Antioxidants, Free Radicals, and why you should care, especially if you're over 50. Too much, too hard, too confusing? I hear you!
But your health can be severely impacted by free radicals. So I have been told. I wanted to understand and try get into the detail.
Got your attention now? Read on.
Antioxidants fight free radicals. (Sounds like a News headline). They also help regulate inflammation. More on these later.
Free radicals can damage cells, and cause illness and aging. Free radicals are linked to aging and disease. They can build up in cells and damage DNA, lipids, and proteins.
If free radicals overwhelm the system, this is not good. Their reactions usually build up with age throughout the body, and can produce adverse outcomes. This is also impacted by genetics and environmental differences, which means free radical damage can manifest at certain ages. Cancer and atherosclerosis are considered 2 salient "free radical diseases" (1)
Free radicals come from where exactly?
Free radicals result from normal, and essential metabolic processes (reactions) or external sources. They are the result of enzymatic (chemical reactions involving enzymes to synthesize complex molecules in the body), and non-enzymatic reactions (chemical reactions that can occur in the absence of enzymes due to their inherent reactivity and proximity).
Basically, enzymes speed up reactions by helping lower the activation energy needed to start the reaction. In simple terms, these chemical reactions keep people alive and well, by for example breaking down food and drink into energy.
Make sense?
Why do we need them?
While they are damaging, they are the body's natural byproduct of normal internal processes and also how our bodies deal with environmental insults.
You need bad things to get rid of bad things. Just don;t let them takeover.
Free radicals don't have a full stack of electrons, they steal these from other molecules and damage them in the process. If these are viruses or bacteria, for example, that is how the immune system fights them off. Free radicals can also occur during exercise for example to induce some of the benefits of exercise. (2)
Antioxidants then neutralize the free radicals by giving up some of their electrons. This helps break the chain reaction.
Examples of sources:
Internal:
- Inflammation
- Exercise (You read that right)
External:
- Environmental pollutants
- Radiation
- Certain drugs and pesticides
- Industrial solvents
- Cigarette smoke
So we need antioxidants to balance out the free radicals to avoid damage?
How much antioxidants?
Antioxidants in larger than usual amounts are not always beneficial as they can interfere with normal cell functions.
There are also different types of antioxidants, and they may not all be interchangeable.
One measure for antioxidants is ORAC (Oxygen Radical Absorbance Capacity) units. Developed by the National Institute of Health & Aging. ORAC measures the antioxidant capacity of different foods.
- USDA recommends 3000-5000 ORAC units a day
- Nutrition.org 8000 (female) -11000 (male) ORAC units a day
But, the US Dept of Agriculture withdrew its ORAC values in 2012 due to an absence of scientific data that ORAC has any biological significance, apparently the page has since been removed. ORAC values can help identify foods, but they only measure the potential antioxidants in that food.
Also, there is not necessarily a direct relationship between antioxidant intake and antioxidant activity which results from varying absorption and metabolism. It's complicated.
Studies
NCBI Study
The best we could do is this study, which considered 24 categories of animal and mixed foods. The results showed big differences within the categories and each had foods with zero antioxidants.
- The spices, herbs, herbal/traditional plant medicines, and vitamin and dietary supplements category had the highest and most antioxidant-rich products.
- Berries and related products, fruit, fruit juices, nuts/ seeds, breakfast cereals, and vegetables, and related products had medium to high antioxidant values. Plant-based foods were generally higher.
- Meat, poultry, and fish on average were low in antioxidant value.
The study was published in NCBI (3).
USDA Study
The USDA did have this to say: High ORAC foods may slow aging. This was according to animal and human blood studies which found foods high in antioxidants protected cells and their components from oxidative damage (3).
Antioxidant-rich foods may help slow the processes associated with aging in both body and brain. (Big call).
In the studies, antioxidant power was raised by 10% - 25%, and the loss of long-term memory and learning ability was prevented (in rats), as well as maintaining their ability to respond to a stimulus (this normally decreases with age), and it protected their capillaries against oxygen damage. Spinach is the most effective at protecting different types of nerve cells in 2 separate parts of the brain against aging. Might be rat research, but I'll take it.
Vitamin C & Vitamin E
The RDA for Vitamin C is 75 mg / day for adult females, and 90 mg/ day for adult males, and the tolerable upper limit is 2000 mg/ day. High levels of vitamin C can however act as pro-oxidant with potential negative effects.
The RDA for vitamin E is 15 mg/day with the upper limit being 1000 mg/day. High doses can also have negative effects when it comes to exercise.
High doses of both can result in oxidative stress. So high doses of supplement based antioxidants may always not be great, choose wisely.
Read the NCBI study here (4).
Summary #1.
Fact: Our bodies produce free radicals, but this is natural and we need them.
Fact: Free radicals can cause oxidative stress which can damage cells.
Fact: Antioxidants are needed to counter free radicals.
Fact: Too many of either, are not good for us.
Fact: Sources include vitamins, traditional medicines, spices, fruit and vegetables.
Research: High ORAC foods may slow aging and protect brain. Don't overdo vitamin C and vitamin E supplements.
What I do.
Definitely try to eat spinach, sometimes in soups, however boiling can remove up to 90% of antioxidants, and a more balanced diet (I try). I do use some supplements, but plant and traditional medicine based as opposed to vitamins, and in lower amounts, and as they say, "an apple a day..." But thats just me.
Summary #2.
How many ORAC units or antioxidants we need appears debatable, there are different types, absorption and metabolism can differ, and needs may differ depending on what our bodies are dealing with.
ORAC units examples (5).
- 1 cup blueberries - 9,019
- 1 cup strawberries - 5,938
- 1 red delicious apple - 5,900
So we need antioxidants. The more we put our bodies through, the more poor environments we exposed it to, logic would suggest the more antioxidants we require.
Good sources include spices, transitional medicines, fruits, vitamins and vegetables.
Eat a variety of foods (fruit & vegetables), and spices, and consider your antioxidant related supplements carefully, if needed. Try to avoid mega high doses.
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