Bio 28: Nutrition Instructor: Paul Nagami Laney College

1. Carbohydrates, pt. 2 Bio 28: NutritionInstructor: Paul NagamiLaney College Jan. 30, 2014

2. Today’s Agenda • Reminders + Administrative Details • Review • More on chemistry, to help prepare you for next chapter. • Benefits of Carbohydrates • Blood Glucose • Diabetes • Tooth Decay • Pick up work

3. (Review and Chemistry Chalk Talk here) If you missed this class, you may want to pay close attention to the opening parts of chapter 4 and ask me to clarify any confusing details at office hours! You should know how atoms make molecules (what a chemical bond is) and what the difference is between a single and a double bond.

4. Why Carbohydrates? Many diets (Atkins, etc) emphasize reducing non-fiber carbohydrates. What useful roles do carbohydrates serve in our body? Energy source: How many kcal of energy are there in a gram of carbs? Protein sparing:The body needs glucose to run its cells! Without carbohydrates, it will get glucose from other sources, such as proteins, via gluconeogenesis. Preventing ketosis: Without carbs, the body turns fats into acidic ketonebodies, which can potentially lower blood pH, hurt the kidneys, and have other ill effects. (Though it may help epileptics.)

5. Glycemic Index Carbohydrates raise your blood sugar, but not all of them raise it equally quickly. For diabetics, it’s important to avoid sudden spikes in blood sugar! Glycemic index is a measure of how quickly food causes blood sugar to rise – in theory, anyway. Use as a weight-loss tool remains controversial. A low glycemic index food can still have plenty of calories!

6. Mobilizing Blood Sugar

7. Balancing Blood Sugar

8. Diabetes mellitus occurs when the body can’t control blood sugar levels. Fat is incompletely broken down, creating acidic ketones. The loss of water through the urine (to get rid of excess sugar) causes dehydration. Blood vessels can get narrow, leading to the death of tissue.

9. Diabetic Retinopathy

10. Types of Diabetes Type I Diabetes (Juvenile-onset, usually): Pancreas doesn’t make insulin. Beta cell damage. 10% of all diabetes patients. Type II Diabetes (adult-onset, usually): Body makes insulin but doesn’t respond to it! (Insulin resistance) Gestational diabetes: Pregnant women are at higher risk of insulin resistance. Untreated, this can harm the fetus. U. S. Diabetes cases per year, in thousands, from 1980 to 2011. Source: Centers for Disease Control

11. Risk Factors for Diabetes Estimated 24 million Americans with diabetes. Obesity: A huge risk factor for Type 2 Diabetes. In one study of nurses aged 30-55, severe obesity raised the risk of diabetes 49 timesover! Age: As people approach middle age, the risk of diabetes rises. Genetics: Inherited differences in metabolism can play a role. Race/Ethnicity: African-American, Native American, and Hispanic patients, especially women, are more likely to develop diabetes than men.

12. Managing Diabetes Considering the differences between Type I and Type II diabetes… How much would you expect insulin shots to help someone with Type I diabetes? How much would you expect insulin shots to help someone with Type II diabetes? How could Type II diabetes be managed?

13. Tooth Decay Sugary foods increase the risk of tooth decay, since they stick to the teeth, forming a film that bacteria can consume and live in. The bacteria convert the sugar into lactic acid, which eats away at the enamel of teeth!