General Overview of Nutrition & Health

1. General Overview of Nutrition & Health ©C. Murray Ardies, 2014

2. Nutrition & Health To get an accurate idea of what (modern) nutrition encompasses all one has to do is glance through the DRI publications of the Institute of Medicine. The Dietary Reference Intakes are values that relate to nutrient function in humans and their derivation is based on research into the specific biochemical function of the nutrient, how that function contributes to overall cellular function, how much of the nutrient has to be consumed to satisfy that cellular function, and how that function relates to health and disease. In the past, nutrition research focused predominantly on deficiency diseases and what had to be eaten in order to avoid them. Today, a major focus of research in nutrition is on the role of nutrients in optimizing cell functions, health, and preventing chronic disease. ©C. Murray Ardies, 2014

3. In order to understand current concepts in nutrition and health you have to have an integrated knowledge of: Chemistry Molecular Biology Anatomy Toxicology Biochemistry Cell Biology Enzymology Pathophysiology Physiology Signal Transduction Oncology Immunology Endocrinology and others …

4. Just about any of the macronutrient sources (carbohydrates, lipids, proteins) you eat can be metabolized to carbon dioxide & water with the concomitant synthesis of ATP to provide the chemical energy necessary for normal cellular functions (maintaining membrane potentials for example) as well as for synthesizing the various cellular components in order to replace damaged ones or to enhance particular cell functions. ©C. Murray Ardies, 2014

5. Overview of Nutrition Before molecules can be metabolized, they must first be eaten; and because we do not eat nutrients (molecules that we can’t synthesize so we have to eat them), but rather, dead things (and some living things) that contain nutrient molecules, we have to separate the various useful molecules from the not so useful ones in our food before we can actually use them. This process is commonly called digestion and absorption. ©C. Murray Ardies, 2014

6. We chew up our food in our mouth and it mixes with water, acids, and enzymes in our stomach. The chyme then gets mixed with more water and a variety of digestive “juices” and enzymes in the duodenum of the intestine to break down the food particles into their component nutrient and non-nutrient compounds. Most of the useful molecules are absorbed (ultimately) into the blood . . . Specific details of each of these processes, especially as they relate to nutrient function, will be covered in more detail in the digestion Ppt. ©C. Murray Ardies, 2014

7. A Nutritionist’s View of Cells: This is the model to keep in mind! Once the useful molecules are in the blood, they can then be used to support all those essential cell functions . . . ©C. Murray Ardies, 213 ©C. Murray Ardies, 2014

8. In many cases, vitamins and minerals play a functional role in metabolic reactions ©C. Murray Ardies, 2014

9. Some Of The Major Metabolic Pathways For “ATP Metabolism” Glycolysis:produces pyruvic acid for acetyl CoA production in mitochondria, produces NADH (electrons) for ETC in mitochondria, anaerobic production of ATP MK & CPK:anaerobic production of ATP TCA:accepts acetyl-CoA for citrate synthesis, production of NADH (electrons) for ETC, “anaerobic” production of GTP β-oxidation:produces acetyl CoA for TCA Transamination:produces pyruvic acid, or acetyl CoA, or TCA intermediates ETC:electrons from TCA cycle & glycolysis are “joined” to oxygen to make water & the production of ATP Pentose Phosphate Pathway:production of ribose and NADPH for nucleotide, lipid, and protein (and other) synthesis processes Specific details of each of these processes, especially as they relate to nutrient function, are covered in detail in other Ppts. ©C. Murray Ardies, 2014

10. Glycolysis, TCA cycle, β-oxidation, Transamination reactions, ETC, and Pentose Phosphate Pathway are essential metabolic reactions that constantly produce both ATP and other chemicals that are essential for a cell’s function. ATP is the universal energy compound produced by an enzyme in the mitochondria while many of the chemicals produced with each of the metabolic pathways can be used for synthesis into much larger molecules for a variety of functions. When cell functions are compromised or fail, then the entire organ may suffer and health can be compromised. The focus on cell function in modern nutrition is simply the current iteration of the scientific process that started with trying to understand how specific foods, and then specific components of foods were necessary to avoid deficiency diseases. As the technology in biological sciences advanced to be able to ask detailed questions about how nutrients were actually used in cells and how those functions contributed to the health of a cell, the field of nutrition evolved along with that of biology. A major focus of nutrition is now on how nutrient functions interact with overall cell, organ, and whole-body functions and on health with the goal of understanding how to optimize health and prevent disease.