if adult cells can be reprogrammed into stem cells, their biological clocks could potentially be reset as well. Could this be the key to being forever young?

This discovery could possible reverse the aging process, a scientific Fountain of Youth.  But first, the actual connection between the biological clock and aging still needs to be defined more precisely. Then we can move on to questions like whether slowing the aging process also reduces the incidence of cancerous diseases.

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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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