A family history of disease? It matters much less in your 50s

If you have a family history of cancer or diabetes, you may assume that your chances of ending up with these diseases are high and there’s not much you can do about it.

Well, you’d be wrong about that… especially if you’ve reached your 50s without those diseases showing up.

There’s been new research into how much influence your genes actually have on your susceptibility to these life-threatening conditions.

And the good news is that the older you get, the more control you have over your health…

Genetics aren’t written in stone

If dad and granddad had cancer or diabetes, most of us believe we have a high chance of ending up with those diseases as well.

But according to Peter Sudmant, UC Berkeley assistant professor of integrative biology and a member of the campus’s Center for Computational Biology, “There’s been a huge amount of work done in human genetics to understand how genes are turned on and off by human genetic variation. Our project came about by asking, ‘How is that influenced by an individual’s age?’ And the first result we found was that your genetics actually matter less the older you get.”

And that’s right in line with something known as “Medawar’s hypothesis.”

Sir Peter Medawar was a Nobel Prize-winning scientist who proposed that genes are a lot less important later in life than they are when we are young — because then they’re usually critical to making sure we survive long enough to reproduce and ensure the survival of our species.

In contrast, genes that are expressed after we’ve passed reproductive age are far less controlled by evolutionary forces — and therefore don’t carry as much weight in how things turn out for us in our later years, health-wise.

In other words, though your genetic makeup can help predict gene expression when you’re young, it’s less useful in predicting which genes may be ramped up or down when you’re older — in this study, older than 55 years.

Your genes may matter less, but you’re not off scot-free

So, what does all this mean for you if you’re over 55 and you’ve made it to this point without falling victim to a condition that could cut your life short?

It doesn’t mean you’re scot-free from health concerns. But what it does mean is that contrary to popular belief, you have much more control over your health now than you did in your 20s or 30s.

That may seem counter to everything you think you know about age and disease. But it could be a game-changer if you’re ready to play. Where do you start?

Prof. Sudmant noted that the study indirectly indicates controlling your health over 55 falls under “environment” — the impact of everything other than age and genetics, including the air we breathe, the water we drink, the food we eat and physical exercise.  

All of those things amount to up to a third of gene expression changes with age.

That means diet and getting physically active are dealbreakers. If you’re not already following a healthy diet, like the Mediterranean diet, or exercising, time to get busy.

Now there were a few areas in the body where Medawar’s hypothesis didn’t hold true…

“From an evolutionary perspective, it is counterintuitive that these genes should be getting turned on, until you take a close look at these tissues,” Sudmant said…

“In your blood, colon, arteries, esophagus, fat tissue, age plays a much stronger role than your genetics in driving your gene expression patterns,” says Prof. Sudmant.

These five tissues are ones that constantly turn over throughout the human lifespan. Every time they replace themselves, there’s risk of a genetic mutation that can lead to disease, especially cancer.

So in addition to staying on top of diagnostics, take care to live a lifestyle that makes cancer much less likely. The same diet and exercise routine you should tackle to cover how your environment affects your health are also at the top of the list to keep cancer away.

Sources:

Age vs. genetics: Which is more important for determining how we age? — Science Daily

Tissue-specific impacts of aging and genetics on gene expression patterns in humans — Nature Communications