Asia
Pacific Journal of Clinical Nutrition
Volume 11, supplement
6, 2002
Nutrition for Life's Stages: The Evidence
Base
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Contents
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Abstract
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Paper
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 Nutrition:
the new world map
GEOFFREY CANNON
Asia
Pac J Clin Nutr. 2002;11(S6):S480-497.
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Nutrition:
the new world disorder
GEOFFREY CANNON
Asia
Pac J Clin Nutr. 2002;11(S6):S498-509.
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Discrepancies
in nutritional recommendations: the need for evidence based nutrition
JIM MANN
Asia
Pac J Clin Nutr. 2002;11(S6):S510-515.
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Will
feeding mothers prevent the Asian metabolic syndrome epidemic?
W PHILIP JAMES
Asia
Pac J Clin Nutr. 2002;11(S6):S516-523.
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Child and adolescent obesity in the 21st century: an Australian
perspective
LOUISE A BAUR
Asia
Pac J Clin Nutr. 2002;11(S6):S524-528.
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Nutrition
and the early origins of adult disease
JOHN P NEWNHAM, TIMOTHY JM MOSS, ILIAS NITSOS, DEBORAH M SLOBODA,
JOHN RG CHALLIS
Asia
Pac J Clin Nutr. 2002;11(S6):S537-542.
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Risk
of suboptimal iron and zinc nutriture among adolescent girls in
Australia and New Zealand: causes, consequences, and solutions
R S GIBSON, A-L M HEATH, E L FERGUSON
Asia
Pac J Clin Nutr. 2002;11(S6):S543-552.
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Family
food environments of 5-6year-old-children: Does socioeconomic
status make a difference?
KAREN CAMPBELL, DAVID CRAWFORD, MICHELLE JACKSON, KAREN CASHEL,
ANTHONY WORSLEY, KAY GIBBONS, LEANN L BIRCH
Asia
Pac J Clin Nutr. 2002;11(S6):S553-561.
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Asian migration to Australia: food and health consequences
MARK L WAHLQVIST
Asia
Pac J Clin Nutr. 2002;11(S6):S562-568.
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Morbidity mortality paradox of 1st generation Greek
Australians
ANTIGONE KOURIS-BLAZOS
Asia Pac J Clin Nutr. 2002;11(S6):S569-575.
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Acculturation: Aboriginal and Torres Strait Islander
nutrition
CINDY SHANNON
Asia
Pac J Clin Nutr. 2002;11(S6):S576-578.
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Nutrition
knowledge and food consumption: can nutrition knowledge change
food behaviour?
ANTHONY WORSLEY
Asia
Pac J Clin Nutr. 2002;11(S6):S579-585.
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An innovative program for changing health behaviours
V BURKE, TREVOR A MORI, N GIANGIULIO, HELEN F GILLAM, LAWRIE J
BEILIN, S HOUGHTON, HAYLEY E CUTT, JACQUELINE MANSOUR, AMY WILSON
Asia
Pac J Clin Nutr. 2002;11(S6):S586-597.
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Sustaining dietary changes for preventing obesity
and diabetes: lessons learned from the successes of other epidemic
control programs
BOYD SWINBURN
Asia
Pac J Clin Nutr. 2002;11(S6):S598-606.
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Eating well: ageing gracefully!
KAREN E CHARLTON
Asia
Pac J Clin Nutr. 2002;11(S6):S607-617.
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Preventing cancer: dietary lifestyle or clinical
intervention?
GRAEME P YOUNG, RICHARD K LE LEU
Asia
Pac J Clin Nutr. 2002;11(S6):S618-631.
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Importance of preventing weight gain in adulthood
TIM GILL
Asia
Pac J Clin Nutr. 2002;11(S6):S632-636.
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Can food variety add years to your life?
GAYLE S SAVIGE
Asia
Pac J Clin Nutr. 2002;11(S6):S637-641.
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Benefits of exercise and dietary measures to optimize shifts in
body composition with age
MARIA A FIATARONE SINGH
Asia
Pac J Clin Nutr. 2002;11(S6):S642-652.
