macro- and micro-nutrients: application to chronic diseases
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Macro- and Micro-nutrients:Application to Chronic Diseases
Cardiovascular Disease
Diabetes Mellitus
Cancer
Obesity
Application to Chronic Diseases
Nutrition
Cardiovascular Disease (CVD):
Hypertension (abnormally high BP - 140/90)
Coronary Heart Disease (CHD) – degenerative changes in the inner linings of the large arteries supplying the heart
Application to Chronic Diseases
Lesions (fatty streak)
Inflammation leads to lipid filled plaques and scar tissue
Atherosclerosis
Vascular degeneration can begin early in life
Cardiovascular Disease (CVD):
Myocardial Infarction (MI) – “heart attack”: Death of heart muscle from blockage of one or more arteries supplying heart (lack of blood flow and oxygen)
Angina Pectoris – Temporary chest pains from coronary artery narrowing and brief periods of inadequate blood flow to heart (occurs during exertion)
Stroke – Deprivation of oxygen to the brain due to blockage (ischemic) or rupture (hemorrhagic) of arteries and blood vessels supplying brain
Congestive Heart Failure (CHF) – Progressive weakening of the heart muscle and inability to pump oxygen rich blood to tissues
Application to Chronic Diseases
Cardiovascular Disease (CVD):
Since 1900, heart disease has been the number one killer in the U.S. every year except for one (1918) - in both men and women
At least 1 in 4 (58 million) people in the U.S. suffer from some form of CVD
Every 29 seconds, an American suffers a coronary event, each minute someone dies (~2,500 each day)
Application to Chronic Diseases
34% of 5-10 year old children have 1 risk factor and 26% have 2 risk factors for CVD (obesity, physical inactivity, blood lipid profiles, genetics)
Major risk factor for CVD: Obesity
70% of all CVD is related to obesity
58 million Americans are overweight; 40 million are obese, 3 million are morbidly obese (BMI: body mass [kg]/height [m]2)
8 out of 10 Americans over 25 are overweight
35% of college students are overweight or obese
Obesity is the second leading cause of preventable death in the U.S. (300,000 deaths yearly)
Application to Chronic Diseases
Obesity
Obesity has doubled over the past two decades (1 in 4 adults in U.S. are obese – 14% in 1980)
Application to Chronic Diseases
Why?
Increase in sedentary activities
Community design
Less physical activity
Fast food epidemic
"Supersize Me"
Obesity
In children:
22 million children under 5 are overweight or obese
4% of children in U.S. were overweight in 1982; 16% in 1994; ~25% in 2001
Children spend 4.5 x more time in sedentary activities than 50 years ago (45 hours - 27% of the week)
Application to Chronic Diseases
How does what we eat contribute to obesity?
How does nutrition contribute to Obesity?
Application to Chronic Diseases
Impressive consistency in energy balance
Increases in calorie intake over time can result in substantial increase in weight gain –
Creeping obesity Figure 3.14
Creeping Obesity
Just a 100 kcal (2 Fig Newtons) daily increase in energy intake would substantially increase weight gain in 1 year:
100 kcal x 365 days = 36,500 kcals1 lb fat = 3,500 kcals36,500 kcals / 3,500 kcals•lb = 10.4 lbs
Application to Chronic Diseases
If a college freshman ate two Fig Newtons (or drank 1 lite beer) above your daily caloric intake (assuming energy balance), by graduation you would gain ~42 lbs
*If you INCREASED energy expenditure by 100 kcals (1 mile jog) and DECREASED energy intake by 100 kcals (one 12 oz soda), in one year you would lose 21 lbs of body fat
200 kcals x 365 = 73,000 kcals73,000 kcals / 3,500 kcals•lb = 21 lbs
Application to Chronic Diseases
Three ways to “unbalance” the energy equation to produce weight gain:
Application to Chronic Diseases
Increase caloric intake above daily energy requirements
Maintain caloric intake, but reduce daily energy expenditure
Increase caloric intake, and reduce daily energy expenditure
Dietary fiber may play a role in reducing obesity:
Fiber holds water, increasing “bulk” of food residues in small intestine by 40-100%
Because the digestive tract can only handle so much bulk, fiber-rich foods are more filling than other foods, so people tend to eat less food
Study: Eating a fiber-rich meal at breakfast reduced the overall number of calories consumed during that meal as well as the next meal
Insoluble fiber passes through the digestive tract virtually intact, contains few calories, and may reduce absorption of calorie rich dietary fat.
Application to Chronic Diseases
How does what we eat contribute to, or improve,
our risk of developing chronic diseases?
How does nutrition impact CVD?
When soluble fiber is eaten as part of a diet low in saturated fat and cholesterol, it has been shown to reduce blood cholesterol (LDLs, but not HDLs)
Insoluble fiber does not appear to reduce cholesterol
Application to Chronic Diseases
Dietary fiber may have modest impact on serum cholesterol
Cholesterol levels are highly associated with risk of death from CHD
• Studies supporting the role of fiber in CVD:
Adding 100 g Oat Bran to diet of men with high cholesterol reduced cholesterol 13% and favorably affected ratio of LDL/HDL
Finnish study of 21,900 smokers (50-69) – Men who ate the most fiber rich foods (35 g/day) had 1/3 fewer heart attacks than those who had the lowest fiber intake (15 g/day)
Each 10 g increase reduced risk of dying of CVD by 17%
U.S. study - 43,757 male health professionals – Those who ate more than 25 g fiber/day had a 36% lower risk of developing CVD than those who ate the lowest amount of fiber (15 g/day)
Each 10 g increase reduced risk of dying of CVD by 29%
Application to Chronic Diseases
Nurses Health Study (10 year prospective study):69,000 middle age nurses (age 37-64)Each 5 g/day increase in cereal fiber (1/2 cup of bran
flake cereal) reduced risk of MI and CHD 37%
*Clear evidence that in both men and women, dietary fiber reduced risk of CVD
Application to Chronic Diseases
How does Fiber reduce cholesterol and risk of CVD?
Dietary fiber may simply replace cholesterol rich food
Fiber may hinder absorption of cholesterol in the intestines
Soluble fiber binds cholesterol in the gut and excretes cholesterol-bound fiber in feces
Dietary fiber may have affect on CHD by reducing blood pressure (hypertension) and improving blood clotting characteristics
Application to Chronic Diseases
How do fatty acids contribute to CVD?
TC HDL LDL
Monounsaturated
Polyunsaturated
Saturated
Trans
*Dietary lipid intake can impact risk of CHD by increasing cholesterol levels and ratio of LDL/HDL
*1% reduction in cholesterol = 2% reduction in CVD risk
Application to Chronic Diseases
Omega-3 fatty acids (polyunsaturated) are found in shellfish, cold water tuna, herring, sardines, mackerel, sea mammals
Fish oils may improve blood lipids (triglycerides) and heart disease risk by preventing blood clot formation on artery walls
Application to Chronic Diseases
How do fatty acids reduce risk of CVD?
Also recommended: Tofu, soybeans because these contain linolenic acids (omega 3s)
How does vitamin deficiency and amino acid metabolism contribute to CVD?
Vitamin B6, B12 and Folic acid play a major role in preventing atherosclerosis through their role in enzymatic processes involved with the amino acid Methionine
Homocysteine is an intermediate product in the metabolism of Methionine and promotes cholesterol damaging effects on artery walls
Application to Chronic Diseases
Application to Chronic Diseases
Figure 31.27