NUTRITION AND CHRONIC DISEASE

Overweight and obesity

Cardiovascular disease (CVD)

Coronary Heart Disease and Stroke

Diabetes mellitus

Chronic Disease• A long-term condition

• e.g., obesity, diabetes, and cardiovascular disease

• May be prevented or delayed with lifestyle changes• e.g., healthier eating and more physical activity

• Projections show that chronic diseases will be the predominant global source of morbidity and death in the 21st Century.• According to the WHO “…by 2020, chronic diseases will account for

almost three-quarters of all deaths worldwide, and that 71% of deaths due to ischaemic heart disease (IHD), 75% of deaths due to stroke, and 70% of deaths due to diabetes will occur in developing countries. The number of people in the developing world with diabetes will increase by more than 2.5-fold, from 84 million in 1995 to 228 million in 2025. On a global basis, 60% of the burden of chronic diseases will occur in developing countries.”

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Lancet 2005; 366: 1578–82

Interrelationships among Chronic Diseases

Risk Factors for Chronic Diseases

Nutrition and Chronic Illness• Historical Focus on Undernutrition• Nutrition Transition Today• Globalization and changing food habits• Non-communicable diseases can be prevented and

controlled• Chronic diseases are a major global burden• Policies and health services should promote healthy diets

Nutrition for Chronic Disease Prevention and Treatment

• Dietary factors associated with 4 of the 10 leading causes of death: coronary heart disease (CHD), some types of cancer, stroke, and type 2 diabetes

• Nutrition is a widely accepted tool for prevention of chronic diseases

• also very important for management and treatment

of a chronic diseases

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Worldwide Obesity Epidemic• Obesity now classified as a disease by AMA• 2.5 million deaths can be attributed to overweight/obesity

worldwide

• Nearly 70% of cases of CVD associated with obesity• Worldwide, more than 1.1 billion overweight adults

• At least 312 million of them are clinically obese• By the end of 2010, an estimated 43 million children under five will be

overweight

• Obesity levels range from 20-30% in European countries, to over 70% in Polynesia

• By 2015, the worldwide obese population will reach 1.5 BILLION 8

Obesity and Nutrition Transition“Obesity in the developing world can be seen as a result of a series of changes in diet, physical activity, health and nutrition, collectively known as the 'nutrition transition.' As poor countries become more prosperous, they acquire some of the benefits along with some of the problems of industrialized nations.”

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• Since mid-seventies, prevalence of overweight and obesity has increased sharply for both adults and children.

• Now more than 2/3 of U.S adults are overweight or obese• Obesity rates are expected

to increase

Classification BMI(kg/m�)

Principal cut-off points

Additional cut-off points

Underweight <18.50 <18.50

     Severe thinness <16.00 <16.00

     Moderate thinness 16.00 - 16.99 16.00 - 16.99

     Mild thinness 17.00 - 18.49 17.00 - 18.49

Normal range 18.50 - 24.9918.50 - 22.99

23.00 - 24.99

Overweight ≥25.00 ≥25.00

     Pre-obese 25.00 - 29.9925.00 - 27.49

27.50 - 29.99

     Obese ≥30.00 ≥30.00

          Obese class I 30.00 - 34-9930.00 - 32.49

32.50 - 34.99

          Obese class II 35.00 - 39.9935.00 - 37.49

37.50 - 39.99

          Obese class III ≥40.00 ≥40.00http://apps.who.int/bmi/index.jsp?introPage=intro_3.html

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What causes obesity? Inside-the-Body Theories• Set-point theory

• Body organs regulate body fatness

• Thermogenesis • Brown adipose tissue (BAT)

• Genetics and obesity• Influence tendency to gain weight or stay lean• Environmental factors

• Microbes in gut?

What causes obesity? Outside-the-Body Theories

• External cues to overeating• Available foods• Human sensations• Larger portions

• Food supply• Addictive?

• Dopamine • HFCS???