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Ethical consequences for professionals from the globalization
of food, nutrition and health
NOEL SOLOMONS
Asia
Pac J Clin Nutr. 2002;11(S6):S653-665.
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Focusing
on novel foods: Their role, potential and safety
GEOFFREY CANNON
The map of nutrition, evident in the structure of any course or textbook,
derives from theses that framed a science begun in the 1840s, developed
until the 1940s, and consolidated until now. Nutritionists now are
as perplexed as the explorers of half a millennium ago, who continued
to use maps that did not fit the wider world they found. Until the
1600s, alternatives to Ptolemaic cosmology remained unthinkable despite
its obvious inadequacy, because it was of a universe with the earth,
and man made in the divine image, at its centre. Nutritionists now
are inhibited for similar reasons. Two determining principles of nutrition
science, the identification of health with growth and the belief that
animal food is superior to plant food, have a deep origin; they derive
from the materialist ideology that asserts a manifest destiny of humans
to exploit and consume the living and natural world. In response,
a new nutrition is emerging, with a global perspective, whose ideology
places humans within nature, and whose theses make a wider frame,
able to fit the world as we can discern it now. The new nutrition
gives equal value to personal, population and planetary health, with
all that implies, including the concept that the world is best perceived
as a whole. The Copernican revolution changed the meaning of movement
on earth. The new nutrition can change the meaning of life on earth.
Now is the time to draw its map.
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Nutrition:
the new world disorder
GEOFFREY CANNON
Scale up 'we are what we eat' and nutrition is revealed as an aspect
of world governance. The quality and nature of food systems has always
tended to determine not only the health and welfare but also the fate
of nations. The independence of nations depends on their development
of their own human and natural resources, including food systems,
which, if resilient, are indigenous, traditional, or evolved over
time to climate, terrain and culture. Rapid adoption of untested or
foreign food systems is hazardous not only to health, but also to
security and sovereignty. Immediate gain may cause permanent loss.
Dietary guidelines that recommend strange foods are liable to disrupt
previous established food cultures. Since the 1960s the 'green revolution'
has increased crop yield, and has also accelerated the exodus of hundreds
of millions of farmers and their families from the land into lives
of misery in mega-cities. This is a root cause of increased global
inequity, instability and violence. 'Free trade' of food, in which
value is determined by price, is imposed by dominant governments in
alliance with industry when they believe they can thereby control
the markets. The World Trade Organization and other agencies coordinate
the work of transnational corporations that are the modern equivalents
of the East India companies. Scientists should consider the wider
dimensions of their work, nutrition scientists not least, because
of the key place of food systems in all societies.
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Discrepancies
in nutritional recommendations: the need for evidence based nutrition
JIM MANN
The
widespread acceptance that 'evidence-based medicine' should determine
all aspects of clinical practice leads to a consideration as to whether
'evidence-based nutrition' should be based on similar principles.
Randomised controlled trials (RCT) are universally regarded as the
gold standard by which to determine whether a drug is appropriate
in a particular clinical situation. The evidence for some nutritional
recommendations is indeed substantiated by RCT but in the case of
some chronic diseases, notably cancers, where nutritional factors
may operate as promoters or protectors many years before the onset
of clinical disease, RCT may not be particularly appropriate. A range
of experimental studies and descriptive epidemiological approaches
may be regarded as sufficient to justify nutritional recommendations
or dietary guidelines. Recommendations for the prevention and treatment
of selected diseases will be considered in the context of their evidence-base.
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Will
feeding mothers prevent the Asian metabolic syndrome epidemic?
W Philip T James
Evolutionary pressures
have probably amplified the mechanisms for minimizing the impact of
environmental factors through compensatory maternal mechanisms. Nevertheless,
experimentally there are clear long-term programming effects of manipulations
to the maternal diet on the likelihood of neural-tube defects associated
with folate deficiency The fat/lean ratios of the newborn, and subsequent
development, seem to be linked to amino acid or folate supply. An
altered balance in the hypothalamicpituitaryadrenal axis, which experimentally
has profound effects on brain development, is induced by low-protein
maternal diets. Such diets are linked to a reduced pancreatic capacity
for insulin production and to an altered hepatic architecture, with
a change in the control of glucose metabolism. Human studies suggest
that what happens in pregnancy is modified by the child's diet in
the first months of life. Low birthweight is linked to early stunting,
and predisposes to abdominal obesity and metabolic syndrome in later
life. Metabolic syndrome amplifies the risks of diabetes, hypertension,
coronary heart disease and probably some cancers. Mothers with gestational
diabetes are themselves prone to early type 2 diabetes and produce
heavier babies prone to childhood obesity and adolescent type 2 diabetes.
