Find the right genes and we’ll have a way to prolong life and good health, perhaps indefinitely.
Better food, healthcare, working conditions, and safety protocols have allowed humans to live longer and healthier than ever before. In most developed countries today, the average lifespan is 80 years, while in 1906, a little more than 100 years ago, it was 48. Projections moving forward look so good that there’s a debate in the medical community on whether or not we can increase human longevity indefinitely.
There are far more centenarians than ever, or those who’ve lived to 100, and more supercentenarians or those 110 or above. A study published last year in the journal Nature proposes that 122 may be the human lifespan's ceiling. Most of those in the upper reaches of our lifespan assign their longevity to lifestyle choices or healthy habits, which of course play an enormous role. But many scientists believe important secrets to longevity lie within our genes as well.
Moreover, quite a number of studies suggest a strong genetic link. For instance, a 1996 study published in the journal Human Genetics, looked at thousands of Danish twins. It concluded that 20-26% of longevity is up to one’s genetic code. Meanwhile, a Boston University study found that a centenarians’ siblings have about a 3½ times higher chance of reaching 100, over non-centenarians’ siblings.
What’s more, supercentenarians don’t often experience any of the serious diseases people succumb to in old age, such as heart disease or cancer. Turns out, the longest living among us carry fewer of the genetic variations involved with such diseases.
While lifestyle plays an enormous role, certain genes or gene combinations add significantly to longevity and good health later in life. Credit: Getty Images.
To find out what all those who’ve reached 110 have in common, a nonprofit known as Betterhumans is studying the DNA of those who have shown impressive longevity. It bills itself as “the world's most comprehensive genomic study of supercentenarians and their families.” DNA samples collected will not only be sequenced, the data produced will be made available to the public. In fact, a series of genomes are to be released this week.
The idea is to find out what genes gives people an exceptional lifespan, synthesize those genes, and from there develop a way to prolong life and health in others. So far, the project has collected over 30 samples from people in North America, Europe, and the Caribbean. Those who qualify can donate their saliva, a blood sample, or if their long-lived relative is deceased, a tissue sample, to the project. Then the samples are analyzed by Betterhumans and their research partners.
It may be more than being devoid of disease causing mutations that keep those over 110 in good health. Credit: Getty Images.
Supercentenarians live more healthy, disease-free lives in their autumn years than even centenarians. Their genomes are not just devoid of disease causing mutations, they must also contain actively protective genes. Previous work has been stunted however by a lack of supercentenarian DNA to work with. Betterhumans is hoping to overcome this problem.
The nonprofit says it uses a specific identification system, assigning a proprietary number to each sample, so that the subject can remain anonymous. Once a large number of samples have been processed, they’re sent to a lab for sequencing. Both proprietary and public-domain software is used. Besides sequencing, Betterhumans is comparing and contrasting supercentenarian DNA with non-supercentenarian DNA. It takes three months total from the time they take the sample to the time it’s turned into data.
2,500 differences in supercentenarian DNA have been tagged thus far, but it’s hard to discern which are significant. Extremely rare mutations might be difficult to detect using standard methods. Scanning procedures are set to look at places that are already known to harbor mutations.
A significant number of variants for supercentenarians have been found so far. Deciphering them is another matter. Credit: Getty Images.
So will we all be living to 110 in a decade or two? There’s still a contentious debate on whether or not there's a limit to the human lifespan or if science can eventually make it limitless. But let’s say for the sake of argument that we can, should we?
The project has natural limitations. To understand all the phenotypes or combination of genes involved, tens of thousands of genomes would need to be sequenced. Yet, there are only about 150 supercentenarians worldwide. Just one in five million Americans is one. Also, some of them are hard to find. They may be living in rural areas in developing countries and did not receive a birth certificate when they were born.
Those who have a supercentenarian in their life or are one and want to contribute, contact Betterhumans and donate a sample. Contact them by phone at: (509) 987-5282, email: firstname.lastname@example.org, or by filling out an enrollment form here.
To learn about another significant breakthrough in the quest for longevity, click here:
Being able to rewrite DNA as we wish could give us almost god-like power over all life on earth.
