Tuesday, August 4th, 2009

Can We Change Our DNA Naturally?

The discovery of DNA and genetics was a pivotal and awe-provoking landmark of the last two centuries. From it we understand the incredibly complex physical link between ourselves, animals, plants, and all other forms of life on our planet. Everything that we see is made from atoms and molecules, but everything that lives has a “secret code” which shows how to organize these molecules into complex protein strands, which are pretty much responsible for every bodily function.1 This “secret code” is the DNA strand, and resides in each cell.

Biological diversity is the result of genetic diversity – differences in DNA among and across different species. It is the reason there are mammals, amphibians, flowering plants, insects – there could be no ecosystems or food chains without it. Whether the planet is responsible for genetics, or the other way around, it is certain that neither would look quite the same alone.

I have always been curious and excited about the potential for change in the individual. This blog is obviously a study into personal change, but how much is conscious and how much is physical? This question is more commonly known as the “Nature versus Nurture” debate, however I want to frame it slightly differently. The usual connotation is that “nature” is that part of a human being that cannot change, or is preprogrammed. I want to explore the part of our nature that can change.

To do that, we have to ask, “What does DNA do?”

The Periodic Table of Elements. Complex DNA molecules are comprised of only five elements: Hydrogen, Carbon, Nitrogen, Oxygen, and Phosphorus (highlighted above).

The Periodic Table of Elements. Complex DNA molecules are comprised of only five elements: Hydrogen, Carbon, Nitrogen, Oxygen, and Phosphorus (highlighted above).

As a student of physics, I often find it helpful to build things up from their individual components, so I’ll start with atoms. DNA consists of mostly carbon and hydrogen, with some oxygen, nitrogen and phosphorus atoms. Simple, isn’t it?

Chemical Structure of DNAWell, by my calculations, there are 15.4 billion atoms in the longest human DNA strand. But the real beauty and simplicity of DNA lies in it’s three-dimensional layout – the double helix, which is similar looking to a very long twisted ladder. The rungs of this ladder are each made by pairing together two of four smaller molecules – Adenine, Guanine, Cytosine, and Thymine (A,G,C and T) – forming “base-pairs”. Groups of these base-pairs are called genes, which provide instructions how to build proteins and enzymes, the cell’s essential tool set.

So DNA is the source of protein structure, or rather the source of each cell’s abilities. This is obviously important because cells do everything in the body. Without cells, there is no life, and without proteins there are no cells.

If you are still with me, you’ll see that a change in DNA can result in a change in protein structure, which can result in a change in cell function, which can result in a change in the body. Cancer is probably the most well-known example of this: Damaged DNA results in a change in the structure of proteins which control cell-production rate, and thus cause uncontrolled cellular growth.

Recently I learned that the human genome does not have the ability to synthesize ascorbic acid (Vitamin C), although our ancient primate ancestors and other animals do. To return to a previous post’s line of questioning, is it possible to stimulate our genes to regain this ability?

Theoretically, yes it is possible. The gene formerly responsible for ascorbic acid synthesis has been identified in humans, and has been compared to working counterparts in other species.2 It is called the “L-gulonolactone oxidase” gene. Since we know the structure of the working gene, with the right genetic tools we might be able to repair our own.

DNA can undergo mutation by a number of factors. Illustrated is base-mutation, where "A" becomes "C".

DNA can undergo mutation by a number of factors. Illustrated is base-mutation, where "A" becomes "C".

Another possibility is random genetic mutation. In the process of cell-division (reproduction), a copy of our DNA is passed to the new cell. Apparently one error is made for every 100 million base-pair copies.3 Other factors such as exposure to ultra-violet light or nuclear radiation can also cause DNA mutation.

Recently, epigenetic changes (changes in DNA not associated with its base-pairs) have been found to change within an organism’s lifetime, and may have some impact on the interpretation of the genetic codes.4

All of these changes can lead to the synthesis of new enzymes, but the chances of randomly repairing the gene responsible for ascorbic acid production are incredibly slim.

It remains to be seen whether or not we as individuals have any natural and direct means of reprogramming our DNA – but at least we know it isn’t physically impossible. After all, the fact that genes function so well despite their immense complexity is encouraging. Remember, the appearance of life on our planet was also an incredibly unlikely event.

  1. Proteins are the Body’s Worker Molecules []
  2. Re: Has the nonfunctioning vitamin c gene been identified in humans? []
  3. What Causes DNA Mutations? []
  4. Our Genome Changes Over Lifetime []

Chris Gerber is 33 and lives in Vancouver, Canada.

After graduating from a B.Sc (Physics major) program in 2007, he spent seventy days in Southeast Asia with the goal of discovery, on both personal and cultural levels.

Since his return, he has resisted automatic entry into the work-force, spending his time instead wondering how best to serve the world.