• Physical inactivity• Screen time• Sedentary jobs

• Neighborhoods• Built environment• Food deserts

Estimated intakes of total fructose (•), free fructose ( ), and high-fructose corn syrup (HFCS, ▴♦) in relation to trends in the prevalence of overweight (▪) and obesity (x) in the United States.

Bray G A et al. Am J Clin Nutr 2004;79:537-543

©2004 by American Society for Nutrition

The role of genetics in body weight• Epidemiological evidence shows that obesity, excess energy (Calorie) intake, and sedentary lifestyle are primary contributors to the chronic disease epidemic • 40% of BMI is attributable to independent genetic

influences

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Nutritional Genomics Research• Nutritional genomics• Epigenetics • Nutritional genomics researchers

strive to:• Identify genes• Explain the mechanisms• Develop practical applications

Epigenetics• Epigenome

• Proteins and other molecules that regulate expression of genes• Turning genes “on” and “off”

• Inherited or altered • Cell differentiation• Regulation

• Histones• Methyl groups

Value of waist circumference• Risks of visceral fat/Subcutaneous

fat• Increases risk of death from all causes • Metabolic syndrome

• Location of excess fat is important• If excess fat is mainly around

midsection = more likely to develop health problems than if excess fat is mainly around hips and thighs

• Apple vs. Pear shapes• True even if BMI falls within the normal range

• Women: waist measurement of more than 35 inches (88 cm)

• Men: waist measurement of more than 40 inches (102 cm)

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Higher risk body shape

Lower risk body shape

Visceral Fat and Subcutaneous Fat

Nutrition and CVDs • Coronary vascular disease (CVD) Caused by disease of the blood vessels (atherosclerosis) of the heart, usually as part of the process which affects blood vessels more generally

• Stroke and heart disease are the main cardiovascular diseases• Stroke is the main cardiovascular disease in many east Asian countries

Major Risk Factors for Heart Disease

Atherosclerosis and CVD • Atherosclerosis is a generalized and progressive

disease that effects the arterial circulation• major result of atherosclerosis is heart attack and stroke,

• myocardial infarctions, and angina.

Atherosclerosis epidemilogy • World Health Report documents that CVD has overtaken infectious disease as leading cause of death worldwide representing 23% of all deaths.

• In US CVD , affects over 71 million individuals with an annual mortality exceeding 900,000 per year.• costs taxpayers approximately 400 billion dollars per year

How Does It Start?• Atherosclerosis usually begins with the epithelium, the

inner most layer of the artery. • Damage can occur because of elevated cholesterol,

high blood pressure, tobacco smoke, and diabetes. • Buildup occurs thickening the arterial wall, decreasing

blood flow, and reducing the oxygen in the blood.

The Five Phases of Atherosclerosis• Phase One: LDL deposits into

cells of inner wall of the artery

• Phase Two and Three: inflammatory cells move into vessel wall and the plaque continues to grow, a fibrous cap formed

• Phase Four: smooth muscle cell proliferation changes and begins to break down, the fibrous ruptures or the plaque is exposed to the blood stream, the plaque contains materials which encourage clotting

• Phase Five: platelets are attracted to this prothrombotic material and a clot forms in the vessel which may interrupt blood flow and damage tissues

Heart Disease is NOT a Man’s Disease

• Women tend to develop heart disease about ten years later than men.

• Many public health initiatives have relied on studies comprised disproportionately of men.

• In 1991, NHI launched the Women’s Health Initiative to study the affects of different treatments, dietary modifications, and supplements on generally healthy post menopausal women.

Stroke• occurs when blood flow to the brain is interrupted by a clot

in a artery or other vessel. When this occur brain cells begin to die and brain damage occurs.

• U.S., approximately 700,000 new strokes per year and 500,000 new transient ischemic attacks (TIAs).

• Stroke is 3rd leading cause of death in US and leading cause of disability.

• Stroke cost US an estimated $62.7 billion dollars in 2007.

Racial/Ethnic Considerations

• In the US, African Americans have a nearly 2 times higher occurrence of first time stroke than Caucasians and have 1.5 times greater death rates from stroke than Caucasians.

