More Evidence for the Inheritance of Longevity

There is plenty of evidence to show that comparative longevity for individuals within a species is to some degree inherited, running in families. Humans are no different in this regard. We might compare that with present thinking on the degree to which life expectancy in our species is genetic versus environmental, however: it is thought that genetic differences only become significant in old age, during the struggle of damaged systems to maintain some level of function. A commonly quoted assessment is that 75% of life expectancy variation is due to choice and environment, and only 25% is due to genetics. So what is the important inheritance here, genes or culture? I use the term culture in the very narrow sense of your upbringing, the habits, values, and knowledge you acquire or choose due to the influence of those around you. In the wealthier parts of the world the most important cultural outcomes for recent generations are whether or not you smoke, whether or not you become overweight, and whether or not you keep up with regular moderate exercise. Arguably formal education and a disposition towards personal wealth are important too, but the true nature of these relationships is very hard to disentangle from other associated factors when examining population statistics.

In the years ahead this will all change, and natural variations in life expectancy will become unimportant in comparison to whether or not people have access to rejuvenation therapies that can repair the molecular damage that causes aging. A class of therapy capable of adding ten healthy years to life would swamp all of the existing common lifestyle effects on human life span. After the advent of several of these types of therapy, long-term health will become almost entirely determined by medical technology. This is the goal to aim for, to lift up everyone into a future in which there is no more ill health or age-related disease, no more short straw in the genetic lottery, and life in good health is a choice for as long as desired. Freedoms of this sort must be built; they cannot simply be declared.

The paper here, like most assessments of the data for inheritance of longevity, doesn't have much to add on the contribution of genes versus environment. Genetic associations are known to exist, and they are found here as they are in other studies. I suspect that accurate assessments of the individual contributions to human longevity for all of these various factors, genes and lifestyle choices, will not be completed by the research community before they become moot. Medical progress will ultimately make natural variations in longevity just as irrelevant as natural variations in resistance to smallpox - an interesting historical question, but not one studied by any great number of people.

Long-lived parents could mean a healthier heart into your seventies

The longer our parents lived, the longer we are likely to live ourselves, and the more likely we are to stay healthy in our sixties and seventies. Having longer-lived parents means we have with much lower rates of a range of heart conditions and some cancers. A major study found that our chances of survival increased by 17 per cent for each decade that at least one parent lives beyond the age of 70. The researchers used data on the health of 186,000 middle-aged offspring, aged 55 to 73 years, followed over a period of up to eight years. The team found that those with longer lived parents had lower incidence of multiple circulatory conditions including heart disease, heart failure, stroke, high blood pressure, high cholesterol levels and atrial fibrillation. For example, the risk of death from heart disease was 20% lower for each decade that at least one parent lived beyond the age of 70 years. In addition, those with longer lived parents also had reduced risk of cancer; 7% reduced likelihood of cancer in the follow-up per longer-lived parent.

Although factors such as smoking, high alcohol consumption, low physical activity and obesity were important, the lifespan of our parents was still predictive of disease onset after accounting for these risks. The study built on previous findings which established a genetic link between parents' longevity and heart disease risk. That paper studied 75,000 participants in the UK Biobank, and found that offspring of longer-lived parents were more likely to have protective variants of genes linked to coronary artery disease, systolic blood pressure, body mass index, cholesterol and triglyceride levels, type 1 diabetes, inflammatory bowel disease and Alzheimer's disease.

"This work helps us identify genetic variations explaining the better health of people with longer-lived parents. We prominently found genetic factors linked to blood pressure, cholesterol levels and smoking, which underlines how important these avoidable and treatable risks are. However, we also found novel genetic factors, which could provide new clues to help us understand why having longer-lived parents has health benefits. This study provides additional fuel to really bolster research efforts by us and others in geroscience, a field that seeks to understand relationships between the biology of aging and age-related diseases. Aging is the most important risk factor for common chronic conditions such as heart disease, Alzheimer's and cancer, which are likely to share pathways with aging and therefore interventions designed to slow biological aging processes may also delay the onset of disease and disability, thus expanding years of healthy and independent lives for our seniors."

Longer-Lived Parents and Cardiovascular Outcomes

Cardiovascular risk assessment currently identifies higher risk individuals through parental histories of early onset myocardial infarction. However, having relatively long-lived parents is associated with markedly lower coronary heart disease (CHD) risks and longer survival. Parental longevity associations with other common cardiovascular outcomes are little studied. We estimated associations between parents' age at death and common incident conditions plus mortality in a large middle-aged cohort.

Comments

"But over the long haul all that really matters is progress in medicine: building new classes of therapy to repair and reverse the known root causes of aging."

I believe this statement is incorrect. What really matters is societal progress. Safe water protected us from cholera. The industrial revolution reduced the scourge of tuberculosis much more than anti-tuberculous drugs. Diplomacy reduces death from war. I could go on.

Don't get me wrong. My wife had 15 months of quality, progression free survival because of one of the new gene targeting drugs. She died a week ago but might have lived longer had she the time to go on one of the next generation of drugs in its class. But we shouldn't forget that our politicians have a huge impact on longevity.

Posted by: Dana at July 5th, 2017 12:00 AM

My condolences.

But I beg to differ.
There is a certain point at which the advancement of a society and the advance in health and lifespan become decoupled.

It's good to remember better hygiene is a direct result of medical advancement - medical professionals realized we need better hygiene if we are to prevent infectious disease.

Sure, there are good examples in tuberculosis and cancer, both conditions were not considered something we should treat - they were just causes of a natural death as anything else - that changed with advocacy.

But with cancer the real results came decades later - once the medical field was mature enough to produce viable treatments.
50 years of advocacy and political will led us to this point - and unfortunately people still die from cancer. Less so than before. And progressively less so in the future quite possibly.

The will to defeat a disease alone doesn't translate into cures.
Advancement in medicine does. They are correlated but not causally.

Posted by: Anonymoose at July 5th, 2017 1:07 AM

Also, see for example female life expectancy at birth in Spain:

http://imgh.us/1_3429.png

The civil war (1936-1939) had only a short-term influence (post-war poverty can't be seen in the graph) and other major social changes, like the end of dictatorship (1978) or the global financial crisis (2008) can't be seen at all.

Posted by: Antonio at July 5th, 2017 2:18 AM

Post a comment; thoughtful, considered opinions are valued. New comments can be edited for a few minutes following submission. Comments incorporating ad hominem attacks, advertising, and other forms of inappropriate behavior are likely to be deleted.

Note that there is a comment feed for those who like to keep up with conversations.