Joseph R. Anticaglia MD
Medical Advisory Board
Over thousands of years, people on different diets from Kenya to Alaska have adapted to their environments in order to survive and thrive. These adaptations have become programmed into a person’s DNA, the genetic material which affects every aspect of our lives, including how people react to food and drink.
A mother tells a friend that her daughter can’t tolerate dairy products. “If she has a glass of milk or eats ice cream, she’ll complain of abdominal cramps and diarrhea.”
A woman praises her friend,
— “You look great! What have you been doing?”
— “I’ve been on a high protein low carb diet and I lost 15 pounds. I cut out the carbs, but I can eat as much protein and fats as I want.”
— “It seems strange. I’d think you would gain weight on such a diet.
— “I don’t have an explanation,” her friend said, “but it works for me.”
DNA or deoxyribonucleic acid is the substance found inside every cell which is essential for an organism to develop, survive and reproduce. It contains hereditary information passed down from parents to children.
A gene is a segment of DNA, a basic unit of heredity which gives instructions to make proteins. Proteins are essential building blocks for our bodies which include enzymes, hormones and vitamins.
Enzymes are the catalysts, the ignition switches, that quickly get the cells chemical engines going. Difficulties can occur; for example, when abnormal genes cause malformed, “sickle” shaped red blood cells as in sickle cell anemia or when there is an extra gene, trisomy 21, as in Down’s syndrome.
Genes and vitamin deficiency
The body doesn’t manufacture vitamin B12 and you need to incorporate animal-based foods or B12 supplements into your diet to be healthy. People of Scandinavian or Northern European heritage at times lack a special protein called “intrinsic factor” needed to absorb vitamin B12 from the intestines. Intrinsic factor is produced in the stomach and this deficiency causes pernicious anemia, a decrease in red blood cells.
Genes and enzyme deficiency
Several years ago I was travelling in various regions of China for 2-3 weeks. What was noticeable, I never saw a glass of milk or a piece of cheese in stores or restaurants. Requests for a dairy product by fellow travellers at that time resulted in a blank stare and a shake of the head.
A significant portion of Asians are lactose-intolerant. They are deficient or lack the enzyme, lactase. Lactase breaks dairy products into sugar — glucose that the body can use for energy. When the protein lactase is lacking, patients complain of bloating, pain and gas. Lactose intolerance is not an allergy and it’s not limited to Asians.
Genes and Metabolism
Diabetes is a disorder of metabolism resulting in elevated levels of sugar (glucose) in the blood.
Your digestive system breaks down the foods you eat, starches and sugars, into glucose which the body absorbs into the bloodstream. The level of glucose in the blood triggers the release of the hormone insulin from the beta cells of the pancreas, making it possible for glucose to enter the cells.
In Diabetes Type 1, the body does not produce insulin. In Diabetes Type 2, the body does not produce enough insulin or the cells in body do not respond to insulin (insulin resistance). As a result, glucose levels in the blood remain high after a meal, which eventually leads to health problems. Genes, diet and lifestyle factors contribute to diabetes.
Gene testing
Genetic differences may interfere with the way people digest and use food. Nutrigenetics aims to identify how genetic variations affect a person’s response to nutrients. The ultimate goal of nutrigenetics is to offer people personalized nutritional guidance based on one’s genetic makeup.
Gene testing can help identify your metabolic–nutritional type (protein carbohydrate or balance). Matching the right foods to your metabolism can result in more energy and a healthier lifestyle. It can provide insights as to why a person on a high protein diet loses weight while another gains weight.
Glossary
Genes are material made of DNA stored inside the chromosomes and are the basic units of heredity. It gives instructions to make protein.
Genetics is a branch of biology that focuses on the study of individual genes in isolation. It studies heredity and the variation of inherited characteristics in living organisms.
Genome means all of the genes. It’s the complete set of genes in a cell or organism
Genomics focuses on the study of all of the genes in a cell or organism. It is the study of the genome — its DNA and how the molecules absorb, function, transport and store them
References
NIH Your Guide to Genetic Conditions’ October 18, 2016
NIH Causes of Diabetes’ August, 2014
Anticaglia, Joseph R; MD; Metabolic-Nutritional Typing What Type Are You? HC Smart, 2016
NCBI Protein Function and Malfunction in Cells 1999, W. H. Freeman and Company.
This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.