The Challenge of Living Longer and Healthier: A Comprehensive Guide

Posted on Aug 30, 2024 in Biology

HEALTH: THE CHALLENGE OF LIVING MORE AND BETTER

You will have a world without hunger, without illness, without cancer or pain. You just need to want it. – György Albert Szent

Outline of Unit

  • What is Health?
  • Healthy Habits
  • Disease: Types of Diseases
  • Treatment of Diseases
  • Medical Research Patents
  • Medicine in Different Countries

WHAT IS HEALTH?

According to the World Health Organization (WHO), health is a state of complete physical, mental, and social well-being, not merely the absence of disease. Health is a balance between the following factors:

  • Genetic Factors: Inherited from parents, these factors control longevity, disease resistance, and the risk of congenital diseases.
  • Environmental Factors: Harmful elements in the environment where we live, such as pathogens, radioactive substances, and toxic materials.
  • Personal Factors: Biological characteristics of each individual (age, sex, immune system, etc.) which, together with lifestyle, make them more or less vulnerable to disease.

Well-being can be categorized into three aspects:

  • Physical Well-being: The result of a balanced diet, personal care habits, and engaging in healthy activities without undue risk.
  • Mental Well-being: Self-acceptance, the ability to convey feelings, and the attitude to face problems.
  • Social Well-being: The ability to relate and share with others some aspects of life.

GENETIC FACTORS

The interaction between genes and the environment is a determinant of health and, conversely, its imbalance is responsible for some pathological processes.

  • Genetic Diseases: Caused by mutations affecting a gene (e.g., hemophilia, cystic fibrosis).
  • Congenital Malformations: Present at birth, some are genetic and others environmental.
  • Predisposition to Certain Diseases: Cardiovascular disease, some cancers, rheumatic diseases, mental illnesses.
  • Biological Factors: Biological factors that can influence health status include the sex of the individual and the natural aging process.

Sex: Differences between men and women are also reflected in health, either by natural processes (pregnancy) or pathological conditions (prostate cancer).

Aging Process: Life has a limited duration. Natural death is the result of aging at the cellular level, which is genetically conditioned and influenced by environmental causes.

  • Causes: Errors in biochemical processes, aging and cell death, processes linked to free radicals.
  • Consequences: Atrophy of tissues and organs, immune deficiency, vulnerability to trauma.

ENVIRONMENTAL FACTORS

The environment has a huge impact on the health of individuals and populations. The factors that affect health are related to the area in which we live, housing, and the workplace. The most important factors include:

  • Water Quality: Clean and free of germs. In the 20th century, average life expectancy doubled thanks to clean water.
  • Healthcare: It depends on each country, its resources, and the rate of healing. Comprehensive healthcare based on prevention, vaccination, and epidemic control is necessary to maintain the level of population health.
  • Quality of the Environment: Global risks such as air pollution and other factors such as the presence of industry, noise, waste management, and pesticides.
  • Exposure to Carcinogens: Mutations occur that induce cancer development. Examples include radioactivity, UV rays, and certain chemicals.

PERSONAL FACTORS

Personal factors depend on each person and their lifestyle:

  • Socio-economic Conditions: Stable work that promotes integration. Poverty leads to social marginalization.
  • Culture
  • Family and Social Relationships
  • Stress: The body’s response to problems, causing physical and psychological changes.
  • Attitude and Behavior: Acquired habits affect health and contribute to risk factors.
  • Food Habits
  • Moderate and Regular Physical Exercise
  • Alcoholism, Smoking, and Drugs
  • Hygiene and Personal Care

In developed countries, there is a high incidence of cardiovascular diseases linked to obesity. In deprived areas, food shortages cause major famines, resulting in malnutrition and death.

Health Indicators
  1. Life Expectancy
  2. Mortality: Divided into groups and types of illness, accidents, etc.
  3. Morbidity: Effects of disease in a population, represented by the proportion of people who suffer in one place and time.
  4. Disability and Subjective Health: Types of disability, days of hospitalization, sick leave, pensioners.
  5. Maternal and Child Health: Infant mortality, vaccinations, weight of newborns.
  6. Habits and Lifestyles: Tobacco consumption, drugs, physical inactivity, obesity.

