Welcome!Nutrition and Health:

The Power of Diet in Disease Prevention

Dr. Barbara Demming-Adams and

Dr. Suzanne Nelson

The Tongan Fruit bat, Pteropus tonganus

Females bear almost the entire mineral cost of raising their offspring

by donating their own skeletal reserves

•Extended lactation: bones porous, osteoporosis, long bones of the wings

•Increased risk of wing-bone fractures can affect health and fitness

Newsweek, December 6, 1999

Diabetes in Native Americans:The interaction between diet and genes

ObesityOsteoporosis

Cardiovascular Disease (CVD)

Cancers (prostate, breast, colon)

Hypertension

Type 2 diabetes

High Cholesterol

Completely absent from ancestral diet:

•Dairy foods

•Separated oils

•Commercial processing

•Empty calorie foods

Plus! Many chronic diseases seen after the onset of the Industrial Revolution (ex. Type 2 Diabetes and frequency in CVD)

Ancestral vs Modern diet

The Average U.S Citizen is provided with 100 pounds of added sugars each year.

©2003 Wadsworth, a division of Thomson Learning, Inc. Thomson Le arning™ is a trademark used herein under license.

• Diabetes is an increasing worldwide concern– Native Americans affected the most in US

• Interaction of diet, physical activity and genetic predisposition

Diabetes

• An insufficient secretion of insulin• Or a resistance of body cells to effects of

insulin• Glucose can not enter the cells and will

remain in blood, increasing blood sugar levels

• Secreted in urine at elevated levels• Linked with inflammation

Diabetes – Type 1

• Insulin dependent

• Discovered early in life

• Need exogenous insulin

• Most often seen in children

Diabetes – Type -2

• Decrease in insulin sensitivity

• Pancreas is able to secrete insulin, may actually be over-secreting insulin

• Develops slowly• Used to not be seen until after 40

• Seen more recently in obese children

Diabetes – Type-2

• Influenced by environmental factors

• May be controllable with diet

• Does lead to serious health problems:– Retinal disease– Heart disease– Renal disease– Amputation

Diabetes Today

• Affects 16 million people in US

• Death rate due to diabetes has increased 30%

• 220 million worldwide are expected to be diagnosed by 2010

The Increasing Prevalence of Obesity Among U.S. Adults

Diabetes in Native Americans Today

• 2.8 times higher than in overall US population

• Pima, Havasupai, Oji-Cree tribes

Diabetes in Native Americans Today

• 25% of Native American males

• 30% of the females-double the total US population

From 1994 to 2004, the rate of diagnosed Native Americans and Alaska Natives younger than 35 years increased from 8.5 to 17.1 cases/1000 people.

Pima Indians in the US

Traditional Pima Indian Diet

• Beans

• Squash

• Maize

• Mule deer, pronghorn, cottontail, jackrabbit, wild turkey

• Acorns, pinyon nuts, walnuts, prickly pear, strawberries, grapes, local grasses

Genetic Predisposition• Inflammation is involved in causing diabetes

• Several genes for pro-inflammatory messengers come in different versions: a less active version and a more active one

• The more active version is much more frequent in Native Americans and diabetics

• All full Pima had two copies of the more active gene– Same genotype found in Afro-Caribbean and Gujarati

Indians (have high type-2 diabetes prevalence)

Genetic Predisposition

• Example of a pro-inflammatory messenger: the cytokine interleukin-6 (IL-6)

– Involved in glucose and lipid metabolism– Circulating levels of IL-6 are positively

correlated with obesity – Baseline IL-6 levels are predictive of type-2

diabetes development

Genetic Predisposition• Chronic inflammation leads to development of insulin

resistance – type-2 diabetes

• Another example (in addition to IL-6): inflammation-promoting COX-2 gene (the one targeted by aspirin)

• Strong association between more active version of COX-2 gene and development of type-2 diabetes within Pima Indians

Interaction of Genes and Health• Many chemicals in plant-based foods (“phytochemicals”)

are anti-inflammatory- Act as COX-2 inhibitors, lower IL-6 levels

- Lack of fruit/veggies/herbs/spices creates

pro-inflammatory state

• Polyunsaturated fats with moderate ratios of omega-6 to omega-3 fatty acids are anti-inflammatory

- However, polyunsaturated fats with high ratios

of omega-6/3 (in many packaged/fast foods)

= highly pro-inflammatory

Genetic Predisposition

• Evolutionary advantage to have highly active immune system– Lifespan was shorter– Injury, infectious diseases were more prevalent

• Native Americans exposed to repeated epidemics following contact with Europeans

• May have led to selection of individuals more resistant to infectious diseases but more prone to diabetes

Genetic Predisposition

• The thrifty gene hypothesis

• Decreased metabolism to preserve fat reserves for long winters “starvation season”

• Now, extreme food abundance, types of food available, with genetic combination, results in a food toxic environment.

Today’s Lifestyle

• Pima Indians:– Less active– Buy (highly processed) food– Unhealthy diet: decreased fiber, decreased

phytochemicals, increased omega-6 fats– All promote inflammation

• Already genetically predisposed to have increase in inflammation messengers and other proteins

Diet and Prevention• Reduce total fat intake and alter fat composition

– Substitute unsaturated fatty acids for saturated fats– Moderate n-6/n-3 ratio of unsaturated fats– Eliminate saturated fats, cholesterol, trans-fatty acids

• Increase fiber intake– Whole grains, fruits, vegetables

• Carbohydrates with low glycemic index – Avoid refined grain products – Highest glycemic index- potatoes

Physical Activity

• Improves long term weight maintenance

• Exercise:– Enhances insulin sensitivity– Improves glucose uptake by the muscles– Improves ability to burn fat

• In Pima Indians – improvement in insulin action after weight loss of 10% total body weight

Prevention

• CSU- Program ENERGY

• Denver conference on Native American health and obesity

• Greater awareness- requests for Native American health/diabetes prevention programs.

• Indigenous news network/ Indiancountrytoday