• Atherosclerosis also affects different groups at different sites. • Caucasians: common site is carotid artery in neck. • African Americans: intracranial arteries more commonly

involved.

Pathophysiology• When blood flow is interrupted the brain can not get the

glucose or oxygen it needs. • The mitochonria that rely on O2 can not maintain the

electrical state of the neuron.• This change in the electrical state cause communication

between cells to cease, as well as trigger apoptosis.

Two Major Types of Strokes• Ischemic stroke: blood flow to

brain region is interrupted due to a artery blockage • Accounts for the majority,

approximately 80-85%. • Caused by direct blockage or

a clot from elsewhere• Hemorrhagic stroke: due to a

rupture of blood vessel; result of hypertension, bleeding disorders, tumors, vascular disease.2 types:

• intracerebral hemorrhage(ICH)

• subarachnoid hemorrhage (SAH)

Symptoms of Stroke

• Inability to move or feel parts of the body (face, arm, hand or leg) on one side

• Inability to speak or understand speech• Any loss of vision (in one eye or to one side)

• Double vision• Dizziness/vertigo• Confusion• Sudden severe headache

Stroke Treatment: Time is Tissue• If caught early (3-6 hours) can be treated with clot

dissolving medication tPA (tissue plasminogen activator). • At present, only about 5-10% of acute stroke patients will

receive tPA therapy.

Recommendations for Reducing CVD Risk

Recommendations for Reducing CVD Risk• Diet to reduce CVD risk

• Reduce fat intake• Saturated and trans fats

• Limit refined starches and added sugars• Eat fruits, vegetables, and whole grains• Diet rich in omega-3 fatty acids• Other dietary factors

• Balance calorie intake and physical activity to achieve or maintain a healthy body weight.• Consume a diet rich in vegetables and fruits.• Choose whole-grain, high-fiber foods.• Consume fish, especially oily fish, at least twice a week.• Limit intake of saturated fat to 7% of energy, trans fat to 1% of energy, and cholesterol to 300 mg per day by:

— choosing lean meats and vegetable alternatives;— selecting fat-free (skim), 1%-fat, and low-fat

dairy products; — minimizing intake of partially hydrogenated fats

American Heart Association (AHA) 2006 Diet and Lifestyle Recommendations for Cardiovascular Disease Risk Reduction

Nutrition and Hypertension

• One of most prevalent forms of CVD• According to American Heart Association (2007) 1 in 3 U.S.

adults has high blood pressure, but because there are no symptoms, nearly 1/3 rd of these people don't know they have it.

• Uncontrolled high blood pressure can lead to stroke, heart attack, heart failure or kidney failure.

• high blood pressure is often called the "silent killer.“

• In a healthy adult blood pressure is 120/80 mmHg• Systolic pressure: refers to the level of blood pressure while

heart is contracting; is represented by top number (120 mmHg). • Diastolic pressure level of blood pressure in between heart

contractions; represented by the bottom number.

Factors Contributing To Blood Pressure

• 2 factors, • cardiac output, volume of blood pumped by heart each minute, • resistance to blood flow in the vessels, primarily the arterioles.

Vascular resistance is result of friction as blood flows through vessels

< diameter of vessels the > resistance.

Relationships among pressure, flow and resistance quite simple: Pressure = flow X resistance

Kidney – Blood Pressure Relationship

• By regulating the total volume of the extracellular fluid (ECFV), kidneys control blood volume.

• If ECFV and blood volume increases, blood pressure increases• ECFV regulated, in large part, by total body sodium levels, which are

regulated by variable sodium excretion in urine.• Sodium ion (Na+) balance determines ECFV, blood volume and blood

pressure• To stay in balance, Na+ eaten must equal Na+ lost

• most Na+ is lost in urine.

• 70% of Na+ reabsorbed in the proximal tubule• Fine regulation of Na+ excretion takes place in distal tubule and collecting ducts

• Renin-angiotensin hormone system (RAAS) regulates sodium excretion.

