Mirror, mirror on the wall—who will live the longest of them all?

By Armaan Singh


It’s a common desire to live a long life. Up until very recently, death has often come unpredictably and inexplicably early. However, as medicine and humanity evolved, we have developed a firm but developing idea of how aging and death occurs. Some have settled on the idea that accelerated aging has been linked to dietary and stress related variables. But before dealing with the finer details, let us first determine the reason behind aging. Is it a matter of environment or rather that of genetics? What is unique about “Blue Zones?” There are two areas that we can explore to answer these questions: DNA damage and repair, and lifestyle factors.


The “Blue Zones” of the world have been identified as the Italian island of Sardinia; Okinawa, Japan; Loma Linda, California; Costa Rica’s isolated Nicoya Peninsula; and Ikaria, an isolated Greek island. In these Blue Zones, people have been documented to live longer and healthier, with a lifespan of 90 to 100 years, than anywhere else on earth. Is there a magic formula? These centenarians incorporate very healthy diets and physical exercise into their everyday lifestyles. According to Dan Buettner, “A healthy diet, according to mountains of literature, and now supported by blue zone investigation, is one that is loaded with vegetables, fruits, fish, and nuts, and low on meat, sugar, fat, and the toxic processed foods of modern civilization.” Buettner goes into even more detail, highlighting red wine, goat's milk, local teas, and several other aspects of Blue Zone diets that seem to be beneficial. He states, “Sure, you can get all precise about it if you want, but my take is that the exact details, such as red wine, are not so important. What is most important is the high level theme of generally eating healthy food [fruits, veggies, fish] and cutting out the food with deficient aspects [meat, fat, sugar].” Buettner also noted that these communities are rich with healthy relationships and low stress lifestyles. In the Blue Zones, rates of heart disease and cancer are 50% and 20% less respectively. So now that we have lifestyle covered, what is happening in our genes? Is there a secret or is magic occurring there? This is where DNA damage and repair is very important to understand.

DNA repair has been noted to be one factor that can be a determinant for longevity. Sirtuins are a family of proteins that facilitate cellular function and have long been recognized to play a role in aging. More specifically, they are responsible for functions such as gene expression and are involved in DNA repair. A key factor to understand is that as we and other animals age, our DNA is increasingly prone to damage and breakage: this can then lead to mutations and rearrangement of our genes, a precursor for cancer and aging. This is why DNA repair plays a key role in how long an organism lives. SIRT6 is known as a “longevity gene” due to its key role in DNA repair and metabolism. In studies, it has been shown that mice with additional copies of the gene live longer than their regular counterparts, and mice that have the gene knocked out experience accelerated aging. SIRT 6 is a chromatin associated protein that is required for DNA damage in mammalian cells. SIRT 6 is often called the “longevity gene” because of its importance in organizing proteins and recruiting enzymes that repair broken DNA—mice without the gene prematurely age whereas mice with extra copies live longer.


A research team consisting of Dr. Vera Gorbunova, Dr. Andrei Seluanov, and Dr. Dirk Bohmann hypothesized that if better DNA repair supports longer lifespans, organisms with longer lifespans may have evolved more efficient regulation of DNA repair. So, could this mean that higher SIRT6 activity is present in longer-lived species? One possible approach may be to insert additional SIRT 6 genes into our cells; mice that have been genetically engineered to overexpress or produce more SIRT 6 protein exhibit an extended maximum lifespan, so there are possibilities that doing the same may have a similar effect on our own bodies. Additionally, researchers are exploring the intriguing mix of gene-environment interactions. Our individual genetics interact with the external world and environment and lead to various levels of longevity, which is a very dynamic process. Family ecology also matters, as a study on longevity in families was researched in Sardinia. The research has a long way to go and the fountain of youth may not be on the horizon for everyone. As we wait for the ongoing results of these studies, it would be wise to lower one's stress levels, consume healthy wholesome foods, grab those sneakers and take a walk!!


What did you learn?


Where are the “Blue Zones”?

Answer: The Italian island of Sardinia; Okinawa, Japan; Loma Linda, California; Costa Rica’s isolated Nicoya Peninsula; and Ikaria, an isolated Greek island.


What are sirtuins?

Answer: A family of proteins that facilitate cellular function and have long been recognized to play a role in aging. More specifically, they are responsible for functions such as gene expression and are involved in DNA repair.


What is SIRT 6?

Answer: SIRT 6, often called the “longevity gene,” is important in organizing proteins and recruiting enzymes that repair broken DNA.




Citations

https://www.bluezones.com/about/history/

https://www.cell.com/cell/pdf/S0092-8674(19)30344-7.pdf

https://www.nature.com/articles/nature10815

https://www.lifespan.io/news/more-insights-into-the-longevity-gene/

https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.118.312562


Image Credit:

https://www.pexels.com/photo/sliced-bread-on-brown-wooden-chopping-board-beside-green-glass-bottle-4684185/

https://www.pexels.com/photo/woman-wearing-brown-overalls-near-brown-tree-2050991/


126 views1 comment

Recent Posts

See All