There is increasing evidence of an intergenerational effect, with
big babies being prone to excess weight gain, which then, in girls,
predisposes them to diabetes in pregnancy, which, in turn, promotes
an accelerating cycle of early diabetes in subsequent generations.
Essential fatty acids and fat soluble vitamins are important, but
we need early interventions and monitoring systems to justify coherent
policies.
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Child
and adolescent obesity in the 21st century: an Australian perspective
LOUISE A BAUR
The early 21st century has seen the development of a global epidemic
of obesity in both developed and developing countries. In Australia
at least one in five children and adolescents are overweight or obese,
with rapid rises in prevalence apparently continuing. Similar trends
are seen in other countries. Child and adolescent obesity is associated
with both immediate and long-term medical and psychosocial problems,
including a clustering of risk factors for the development of cardiovascular
disease and diabetes. Thus, obesity poses a major health problem for
the paediatric population. Major environmental and societal changes
have led to a decrease in physical activity, a rise in sedentary behaviour
and the consumption of high fat and high-energy foods, all in turn
influencing the development of obesity. Effective management involves
a multimodal approach with a developmentally aware approach, involvement
of the family, a focus on healthy food choices, incorporation of physical
activity and a decrease in sedentary behaviour all being important.
Ultimately, however, the obesity epidemic requires a major focus on
primary prevention. Australia has a national strategy for the prevention
of overweight and obesity that depends upon intersectoral and intergovernmental
cooperation, supported by adequate resourcing and significant community
ownership.
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Nutrition
and the early origins of adult disease
JOHN P NEWNHAM, TIMOTHY JM MOSS, ILIAS NITSOS, DEBORAH M SLOBODA,
JOHN RG CHALLIS
There
is now overwhelming evidence that much of our predisposition to adult
illness is determined by the time of birth. These diseases appear
to result from interactions between our genes, our intrauterine environment
and our postnatal lifestyle. Those at greatest risk are individuals
in communities making a rapid transition from lives of 'thrift' to
a lives of 'plenty'. From a global perspective, such origins of diabetes,
coronary heart disease and stroke, should render research in these
fields as one of the highest priorities in human health care. Prevention
will be enhanced by elucidation of the mechanisms by which the fetus
is programmed by the mother for the life she expects it to live. At
the present time, there is evidence that fetal nutrition and premature
exposure to cortisol are effective intrauterine triggers, but a multitude
of alternative pathways require investigation. It is also likely that
programming extends across generations, and may involve the embryo
and perhaps the oocyte. An oocyte that becomes an adult human develops
in the uterus of its grandmother, so further research is required
to describe the role of environments of grandmothers and mothers in
predisposing offspring to health or illness in adult life.
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Risk
of suboptimal iron and zinc nutriture among adolescent girls in Australia
and New Zealand: causes, consequences, and solutions
R S GIBSON, A-L M HEATH, E L FERGUSON
Surveys in Australia, New Zealand and other industrialised countries
report that many adolescent girls have dietary intakes of iron and
zinc that fail to meet their high physiological requirements for growing
body tissues, expanding red cell mass, and onset of menarche. Such
dietary inadequacies can be attributed to poor food selection patterns,
and low energy intakes. Additional exacerbating non-dietary factors
may include high menstrual losses, strenuous exercise, pregnancy,
low socioeconomic status and ethnicity. These findings are cause for
concern because iron and zinc play essential roles in numerous metabolic
functions and are required for optimal growth, immune and cognitive
function, work capacity, sexual maturation, and bone mineralization.
