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UGEB 2362 Nutrition for Healthy Living
Nutrition and Aging
KN Leung
Nutrition and Aging
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Key References Clifford
J and Bellows L (2015) Nutrition and Aging.
Colorado State University Extension Fact Sheet
No. 9.322. (http://www.ext.colostate.edu)
Debruyne LK and Pinna K (2017) Nutrition through the
life span: Later adulthood. In “Nutrition for Health and
Health Care” (6th ed.) Chapter 12, p.343-364.
(QU145.N856 2017)
Sharma S (2016) Nutrition in older adults. In “Nutrition
at a glance” (2nd ed.), Chapter 50, Wiley Blackwell.
(e-book)
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"Nurture" for the elderly: the way of nutrition and diet for the elderly
Hu Lingfang [et al] co-
authored Chinese University
Press, 1999
WT115L36 1999
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Lecture Outline
ÿ Aging Process and Physiological Changes
ÿ Nutritional Problems and Needs in the Elderly
ÿ Caloric Restriction and Aging
ÿ Nutritional Support for Age-associated Diseases
(Alzheimer's Disease and Osteoporosis)
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I got wrinkles!
Should I need to inject
Botox?
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Term Commonly Used in the Study of Aging
ÿ Life Expectancy: the average number of years
lived by people in a given society
ÿ Life Span: the maximum number of years of life
attainable by a member of a
species (eg humans: 110-120
years) ÿ Longevity: long duration of life
ÿ Aged Groups:
Young old ( 65-74 years)
Old (75 - 84 years)
Oldest old (ÿ85years)
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Human Life Expectancy
Country Both sexes Males Females
the world 73.2 70.8 75.6
China (64) 77.5 75.4 79.7
HKSAR (1) 85.3 82.4 88.2
Japan (2) 85.0 81.9 88.1
Central African 54.4 52.2 56.6
Republic (193)
https://www.worldometers.info/demographics/life-expectancy/#countries-ranked-by-life-expectancy
Data from Worldometers, USA, accessed on March 17, 2023
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Projected Increase in the World's Aging Population
Dorshkind K et al. (2009) Nature Reviews Immunology 9, p. 57, Fig. 1.
Humans are living longer and longer!
In 2050, ~1/5th of the world's population will be 60 years or older!
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What is Aging?
ÿ A normal (inevitable) process - functional and
structural changes
ÿ A progressive post-maturational deterioration
ÿ Leads to disease and mortality
Aging ÿ Aging Degenerative Aging
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An Overview of the Theories of Aging ÿ Aging
results from the interplay between genetic programming, lifestyle
and nutrition (environmental factors)
Major Theories
of Aging
Limited Cell
Replication Theory
(Genes control replication Immunological
Oxidative Stress Theory potential of cells)
Deterioration Theory
(Free radicals cause
damage to cells (Age-related decline
and molecules) in immune functions)
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Strategies to Achieve Healthy Aging
Healthy Eating and Living Strategies:
restricting calories intake, exercising, quitting smoking and limit
alcohol use, obtaining appropriate health care
Cognitive and Psychological Strategies:
positive attitude, resilience, reducing stress, emotional
adaptation to chronic illnesses, seeking help for mental illnesses
Social Strategies:
seeking and giving social support through volunteering,
working in a group, learning new skills, mentoring younger
individuals
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Declines in Physiological Functions Seen with Aging
Wardlaw GM and Smith AM (2012) Contemporary Nutrition Fig. 18-1, p.655.