• RAAS activated by reduced blood volume or low blood sodium concentration

Water Balance• Water is added to ECF by drinking and oxidative

metabolism. • lost mostly in expired air, sweat and urine.

• amount of water lost in urine is controlled by antidiuretic hormone vasopressin. • Vasopressin decreases urinary water loss.

• Vasopressin levels increase in response to dehydration, blood loss and angiotensin II.

Treatment Of Hypertension- Drugs That Target Kidney Function

• Diuretics such as Lasix – Block sodium reabsorption and increases urine volume

• Spironolactone and Eplerenone block aldosterone action• ACE inhibitors block conversion of Angiotensin I to

angiotensin II• Losartan blocks binding of angiotensin II to cellular

receptors

Nutrition and HypertensionGuidance to prevent or reduce

high blood pressure • Choose and Prepare Foods with

Little or No Salt• In some people, sodium increases

blood pressure because it holds excess fluid in body, creating an added burden on the heart

• Dietary Approaches to Stop Hypertension (DASH) • Health benefits beyond blood

pressure

• Weight control • Physical activity

• Alteration of hormones

The DASH Diet: Preventive Medicine

• Dietary guidelines• Fruits and vegetables

• More Matters

• Make only a few dietary changes at a time

Diabetes• Characterized by increased blood glucose (sugar) levels

• Due to1. a lack of insulin (a hormone), which

controls blood glucose levelsAnd/Or

2. an inability of the body’s tissues to respond properly to insulin (a state called insulin resistance)

• The most common type of diabetes is type 2• Diabetes can benefit from good nutrition

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Diabetes Epidemiology• 4th  leading cause of death by disease globally • Prevalence has doubled since 1991

• 7.0 million to 14.6 million (2005)

• 6.2 million people unaware they have diabetes• Almost 10 % of population aged 20 years or older has

diabetes• 1.5 million new cases were diagnosed in 2005. • Projected prevalence will exceed 29 million in year 2050

Types of Diabetes• Type 1 diabetes

• an autoimmune condition resulting in the need for lifelong insulin therapy

• Type 2 diabetes• Progressive disease related to insulin resistance• May be managed with just diet and exercise, or

may require oral medication and/or insulin injections

• Most commonly seen in overweight/obese people, but can also develop in normal weight people

• Gestational Diabetes• Diabetes that develops during pregnancy

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Relative Risk of Diabetes for race/ethnicity population as compared to non-Hispanic whites among people age 20 years or older in the United States, 2005

Non-Hispanic white 1.0

American Indians and Alaska Native 2.2

African Americans 1.9

Mexican Americans 1.7

Asians, native Hawaiians and Pacific Islanders in Hawaii 2.0

California Asians 1.5

CDC Diabetes, National Diabetes Fact Sheet: United States, 2005. Accessed March 2007 at http://www.cdc.gov/diabetes/pubs/pdf/ndfs_2005.pdf

Complications• Macrovascular complications

• coronary artery disease • stroke • peripheral vascular disease

• Microvascular complications • retinopathy • nephropathy • neuropathy

EVERY 24 HOURS• New Cases - 4,100• Deaths - 810• Amputations - 230• Kidney Failure - 120• Blindness – 55

Nutrition and Diabetes

Nutrition-related risk factors of Diabetes• BMI 25 or more• Prediabetes: Impaired glucose tolerance and

impaired fasting glucose• Lack of regular exercise• Abnormal lipid levels

Diabetes prevention: 5 steps

• Losing extra weight• Eating plenty of fiber • Skipping fad diets• Choosing whole grains • Getting more physical activity

Overall Preventing Chronic Diseases

• Nutrition in the Management of Dietary Changes• Energy density• Nutrient-rich foods• The right carbohydrates• Limit sweets and reduce fat• Portion sizes and count calories

• Increase Physical Activity

• Maintain a healthy body weight• The WHO goals are

• For an adult median BMI of 21 to 23 kg/m2

• For individuals, the recommendation is to maintain a BMI in the range 18.5 to 24.9 kg/m2 and to avoid a weight gain greater than 5 kg (11 pounds) during adult life

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