Final Flashcards
Definition of Adulthood in the Life Cycle: Young Adult Years
◦Growth and maturation typically complete
◦Shift in focus to maintain health and physical activity to avoid weight gain
◦Bone density and muscle mass continue to grow
Definition of Adulthood in the Life Cycle: Middle Adult Years (31-50)
-physiologic functions that impact mobility begin to decline 1% per year
◦Body composition begins to shift, fat increases and LBM decreases
Definition of Adulthood in the Life Cycle: Older Adult Years
◦Typically have more time to enjoy life with less responsibility; more disposable income
-muscle mass and strength decreases but can be offset with exercise
◦Immune system weakens with age
-changes in ability to taste and smell food
◦Saliva decreases, gastric secretions decline, and constipation, gas and bloating can become more problematic
Physiological Changes in Adulthood
Growing stops by the 20’s
Bone density continues until 30-35
Muscular strength peaks around 25 to 30 years of age
Decline in size and mass of muscle and increase in body fat
Dexterity and flexibility decline
Hormonal and Climacteric Changes: Women
◦Decline of estrogen –> menopause
- increase in abdominal fat
- increase risk of cardiovascular disease and accelerated loss of bone mass (estrogen protects)
Hormonal and Climacteric Changes: Men
-gradual decline in testosterone and muscle mass
Body Composition Changes in Adults
◦Bone loss begins around age 40
◦Positive energy balance resulting in increase in weight and adiposity; decrease in muscle mass
◦Fat redistribution- gains in the central & intra-abdominal space, decrease in subcutaneous fat
◦Associated with increased risk of chronic disease:
◦hypertension
◦Insulin resistance
◦Diabetes (type ll)
◦Stroke
◦Gallbladder disease
◦Coronary artery disease
The span of years between ages 20 and 64 is a time when the future course of health & wellness are influenced by:
◦Diet
◦Physical activity
◦Smoking
◦Body weight
DRIs for adults
- Follow dietary pattern guidelines
- Emphasis on good nutrition/provision of required nutrients and wellness/prevention of chronic disease
Dietary Recommendations-Total Diet Approach:
◦Use 2015 Dietary Guidelines and MyPlate
◦Follow a healthy eating pattern across the lifespan
◦Focus on variety, nutrient density and amount
◦Limit calories from added sugars and sat. fat and decrease sodium
◦Shift to healthier food and beverage choices
◦Support healthy eating patterns for all
Dietary guidance systems focus on:
◦Consuming greater amounts of fruits, vegetables, fiber and low fat dairy
◦Limiting saturated fat intake, trans fats
◦More nutrient rich foods, less sugar
◦Keeping sodium low
◦If consumed, moderate alcohol: 1 standard drink per day for women, 2 for men
◦Regular physical activity
-energy intake= energy expenditure
Health Promotion and Chronic Disease Prevention- Target diseases:
◦Atherosclerotic heart disease - narrowing of blood vessels bc of plaque buildup= increased risk of heart disease (leading cause of death)
◦Hypertension- high blood pressure, increases with age (1/3 of adults)
◦Overweight and obesity - 2/3 of adults
◦Cancer
-Diabetes mellitus- high blood sugar, 10% but is declining
-about 50% of our population has a chronic disease (our guidelines are for healthy individuals)
Four Common Causes of Chronic Disease
Lack of physical activity
◦ 1/3 of all adults do not meet recommendations for aerobic physical activity and 23% report no leisure-time physical activity
Poor nutrition
◦ 24% of adults report eating 5 or more servings of fruits and vegetables per day
Tobacco use
◦20% still smoke
Excessive alcohol consumption
◦Contributes to over 54 different diseases and injuries ◦Binge drinking is reported by 17% of US adults, averaging 8 drinks per binge
◦3rd leading preventable cause of death in the U.S.
Wellness versus health
Wellness: development of maximal potential
Health: absence of disease or dysfunction
Approaches to Health and Well-being:
Traditional: Change when symptoms of illness exist
Preventive: identify risk factors and then minimize risks
Wellness: positive lifestyle choices
Determinants of Health Status
Heredity Environment Health outlook Health care Lifestyle
Healthcare Reform
- many americans have limited access to health care
- Postponement of care worsens many conditions
- Limited attention to health promotion
- Health care costs increasing fast
- prevention will save money and increase quality of life
Components of a Healthy Lifestyle
Diet
Physical Activity
Stress Management
Healthy Diet
Assess risks and benefits
Use Food and Nutrition Board recommendations
Physical Activity- positive benefits
◦Energy balance ◦Body composition ◦Improved cardiovascular efficiency ◦Improves serum lipid levels ◦Lowers disease risk Exercise program must be developed - 30 mins per day of moderate intensity
Stress Management
Stress is a specific reaction to a life event
◦new job, death in the family, new baby, etc.