Moreover, if adolescents enter pregnancy with a compromised iron and
zinc status, and continue to receive intakes of iron and zinc that
do not meet their increased needs, their poor iron and zinc status
could adversely affect the pregnancy outcome. Clearly, intervention
strategies may be needed to improve the iron and zinc status of high
risk adolescent subgroups in Australia and New Zealand. The recommended
treatment for iron deficiency anaemia and moderate zinc deficiency
is supplementation. Although dietary intervention is often recommended
for treating non-anaemic iron deficiency and mild zinc deficiency,
it is probably more effective and appropriate for prevention than
for the treatment of suboptimal iron and zinc status. Many of the
strategies for enhancing the content and bioavailability of dietary
iron are also appropriate for zinc.
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Family
food environments of 56-year-old-children: Does socioeconomic status
make a difference?
KAREN CAMPBELL, DAVID CRAWFORD, MICHELLE JACKSON, KAREN CASHEL, ANTHONY
WORSLEY, KAY GIBBONS, LEANN L BIRCH
see pdf paper
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Asian
migration to Australia: food and health consequences
MARK L WAHLQVIST
Australia's
food and health patterns are inextricably and increasingly linked
with Asia. Indigenous Australians arrived in the continent via Asia
and have linguistic connections with people who settled in south India;
there was interaction and food trade between both South-East Asia
and China and northern indigenous Australians over thousands of years.
After European settlement in 1788, there have been several and increasing
(apart from the period of the infamous White Australian Policy following
the Colonial period and Independence, with Federation, in 1901) waves
of Asian migration, notably during the gold rush (Chinese), the building
of the overland Telegraph (Afghans), the Colombo Plan and Asian student
education in Australia from the 1950s onwards (South-Eeast Asians),
and with refugees (Vietnamese and mainland Chinese), and business
(late twentieth century) and progressive family reunion. Each wave
has injected additional food cultural elements and caused a measure
of health change for migrants and host citizens. Of principal advantage
to Australia has been the progressive diversification of the food
supply and associated health protection. This has increased food security
and sustainability. The process of Australian eating patterns becoming
Asianized is evident through market garden development (and the introduction
of new foods), fresh food markets and groceries, restaurants and the
development of household cooking skills (often taught by student boarders).
Most of the diversification has been with grain (rice), legumes (soy),
greens, root vegetables, and various 'exotic fruits'. Food acculturation
with migration is generally bi-directional. Thus, for Asians in Australia,
there has been a decrease in energy expenditure (and a lower plane
of energy throughput), an increase in food energy density (through
increased fat and sugary drink intakes), and a decrease in certain
health protective foods (lentils, soy, greens) and beverages (tea).
This sets the stage for 'eco-diseases'. In a population probably genetically
programmed (but modifiably) in utero to abdominal obesity, diabetes
(type II and gestational) and cardiovascular disease, these conditions
may be rapidly acquired on migration, along with certain cancers (breast,
colo-rectal and prostate). Thus, whilst Asian migration to Australia
has provided health opportunities for host citizens, there have been
threats to migrant citizens in regard to nutrition-related health.
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Morbidity
mortality paradox of 1st generation Greek Australians
ANTIGONE KOURIS-BLAZOS
There is evidence
in Australia that 1st generation Greek Australians (GA), despite their
high prevalence of cardiovascular disease (CVD) risk factors (e.g.
obesity, diabetes, hyperlipidaemia, smoking, hypertension, sedentary
lifestyles) continue to display more than 35% lower mortality from
CVD and overall mortality compared with the Australian-born after
at least 30 years in Australia. This has been called a 'morbidity
mortality paradox' or 'Greek-migrant paradox'. Retrospective data
from elderly Greek migrants participating in the International Union
of Nutrition Sciences Food Habits in Later Life (FHILL) study suggests
that diets changed on migration due to the: (i) lack of familiar foods
in the new environment; (ii) abundant and cheap animal foods (iii)
memories of hunger before migration; and (iv) status ascribed to energy
dense foods (animal foods, white bread and sweets) and 'plumpness'
as a sign of affluence and plant foods (legumes, vegetable dishes,
grainy bread) and 'thinness' as a sign of poverty. This apparently
resulted in traditional foods (e.g. olive oil) being replaced with
'new' foods (e.g. butter), 'traditional' plant dishes being made more
energy dense, larger serves of animal foods, sweets and fats being
consumed, and increased frequency of celebratory feasts. This shift
in food pattern contributed to significant weight gain in GA. Despite
these potentially adverse changes, data from Greece in the 1960s (seven
countries study) and from Australia in the 1990s (FHILL study) has
shown that Greek migrants have continued to eat large serves of putatively
protective foods (leafy vegetables, onions, garlic, tomatoes, capsicum,
lemon juice, herbs, legumes, fish) prepared according to Greek cuisine
(e.g. vegetables stewed in oil). Furthermore, GA were found to return
to the traditional Greek food pattern with advancing years. We suspect
that these factors may explain why GA have recently been found to
have over double the circulating concentrations of antioxidant carotenoids,
especially lutein, compared with Australians of Anglo-Celtic ancestry.
