Chapter 3 Nutrition and Health: Chronic Disease, Inflammation, and Evolutionary Mismatch

Body Performance and the Aging Process

• Determinants of Physical Performance and Aging:

  • Genetic Traits: Inherited biological characteristics.

  • Age: Biological progression over time.

  • Sex: Differences between Males and Females.

  • Lifestyle Factors:

    • Dietary habits (including alcohol consumption).

    • Levels of physical activity.

    • Smoking status.

    • Drug use.

    • Stress levels.

    • Sleep quality and duration.

Historical Shifts in the Nutritional State of the United States

• Historical Disease Prevalence:

  • Nutritional deficiency diseases were once common in the U.S. population. Notable examples include:

    • Rickets: Caused by deficiencies in vitamin D, calcium, or phosphate.

    • Pellagra: Resulting from a deficiency of niacin (vitamin $B_3$).

  • During the early 1900s and earlier, deaths from contagious diseases were prevalent.

• The Transition to Chronic Disease:

  • Improvements in pharmaceuticals and sanitation infrastructure led to a significant decrease in contagious disease rates.

  • Conversely, there has been a rise in chronic diseases.

• Definition of Chronic Diseases:

  • Slow-developing conditions.

  • Long-lasting in duration.

  • Non-contagious nature.

• Primary Causes of Death Today: Modern lifestyle-related chronic diseases are the leading causes of mortality, specifically:

  • Heart diseases.

  • Cancers.

  • Diabetes.

  • Stroke.

Diet and Diseases of Western Civilizations

• Evolutionary Context of the Western Diet:

  • Current chronic diseases prevalent in the U.S. and other Western nations are rooted in dietary changes occurring over centuries.

  • 40,000 Years Ago: Humans survived as hunter-gatherers. This lifestyle involved intense physical exertion to find food and periods of famine.

  • Modern Era: Foods are highly processed. Food acquisition requires little to no strenuous physical activity. Human biological patterns now involve constant "feasts" with no intervening periods of famine.

• Specific Dietary Components and Disease Links:

  • Heart Disease: Linked to high intakes of saturated fat and cholesterol; low intake of vegetables and fruits; and excessive body fat.

  • Cancer: Linked to low intake of vegetables, fruits, and fiber; excessive body fat; and excessive alcohol consumption.

  • Diabetes: Linked to excessive body fat; low vegetable and fruit intake; and high saturated fat intake.

  • Hypertension: Linked to high sodium and alcohol intake; and excessive body fat.

  • Obesity: Linked to excessive calorie intake and high-fat diets.

Mortality Statistics in the United States

• Leading Causes of Death and Their Proportional Impact:

  • Heart diseases: Positioned as the primary cause of death (occupying approximately $25\%$–$30\%$ of total deaths).

  • Cancers: The second leading cause.

  • Strokes: A major contributor to mortality.

  • Chronic Obstructive Lung Disease: Principally includes conditions such as bronchitis, emphysema, and asthma.

  • Accidents.

  • Pneumonia and Influenza.

  • Diabetes.

  • Alzheimer's Disease.

  • Kidney Disease.

  • Septicemia: Defined as blood infections.

Inflammation and Oxidative Stress

• Biological Mechanisms of Damage:

  • Chronic inflammation and oxidative stress are sustained by irritants known as Free Radicals.

• Free Radicals Defined:

  • Reactive chemical substances that are missing electrons.

  • Prone to oxidizing nearby molecules by stealing their electrons.

• Primary Triggers for Chronic Inflammation:

  • Excess body fat.

  • High intake of saturated fats and trans fats.

• Reduction of Damage:

  • Damage can be mitigated by the loss of excess body fat.

  • Dietary intake of Antioxidants and Omega-3 fatty acids.

• Antioxidants Defined: Chemical substances that prevent or repair damage to cells caused by free radicals.

Dietary Associations with Inflammation and Oxidative Stress

• Foods Associated with Decreased Inflammation/Oxidative Stress:

  • Colorful fruits and vegetables.

  • Dried beans.

