Macro- and Micro-nutrients: Application to Chronic Diseases

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


Lesions (fatty streak)

Inflammation leads to lipid filled plaques and scar tissue

Atherosclerosis

Vascular degeneration can begin early in life


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



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)


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)


Obesity

Obesity has doubled over the past two decades (1 in 4 adults in U.S. are obese – 14% in 1980)


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)


How does what we eat contribute to obesity?

How does nutrition contribute to Obesity?


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


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


Three ways to “unbalance” the energy equation to produce weight gain:


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.


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


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%


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


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


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


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


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



Figure 31.27

Macro- and Micro-nutrients: Application to Chronic Diseases

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