6/1 Antioxidants and Free Radicals

I'm beginning to think that free radicals and antioxidants are the most effective focal point if you want to be healthy for longer.  We hear these terms thrown around all over the world of nutrition, but I'm not sure if they're understood very well.  This blog post is my official entry into the discussion.

First, let's define free radicals.  To understand what a free radical is, let's look at a standard atom.  All biological molecules are composed of different types of atoms.  Each atom is composed of three types of particles: neurons, electrons, and protons.  The nucleus of an atom contains all of the protons and neutrons.  Protons carry a positive charge, so they are just fine co-existing in the same space as neutral neutrons.  Around the nucleus, there exists shells of space within which reside electrons, which are negatively charged.  In its most stable form, an atom has an equal number of electrons and protons.  Under certain circumstances, one of the outermost electrons in an atom can be kicked out of orbit around its nucleus.  An atom with a proton/electron imbalance is extremely unstable, and an electron deficiency is called a free radical.

The electron knocked free from the atom is highly energetic and also unstable. It bounces around until it forces its way into another atom's electron cloud, which naturally knocks one of its original electrons out because an atom must contain the same number of protons and electrons to remain stable.  This free electron then knocks an electron free from another atom.  If this cascade spreads to important cellular material, such as DNA, it can be dangerous.

Let's pause to talk about DNA.  In nearly every one of our body's cells, an area called the nucleus (not to be confused with the nucleus of an atom) protects 23 pairs of chromosomes, which are tightly coiled strands of DNA.  These strands are comprised of millions of nucleotides, which are tiny building blocks, which, when aligned in certain three-letter patterns, represent codons.  A gene is a string of specific codons, which is used as a blueprint to produce specific proteins. 
                                                                                                                  http://www.uic.edu/com/dom/gastro/fgicu/assets/images/Genes_DNA_chart.jpg

Keep in mind that human cells are invisible to the naked eye, let alone chromosomes, let alone nucleotides, LET ALONE ATOMS!  So when we talk about free radicals, we are talking about some very very tiny particles.  DNA is the long line of nucleotides present along the strands of chromosomes.  These strands are simply millions upon millions of genes lined up next to one another.  At the beginning and end of each gene in the strand, there are specific nucleotide sequences that represent the respective beginnings and ends.  There are only four bases comprising our DNA, which we will simply refer to as T, C, A, and G.  A line of DNA may look like this:  CGATGCCTCGAAGCCTCGATC.  As mentioned before, genes are comprised of codons, and codons are comprised of nucleotides.  

When a cell requires the production of a specific protein, its internal machinery begins the process of transcribing the DNA into another type of genetic material called RNA.   In an RNA strand, we see the same nucleotides that we saw in DNA, only T is dropped, and instead we see U, so RNA is comprised of U, C, A, G.  The way that the enzymes do this is by first unwinding a part of the DNA near the beginning of the gene, then other proteins lock themselves in place.  This protein complex works its way along the strand, creating a chain of RNA that is complementary to the DNA strand.  Everytime it sees a T, it adds an A on to the growing RNA strand.  Everytime is sees a C, it adds on a G to the RNA.  When it sees an A, it adds a U.  When it sees a G, it adds a C.  The RNA strand complement to the DNA strand above is: GCUACGGAGCUUCGGAGCUAG.

This RNA is then worked on by other machinery to slowly build a strand of amino acids which are then folded into a protein.  The translation of RNA into protein is easy.  A series of proteins surround the RNA strand and work their way along the strand three nucleotides (one codon) at a time.  Each codon represents an amino acid.  As the protein complex passes over a codon, another protein brings the corresponding amino acid (eat lots of amino acids, dummy) from the surrounding area to add it to the growing protein.  The RNA strand thus gives directions for the construction of a protein. 