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Age-related Physiological Changes
and Their Impact on Nutrition (I)
Physiological Changes Potential Impact on Nutrition
Weight and Body Composition
ÿ body fat, loss of lean body mass ÿ Metabolic rate
(rate at which our body burns calories)
Mobility
Reduced muscle and skeletal strength Poorer nutrient intake
Sensory Functions
Decline in sensitivity of taste, smell, Reduced enjoyment of food and less
hearing and vision desire for eating
Dental and Oral Health
Loss of teeth and ÿ saliva production Eating problems and less choice of food
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Age-related Physiological Changes
and Their Impact on Nutrition (II)
Physiological Changes Potential Impact on Nutrition
Gastrointestinal Functions
Reduced acid and enzymes secretion ÿ Appetite and prolonged satiety
Reduced intestinal motility Poorer nutrient digestion and absorption
Kidney Functions
Reduced function Risk of dehydration
Immunity
Decline in body's immune functions ÿ risk of infection and
ÿ food intake resulting in malnutrition
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Why is Nutrition Important in Old Age?
ÿ Changing in nutrient requirements as we age
ÿ Nutrition interacts with the aging process in
numerous ways
ÿ Risk of nutrition-related health problems
increases in later life
ÿ Good nutrition plays a key role in “healthy” or
“active” aging
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Potential Contributors to
Nutritional Problems in Elderly
Physical Factors:
ÿ Declining absorptive and metabolic capacities
ÿ Poor dental health
ÿ Physical disability
ÿ Chronic diseases and poor appetite
Modified from: Horwath C and van Staveren W (2007)
ESSENTIALS OF HUMAN NUTRITION, Table 34.3, p.510.
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Potential Contributors to
Nutritional Problems in Elderly
Socioeconomic and Psychological Factors:
ÿ Low income
ÿ Social isolation
ÿ Loss of interest in food or cooking
ÿ Limited nutritional knowledge
Modified from: Horwath C and van Staveren W (2007)
ESSENTIALS OF HUMAN NUTRITION, Table 34.3, p.510.
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Nutritional Needs for the Elderly (I)
Nutritional Needs Reasons
More nutrient-dense foods ÿ metabolic rate and ÿ physical activity
which reduces daily calorie needs
more fibers Fiber may help to reduce many age-related diseases
(heart disease, certain cancers, diabetes)
More water but less To avoid dehydration (ÿ ability of kidneys to
sugary drinks concentrate urine and blunted thirst mechanism)
Modified from: Blake JS (2008) Nutrition and You Table 13.4, p.472.
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Nutritional Needs for the Elderly (II)
Nutritional Needs Reasons
More ÿ-carotene-rich foods Act as an antioxidant in the body
(Vit. A precursor)
More Vit. B12-fortified foods Many aging people fail to absorb the natural
natural form of Vit. B12 from meat, fish and
dairy foods (Vit. B12 is essential for cognition,
vascular health and red cell synthesis)
More Vit. D-fortified foods ÿ ability of skin to make Vit. D from sunlight (Vit.
D is need for Ca++ absorption and bone
health)
Modified from: Blake JS (2008) Nutrition and You Table 13.4, p.472.
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Nutritional Needs for the Elderly (III)
Nutritional Needs Reasons
More iron-rich foods High prevalence of anemia in aging people
More zinc-rich foods Suppressed immune system and appetite in
aging people
More calcium-rich foods High risk of osteoporosis (weak bones and
fractures) in aging people
Modified from: Blake JS (2008) Nutrition and You Table 13.4, p.472.
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Nutritional Intervention for
Immune Deficiency in the Elderly
Dietary supplementation with
eg Milk proteins
Probiotics
Micronutrients
(Vitamin E, Zinc, Selenium)
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Nutritional Approaches to Prevention of
Age-associated Diseases
Age-associated disease Nutritional approach
Anemia Iron, folate and Vit. B12 supplementation
Arthritis Omega-3 fatty acids supplementation
Cancer Avoidance of very high fat diet
(Colon, Breast, Prostate) Intake of phytochemicals and fibers
Cardiovascular disease ÿ fish intake (Omega-3 fatty acids)
Supplementation with Vit. B6 , B12 and folate
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Nutritional Approaches to Prevention of
Age-associated Diseases
Age-associated disease Nutritional approach
Hypertension and Stroke ÿ salt (Na+ ) intake
ÿ Ca++, K+ and Mg++ intake
Infection Vitamin and mineral supplementation
Alzheimer's disease Supplementation with antioxidants,
Vit. C and E, carotenoids
Osteoporosis Calcium and Vit. D supplementation
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What is Caloric Restriction ?