This in turn may have helped to make the CVD risk factors 'benign'
and reduce the risk of death. This raises the question whether specific
dietary guidelines need to be developed for recent migrants to Australia,
encouraging them to retain the best of their traditional cultures
and include the best of the mainstream culture.
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Acculturation: Aboriginal and Torres Strait Islander
nutrition
CINDY SHANNON
The
health status of Australia's indigenous people remains the worst of
any subgroup within the population, and there is little evidence of
any significant improvement over the past two decades, a situation
unprecedented on a world scale. Compared with non-indigenous Australians,
adult life expectancy is reduced by 1520 years, with twice the rates
of mortality from heart disease, 17 times the
death rate from diabetes and 10 times the deaths from pneumonia. Despite
improvements in perinatal mortality, they continue to represent a
major cause of death, with infant deaths up to 2.5 times higher than
the general population. The problems of educational disadvantage and
unemployment are reflected in twice the rates of smoking and high
obesity levels. Seven percent of indigenous families are homeless,
with many more in inadequate and overcrowded housing, sometimes lacking
water or sewerage. Economic disadvantage is real: 23% worry about
going without food. Nutritional deficiencies in children have resulted
in failure to thrive, contributing greatly to the problems of pneumonia
and infectious diseases. The remoteness and isolation of many Aboriginal
communities limit education and employment opportunities. It is important
to consider the historical context of Aboriginal and Torres Strait
Islander people, in order to gain an understanding of current health
problems. The impact of past policies and practices and the 'introduced
diet' are reflected in the poor health outcomes described above. This
session will explore some of the underlying historical, cultural,
structural and political factors that can be linked to the current
problems.
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Nutrition
knowledge and food consumption: can nutrition knowledge change food
behaviour?
ANTHONY WORSLEY
The status and explanatory role of nutrition knowledge is uncertain
in public health nutrition. Much of the uncertainty about this area
has been generated by conceptual confusion about the nature of knowledge
and behaviours, and, nutrition knowledge and food behaviours in particular.
So the paper describes several key concepts in some detail. The main
argument is that 'nutrition knowledge' is a necessary but not sufficient
factor for changes in consumers' food behaviours. Several classes
of food behaviours and their causation are discussed. They are influenced
by a number of environmental and intra-individual factors, including
motivations. The interplay between motivational factors and information
processing is important for nutrition promoters as is the distinction
between declarative and procedural knowledge. Consideration of the
domains of nutrition knowledge shows that their utility is likely
to be related to consumers' and nutritionists' particular goals and
viewpoints. A brief survey of the recent literature shows that the
evidence for the influence of nutrition knowledge on food behaviours
is mixed. Nevertheless, recent work suggests that nutrition knowledge
may play a small but pivotal role in the adoption of healthier food
habits. The implications of this overview for public health nutrition
are: (i) We need to pay greater attention to the development of children's
and adults' knowledge frameworks (schema building); (ii) There is
a need for a renewed proactive role for the education sector; (iii)
We need to take account of consumers' personal food goals and their
acquisition of procedural knowledge which will enable them to attain
their goals; (iv) Finally, much more research into the ways people
learn and use food-related knowledge is required in the form of experimental
interventions and longitudinal studies.
