Monday, December 29, 2014

Is Aging Determined by our Gut Bacteria?

Carolyn Bohach, a microbiologist at the University of Idaho estimates that there are 10 times more bacterial cells in your body than human cells. Although smaller than human cells, and weigh only 1-3% of our body weight, the 500-1,000 species of bacteria that inhabit our body have evolved with us for millions of years.

Although bacteria are all over our body--inside and out--we see how it maintenance balance particularly in the human gut.  There are fewer physical changes in older adults' gastric system than any other system in the body. Although the stomach looses its elasticity and might be more prone to damage—primarily as a result of taking some medications—the small and large intestine, pancreas, liver, and gallbladder change minimally with age. So the changes that evolve inside our gut are argued to come from bacteria that inhabit this internal world.

In the gut there are 100 trillion microorganisms that engage in fermenting, killing off other harmful bacteria and viruses, enhancing our immune system and producing vitamins and hormones. This bacterial activity is so necessary to the body that their outcome, function as an independent organ--a virtual "forgotten" organ. Here, bacteria help extract energy and nutrients from our food. This sharing of benefits shows in experiments where bacteria-free rodents have to consume nearly a third more calories than normal rodents to maintain their body weight. Less well understood is the role of fungi and protozoa that are also part of the gut flora.

In 2012 Marcus Claesson and Ian Jeffery from University College Cork in Ireland and their colleagues, reported this gut flora changes among some older adults, and they correlated changes in the type of bacteria with frailty and mortality. They found that institutionalized older adults have a different gut flora than community older adults and younger people. And they related this flora—caused by a restricted diet—to diminished physical capacity.

But it was only in December 2014 that Martin Blaser from New York University and Glenn Webb from Vanderbilt University, Nashville, Tennessee, tried to explain how bacteria are designed to kill older adults. They argue that modern medical problems, such as inflammation-induced early cancer, resistance to infectious diseases and degenerative diseases are in response to bacterial change as we get older and this has an evolutionary cause. Using mathematical models the authors show how bacteria evolved because they contributed to the stability of early human populations: Enhancing the survivability of younger adults while increasing vulnerability of older adults. Such an evolutionary process has advantages, but in the modern world, bacteria's legacy is now a burden on human longevity. Although this mathematical model has many flaws—primarily the theory of antagonistic pleiotropy and that there are other factors other than bacteria responsible for specific diseases—it allows gerontologists to see aging as a balance, not an all or nothing event.

http://www.nih.govBacteria is necessary in balancing the biological activities in our human body. In one example scientists are using bacteria that cause botulism to eradicate tumors. While in another example, Linlin Guo and her colleagues from the Buck Institute for Research on Aging in California, have increased lifespan in flies by altering bacteria in their intestine.  It seems that bacteria form an important system in the body which might have repercussion on our longevity. Our body is a universe of organic activity and we are still learning about this miracle.

© USA Copyrighted 2014 Mario D. Garrett

Monday, December 22, 2014

Reclaiming the word "Senile"

The other definition of senile is “pertaining to old age”.  Senile is not “being demented.” That mistake comes from the earlier definition of dementia when in 1895 Arnold Pick identified premature dementia as separate from dementia of old people—senile dementia. Later of course, Emil Kraeplein defined Alzheimer’s dementia, which quickly separated old  (senile) dementia from young (Alzheimer’s disease) dementia. But we still confuse “senile” with “dementia”.

The single most important factor that accelerates aging is negativity—our own and other people’s. In the blue zones we see people living past 100 years of age. Twenty years more than the average, nearly a quarter of a life more. What they do not have in these zones is negative stereotypes.  Although stereotypes exist for everyone—race, gender, sexual preference, size, height, intelligence and even geographic residence—for older adults it is transient and develops fast and have little time to develop resilience.

Richard Eibach from the University of Waterloo, Ontario, Canada and his colleagues explained how older people internalize negative stereotypes. In one study the authors asked older adults to read text that had small type and low contrast. Some participants were told that the lack of clarity was due to a photocopying problem, while the rest received no explanation. Older adults that did not receive an explanation reported feeling 10 years older than the participants who had an explanation. And it is not just about feeling old but that they associated feeling old as a negative. Accepting the term “old” you accept an omnibus of negative stereotypes.

Thomas Hess and his colleagues from North Carolina State University in Raleigh, NC explored how stereotypes create a world of negative memes. There is a self-fulfilling prophesy. When older adults encounter negative stereotypes about age-related cognitive decline, their memory performance decreases, rate their own health as being worse than others, and rate themselves as lonelier.  Stereotypes play a significant self-fulfilling role in diagnosis as well. Physicians who have been primed about the connection between memory loss and dementia—and it is now everywhere in the media—diagnosed 70% of their older adult patients who reported having memory problems, as having dementia rather than 14% when there was no stereotype.


And the stereotype does not have to be transmitted negatively. Even providing assistance while completing a puzzle—implicitly suggesting that they need help—resulted in decreased performance over time, whereas those older adults who were only provided with verbal encouragement showed increased performance over time. Don't let others patronize. Lets take over the concept of senile again. That pertaining to old age is not a negative. Be aware of accepting such negative judgments and of making them about yourself.  We can reverse this process by starting with recognizing that senile does not have to be a negative term.

© USA Copyrighted 2014 Mario D. Garrett