Physiologic and psychologic reaction
Poorly managed stress detrimental for physical and mental health
Stress management involves cognitive and behavioral approaches
Addictive Behaviors Harming Health
Cigarette smoking: free radicals, toxins - increased risk of heart disease and cancer
Alcohol abuse: increased risk of cancer and cardiovascular diseases
Primary prevention
◦Promote health
◦Provides specific protection against onset or incidence of a health problem (don’t actually have yet)
◦i.e. “Five a Day” for cancer prevention
◦Family Health history risk identification
Secondary prevention
Early diagnosis and treatment of health problems
◦Screening
◦Early diagnosis
◦Treatment Follow-up
Tertiary prevention
Minimizing existing disability through treatment and rehabilitation efforts
ex: diabetes management
Individual-based interventions
◦Creates changes in the knowledge, behavior, or health outcomes of individuals, either singly or in small groups ◦Direct client service
Community-based interventions
Focus on creating changes in populations
◦Directed toward groups or sub-groups or persons within a community
◦i.e. immunization clinics, health fairs
Systems-based Interventions
Focus on creating change in organizations, policies, and laws or structures
◦Focus is not on people or communities but on the systems that serve them
◦i.e. food labeling laws, revised school lunch recipes to reduce fat content, etc.
Characteristics of Aging
In “normal” aging, inevitable, & irreversible physical changes occur over time
The pattern and sequence of changes associated with normal aging are the same
Rate at which they occur will be different from one person to another
Decrease in the rate of cell division which leads to a progressive decline in organ function
Decrease in the ability to maintain homeostasis and ability to respond to different environmental stimuli
Characteristics of Aging: Changes in body composition
Changes in body composition – decrease in LBM, H2O and bone density with an increase in fat
◦Muscle mass decline in an almost linear fashion at the rate of 2-3% per decade after age 30
◦22% for women and 23% for men from age 30 to 70 without exercise
◦Resistance training in elderly has been shown to improve muscle strength and gait velocity and enhance thigh muscle area
◦LBM has been shown to improve with physical activity, and weight loss
◦Also a shift from subcutaneous to truncal body fat ◦Associated with insulin resistance
◦Less LBM leads to decreased BMR and lower energy requirements
◦As LBM is lost and fat increase, total body water decreases which leads to faster dehydration
Decrease in bone density
◦Bone mass is achieved in the third decade of life and then plateaus
◦Bone loss begins in the 4th or 5th decades and continues until death
◦ Greater risk of fracture due to loss of bone mineral coupled with less muscle strength
What Causes Aging?
Environmental
Genetics (35%)
Theories of Aging: Programmed Theories
Programmed longevity- sequential switching on and off of genes and age associated deficits
Endocrine theory- biological clocks act through hormones to control pace of aging
Immunological- programmed decline in immune system function
Theories of Aging: Error Theories
Wear and Tear
Rate of Living: Increased BMR = shorter life span
Crosslinking
◦An accumulation of crosslinked proteins damages cells and tissues, slowing down bodily processes
Free radicals = accumulated damage
Somatic DNA Damage
◦Genetic mutations occur and accumulate with increasing age
◦Causes cells to deteriorate and malfunction
◦Damage to mitochondrial DNA might lead to mitochondrial dysfunction
Longevity Genes
◦Fruit flies (INDY gene) and SOD
◦C. elegans (daf-2 activity reduction)
◦Human studies using microarrays for gene activity now being studied
- proteins are made that limit lifespan
Cellular Senescence
◦Hayflick limit: number of times a cell can divide (at least 4 genes involved)
◦Most aging cells are not dead or dying – responsive but don’t proliferate and continue to work
◦Causes changes in gene expression
◦may promote unregulated growth and tumor formation
◦“antagonistic pleiotropy ” – genes that have beneficial effects early in life can also have detrimental effects later
◦However, no feature of aging has been explained by in vitro cellular senescence
