Free Radicals, Oxidative Stress & Antioxidants
19 November 2019
Antioxidants, free radicals and oxidative stress: have become trendy topics as far as health and longevity are concerned - let's explain this all a little more.
The best way to think about oxidative stress is as the wear and tear that happens on your system as part of our general and normal running of bodily functions, called metabolism. Normal metabolism, from making thyroid hormone to creating the master fuel our bodies run on - ATP, generates oxidants that cause a degree of oxidative stress. And that is why, no matter how healthy you are, as you get older you will have accumulated more and more exposure to those natural oxidants just generated as a natural byproduct of normal metabolism, but it accelerates under certain conditions, like diabetes, autoimmunity and weight gain for example. Layered onto this is the accumulation of many insults from our environment, from dis-ease to poor diet choices and exposure to “toxins”.
To protect ourselves against oxidative stress and free radicals (more on this next) we have a built in antioxidant system designed to mitigate this wear and tear, but can run into health problems if these reserves are overused and become depleted.
Ageing really is the accumulation of insults on the bodies cells, organs and tissues over time.
What Are Free Radicals and How Do They Cause Damage?
The definition of free radicals is “uncharged molecule (typically highly reactive and short-lived) having an unpaired valence electron.” - right!.... So let’s make that a bit more real….
A free radical technically is something that has an unpaired electron and this goes back to chemistry. All electrons want to exist in pairs. If one of them is missing, then that atom has a voracious appetite to pair up that electron. It's like having 3 people in a relationship - it's a very unstable and unpredictable situation!
On their search of an electron to “pair” free radicals will “react” with just about anything they come into contact with, robbing cells and compounds of one of their electrons. This process makes the affected cell or compound unable to function normally, as essentially it’s damaging DNA, cellular membranes, blood vessels and enzymes. The damage to the body by free radicals is known as oxidation, exactly the same process that browns an apple when you cut it and leave it exposed to the air or rusts metal.
The amount of oxidation in the body is a measure of oxidative stress and high levels affect every organ and system in the body, especially linked to heart disease, accelerated ageing, and diabetes.
All that said, we have to understand that free radicals in excess is indeed harmful, but their production within the body is certainly not abnormal, the very process of breathing in and out creates free radicals. Our bodies produce free radicals as byproducts of cellular reactions (for example, the thyroid gland produces high levels of hydrogen peroxidase in the process of making thyroid hormones, the metabolism - break down of our foods and breathing all produce free radicals.
Antioxidants, as the name might suggest - mitigate or “pair up” free radicals.
We have a built in antioxidant system, and Glutathione is considered the most important “master” antioxidant, made in the liver from the amino acids cysteine, glycine and glutamic acid (and this is why getting adequate protein in your diet is paramount, 0.5 g per kg of your body weight is plenty, and can be plant or animal).
Other major antioxidants include vitamins A, C, E, CoQ10; selenium; zinc, copper and manganese.
Nitric Oxide is another one of the master antioxidants that the body makes - its overall function is to dilate (widen) blood vessels. When nitric oxide (NO) is released by the endothelium (the cells that line our arteries), it allows the vessels to open and facilitates optimal blood flow. This is exactly how the medication nitroglycerin works for high blood pressure. The nitroglycerin is converted to NO, which dilates the arteries allowing more blood flow to the heart. Viagra, works in exactly the same way! It boosts nitric oxide signalling and improves blood flow to the penis.
The enzyme that produces nitric oxide, NO synthase gets “damaged” by free radicals in that its structure changes and becomes a free radical itself. Without enough nitric oxide the endothelium becomes impaired, it can’t dilate as freely and the arteries become stiff, blood pressure rises and your overall cardiovascular risk goes up dramatically. As a note - the beauty of running an advanced cardiovascular blood panel with Cleveland Heart Labs is that they have peer reviewed markers of endothelial health, and why I offer in my clinic with my 1:1 clients.
A diet rich in plant foods is THE best way to extinguish free radicals and boost your bodies natural production of NO, most especially those that are high in natural nitrates. The top ones are:
The major sources of free radicals include:
Science first, we need to view the antioxidant system in two ways:
Take the thyroid as an example; the thyroid gland deliberately produces superoxide, which is a highly reactive free radical, missing an electron, so it’s highly unstable for the sole purpose to them make hydrogen peroxide because we use hydrogen peroxide to make thyroid hormone. Right there in the cytosol of the thyroid gland is an antioxidant, called superoxide dismutase to mitigate the potential damage. And the minerals that are required for the body to make superoxide dismutase are zinc and copper. We also need selenium, manganese, and iron as cofactors and Glutathione is the main system defending against oxidative stress.
When we consider membranes and defending against oxidative damage to the lipids in the membranes, vitamin E is vital, as this is the antioxidant inside the cell membrane. But if vitamin E gets oxidised and needs to be recycled, vitamin C which is on the outside edge of the membrane - donates an electron and acts as a primary antioxidant. And guess what recycles vitamin C ……. Glutathione!
As such, my practical advice is as follows for you:
1. Eating more plants
There is a scoring system to measure the amounts of antioxidants in foods, it’s called the ORAC score. ORAC stands for “Oxygen Radical Absorbance Capacity.” This is a lovely website resource to view scores:- Superfoodly.
Here are a few foods that have very high ORAC scores:
2. Use natural, cold-pressed oils like olive oil, as heat oxidised fats in refined oils.
3. Avoid Toxin or Pollutant Exposure.
Besides improving your diet, here are other ways to start reducing free radical damage: Reducing chemical exposure in household and makeup (have a look at the Limelife brand and products, free of parabens and phthalates
4. Regularly getting short bursts of exercise
Like HIIT or strength workouts as this acts as a hormesis stressor. The exercise damages your muscles, and increases levels of oxidative stress and inflammation in your body. But at the same time, the training stimulates hormones like growth hormone and testosterone. When your body heals those tiny injuries, it builds up some new muscle fibres to go along with the newly-repaired tissue. Also, the increase in oxidative stress provokes a “supercompensation” from your own antioxidant defences, so you end up with lower levels of inflammation in the long run!
5. Maintain a healthy body weight, as excess weight secretes inflammatory hormones and molecules
6. Keep blood sugar levels stable, as peak and troughs are inflammatory by nature.
Next week I’ll recommend some supplements to consider, but for now, as always, it's food and lifestyle first!
In health, Tanya x