HEALTHY HABITS

A healthy lifestyle includes habits that prevent health risk factors. Healthy habits are acquired through learning. The main aspects include:

  • Nutrition
  • Physical Activity
  • No Drug Use

The Food

Diet is the amount of solid foods and liquids we ingest throughout the day.

Healthy Diet: Provides adequate amounts of nutrients for the body’s daily energy needs. It is balanced and complete.

Eating Disorders

An eating disorder is an alteration of eating habits that can have very negative consequences for people.

Obesity: Weight gain due to abnormal accumulation of fat. It is a risk factor for multiple diseases.

BMI (Body Mass Index) = Weight (kg) / (Height)2 (m2)

  • BMI < 18.5: Underweight
  • BMI 20-25: Normal
  • BMI 25-30: Overweight
  • BMI > 30: Obesity

Excess weight is associated with cardiovascular disease, type II diabetes (non-insulin dependent), some cancers, and musculoskeletal diseases like osteoarthritis.

Anorexia: Continued loss of appetite, resulting in severe malnutrition that can cause death. It involves voluntarily stopping eating and is an illness of psychological origin. People who suffer from anorexia often perceive themselves as obese, and it mainly affects women. It is related to inadequate diets, laxatives and diuretics, and family problems. It requires specialized treatment.

Bulimia: Alternation of excessive ingestion of food with eliminating it through induced vomiting. Common stages include fasting, excessive physical activity, and the use of laxatives to counter excess food consumption. Abrupt changes in weight occur. It is associated with low self-esteem and feelings of guilt when eating.

Avitaminosis: Occurs when certain vitamins are lacking.

  • Vitamin A: Night blindness
  • Vitamin B1: Beriberi
  • Vitamin B2: Dermatitis
  • Vitamin B3: Pellagra
  • Vitamin B12: Pernicious anemia
  • Vitamin C: Scurvy
  • Vitamin D: Rickets
  • Vitamin E: Nerve injury
  • Vitamin K: Hemorrhages

Marasmus: Severe malnutrition with severe protein deficiency, which can cause death. It can occur in underdeveloped countries.

External Power Connector, Cancer, and Cardiovascular Disease

Risk factors for cardiovascular disease are obesity, hypertension (high blood pressure), and hypercholesterolemia (excess cholesterol).

Some cancers are favored by substances in food.

These diseases can be prevented with proper nutrition, low in animal fats, high in fiber, reducing salt intake, eating foods high in unsaturated fatty acids (oily fish), and moderate consumption of tea, coffee, and alcohol.

The Physical Activity

The practice of regular physical exercise is beneficial to health. Physical activity generates well-being. The most important effects on health include:

  • Reduced heart rate, reducing cardiovascular disease risk.
  • Reduction of bone loss and osteoporosis.
  • Helps maintain weight.
  • Delays cell aging.
  • Helps fight stress and emotional tension.

Tobacco, Alcohol, and Drugs

Tobacco, alcohol, and drugs are a problem for millions. A healthy lifestyle requires the absence of these habits. This can be achieved through:

  • Prevention against the acquisition of habits, favored by environmental stress, lack of self-control, and imitation.
  • Reduced and quitting requires support personnel.

Tobacco: Responsible for 20% of deaths in developed countries. Affects both smokers and people around them. Tobacco smoke is responsible for cardiovascular diseases, lung cancer, and chronic obstructive pulmonary disease (COPD).

Contains:

  • Nicotine: Causes addiction and promotes lung diseases.
  • Carbon Monoxide: Combines with hemoglobin and reduces the blood’s ability to transport O2.
  • Tars: Substances that release free radicals, which are highly carcinogenic.

Alcohol: Ethanol is the most widely known and dangerous psychoactive drug in the world. It is a CNS depressant. It reduces inhibitions and feelings of fatigue, but also self-control and concentration. It is responsible for numerous car accidents and workplace incidents. It can cause digestive system diseases: gastritis, ulcers, cirrhosis, and some cancers. It can also lead to intellectual impairment, memory loss, impotence, and infertility.

Drugs: Substances that are used to alter behavior and mental state and interfere with the functioning of the body. They are addictive and have very serious effects on the three pillars of health: physical, mental, and social. They produce physical and psychological dependence.

Physical dependence means the body gets used to these chemicals and needs to maintain a certain level of the substance to function normally. When this level decreases, withdrawal occurs.

Psychological dependence is the need to consume drugs to maintain a pleasant affective state.