Most of us like the idea of superpowers. Though we may never have the strength of Superman, we could be made stronger, faster, and even better-looking, with total control over our genome, or genetic makeup. What about becoming disease-resistant, weight gain resistant, and even slowing down the aging process? This might be possible in decades to come, as geneticists are now getting ever closer to, not just removing and replacing genes, but rewriting entire genomes. It sounds like the realm of science fiction. Yet, consider that geneticists at Harvard recently recoded the genome of a synthetic E. coli bacteria. Prof. George Church and colleagues conducted the study.
Researchers replaced 62,214 base pairs of DNA. What they have done is recreate the DNA from scratch, though they haven’t actually brought the bacteria to life, yet. What was once thought impossible is no longer. This is the first synthetic genome ever assembled, and is being hailed as the most complex feat of genetic engineering, thus far.
With this technique, we could create any kind of life form we wanted, reprogram organisms, and even create synthetic proteins and compounds. MIT bioengineer Peter Carr, told the journal Science, "It's not easy, but we can engineer life at profound scales.” Note that he was not involved in this project. So how exactly are they rewriting a genome? DNA is made up of four nucleobases which arrange themselves as base pairs, A and T, C and G. These create one strand of the double helix, known as RNA.
Nucleobases. Photo by Difference DNA_RNA-DE.svg: Sponk (talk)translation: Sponk (talk) - chemical structures of nucleobases by Roland1952, CC BY-SA 3.0,
Each combination equates to a certain amino acid, which is what cells are essentially made up of. Cell’s read combinations of nucleobases to know which amino acids to produce. There are only 64 possible combinations. When put in a group of three—called codons, they create a certain kind of amino acid. There are 20 different kinds in total. C-C-G for instance creates the amino acid proline. C-C-C does as well. So there is some overlap. In this way, geneticists can erase redundant genes without affecting the development of the organism.
That’s what Harvard geneticists did here. They edited out the overlap. Scientists removed seven of 64 codon types throughout 3,548 genes. Instead of editing the genome one gene at a time, researchers used machines to synthesize whole segments of RNA from scratch, each portion containing several alterations. Then they inserted these segments into the E. coli’s DNA, one-by-one, making sure as to not make changes that would destroy the cell. So far, 63% of recoded genes have been tested. Very few have caused any problems for the cell. Researchers still have several years of experimentation and testing ahead. Still, geneticists are marveling at how malleable the genome actually is.
In the near term, scientists are excited about the prospect of creating bacteria that is invulnerable to viruses. Usually, a virus infects a living cell by adding its own DNA to the host’s genome. In this way, it replicates itself. Genetically recoded organisms (GROs) would have a genome so different, the virus wouldn’t be able to read it and so couldn’t inject its DNA, making it unable to replicate.
One possible use for GROs is manufacturing. By rewriting a bacterium’s genetic code, it would change what kind of protein it makes. Synthetic bacteria could become living factories, programmed to produce whatever amino acid wished for. These would then churn out the next generation of synthetic materials, perhaps even medicines. Such engineered bacteria could also become reliable test subjects for future scientific research.
Prof. Church’s experiments have been controversial in the past. In that, one issue is whether or not this technique is 100% safe. The concern is that recoded bacteria could produce a toxin. Since it would be resistant to viruses, it would have an edge over competitors in the environment. If it should say get loose, it could result in ecological damage or even cause the next great plague. To overcome this concern, Church and colleagues have built a few safety measures into the system.
Model of the human genome.
A special nutrient must be fed to these bacteria or else they die off. Unless they find this selfsame nutrient in the environment, which Church says is unlikely, they would not be able to survive. Another fail-safe is a special barrier which has been erected to make it impossible for the bacteria to mate or reproduce, outside of the lab. But other experts wonder how “unbeatable” Church’s fail-safe’s actually are. Carr says that instead of discussing these measures as foolproof, we should be framing it in degrees of risk.
The next step is further testing of the artificial genes that have been made. Afterward, Church and colleagues will take this same genome and produce an entirely new organism with it. Since DNA is the essential blueprint for almost all life on earth, being able to rewrite it could give humans an almost god-like power over it. That capability is perhaps decades away. Even so, combined with gene editing and gene modification, and the idea of a race of super humans is not outside the realm of possibility.
Want to hear Dr. Church speak for himself? Click here: