New Genetic Factors Identified in Successful Aging of Amish Population


Avoiding disease, maintaining physical and cognitive function, and continuing social engagement in late life are considered to be key factors associated with what some gerontologists call “successful aging.”

First and foremost, let me strongly disagree here with those gerontologists. I believe the term “successful aging” is absolutely intolerable. Just think about it. How on Earth can aging be somewhat successful? Aging brings diseases, mental incapacity and other deteriorating effects on the human body. We cannot call that successful under any circumstances.  So for the purpose of this article, we have replaced the term “successful aging” with “less destructive aging.”

While conducting studies of Amish families in Indiana and Ohio, a group of researchers led by William K. Scott, PhD, Professor of Human Genetics at the University of Miami Miller School of Medicine, began to notice that a significant number of people over age 80 in these communities demonstrated the three main factors associated with less destructive aging.

In the current study, presented at the American Society of Human Genetics (ASHG) 60th Annual Meeting in Washington, D.C., Scott and his colleagues investigated the genetic differences between Amish individuals who had less destructive aging as compared with individuals from the general population to see what genetic factors are keeping them healthier and happier well into their later years.

A total of 263 volunteers, age 80 and older, were enrolled in a population-based door-to-door survey of Amish communities in Indiana and Ohio. The researchers studied this particular Amish population because they have fairly large families with well-documented genealogies. Furthermore, because they live relatively homogeneous lives, non-genetic factors such as environment and diet would have a smaller effect on less destructive aging, as compared to the general population. Study participants who scored in the top third of the sample for lower limb function, required little assistance with self-care tasks, had no symptoms of depression, and expressed a high level of life satisfaction were considered to be ‘less destructively aged’ (73 participants in total). The remaining 190 study participants were retained as controls.

Researchers have theorized for some time that mitochondria — the organelles that produce energy in human cells — may play a role in aging. There is evidence that people who experience less destructive aging have genetically different mitochondria when compared to the general population. Furthermore, mitochondrial lineages described by patterns of common genetic variants (or “haplogroups“) have also been shown to be associated with increased longevity in different populations. To better understand these underlying genetic factors, Dr. Scott and his colleagues studied the influence of mitochondrial haplogroups on less destructive aging and sought to identify the common genetic variations in the mitochondrial genome that are potentially associated with less destructive aging in a sample of Amish individuals age 80 and older.

The common variations in the mitochondrial genome define distinct ‘haplogroups that are found in specific geographic regions around the world. For this study, Scott’s research team looked at the nine most common European haplogroups, since the Amish are descendants of individuals from Europe.

The current research results indicate that one fairly rare mitochondrial haplogroup found in only 2% of all Europeans — which is known as ‘haplogroup X’ — was found in 15% of the less destructively aged Amish population (versus only 3% of the controls) and had a significant positive association with less destructive aging. On the other hand, the researchers also reported that another mitochondrial haplogroup called ‘haplogroup J’ which is typically found in about 10-25% of Southern Europeans, was found in only 5% of the Amish population and had a negative association with less destructive aging factors.

Thus, a significant positive association with less destructive aging was found with mitochondrial haplogroup X (which was more prevalent among the aged Amish population), while a negative association was found with haplogroup J (which is more prevalent in European populations than the Amish). All positively associated alleles were found together on haplogroup X, while all negatively associated alleles fell in haplogroup J. All positively associated alleles were found together on haplogroup X (1719A), while all negatively associated alleles fell in haplogroup J (rs2854122, rs3135030, and 10398G). This data represents a novel association of mitochondrial haplogroup X with less destructive aging that conflicts with previous positive associations of haplogroup J with longevity in other populations.

“In this study, we focused on looking for genes that may have an influence on keeping people healthy, rather than identifying genes associated with disease,” said William Scott, PhD, the senior author of the research abstract presented at the ASHG 2010 Annual Meeting. “Our research results support the idea that mitochondria play an important role in aging, and our findings also suggest a specific subset of genetic variants that might influence less destructive aging in this group of people.”

“In our future research, it is important that we attempt to broadly associate this mitochondrial variation to aging in this population, figure out what it does biologically, and then see if we can reproduce it in other samples,” said Scott. “Furthermore, we will also need to look more closely at the mitochondrial genome for specific variants that influence aging.”

I personally think that placing a strong focus on the factors responsible for maintaining youthful human function has the potential to be very fruitful because it can provide insight into what keeps us healthier for longer periods of time. By identifying these causes, we can start looking at ways to promote longer and healthier lives in general population.

Read more about the genetic factors that affect aging in the MIT Technology Review article

Maria Konovalenko
SCIENCE FOR LIFE EXTENSION FOUNDATION
http:/mariakonovalenko.wordpress.com/
maria.konovalenko@gmail.com

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4 responses to “New Genetic Factors Identified in Successful Aging of Amish Population

  1. Pingback: World Spinner

  2. I actually object to the word “aging” altogether to describe life changes over time. After all, aging from 0 – 20 years, or so, is “good” aging in that we mature into our primes (minus a few oddities, like peak hearing at age 10, probably due to environmentally caused premature “aging” from our noisy environment).
    Even “aging” from age 20-40 doesn’t have to mean deterioration IF one is very strict about exercise, diet and stress…or. conversely, one has NOT been strict about all those things until then, and then one reverses that for the better. In that sense it is possible to be healthier at age 40 than at age 20, though it certainly is quite rare. But it puts the lie to the concept that just racking up the years is a cause of deterioration. It is obviously more complex than simply “aging.”

    It’s really Senescence that we have to worry about, defined by Wiki as:
    “the process of accumulative changes to molecular and cellular structure that disrupts metabolism with the passage of time, resulting in deterioration and death.”
    This is what we need to prevent in order to have longer Healthspans, and it is longer Healthspans, even more than longer Lifespans, that we want…well, both would be best, but what was the name of that Greek myth character who was given eternal life but not eternal youth? That’s a nightmare.

    • First of all, it is impossible to significantly extend longevity without improving health. Otherwise, the person would die, because of some processes that would go wrong. So when I am talking about increasing lifespan, this automatically means increasing health as well.

      As for using the term aging – well, this word is used to describe both chronological aging and biological. These two things are not the same, as you’ve hinted, but definitely not to the extend that you mentioned. One can’t be biologically younger at 40, than at 20. 40 has a great deal of deterioration. We just don’t always see it all, because it starts on the molecular level. We can only detect some major changes, when an organ is failing, for example, or when we can no longer run as fast as we used to. These are the signs of aging.

  3. Jessica

    Did any of the researchers take religion into account in this aging study? Not to mention the pace of life that the Amish maintain. These two factors contribute greatly to ones longevity. The Amish don’t spend their lives chained to a desk, commuting in hours of traffic to just get home and sit down and watch T.V. Amish people work hard and don’t live sedentary lifestyles.
    As for Amish community having less depression and a overall sense of well being their belief in God I would think contributes greatly to this. American society has become more secular that it’s ever been which leaves society as a whole much less involved in community activities that church creates. Most religious people involved in church spend time together in worship and in fellowship with other church events, people have more relationship with one another and help each other out which leaves people more secure and thus with a better sense of individual well being.
    My point is that it may not be genetics that are contributing to the Amish community aging so much better that the general population as it seems to have more to do with lifestyle choices that modern american society has chosen to forego.
    A little side note, the photograph in your article is a young Amish lady in NC who I know and see just about every week at the community store that she works at with her family.

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