An addict is someone with dependence.

DISEASE: TYPES OF DISEASES

When the balance of health is broken, it causes disease. Disease is characterized by a range of symptoms observed by the patient and physician. They can be classified as:

  • Internal Source: Genetic.
  • External Source: Infectious diseases.
  • Acute: Develop and reach maximum intensity in a short time.
  • Chronic: Develop slowly over a long time.
  • Types: Infectious and non-infectious.

Infectious or Parasitic Diseases

Produced by the colonization of the body or some parts by pathogenic infectious agents (bacteria, fungi, viruses, prions) or vermin infestation.

Modes of Transmission

  • Direct Transmission: Person to person through physical contact or through the placenta.
  • Indirect Transmission: Through intermediate agents. This can be:
    • Air: Respiratory diseases are transmitted through talking and sneezing (e.g., influenza, tuberculosis).
    • Water: Contaminated water can transmit diseases like cholera and dysentery.
    • Food: Contaminated by microorganisms or parasites (e.g., salmonella, Creutzfeldt-Jakob disease, trichinosis).
    • Vectors: Animals such as insects that transmit malaria, or pets that transmit parasites such as tapeworms.

Epidemic: A disease that affects a large number of individuals in a population (e.g., cholera prevalent in Asian countries, AIDS).

Pandemic: Affects the whole world (e.g., COVID-19).

Endemic Disease: A disease that affects an area or a specific region of the world (e.g., malaria, dengue in the tropics).

Infectious Agents

Infection is the result of the establishment and growth of microorganisms in the body, leading to symptoms that characterize the infectious disease.

Pathogenicity is the ability of the organism to cause disease.

Virulence is the degree of pathogenicity, which might be different for different strains.

Phases:

  • Colonization
  • Penetration through defensive barriers
  • Multiplication and invasion
  • Production of abnormal tissues and organs
Bacterial Infections

Bacteria are single-celled organisms without nuclei. They produce toxins, which are spread through the blood and produce the disease.

  • Tuberculosis – Bacillus of Koch
  • Cholera – Vibrio cholerae
  • Pneumonia – Pneumococcus
Fungal Diseases

Fungal infections are called mycoses. Many tend to be opportunistic infections that occur when defense mechanisms are impaired.

  • Ringworm
  • Athlete’s foot
  • Candidiasis
Diseases Caused by Protozoa

Single-celled organisms with a nucleus that produce serious diseases. They live in liquid mediums. Only 20 cause disease in humans. Their impact on human health worldwide is, however, disproportionate to their numbers.

  • Chagas disease – Trypanosoma cruzi
  • Malaria – Plasmodium
Viral Diseases

Viruses have a very simple structure, consisting only of protein and nucleic acid. They grow by using the cellular machinery of the infected cell (obligate parasites). Treatment is complicated because to remove them, we need to remove the cell that contains them or act against their metabolism (which they have not used in the parasitized cell). Outside the cell, they are inert and can crystallize.

  • Encephalitis
  • Fever diseases
  • Yellow Fever
  • Ebola Fever
  • Hemorrhagic Fever
  • Flu
  • Herpes
  • Myxomatosis
  • Infectious Mononucleosis
  • Viral hemorrhagic pneumonia
  • Mumps
  • Rubella
  • Acquired Immunodeficiency Syndrome (AIDS)
  • Smallpox
  • Varicella (Chickenpox)
Human Immunodeficiency Virus (HIV/AIDS)

HIV is a retrovirus, meaning it has RNA as genetic material. It attacks T cells, resulting in the suppression of the immune system. This promotes the development of opportunistic infections and tumors, which are the leading causes of death.

A person who has HIV but has not yet developed the disease (AIDS) is called HIV positive and can transmit it to others. Even without the disease, the virus continues to divide, so there will come a time when the body has no immune system.

Prevention (use of condoms during intercourse, or not sharing needles for drug addicts) is the best treatment.

HIV is found in body fluids: blood, semen, vaginal fluids, and breast milk, so it can be spread by:

  • Sex
  • Sharing syringes
  • During pregnancy
  • During delivery
  • During lactation
Diseases Caused by Prions

Prions are proteins with a different configuration than normal proteins. This configuration change can be transmitted to other proteins, affecting the tissue where they are. They produce diseases in animals and may have infectivity in humans, causing spongiform encephalopathy (mad cow disease) and in humans, Creutzfeldt-Jakob disease.