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An
innovative program for changing health behaviours
V BURKE, TREVOR A MORI, N GIANGIULIO, HELEN F GILLAM, LAWRIE J BEILIN,
S HOUGHTON, HAYLEY E CUTT, JACQUELINE MANSOUR, AMY WILSON
Health-related behaviours affecting diet, weight control and physical
activity are important for long-term cardiovascular health but behaviour
change is difficult to initiate and even more difficult to maintain.
We have developed a health promotion program, in which social support
has a key role, to encourage a prudent diet, weight control and physical
activity. Behaviour change is based on evaluating initial behaviour,
weighing up costs and benefits, assessing barriers to change and goal-setting.
We first evaluated the program in couples beginning to live together,
a group chosen because of the risk of weight gain and decreased physical
activity after marriage, readiness to change behaviour at that time
in the life course and the opportunity to use partner's support in
achieving behaviour change. In an initial short-term study with 39
couples, intake of fat and take-away foods decreased and consumption
of fruit, vegetables and reduced fat foods increased. Physical activity
increased and there was a 6% fall in blood cholesterol. Further evaluation
in 137 couples included assessment after 12 months. A decrease in
fat intake and increase in physical activity and fitness seen at the
end of the program persisted 1 year later. Lower cholesterol and a
trend to lower weight gain and lower blood pressure were also maintained
after 12 months. We have modified the program aiming for weight loss,
improved dietary habits and increased physical activity in overweight
treated hypertensives, supported by their partners. Decreased intake
of energy, total and saturated fat, and weight loss seen at the end
of the 16 week program was significantly greater in the intervention
group than with usual care. Blood pressure fell in the program group
at the end of intervention and, in men, withdrawal of antihypertensive
drugs was significantly associated with the intervention. Weight loss
and a decrease in waist circumference were maintained in the program
group up to 16 months after entering the study. This program has the
potential for wider application in other at-risk groups.
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Sustaining
dietary changes for preventing obesity and diabetes: lessons learned
from the successes of other epidemic control programs
BOYD SWINBURN
A degree of success has been achieved in controlling several epidemics
of infectious and non-infectious causes of death in countries, such
as, Australia and New Zealand. Using the epidemiological triad (host,
vector, environment) as a model, the key components of the control
of these epidemics have been identified and compared to the current
status of interventions to prevent obesity and its main disease consequence,
type 2 diabetes. Reductions in mortality from tobacco, cardiovascular
diseases, road crashes, cervical cancer and sudden infant death syndrome
have been achieved by addressing all corners of the triad. Similarly,
prevention programs have minimized the mortality from HIV AIDS and
melanoma mortality rates are no longer rising. The main lessons learned
from these prevention programs that could be applied to the obesity/diabetes
epidemic are: taking a more comprehensive approach by increasing the
environmental (mainly policy-based) initiatives; increasing the 'dose'
of interventions through greater investment in programs; exploring
opportunities to further influence the energy density of manufactured
foods (one of the main vectors for increased energy intake); developing
and communicating specific, action messages; and developing a stronger
advocacy voice so that there is greater professional, public and political
support for action. Successes in the other epidemics have been achieved
in the face of substantial barriers within individuals, society, the
private sector and government. The barriers for preventing obesity/diabetes
are no less formidable, but the strategies for surmounting them have
been well tested in other epidemics.
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Eating
well: ageing gracefully!
KAREN E CHARLTON
The
potential impact of dietary manipulation on the maintenance of physical
and cognitive function between middle and old age has profound consequences
for optimization of health, independence and well-being for the latter
years. This review article considers four key areas: the role of diet
and longevity; potential dietary measures to prevent sarcopenia; diet
and cognitive function; and dietary interventions with regard to primary
or secondary prevention of age-related chronic disorders. Caloric
restriction has been shown to slow ageing and maintain health status
in both primates and rats. The evidence has limited applicability
to humans, since it is unlikely that 30% reduced diets could be maintained
long-term. The causes of sarcopenia, which manifests as loss of strength,
disability and reduced quality of life, are multifactorial. However,
resistance with ageing to regulatory amino acids known to modulate
translation and initiation, particularly leucine, raise possibilities
with regard to dietary intervention. The pattern of protein intake
appears to be important in whole-body protein retention in older adults.