  • Whole grains.

  • Fish, seafood, and fish oils.

  • Red wines.

  • Dark chocolates.

  • Olive oil.

  • Nuts.

  • Coffee.

• Foods Associated with Increased Inflammation/Oxidative Stress:

  • Processed and high-fat meats.

  • High-fat dairy products.

  • Baked products and snack foods containing trans fats.

  • Soft drinks and other high-sugar beverages.

Evolutionary Mismatch and Human Physiology

• Biological Stagnation: The human body has not adapted to the modern Western diet (high animal fat, salt, and sugar; low vegetables, fruits, and whole grains).

• Survival Mechanisms of Early Humans:

  • Mechanisms that stimulate hunger even when body fat stores are sufficient.

  • Efficiency in conserving sodium.

  • An innate preference for sweet-tasting foods.

  • A digestive system optimized for high fiber intake.

Case Study: Changing Diets and Disease in Japanese Populations

• Traditional Japanese Health Markers:

  • Japan maintains one of the longest life expectancies globally ($83$ years).

  • Traditional Diet: Primarily rice, vegetables, fish, shellfish, and meat.

• Impact of Westernization:

  • When Japanese individuals adopt a Western diet, life expectancy decreases, while heart disease and cancer rates increase.

  • Japanese Immigrant Trends: Increased consumption of meat and a decrease in complex carbohydrates leads to higher rates of diabetes, heart disease, and breast/colon cancer.

• Comparative Data: Japanese Men (Japan vs. U.S.):

  • Japan:

    • Calories from Fat: $16.7\%$

    • Calories from Carbohydrate: $61.1\%$

    • Diabetes Incidence: $5.3\%$

  • United States:

    • Calories from Fat: $32.4\%$

    • Calories from Carbohydrate: $48.5\%$

    • Diabetes Incidence: $20\%$

Global Life Expectancy Comparison (2012 Data)

• Life Expectancy at Birth (Years):

  • Japan: $83$

  • Switzerland: $83$

  • France: $83$

  • Italy: $83$

  • Australia: $82$

  • Spain: $82$

  • United Kingdom: $82$

  • Canada: $81$

  • New Zealand: $81$

  • Austria: $81$

  • Germany: $81$

  • Ireland: $81$

  • Finland: $81$

  • Greece: $81$

  • Belgium: $80$

  • Portugal: $80$

  • Denmark: $80$

  • Costa Rica: $80$

  • Cuba: $79$

  • United States: $79$

Public Health and Prevention

• The Power of Prevention:

  • While heart disease remains the leading cause of death in the U.S., its rate has decreased by over $50\%$ in the last $30$ years.

  • Future improvements depend on: improved dietary intake, lower rates of overweight/obesity, increased physical activity, and decreased smoking.

• Healthy People 2020 Nutrition Objectives:

  • Healthier Food Access: Increase nutritious foods in schools and access to retail outlets selling products encouraged by Dietary Guidelines.

  • Weight Status: Increase the proportion of adults at a healthy weight; reduce obesity in adults, children, and adolescents; and prevent inappropriate weight gain.

  • Food Insecurity: Eliminate very low food security among children and reduce overall household food insecurity to combat hunger.

  • Food and Nutrient Consumption:

    • Increase variety and contribution of vegetables.

    • Increase contribution of whole grains.

    • Reduce calories from solid fats and added sugars.

    • Reduce saturated fat and sodium consumption.

    • Increase calcium consumption.

  • Iron Deficiency: Reduce deficiency among young children, females of childbearing age, and pregnant females.

  • Health Care Settings: Increase nutrition and weight counseling during physician office visits.

Nutritional Recommendations: What to Eat

• Focus Areas for Food Intake:

  • Whole-grain products.

  • Increased vegetable and fruit consumption.

  • Lean meats and fish.

  • Dried beans.

  • Low-fat or fat-free dairy.

• Dietary Flexibility: Sweets, desserts, and packaged snacks are not strictly excluded from dietary recommendations.

• The Golden Rule: Practices should follow the principle of "everything in moderation."