A profound result of discoveries in the field of genetics is that all people on earth today are descended from the same remote ancestors. Humankind appeared on this planet about 150,000 years ago and sometimes are referred to as archaic humans though they were just as human as we are. However a geological catastrophe, possibly the climatic effects of thousands of years of mega-drought or the explosion of a super-volcano, almost ended the human lineage so that about 70,000 years ago human beings like ourselves comprised 2,000, or fewer, men, women and children.
When such events occur in other species they are called 'population bottlenecks'. When population falls too low, and genetic diversity sparse, 'extinction events' can even occur. We survived and our ancestors increased their numbers and set out in migrations out of Africa to populate the world. We are all distant cousins descended from that ancestral population. As we developed cultural arts and technologies, probably beginning about 45,000 years ago, we diversified into the various inhabitants of the world, adapting and evolving in response to the environments we moved into. We continue to adapt and evolve within the DNA common to us all. Modern genomic analysis shows that we are all more alike than we are different despite superficial differences. We truly are all distant cousins, all descended from the original 2,000 founders of the lineage of homo sapiens. As we advance into the decades ahead it would be well to keep that in the forefront of our minds. There is work ahead. Over one billion of our fellow human beings suffer appalling privation, lacking rudimentary standards of living, lacking access to modern medicine, living lives of lowered expectations. Our hopes rest with the young, that with the tools of modern technology and the idealism of youth will tackle the immense problems of humankind, will set forth and bring care and comfort around the world.
So although homo sapiens had existed at least 80,000 years before that 'population bottleneck', the result for humans today is that we have a low genetic diversity which has made us vulnerable to diseases and disorders with a genetic basis. The growing ability to identify genes encompassed in DNA is leading to methods of finding medical approaches to correcting genetic errors, to protecting ourselves against bacteria, viruses, and parasites, and even to the ancient human dream of an extended healthy longevity.
There is, and will be for decades ahead, only one thing to slow down the momentum of discoveries being made on this frontier, and that is the shortage of young scientists heading for the laboratory benches, and organic chemistry, gateway to genetics.
The high rates of cardiovascular disease, cancer, obesity, hypertension, diabetes and other degenerative diseases indicates that our genome is not well adapted to a modern diet and lifestyle.
For those wishing to have a satisfactory healthy longevity the real determinant of our nutritional needs and exercise requirements lies in our distant ancestors from Paleolithic times and before.
Archeological, anthropological, and genome studies have shown that the 'paleolithic genome' we all inherited relied on a diet high in lean protein, vegetable matter, polyunsaturated fats (especially omega-3 fatty acids), monounsaturated fats, fiber, minerals, antioxidants and other beneficial phytochemicals.
Such a diet is described as a 'hunter-gatherer' diet.
It has long been known that a very small percentage of the population lives well beyond the century in good health. Such individuals are described in the medical literature as having 'longevity syndrome' and are known to have an unusual distribution of certain fats found in their bloodstream.
Death from cardiovascular disease or cancer is the fate of most people, falling short by decades the potential of a healthy lifespan extending beyond a century. One culprit is the accumulation of arterial 'plaque' on the walls of arteries. It has been found that plaque formation can take decades before it begins to hinder active exercise and become life threatening. It can begin between the age of 20 and 30 and yet not become a problem until decades later.
Until recent years invasive surgery for heart attack and stroke patients was the only option for those with cardiovascular disease, and still is for those who have reached that stage.
However, a revolution in thinking about heart disease is taking place. The major focus in this therapeutic approach consists of lowering low density lipoprotein (LDL, so called 'bad' cholesterol), which distributes cholesterol (made mainly by our organs), to all body tissues where it is used. It is believed that modern human diets and lifestyles have led to our organs producing excess amounts of LDL-cholesterol which is vulnerable to oxidation and is deposited as insoluble clogging plaque along the walls of arteries and other vessels of the circulation system. Hindered circulation of blood leads to high blood pressure; inflammation of plaque leads to rupture and release of contents and clot forming events, leading to heart attack, stroke, degenerative disorders and death.
The reason to use medications (statins) to help prevent this is because of a fuller understanding of how the body produces cholesterol, distributes it to the tissues, and retrieves excess amounts in a process known as 'the reverse cholesterol transport system'.
Other blood fats, triglycerides, form part of this system and can usually be readily lowered to healthy levels with adoption of healthy diets, exercise, and supplements of omega-3 fish oils.
The fat that retrieves excess cholesterol and returns it to the liver for disposal is known as high density cholesterol (HDL, so called 'good' cholesterol'). Frontier clinical trials by research pharmaceutical companies are aiming at raising HDL levels by substantial amounts in order to rebalance our LDL/HDL/triglyceride blood fats to levels in which plaque deposited on blood vessel walls goes into regression. Once such objectives are achieved it will then be possible to begin the adjustment of blood fats when young so that blood vessel clogging will never occur. Leading medical scientists are already talking about the possibility of eliminating heart attack and stroke as such research advances.
Respected medical professionals are beginning to call for CT screening of the entire adult population to identify plaque location and severity.
It is a characteristic of modern times that our inhererited DNA genome has been assaulted by sedentary ways of life and a demand for copious amounts of rich food. Many studies have shown the benefits of extension of life for animals placed on a calorie restricted, barely sufficient, diet. Episodic periods of starvation have shown the slowing of metabolism. But in being homo sapiens we are disinclined to adopt the exercise habits and struggle for sustenance experienced by our paleolithic ancestors. Consequently research is taking place on molecules that could mimic calorie restriction/starvation effects of slowed metabolism and extended healthy lifespan.
We are entering decades of discovery in which a young person living in western society today can reasonably expect to live well beyond a century in age. Let us at least hope they will take this gift of modern science and use it to reach out to our distant cousins who suffer and need their care and concern, need their work, need their endeavors, and need it soon.