ÿ The practice of limiting energy (calories) intake of
one's diet by 25 - 30% (eg 1,800 kcal vs. 2,400 kcal)
aiming to improve health and retard aging
ÿ Also called Energy Restriction or Dietary Restriction
ÿ Energy intake is minimized, but sufficient quantities
of vitamins, minerals and other important nutrients
must be eaten (CR without malnutrition;
"Healthy" Starving)
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Caloric Restriction and Aging ÿ Shown
to increase lifespan in many animal models (worms,
fruit flies, fish, mice and rats)
ÿ Anti-aging effect of CR may be due to retardation of a wide
variety of aged-associated diseases
(eg renal disease, certain types of cancer, autoimmune
disease, diabetes and neurodegeneration etc.)
ÿ CR can retard age-related decline in immune functions ÿ
Studies on non-human primates (monkeys): on-going ÿ
Effects on human longevity – unclear (long-term studies are
required)
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Summary
1. The age-related physiological changes have significant impact on
the nutritional status of the elderly.
2. Micronutrient supplements are not a substitute for a good diet and
regular exercise in the elderly.
3. Low-fat diet, high fruit and vegetable intake, regular exercise and
Supplemental vitamins not only may promote optimal immunity but
can also reduce the risk of age-associated diseases such
as cardiovascular heart disease and some cancers in the elderly.
4. Effects of Caloric Restriction on human longevity remain unclear.
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Nutrition and Age-associated Diseases
Key References
1. Alzheimer's Disease International
https://www.alz.co.uk/
2. International Osteoporosis Foundation
http://www.iofbonehealth.org/living-osteoporosis
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What is Alzheimer's Disease (AD)?
Alzheimer's disease/senile dementia/dementia/dementia/
ÿ Named after the German neurologist
Alois Alzheimer (1864-1915)
ÿ Characteristic fibrillary tangles
neurofibrillary tangles found
in a postmortem brain of a 51-year
old demented woman who died in 1906
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What is Alzheimer's Disease (AD)?
It is a form of progressive
dementia (progressive dementia) in
which nerve cells degenerate in the
brain and the brain substances shrink.
https://www.nia.nih.gov/health/al
zheimers-disease-fact-sheet
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Introduction to Alzheimer's Disease
ÿ It is chronic, progressive, incurable, irreversible, and complex
neurodegenerative disease that attacks the brain and
impairs thinking, behavior, memory, and emotion
ÿ It afflicts ~10% people > 65 years of age and ~33% people
>85 years of age
ÿ In 2022, estimated >55 million people worldwide have AD or
related dementia (Alzheimer's Disease International)
(Hong Kong figure: estimated ~333,000 in 2039)
ÿ The median survival time is 4-6 years after diagnosis, though
some can live up to 20 years
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1 In the world, every 3s
have a newly diagnosed
AD patient
2
1 in every 10 people
aged ÿ65 has AD
3
1 in every 3 people
aged ÿ85 has AD
Alzheimer's disease is almost twice as
Source: WHO
common in women compared to men.
