How is physiological maturity reached in early 30's?
- Achievement of maximum height
- Formation of peak bone mass
When does loss of bone density begin?
What happens 5 years after maximum height is reached?
Maximal strength, endurance and agility?
When does muscle mass start declining?
Muscle mass increases until 3rd decade, then declines gradually
How long does average body weight increase?
Average body weight increases until 7th decade in both sexes
How is excess body weight and fat accumulated in middle adulthood (50-69 years)?
No adjustment to decreased energy expenditure by decreasing caloric intake
How can one prevent/slow down the decrease in bone and muscle mass in middle adulthood?
What is caused by an increased waistline?
- Greatly increased risk of diabetes, HTN, CVD
- Increased %fat and decreased LBM
How many adults are overweight?
What happened as a result of a shift in industrialization?
- Shift in natural composition of the diet, which lead to increased intake of animal fat and decreased complex CHO and fiber
- Link with cancer, CHD, obesity and dental caries
What happens as a result of insufficient fruit and vegetable intake?
Increased risk of disease
What is a high daily intake of fruits and vegetables associated with?
Associated with protection against a variety of diseases
What are some key aspects that accelerate aging and increased risk for chronic diseases?
- Diets high in saturated at, alcohol, Na, sugar and low in fiber
- Lifestyles that include smoking, little exercise and high stress
Why is it important to educate individuals in their middle years about exercise and food habits?
- Delay onset of aging and chronic disease
- Increase optimal function for longer period of time
- Increase quality of life in the present
What are the unified dietary guidelines?
- Eat a variety of foods
- choose most of what you eat from plant sources
- Eat 5 or more servings of fruits and vegetables each day
- Eat 6 or more servings of bread, pasta, and cereal grains each day
- Eat high-fat foods sparingly, especially those from animal sources
- Keep your intake of simple sugars to a minimum
What is the most prudent and scientifically supportable recommendation?
Consume a balanced diet with emphasis on antioxidant-rich fruits and vegetables and whole grains
How has life expectancy changed over tiem?
- Increased from 45 years at the turn of the century to 75 years in 1990
- in 15 years, the mean life expectancy will be 77 (males) and 84 (females)
In 20 years, how much of the social and health care budget will be used to support the elderly?
What is usual aging?
- Associated with aging process that is accelerated by disease and lifestyle factors
- Poor exercise habits and alcohol and tobacco abuse
What is successful aging?
- Associated with age related changes that are not increased due to lifestyle or disease
- Sound nutrition habits, exercise regularly and habe good blood pressure control
What are the typical causes of death of centenarians?
CHD, cancer, infection
How does nutrition affect aging?
- Nutrition may greatly influence immune function in elderly
- Malnutrition is the best predictor of total number of visits to the hospital or a physician
How do multivitamin and mineral supplements help the elderly?
Elderly who took multivitamin and mineral supplements showed 1/2 infection rate
How does vitamin C and E help elderly?
- decrease incidence of cataracts
- Improve mental ability
- Prevent some forms of dimentia
How does folate supplementation help elderly?
- Decreases dementia like symptoms
- Increases mental functioning
How do fish and fish oils help elderly?
Better cognitive performance among elderly
Why do elderly often show a decrease in LBM and an increase in adipose tissue?
- Due to both decreased physical activity and hormonal changes
- Decreased growth hormone production with age
- Decreased estrogen (females) and testosterone (males) leads to changes in bone mineral density
- Decreased testosterone: contributes to decreased muscle mass (inability to maintain protein stores)
How does one combat negative physical changes in the elderly?
- Physically active older men have lower % body fat than inactive young men
- Physical training in elderly increases muscle strength and LBM which leads to better mobility even among 90 year olds
What is the leading cause of death among the elderly?
CVD due to heart conditions and HTN
What is the second most common cause of death among the elderly?
- 25% of females and 20% of males
How many elderly have diabetes?
40% of elderly after age 80
What is the 'cellular mutations' theory of aging?
- Drugs, UV light, mutagens and radiation
- Cause a decrease in DNA repair activity
- Accumulation of damage from environmental stresses which damage and kill cells
- Errors during copying of DNA accumulate which leads to a change in protein synthesis which leads to decreased cell functioning
What is the 'decreased hormonal secretions' theory of aging?
- Changes in the functioning of anterior pituitary leads to altering of hormonal balance which leads to adverse altering of normal metabolism
- Decreased growth hormone leads to increased adipose tissue and decreased LBM
- Decreased testosterone leads to a decreased ability to maintain protein stores and bone mass
- Decreased estrogen leads to a decreased ability to maintain bone mass
What is the 'cross-linking' theory of aging?
Glycation causes cross-linking between protein molecules
How do free radicals impact aging?
- Environmental exposures via radiation, natural body processes
- Causes macromolecular damage
What is predetermined aging under genetic control?
- Specific genes that predetermine lifespan
- Telomeres: end of chromosomes; decrease with age
How do decreases in body functions affect nutrition in the elderly?
- GI, renal, liver functioning lead to increased risk of malnutrition
- Malnutrition worsens disease and increases likelihood of adverse drug interactions
What factors can cause decreased food intake?
- Anorexic effect of physical trauma
- Decreased ability to prepare food
What are some risk factors for malnutrition in older adults?
- Eating poorly
- Economic hardship
- Reduced social contact
How do antivitamin drugs block action of vitamins?
- Inhibiting their absorption
- Binding to them in the body to make them unavailable to the tissues
- Enhancing their excretion
- Causing an inhibition of their activation in the body to an active form
How do cholesterol lowering drugs effect nutrient metabolism?