A body of evidence is emerging that associates various dietary factors
with a reduction in cognitive decline with age, or a delay in the
progression of Alzheimer's disease, particularly with regard to intake
of vitamin E and C-containing foods, as well as fish intake. Epidemiological
evidence demonstrates a role for dietary intervention in the primary
prevention of chronic diseases, even in old age. However, the potentially
harmful effects of micronutrient supplementation in the secondary
prevention of coronary heart disease raise concern regarding appropriate
dietary messages for the elderly. The role of the antioxidants, lycopene,
lutein and zeaxanthin, in the prevention of cataracts and age-related
macular degeneration support the almost universal dietary guideline
'eat more fruit and vegetables'. In future dietary guidelines for
the elderly need to be evidence-based and take into account protective
food patterns, rather than target specific foods.
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Preventing cancer: dietary lifestyle or clinical
intervention?
GRAEME P YOUNG, RICHARD K LE LEU
In Australia, colorectal, prostate and breast cancers are the most
frequently occurring cancers in our society, a pattern that is quite
different from that of underdeveloped countries. While diet is largely
responsible for these differences, technological advances mean that
the solutions can be viewed as systematic, financial, lifestyle or
technological. They range from those that require self-discipline
and care for personal well-being through to those that are seemingly
a quick technological fix that will work in spite of an unhealthy
lifestyle. There are three main approaches available for prevention
of these cancers: dietary lifestyle, chemoprevention and screening.
It has been estimated that the potential for prevention by a healthy
dietary lifestyle is excellent and might reduce the burden of breast,
prostate and colorectal cancer by 3355%, 1020% and 6675%, respectively.
This should be safe and inexpensive and have collateral benefit such
as reduced cardiovascular disease and osteoporosis. But, population
compliance with more plant-based, less calorie dense foods is uncertain,
the most healthy are likely to be the most compliant and evidence
for effectiveness when interventional programs are undertaken is disappointing.
It is not clear how dependable the dietary approach would be where
inherited genetic factors determine risk for one of these cancers.
Chemoprevention, the administration of natural or synthetic agents
that delay, slow down or inhibit the process of tumorigenesis, are
still under development and study. Hormone receptor modulators for
breast and derivatives of non-steroidal anti-inflammatory drugs for
colorectal cancers seem to have most promise and may reduce tumour
incidence or death by as much as 50%. These agents are simpler to
comply with than changing dietary lifestyle and they are more potent,
hence they may be of particular value in high-risk settings. But they
are likely to be more costly and run the risk of adverse effects with
few collateral benefits. Screening, or the testing of an individual
for a disease when that individual does not have any symptoms or signs
suggesting that the disease is present, aims to prevent or delay the
development of the cancer. Screening impacts on mortality more so
than on incidence, reducing colorectal cancer mortality in the range
15-60% and breast cancer mortality by 23-37%. Screening has the advantage
of being effective in high-risk as well as average-risk groups and
is an 'easy' solution for the person who elects not to follow a healthy
dietary lifestyle. Nonetheless, it is expensive, demanding on resources,
provides no collateral benefits and does not have the same potential
to reduce incidence of disease as does the dietary approach. With
these Western cancers, we are fortunate that there are options for
prevention. At least choices are available and some will suite certain
circumstances and personalities more than others.
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Importance
of preventing weight gain in adulthood
TIM GILL
In
the last 20 years, there has been a dramatic upsurge in the average
weight of Australian adults. In this period, on average, Australian
women have gained 4.8 kg, whilst Australian men have gained 3.6 kg.
Consequently, the prevalence of obesity in men has increased from
8% to 19% and in women from 7% to 21%. This threatens to wipe away
many recent health gains, as obesity has been associated with a wide
range of chronic and debilitating illnesses, such as diabetes, heart
disease, some cancers, sleep apnoea and osteoarthritis. Any weight
gain in adulthood is usually as a result of an increase in fat stores,
and the risk of ill-health from increasing weight actually begins
at quite low BMI. Unfortunately, weight gain can be difficult or slow
to reverse in the middle years because of physiological and behavioural
changes that occur at this time of life. Adults should focus on preventing
or minimizing weight gain over time by retaining physical activity
within their daily living and by sensible dietary changes. Even if
weight gain does occur with age, a regimen of regular exercise and
a diet rich in fruit and vegetables and low in fat will provide some
protection against a rapid decline in health.