Proliferative and Anti-proliferative Genes
◦Promotion and suppression of proliferation
◦Tumor suppressor genes when inactivated leads to tumor formation
◦Replicative senescence appears to have evolved as a defense against cancer
Telomeres
◦Chromosome tails shorten as a cell divides
◦Protective covering with no vital genetic information
◦Shorten with age to point where function is disrupted and cell stops proliferating
◦Telomerase restores telomeres so reproduction continues
◦Suspected to be activated in cancer cells
◦Immortal cancer cells have telomeres that do not shrink
with each cell division
Oxygen Radicals
◦Released from mitochondria as well as produced by environmental factors such as tobacco smoke and sun exposure
◦Cause damage to proteins, membranes, DNA and mitochondria
◦Oxidative damage accumulates over time
◦Implicated in both aging and degenerative disorders
-Antioxidants and cellular repair mechanisms counteract
Protein Crosslinking
◦Glycation of glucose to proteins resulting in crosslinking that alters biologic and structural roles
◦Process slow and complex but accumulates over time
◦Accelerates formation of free radicals
◦Results in stiffening of tissues
◦Macrophage defense system (declines with age also)
DNA Repair and Synthesis
-enzyme systems detect and repair
◦Ability to repair certain types of damage is directly related to lifespan of the species
◦Mitochondrial DNA damage increase with age
Heat Shock Proteins
◦Produced when cells exposed to stresses (not just heat)
-help cells dismantle and dispose of damaged proteins and make and transport new proteins
Hormones
◦Estrogen ◦Growth hormone ◦Melatonin ◦Testosterone ◦DHEA -Growth Factors ◦IGF-I/hGH -decrease w age and affect cognition
Physiologic Clues
Normal Aging
◦Variable so looking for biomarkers
The Immune System
◦Research focusing on T-cells and products
-cal restriction may counteract some natural declines in the immune system
◦Caloric Restriction
-slows metabolism, decreases body temp and blood glucose levels
◦Behavioral Factors
-Diet and exercise
WILL IMPROVED NUTRITIONAL STATUS AND INCREASED EXERCISE DECREASE FURTHER LOSS OF TISSUE FUNCTION OR DELAY THE ONSET OF AGE RELATED DISORDERS?
Antioxidants/fruit and vegetable consumption seem to protect against certain chronic diseases (cancer, atherosclerosis, cataracts
– Low saturated fat diet can delay CHD by delaying or lessening atherosclerosis
Exercise
– less loss of muscle strength, less of a decline in cardiac output with age
Conclusion
Appropriate nutrition along with exercise may increase life expectancy
Probably a combination of things (multifactorial) – genetics may be modified by environmental conditions
CDC Conclusion:
◦Longevity depends on:
◦ 19 % genetics
◦ 10 % access to high-quality healthcare
◦ 20 % environmental factors (i.e. pollution)
◦ 50 % lifestyle factors
◦Not smoking ◦Diet ◦Exercise
Will nutritional manipulation and/or exercise increase the maximum lifespan?
So far, the only intervention shown to increase the MLS is caloric restriction studies done in animals – 30 to 50% less kcal than controls; lifespan increased about 35%
Less kcal, but adequate protein, vitamins and minerals, so not malnourished
MLS increase along with delay of age related changes – healthier longer
◦NIA study showed healthier but not longer lived
CNS- Brain and Spinal Cord
30-50% decrease in neuron number
Decrease in the activity of enzymes participating in neurotransmitter synthesis – less dopamine, epinephrine, serotonin, and acetyl choline produced
Increase in the activity of epinephrine and norepinephrine degradative enzymes
15% reduction in nerve conduction velocity
Reduction in brain blood flow with CVD
Dementia – 20% above age 80 (not normal)
Renal System
30-40% fewer nephrons by age 80
Decreased cardiac output lead to ~30% decline in renal blood flow
Net effect of less nephrons and less blood flow is decreased GFR (less filtration of drugs) (can’t conc. urine and can’t eat high protein diets)
Bladder capacity declines
Pulmonary System
Decrease in effective surface area of lungs for gas exchange – loss of elasticity and reduced blood flow Oxygen transfer to the tissues is decreased- amount of Hgb saturated with oxygen is less with increasing age
– Increase in shortness of breath with exercise due to decreased vital capacity