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Causes of AD
No single causative factor, interaction of multiple
risk factors
ÿ Age-related changes in the brain
ÿ Damage by free radicals
ÿ Inflammation
ÿ Genetics
ÿ Environmental/lifestyle factors
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Two Hallmarks in the Pathogenesis of AD
1. Amyloid plaques Amyloid plaques: peptide deposits found in the
brains of AD patients; and
2. Fibrillary tangles neurofibrillary tangles: aggregates of an
abnormal brain protein called tau protein
Alzheimer's disease
https://www.researchgate.net/figure/Major-pathological-hallmarks-of-AD-are
amyloid-plaques-and-neurofibrillary-tangles-B_fig3_337715716
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Symptoms and Characteristics of AD
ÿ Death of brain cells
ÿ Severe cognitive (cognitive function) impairment
ÿ Gradual memory loss ÿ
Loss of communication ability and physical capabilities
ÿ Personality changes
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Nutritional Problems Associated with AD
ÿ Difficultly in shopping and cooking ÿ
Forget to eat or lack the attention needed to eat
ÿ Refuse to eat or open mouth for feeding
ÿ Changes in taste and smell
ÿ Degeneration of appetite regulation
ÿ Unusual food choices
ÿ Have memory problems related to the use of utensils or the act
of swallowing
ÿ Increased energy requirement due to hyperactive
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Nutrition and AD
“Cognitive losses may have profound
effects on nutritional intake in AD patients”
“Nutrition care aims to prevent malnutrition
and restoration of eating ability”
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Potential Nutritional Intervention for AD
1. Fish, n-3 Fatty Acids and DHA:
May protect against dementia due to their anti-inflammatory
properties
May ÿ amyloid plaques production and ÿ their clearance
DHA supplementation or diet intake (1.5 - 2 g/day) for
mild AD patients may reduce rate of progression of AD
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Potential Nutritional Intervention for AD
2. Antioxidants (Vit. E, Vit. C and Selenium)
Likely to be beneficial to AD patients in combinations
Antioxidant vitamins can protect neural cells from
oxidative damage
Animal studies are convincing but role in human AD
remains unclear
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Potential Nutritional Intervention for AD
3. Curcumin An
active ingredient in an Indian spice - turmeric turmeric
Has potent anti-inflammatory and antioxidant activities
Can prevent brain cell death and reduce oxidative damage in
mouse model of AD
Some epidemiological studies ÿ could be beneficial in the
prevention of AD
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How to Keep the Brain Healthy?
ÿ Eating 4-5 pieces of fruits and vegetables daily
ÿ Consume fish 2-3 times weekly
ÿ Keep a healthy body weight and avoid obesity
ÿ Safe doses of Vit. C, Vit. E, curcumin and DHA
may be beneficial for prevention of AD
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Basic Terminologies
Bone Mass bone mass:
The total amount of bone minerals in the body
Peak Bone Mass (PBM) Peak Bone Mass:
The greatest amount of bone minerals that a person has during his/her
life (maximum bone strength)
Bone (mineral) Density (BMD) : Amount of
minerals contained in a given volume of bone.
It reflects the degree of compactness of bone tissue and the strength
of the bones
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Bone Development
ÿ ~5th week of gestation
ÿ soft, non-mineralized tissues
called cartilages (soft bones)
begin to develop
ÿ ~ 7th weeks of gestation ÿ Ossification
ossification (converting cartilage to
bone by mineralization), continues
through childhood and completed
in early adult life
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Bone Formation and Resorption
ÿ Calcium and phosphate ÿ major minerals
responsible for normal bone formation
ÿ Bone tissue is complex and living
(constantly being absorbed and replaced)
Bone growth : formation > resorption
Bone loss : resorption > formation
Osteoclast Osteoclast Osteoblast Osteoblast
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Determinants of Bone Mass
nutrition
BONE MASS Hormones
Lifestyle
Genetics
Peak Bone Mass (at ~25-40 years of age):
People with larger frames ÿ higher PBM
Men have higher PBM than women
African-American have higher PBM than Caucasians Caucasians
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Changes in Bone Mass During the Life Cycle
~25-40 years of age
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What is Osteoporosis ?
ÿ Thinning and weakening of the bones related to the loss of calcium stores
ÿ Failure to maintain enough bone mass in the body
Bone resorption> Bone formation> Bone formation
Normal
Thompson JL et al. (2011) The Science of Nutrition Fig. 11.16, p.433.
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WHO Definition of Osteoporosis
“Osteo” means “bone” and
“porosis” means “porous“
Osteoporosis is a multifactorial
skeletal disease characterized
by low bone mass (ÿ BMD)
and deterioration of bone tissue
leading to enhanced bone
fragility and a consequent increase in fracture
Wardlaw GMrisk
and Smith AM (2011)
Contemporary Nutrition Fig. 9-28, p.395.