So...let's get back to our free radical discussion.  A free radical begets another free radical begets another free radical, etc.  This cascade isn't dangerous unless it begins to rip through the material in the nucleus of cells.

http://en.wikipedia.org/wiki/File:Rna-codons-protein.png
 
Free radicals can have debilitating effects on our DNA.  Cellular damage is easily managed by the waste management crews in our cells.  But our cells can't simply dispose of damaged DNA; that would be like throwing away your hard drive when you get a virus.    When a nucleotide is damaged by free radicals, it can cause a kink in the sequence.  Remember, the DNA sequence is crucial.  When transcribing DNA into RNA, every single nucleotide in a gene counts.  If one letter is removed from the sequence it causes sequence shift. This throws off the specific three-letter combinations that will later be used to call on amino acids when translating RNA into protein.  For example, if you eliminated the first base in the RNA strand from above, it would look like this: G CUACGGAGCUUCGGAGCUAG.  This sequence no longer calls for even a remotely similar amino acid sequence. A nucleotide can also be damaged, causing the gene to be un-transcribable.  The protein complex will simply stop transcribing once it hits the damaged nucleotide.  Very dangerous.


This is the danger of free radicals.  Our cells' nuclear material is so sensitive to change!  Proteins run the show in our body.  Enzymes are proteins, and they're crucial for all of the chemical processes that take place in our body.  The structural material of tissue is protein.  And proteins are required for the transport of many chemicals into, out of, and around cells.  If a gene is screwed up, it won't produce a piece of equipment (a protein) necessary for cell function.  Cancer is the result of the malfunctioning of programmed cell death.  A cell lives a health life for a while, but eventually it dies, or it malfunctions in some way that triggers it to commit suicide.  At the end of a cell's life, it kills itself through a process known as apoptosis.  Like most cell processes, apoptosis requires various enzymes.  An enzyme is a type of protein, which, as we know, is coded for through the DNA -> RNA -> protein program.  If all of the enzymes required for apoptosis aren't present or properly functioning, we get a cell that divides uncontrollably without the STOP! signal, and you are presented with cancer.  Free radicals are dangerous bastards.


But they are also an important byproduct of regular, oxidative chemical processes taking place constantly in our bodies.  Free radicals are kept in check by antioxidants, which stabilize free radicals by donating their extra electrons.  Our body produces antioxidants in huge amounts.

http://www.health-spy.com/freeradical.gif

The problem is, that we have far more free radicals running amok in our bodies than we have the means to combat.  Many sources in the media have been advocating greater antioxidant intake through our diets as well as behaviors that reduce free radical production. 






We live in a toxic world.  Free radical formation is caused by:

1. over-exposure to the sun
2. pesticide-laden produce
3. chemical additives in processed food
4. a diet in high in trans fat, saturated fat or sugar
5. air pollution
6. pollutants in our water source
7. radiation from electrical devices
8. chemicals in food packaging
9. very strenuous exercise
10. chemicals in toiletries
11. chemicals used in detergents and dry-cleaning products
12. preservatives in processed food
13. smoking

The list could go on and on...I think you get the idea.  The problem is, we want to live in a world where we can consume as much as we want, and the efforts to meet these demands have led to the manipulation of natural products that our bodies have evolved to accommodate.  But with so many toxic sources producing free radicals simultaneously throughout our day, it becomes very daunting to begin to try to change our lifestyles to reduce the damage. 

There are obviously two routes to take, both equally beneficial: 1) reduce behaviors that cause an increase in free radical production; 2) consume more antioxidants to combat the free radicals.  Addressing both are your best bet.

According to this source, the top 20 foods in terms of antioxidant concentration are:

1. small red beans
2. wild blueberries
3. red kidney beans
4. pinto beans
5. cultivated blueberries
6. cranberries
7. artichokes
8. blackberries
9. prunes
10. raspberries
11. strawberries
12. red delicious apples
13. Granny Smith apples
14. pecans
15. sweet cherries
16. black plums
17. russet potatoes
18. black beans
19. plums
20. gala apples

Other foods I would add to the list are grapes, red wine (I know...made from grapes), green tea, oranges, dark greens, broccoli, tomatoes, and raisins.  I try to eat as many antioxidant-rich foods per day as humanely possible.  My typical day might consist of a cup or two of berries, a glass of red wine, three glasses of green tea, a serving of FRS, a serving of broccoli, a Resveratrol capsule, 2 tbsp of honey, a Vitamin C capsule, two servings of kale or spinach, a serving of beans, a variety of nuts, and about five more servings of various veggies and fruits.  

Free radicals are also now being linked to aging. Research into antioxidants and free radicals is still young and evolving, but if you want to live long and healthy, eating more antioxidants couldn't hurt, right?