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Major Ager Bad Genes & Short Telomeres How Genetics Influences Ageing – and You Control Your Genes

As we get older, it’s easier and easier to pass the blame for our own health problems on to other people. Recently diagnosed with high cholesterol? Aha, three grandparents and two great-uncles all died of heart disease. Accidentally put the ketchup in the freezer the other day? Oh yes, Aunt Matilda had a touch of dementia. Battling a weight problem for most of your life? Yup, Dad and his brothers believed in the three food groups of cheese ravioli, meat sauce, and multiple helpings.

In fact, many of us buy into a very similar theory of ageing: we’re born with our health destiny. That is, our genes – the chromosomal alphabet soup that includes ingredients from our parents, their parents and so on – are primarily responsible for determining whether we’ll get heart disease, cancer, Alzheimer’s or any of the other diseases or conditions that can turn a grade-A quality of life to spoiled minced beef.

But that’s simply not the way ageing works. Your genes are important, especially when it comes to one of the most powerful age-related problems: memory loss. Your genetic destiny, however, is not inevitable.

What do we mean by that? Think back to the city that we outlined for you in the introduction, and consider your genes as the physical location of that city. Some characteristics you simply can’t change. Chicago is windy, Manchester is rainy, San Francisco is built on fault lines, Cape Hatteras is in the path of tropical storms. A city’s location serves the same function as your body’s genes. Your genetic traits make you more or less predisposed to health-related windstorms, snowstorms, earthquakes and hurricanes. But just as you can modify cities to adjust to natural geography and natural occurrences, you can also protect yourself from abnormalities in your genes if you’re unhappy with how you’ve been genetically programmed.

FACTOID

The telomeres of people who feel more stressed are almost 50 percent shorter than people who say they’re less stressed. Since scientists have a rough idea what the average telomere length is for a specific age, they can estimate how much older the higher-stress group is biologically: a whopping nine to seventeen years. Just by thinking they were ageing faster, they actually aged faster.

When it comes to your body, here’s what we know, primarily through studies of identical twins: your longevity is based one-quarter on your genetics and three-quarters on your behaviours and lifestyle choices. It’s not about what genes you have but how you express them. Genes work by manufacturing proteins, but whether or not a specific gene is turned on or off is largely under your control.

Think of the ability to manipulate your genes as developing a set of city building codes to adapt to the circumstances you’re in. It would be like a coastal town requiring houses to be built on stilts to protect against surging tides or office buildings in San Francisco using earthquake-resistant materials to better protect against an architectural crumble. You adapt and adjust to deal with whatever nature throws your way. That’s the way your body works. As the mayor of your physiological city, you can create different codes to mitigate the effects of the genes you’ve been dealt. For example, exercise isn’t good for you just because it helps burn fat and assists with bikini satisfaction, but it can also alter the expression of your genetic codes to decrease your risk of getting cancer. That means you do have some control over how your genes manifest themselves in your body and how they control the rate – and way – that you age.

Figure A.1 Geography Lesson Location is location, just as genes are genes. But you can manage the city’s geographic area and climate by being innovative. After all, great cities arise from very different geographies.

Maybe you’ve been dealt a bad hand of genetics, but that doesn’t mean you can’t exchange a few cards, or at least change how you play them. Another way to think about your genetic inheritance: it’s stored information, the factory-installed info that comes with your biological system. You have the power – with your behavioural software – to alter that information along the way. But if you don’t take any action, then the stored information is what dictates how those genes play out.

Which of Your Genes Is Turned On?

Controlling your genetics can help you avoid the major age-related diseases and improve the chances that you’ll spend more time with your grandkids than you will in doctors’ waiting rooms reading large-print magazines that are three years old.

If you remember our Swiss cheese model, it makes sense: by fixing one thing about your body – like adding a daily thirty-minute walk – you’ll end up (perhaps unintentionally) fixing many others along the way, so that the holes of ageing don’t line up and cause total system failure. And by making small changes, you’ll reach that goal of adding years and quality to your life.

So how do you change the function of your genes? One way is through the rebuilding of chromosomes. Your chromosomes, the little rascals, have small substances on the ends called telomeres (see Figure A.2). Think of them as being like those little plastic tips of shoelaces (which are called aglets, in case you want to show off in your next Scrabble competition). Every time a cell reproduces, that telomere gets a little shorter, just as the shoelace tip wears off with time. Once the protective covering on the tip is gone, your DNA and shoelace begin to fray and are much harder to use. That’s what causes cells to stop dividing and growing and replenishing your body. The cell realizes that it is no longer helping the body and commits suicide (that’s called apoptosis), which can contribute to age-related conditions. But your body also has a protein – called telomerase – that automatically replenishes and rebuilds the ends of the chromosomes to keep cells (and you) healthy. However, lots of cells in your body don’t have telomerase, meaning that many of them have a reproduction limit – thus putting a cap on how well your systems can be replenished. (Telomerase, by the way, is overactive in 85 percent of cancers. That makes sense, right? Rebuilding the aglet that allows cells to divide helps those cancer cells reproduce and spread.)

Figure A.2 A Good Tip Your chromosomes have small caps on the ends called telomeres, which are like those little plastic tips on shoelaces. Every time a cell reproduces, that telomere gets a little shorter, just as the shoelace tip wears off with time. You need a substance called telomerase to rebuild the cap.

The amount of telomerase depends on your genetics, but we’re now starting to see that we can influence the size of those little tips, the telomeres. For example, researchers have found that mothers with chronically ill children have shortened telomeres, indicating that chronic stress can have a huge influence on how cells divide – or fail to. The implication is that if you can reduce the effects that stress has on you, through such techniques as meditation, you can increase your chance of rebuilding the telomeres and decrease the odds of having your cells die and contribute to age-related problems.

Yes, you’re stuck with the genes you were given, just as you’re stuck with the decisions your parents made about where you grew up, and you can’t return your genes for a complete refund. You can, however, change the way they function. We’re starting to uncover more and more ways that you can change how your genes function, which we’ll detail in the following chapter about your memory. For example, just ten minutes of walking turns on a gene that decreases the rate of cancer growth, and resveratrol (the ingredient found in red wine) turns on a gene that slows or stops a dangerous inflammatory process that happens inside your body. And in the very near future, we’re going to be able to develop medicines tailored to individuals whose genes work differently from others’.

Because each of us has a unique genetic fingerprint, the detection, prevention and treatment of diseases can be difficult. But as we start to unlock the ways that we and modern medicine can dramatically manipulate our genes, we’re going to start seeing how we can make our genes work for us, not against us. Perhaps the best example of how genes affect us is our memory, which is goal one – in part so you can remember the rest.