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Incidence and Prevalence of Osteoporosis
• A very common disease, second only to cardiovascular
disease as a global healthcare problem
• >200 million people worldwide suffered from OP 1
in 2 women or 1 in 3 men over 60 will suffer a
fracture due to OP
• In Hong Kong:
women >65 ÿ ~45% suffer from OP
men >65 ÿ ~13% suffer from OP
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Characteristic Features of Osteoporosis
ÿ An age- and gender-related metabolic bone disorder
ÿ A serious chronic degenerative disease with
numerous personal, social and economical
implications (hospitalization and loss of
independence)
ÿ A “silent disease” as bone loss occurs
gradually over many years without any symptoms
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Symptoms of Osteoporosis
ÿ Loss of height
ÿ Distorted body shape (development
of a curved upper back)
ÿ Bone fractures
ÿ Loss of teeth
ÿ Loss of independence
Wardlaw GM and Smith AM (2011)
Contemporary Nutrition, p. 394, Fig. 9-27. Thompson JL et al. (2011) The
Science of Nutrition p. 433, Fig. 11.17
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1000-1200 mg/day 5-10 ÿg/day
http://kingsbrook.adam.com/content.aspx?productid=10&pid=10&gid=000018
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Calcium and Management of Osteoporosis
ÿ Prevention and treatment of OP ÿ well balanced diet with calcium intake:
ÿ 1000 mg/day for adults 19-50 years old
and 1200 mg/day for adults >50 years old
ÿ Calcium is best ingested from diet (~10-30% absorption rate)
ÿ Vit. D and magnesium facilitate absorption of calcium to the bone tissue
ÿ OP patients should avoid cola-based soda drinks
ÿ Phosphoric acid may interfere with calcium absorption
ÿ Calcium in conjunction with Vit. D ÿ strengthen bones, ÿ
bone mass and ÿ fracture rates
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Dietary Substances that can
Affect Calcium Retention
ÿ Caffeine and sodium
ÿ ÿ urinary calcium excretion
ÿ Potassium ÿ ÿ urinary calcium excretion
ÿ Oxalates and Phytates
ÿ bind calcium and ÿ its absorption
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Calcium Supplementation ÿ Used
if requirements cannot be met by diet ÿ Best
to be taken with meals and spread throughout the day ÿ Two
major forms: 1.
Calcium citrate:
more expensive
better absorbed
can be taken without food
2. Calcium carbonate:
less expensive
needs to be taken with food for better absorption
constipation is common
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Vitamin D and Management of Osteoporosis
ÿ Essential for efficient utilization of dietary calcium
ÿ Vit. D status depends on dietary intake and/or exposure
to sunlight
ÿ Elderly ÿ low levels of circulating Vit. D
ÿ Prevention and treatment of OP
ÿ Vit. D intake of 5 ÿg/day for adults 19- 50 years old
and 10 ÿg/day for adults >50 years old
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Prevention of Osteoporosis
ÿ Diet with adequate calcium and Vit. D
ÿ Regular weight-balancing exercises (walking, jogging or
dancing etc.)
ÿ Exercise to prevent falls
ÿ Maintain an optimal body weight
ÿ Do not smoke
ÿ Drink moderate amount of alcohol
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How to Keep the Bone Healthy?
Strong bones depend on several important nutrients:
Calcium - responsible for normal bone formation
low-fat dairy products are an excellent source
Vitamin D - essential for calcium absorption and incorporation
it into the skeleton
- exposure to sunlight or from diet (oily fish and
dairy products)
Magnesium - essential for Vit. D metabolism and help slow bone
breakdown (green vegetables, low-fat dairy products)
Potassium - can reduce the rate of calcium loss from the body
(banana, melon, fish)
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Nutrition and Aging
A healthy diet and lifestyle results in good
immune status and enables the elderly to live
healthily, happily, more actively, and more
independently and these are the “Secrets of Lon