Defense Against Infection

  • Nonspecific Mechanisms: Defend against any infection.
  • Specific Mechanisms: Aimed at each microorganism.
  • Immune System
Nonspecific Mechanisms
  • Skin: Barrier for most foreign bodies, except with injuries.
  • Mucosa: Epithelial cells lining the body cavities.
  • Antimicrobials: Sweat, saliva, tears.
  • Inflammation: Histamine is released, the area becomes red, swollen, and increases in temperature and pain. Macrophages or phagocytes appear.
Specific Immunity: Immune System
  • B cells: Produce antibodies (proteins that recognize and attack antigens). After infection, they become memory cells.
  • T lymphocytes and macrophages: Act directly by targeting antigens.

Non-infectious Diseases

These are due to alterations in some tissues that cause abnormal function and disease appears.

Cancer

When the balance between cell birth and cell death is broken, a mass of disorganized tissue, a tumor, forms. The majority of tumors are benign. Cancer is a malignant tumor that grows without limit and spreads to other parts of the body.

The word cancer comes from the Greek word ‘karkinos’ (crab), as Hippocrates and his colleagues found it an adequate term to describe a tumor that seems to have legs and tends to extend outward.

Cancer is the second leading cause of death after cardiovascular diseases in the developed world.

Some guidelines for preventable cancer are:

  • No smoking.
  • Protect from sunlight.
  • Eat a healthy diet.
Treatment
  • Surgery: Excision of the tumor mass.
  • Radiotherapy: Use of radiation to damage cancer cells.
  • Chemotherapy: Drugs that affect cells.
  • Hormones: For cancers that require hormones to grow.
  • Immunotherapy: Agents that enhance the immune system.

Cardiovascular Disease

Affects the heart and blood vessels.

  • Coronary heart disease: Disease of the blood vessels supplying the heart muscle (myocardium).
  • Stroke (CVA): Problems in blood vessels supplying the brain.
  • Peripheral arterial disease: Disease of blood vessels supplying the arms and legs.
  • Rheumatic heart disease: Damage to the heart muscle and heart valves due to rheumatic fever, a disease caused by streptococcal bacteria.
  • Congenital heart disease: Heart defects present at birth.
  • Deep vein thrombosis and pulmonary embolism: Blood clots (thrombus) in the veins of the legs, which can break off (embolus) and lodge in the vessels of the heart and lungs.
  • Aneurysm: Narrowing of the arterial wall.

Risk factors: age, male gender, family history, hypertension, hypercholesterolemia, stress, lack of exercise, obesity, tobacco, and alcohol.

Respiratory Diseases

  • Chronic obstructive pulmonary disease (COPD): Narrowing of the airways.
  • Restrictive lung disease: The lungs lose elasticity.

Degenerative Diseases

  • Alzheimer’s disease: Progressive and terminal, causing memory loss and modifying behavior to the point of dementia.

Diseases of the Immune System

  • Allergies: Hypersensitivity of the body to a substance that does not cause an environmental reaction in most people.
  • Autoimmune diseases: Failure of the immune system to recognize its own cells, leading to the creation of antibodies against them (e.g., lupus erythematosus, rheumatoid arthritis).

Mental Disorders

Disorders of thoughts, emotions, and behavior.

  • Schizophrenia: Personality disorder characterized by a loss of sense of reality and disorganized thinking, delusions, hallucinations, and behavioral changes.

Medicines

  • Vaccines
  • Sera
  • Antibiotics
  • Analgesics
  • Anti-inflammatories
  • Antivirals
  • Muscle relaxants
  • Etc.

Vaccines

Medicine in Different Countries

Health is a factor linked to the purchasing power of citizens and states. Developed countries have health systems and human resources of a high standard. Poor countries lack structured drug and healthcare systems.

Priority should be given to expenditure on health and the pharmaceutical industry.

Of the total expenditure for R&D in health, 90% is devoted to diseases affecting developed countries (cancer, cardiovascular disease, degenerative diseases).

The remaining 10% is dedicated to Third World diseases.

Health expenditure in Africa is 7 euros per inhabitant.

Only 15 of the registered drugs are for tropical diseases.

The WHO and many private organizations are devoting money and effort to fighting Third World diseases.

Health Systems
  • National Health System
  • Liberal Model