.
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Can
food variety add years to your life?
GAYLE S SAVIGE
The traditional food habits of Greeks and Japanese differ widely,
yet both populations have the longest life expectancies in the world.
Food variety is one feature common to both food cultures. By eating
a wide variety of foods, numerous chemicals that give rise to the
diverse range of colours, tastes, textures and smells of different
foods are consumed. Many of these naturally occurring chemicals are
likely to play a role in health. Within the broad scope of foods available,
foods for thought include fish, legumes and nuts. These foods are
also likely to protect older adults against some of the diseases more
prevalent with ageing such as coronary heart disease and cancer.
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Benefits of exercise and dietary measures to optimize
shifts in body composition with age
MARIA A FIATARONE SINGH
Ageing is associated with changes in body composition, including an
increase and redistribution of adipose tissue and a decrease in muscle
and bone mass, beginning as early as the fourth decade of life. These
changes have significant implications for the health and functioning
of the individual because of their associations with chronic disease
expression and severity, as well as geriatric syndromes such as mobility
impairment, falls, frailty and functional decline. Therefore, understanding
the preventive and therapeutic options for optimizing body composition
in old age is central to the care of patients in mid-life and beyond.
Pharmacological interventions are currently available for maintaining
or improving bone mass, and much current interest is focused on anabolic
agents that will preserve or restore muscle mass, as well as those
that can potentially limit adipose tissue deposition. However, in
this brief review, non-pharmacological modulation of body composition
through appropriate dietary intake and physical activity patterns,
will be discussed. There is sufficient evidence currently to suggest
that a substantial portion of what have been considered 'age-related'
changes in muscle, fat and bone are in fact related either to excess
energy consumption, decreased energy expenditure in physical activity,
or both factors in combination. In addition, selective underconsumption
of certain macro- or micronutrients contributes to losses of muscle
and bone mass. Each of the three compartments will be considered in
turn, with recommendations for optimizing the size of these body tissue
stores in early adulthood, and minimizing undesirable changes typically
seen in middle and old age.
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Ethical
consequences for professionals from the globalization of food, nutrition
and health
NOEL SOLOMONS
Globalization is the process of increasing interconnections and linkages,
within societies and across geography, due to improved communication
and expanded world trade. It limits the differentiation wrought by
human cultural evolution, and homogenizes health practices, diet and
lifestyle. There are both beneficial and adverse consequences of the
globalization process. Globalization also presents a challenge to
the development of ethics for practice and advocacy by food and nutrition
professionals. Among the related terms, 'morals', 'values' and 'ethics',
the latter connotes the basic rules of conduct for interactions within
society and with the inanimate environment; rules based on recognized
principles (ethical principles). The application of these principles
is to resolve ethical dilemmas that arise when more than one interest
is at play. Recognized ethical principles include autonomy, beneficence,
non-maleficence, justice, utility and stewardship. These can be framed
in the context of issues that arise during advocacy for material and
behavioural changes to improve the nutritional health of populations.
Clearly, at the global level, codes of good conduct and the construction
of good food governance can be useful in institutionalizing ethical
principles in matters of human diets and eating practices. Ethical
dilemmas arise in the context of innate diversity among populations
(some individuals benefit, whereas others suffer from the same exposures),
and due to the polarity of human physiology and metabolism (practices
that prevent some diseases will provoke other maladies). Moreover,
the autonomy of one individual to exercise independent will in addressing
personal health or treatment of the environment may compromise the
health of the individual's neighbours. The challenges for the professional
in pursuit of ethical advocacy in a globalized era are to learn the
fundamentals of ethical principles; to bear in mind a respect for
difference and differentiation that continues to exist, and which
should exist, among individuals and societies; and to avoid a total
homogenization of agriculture and food supplies.
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Last
Updated: September 2004
HEC
PRESS Publisher
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