El Paso, TX. Dr. Jimenez answers the question what is epigenetics, dietetics? And how does it apply to diet?

Dietetics is a field of science that studies how food and nutrition affect human health. Dietetics strongly emphasizes public health and education for all about the importance of healthy dietary choices.

Dietitian nutritionists present nutrition combined with science to help individuals improve their health. Nutrition and dietetic technicians also work with dietitian nutritionists to provide general nutrition education. Both groups are nationally credentialed and are an essential part of health care and foodservice management.

• Design individual nutritional plans to address specific health issues:
• Unhealthy weight
• Diabetes
• Hypertension
• Develop facility-wide nutrition programs:
• Health care
• Educational
• Correctional Institutions
• Increase public awareness of proper nutritional habits
• Improve the accuracy and comprehension of food labels
• Ensure the safety of the food supply
• Research changes in diet:
• Example: Reduce salt intake affects health
• Result: Reduces blood pressure
• Work with food manufacturers to improve nutritional quality of prepared foods

Food Information Council (2005), more than two-thirds of Americans surveyed expressed a favorable opinion toward the idea of using genetic information to develop personalized nutrition recommendations.

International Food Information Council. 2005 Consumer Attitudes toward Functional Foods/Foods for Health Executive Summary. July 2006. www.ific.org/ research/upload/2005funcfoodsresearch.pdf. Accessed September 2, 2007

Epigenetics

A simple definition of epigenetics is the study of biological mechanisms that turn genes on and off.

Our epigenome provides an extra layer of instructions that influence gene activity. This is an extra layer of instructions that affect whether or not various genes are turned on or off, and ultimately affect cellular function and metabolism.

Histone acetylation causes the DNA to loosen, allowing access to genes.

Still confused? Don’t worry; it does take some time to learn how it works. So let’s take a

Crash Course In Biochemistry & Genetics

• Cells are the fundamental working units for all of us.
• The instructions to direct these cells are contained in the chemical deoxyribonucleic acid, also known as DNA.

Our DNA is made up of relatively 3 billion nucleotide bases.

• There are four fundamental bases that make-up DNA:
• Adenine
• Guanine
• Thymine
• Cytosine
• These are typically abbreviated as A, G, T, and C.

The Sequence or Order of These Bases Is What Drives Our Life Instructions

The human DNA sequence is somewhat similar to a chimpanzee. However, only a fraction of different sequences is what makes us human.

Inside The 3 Billion Bases are About 20,000 Genes

Genes are a specific set of sequences/instructions on how to make proteins, (complex molecules that trigger biological actions for carrying out life functions).

The DNA gives the instructions for various essential proteins to be produced inside the cell.

The process is known as the Central Dogma of Molecular Biology.

Epigenetics affects how the genes are read by the cells, and determine whether the cells should produce the proteins.

Example: The COL1A1 gene is present in all types of cells but in skin cells, its expression is to produce Type 1 Collagen protein.

About:

• Epigenetics is what controls our genes: Epigenetics determine a cell’s specialization (e.g., skin cells, blood cells, hair cells, liver cells, etc.) as a fetus develops through gene expression (active) or silent (dormant).
• Nurture: Environmental stimuli can cause genes to turn on or off.

They Are Everywhere

• What We Eat
  
• Where We Live
  
• Who We Interact With
  
• Sleep
  
• Exercise
  
• Age
  
• All of these can cause chemical alterations around the genes that can turn them on or off over time.
  
• In certain diseases, e.g., cancer or Alzheimer’s, certain genes will switch to the opposite state. This means they turn away from being in a normal/healthy state into an unhealthy state.

They Are What Makes Us Unique

• This is why some of us have:
  
• Blonde hair
  
• Dark skin
  
• Dislike certain foods
  
• More social than others
• The different combinations of genes that get turned on or off is what makes each one of us.
• There are even indications that some epigenetic changes are inherited.

It Is Reversible

• With 20,000 genes, the results of different combinations being turned on or off are enormous.
  
• Imagine if we could map every single cause and effect of the different combinations
• Reverse the gene’s state to keep healthy genes while eliminating unhealthy genes
• Therein lies the possibility to cure:
• Cancer
• Slow aging
• Stop obesity
• Much more

To Further Help Understand

The Genetic concept is like screenwriting

• Think of the human lifespan as a movie:
• DNA is the script, the instructions for the actors
• The cells are the actors
• The literal DNA sequence are all the words
• Certain blocks of words are key instructions for events to happen, these are the genes

The Epigenetic concept is like movie directing

• Different directors can shoot the same script
• However, each director makes choices in regard to:
• Adjustments with actors/scenes/dialogue
• What to keep/remove
• These choices are going to alter the movie, hence alter the DNA

Therefore, one director’s movie will be different than another director’s even though they shot the same script.

In other words, the same exact DNA sequence for a particular gene may give rise to different outcomes, depending on its epigenotype and, unlike the genetic code, which Gosden and Feinberg liken to “indelible ink,” the epigenetic code can be altered “like a code written in pencil in the margins”

Gosden RG, Feinberg AP. Genetics and epigenetics—Nature’s pen-and-pencil set. N Engl J Med. 2007;356:731-733.