Cholesterol lowering drugs that are bile acid sequestrants (cholestyramine) prevent reabsorption of bile salts which lead to a decrease in fat soluble vitamin absorption
How do antibiotics affect nutrient absorption?
Destroy intestinal mucosa, villi and microvilli and inhibit brush border enzymes
How do anti-inflammatory drugs affect nutrient absorption?
- Inhibit lactase enzyme
- Directly damage the gut and decrease fat and micronutrient absorption
How do laxatives affect nutrient metabolism?
- Dissolve fat and fat soluble vitamins which allows them to be excreted in feces
- Decrease in transit time from use of laxatives and mineral oil leads to a decrease in nutrient absorption in terms of Ca and K losses
How do anti-ulcer drugs affect nutrient metabolism?
Anti-ulcer drugs (cimetidine) decrease HCl production which leads to a decreased amount of B12 release from foods which means less B12 is available for binding with intrinsic factor for absorption
How do loop diuretics affect nutrient metabolism?
Loop diuretics (furosemide) for blood pressure control lead to an increase in renal excretion of thiamin and can cause cardiac abnormalities (excessive use)
How do other diuretics (thiazide) and corticosteroids affect nutrient metabolism?
Cause potassium depletion and lead to an increased risk of cardiac arrythmias
How does aspirin affect nutrient metabolism?
Binds to folate binding sites on plasma protein normally involved with blood transport of the vitamin (albumin) which leads to increased urinary excretion of folate
What is the definition of diarrhea?
3 or more unformed bowel actions in 24 hours
What is acute and chronic diarrhea?
- Acute: an episode of diarrhea lasting < 2 weeks
- Chronic: diarrhea lasting 3-6 weeks
How can diarrhea cause death?
Frequency and severity of dehydration and electrolyte loss (may cause death)
How do antibiotics cause diarrhea?
- Temporary alteration of colonic bacteria
- Damage to small intestinal mucosa
- Most often mild and self-limiting
- Some cause osmotic diarrhea (alteration of bacterial flora which leads to a decrease in colonic fermentation of CHOs which act as osmotic agents)
What kinds of osmotic agents cause diarrhea?
- Antacids containing magnesium trisillicate or Mg hydroxide
- Drugs to treat peptic ulcer (cimetidine)
How do antineoplastic drugs cause diarrhea?
Damage immature epithelial cells, compromising their absorptive function
What are some contributing factors cause drug-induced diarrhea?
- Polypharmacy, sel-medication, noncompliance in regard to usage
- Inappropriate drug prescribing
What is bone remodelling?
Replacement of old bone with newly synthesized bone tissue
What synthesizes the bone matrix?
What do osteoclasts do?
- Dissolve bone mineral with acids and digest bone matrix
- With recruitment of phagocytes to remove the protein
What is osteoporosis?
- Reduced bone of normal composition
- Bone density <2.5SD below young people
What is type I osteoporosis?
- Bone losses are accelerated in the early postmenopausal period
- Onset 50-70 years of age
How can you reduce your risk of osteoporosis?
- Higher peak bone mass
- Ca supplementation in pubertal growth spurt
Why are women more susceptible to osteoporosis?
Can lose up to 20% of bone mass in 5-7 years after menopause
What are some factors that increase the likelihood of developing osteoporosis?
- Being female
- Thin and/or small frame
- Advanced age
- A family history of osteoporosis
- Abnormal absence of menstrual periods (amenorrhea)
- Anorexia nervosa
- Diet low in calcium certain medications (corticosteroids, anticonvulsants)
- Low testosterone levels in men
- An inactive lifestyle
- Cigarette smoking
- Excessive use of alcohol
- Caucasian or Asian
What is hypogonadism?
abnormally low levels of sex hormones
What type of physical activity is best to prevent against osteoporosis?
Weight bearing exercises
What is type I osteoporosis?
- Primarily associated with increased osteoclast activity
- Rapid bone loss
- Decreased estrogen levels in females and testosterone levels in males
- Estrogen dampens the bone resorbing effects of PTH when there is a decreased blood Ca
- Lower estrogen:PTH ratio during menopause
- Vertebral bone crush, high risk of wrist and spine fractures
- Females:males 6:1
What is type II osteoporosis?
- Senile osteoporosis
- Cortical bone loss
- Slow and steady with age
- Start at ~40 years of age
- Due to osteoblast underactivity
- Females:males= 2:1
How is osteoporosis prevented?
- Acquisition of maximum bone mass in premenopausal years
- Adequate dietary Ca and vitamin D
- Screening for osteopenia and perimenopausal period
- Decrease of BMD more than 1SD but less than 2.5 below the young adult mean
- Control of bone mineral loss during postmenopause
What is the predominant for of therapy for osteoporosis?
Hormone replacement therapy
How does vitamin D affect osteoporosis?
- Elderly and women with osteoporosis
- Thought to absorb Ca less efficiently because of a deficiency in the activated form of vitamin D
- Decreased bone resorption (enhancement of Ca absorption in the gut)
- Aids in the mineralization of the bone matrix
What are some modifiable risk factors that can affect bone loss?
- Decreased calcium, Increased phosphorus, high protein diet, vitamin D deficiency, low physical activity, excess alcohol and caffeine and smoking
- Exercise: stimulates osteogenesis, believed to be helpful in retarding bone loss
What is rankl?
receptor activated nk-kappa-ligand, stimulates inflammation and causes the breakdown of bone matrix