Figure B.3 Radical Demonstration Oxygen free radicals are created when a pair of electrons is separated while spinning around the nucleus of a cell. The odd man out becomes disruptive as it seeks another partner.

      Maybe you’re thinking, So what? So what if my mitochondrial DNA is a little slow on the ol’ energy conversion process? What’s that mean for me?

      Well, for a business, inefficiency may mean losing money. For a student, inefficiency may mean pulling all-nighters. But for mitochondria, inefficiency means you’re that much closer to booking a bed at the extended-care facility.

      Think about it. If your body can’t produce energy efficiently, it means that mitochondria are not getting the most energy out of the oxygen and sugar that their furnaces are fed. So even if you have good nutrition in what you eat, lower levels of your body’s energy currency, called ATP (adenosine triphosphate), are made.

      We know that mitochondrial damage in the heart happens when your body no longer consumes oxygen and glucose efficiently. We also see mitochondrial damage in brain-related disease and in diabetes, where it influences the pancreas’s ability to make insulin. In fact, mitochondrial damage may serve as a contributing factor to certain types of cancer, because the more oxidative damage that takes place, the more DNA is damaged, and that damaged DNA, when it’s replicated over and over again, can evolve into a cancer.

      Damage Control

      Like a politician who gets bad press, your body can also perform damage control. Over time, those furnaces (the cristae) in your mitochondria swell and become lazy fat cats – they don’t do a whole lot of work. At the same time, young, small but efficient mitochondria that are continually born become the energy work-horses of your body.

      In a city model, the big-cristae mitochondria would be the high-salaried bureaucrats who spend all day preventing city government from being reinvigorated by young whippersnappers who could replace them, cut through red tape and do a lot of work for a lower price. In your body, the turf battle happens because the large ones (the bad ones) have the power to survive at the expense of the little ones (the good ones).

      It turns out that you can tolerate a lot of damage to your mitochondria because mitochondrial DNA is resilient. This special SAS brand of DNA is used to dealing with the damage that happens when you bombard them with oxidative substances. In a way, they are a little like parents. The mitochondria can tolerate quite a bit, but eventually they blow a gasket. And that’s when the real damage begins.

      This all happens as a natural part of the ageing process. In fact, people older than sixty have a 40 percent lower mitochondrial efficiency than people younger than forty. But remember, what’s natural is not necessarily inevitable. As you’ll see in our next chapter on the muscle that uses the most energy, that means this: while these seemingly uncontrollable cellular battles may be taking place deep inside your body, you still have the power of an anatomical puppeteer – to control the ways that your cells function. But when the system starts to spew toxic waste and you can’t keep up with the oxidation in your cells, your arteries begin to rust, which puts heat on quite a few organs, including the heart.