The role of the detoxifying enzyme superoxide dismutase in staving off aging, cancer, and dementia and what we can do to boost its activity.
Mitochondrial Theory of Aging,
Let me end with one final topic. In 2010 we earned a lot more about aging and eating. Awarded the highest honor for scientific achievement in this country, one of the greatest biochemists of all time wrote that, “Aging is a disease. The human lifespan simply reflects the level of free radical damage that accumulates in cells. When enough damage accumulates, cells can’t survive properly anymore and they just simply give up.”
First proposed in 1972, the Mitochondrial Theory of Aging suggests that it’s free radical damage to our cells’ powersource, known as mitochondria, that lead to a loss of cellular energy and function over time. It’s a little like charging your ipod battery over and over again; every time the capacity gets less, and less. Mitochondria are like miniature blast furnaces inside our cells where the food that we eat… is converted, into useable energy.
In my Stopping Cancer Before it Starts DVD, I go into detail about the, quantum biology of oxidative phosphorylation, but just to simplify, it is in these fireworks inside the mitochondria, where the oxygen we breathe may get a hold of an electron we ate that was pumped with energy by plants (thanks to photosynthesis) and transform that oxygen molecule into what’s called superoxide, which can damage our delicate cellular machinery—oxidize our cellular machinery. Basically we're rusting—that's what rust is, right? The oxidation of metal. And scientifically, aging has been considered the slow oxidation of our bodies. Like those brown age spots on the back of people’s hands? That's just oxidized fat under the skin. Oxidant stress is why we get wrinkles, that's why we lose some of our memory, that's why our organ systems break down as we get older.
How do we slow down oxidation? By eating foods containing anti-oxidants. If you want to know if a food has a lot of antioxidants in it you slice it open, expose it to air—expose it to oxygen and see what happens. Does it oxidize, does it turn brown? Think about our two most popular fruits: apples and bananas. Turn brown right away—not a lot of antioxidants inside there. How to do you keep your fruit salad from turning brown though? Add lemon juice, which has vitamin C in it, an antioxidant, which can keep your food from oxidizing and can do the same thing inside our bodies.
Here’s the catch, though: Many antioxidants can’t penetrate through the mitochondrial membrane into the mitochondria. So they can protect the rest of the cell, protect our DNA, but they can’t get access inside the powerplants of our cells and so may be helpless to slow down the aging process. That’s why our bodies, have an enzyme called superoxide dismutase. It’s a detoxifying enzyme within our mitochondria that neutralizes superoxide, and turns it back into oxygen.
Because of it’s “bomb-defusing” role, it’s considered a tumor suppressor gene staving off cancer, considered neuroprotective in our brain, staving off dementia. In fact the reason women live longer than men, may be because they have superior enzymatic activity of this superoxide dismutase.
This Mitochondrial Theory of Aging has enjoyed such universal acceptance within the scientific community, that there was even a paper published last year asking whether there was anything more to aging at all?
OK, bottomline: how do we boost the activity of this anti-aging, anti-cancer, anti-Alzheimers enzyme? Become a woman. Or become a vegetarian. Last year researchers compared this enzyme’s activity in omnivores versus vegetarians. This is your superoxide dismutase enzyme activity if you’re over 85. When you’re younger, this enzyme may work a little better, but when one eats vegetarian it works a lot better.
Eating vegetarian appears to boost this anti-aging enzyme’s activity 300%! A three-fold increase in the expression of the superoxide dismutase gene in the vegetarian group compared to the omnivore control group. We had no idea. No wonder vegetarians live longer; no wonder they have less cancer and cardiovascular disease—we had just never tested them for this enzyme before.
A higher enzyme expression, at the genetic level. Thus, a better defense against superoxide radicals might be expected as a consequence of a vegetarian diet. So maybe that’s why lower rates of cancer and chronic cardiovascular disease compared to omnivores. Yes, they eat more phytonutrients, but the higher protection against chronic disease in vegetarians may also be explained by what are called epigenetic changes. You think you’re just born with genes and stuck with them? No, we now know that what we eat can turn on and off gene expression. And in this case, eating vegetarian seems to significantly boost the activity of one of the most important workhorse enzymes in the body.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring watch the above video. This is just an approximation of the audio contributed by veganmontreal.
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Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out theother videos on aging. Also, there are 1,449 other subjects covered in the rest of my videos--please feel free to explore them as well!
Also, check out my associated blog posts for some more context: Acai to Zucchini: antioxidant food rankings, Kiwi Fruit for Irritable Bowel Syndrome, Eating Green to Prevent Cancer, and Ergothioneine: A New Vitamin?