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AGING:
You’ve
seen people who age gracefully. Though their hair may be graying,
their eyes are bright, their smiles are quick and their bodies
move with agility and freedom.
Most
people are not concerned about a healthy heart until they get
older. But according to the National Centers for Disease Control
and Prevention, heart disease is a leading cause of death amongst
people 35 - 54. Now is the time to consider what you can do to
ensure a healthy heart.
Studies
show that aging reduces absorption of critical nutrients. Bones
thin and joints creak, memory dims and fatigue becomes all too
common. Our products can’t make you younger, but it can help you
start feeling your best and enjoying life to the fullest.
The Therapeutic Research Group can help you feel energetic and
vibrant. We’ve combined natural herbs with state-of-the-art
formulas that can help improve bone and joint health, increase
energy, promote mobility, restore alertness, maintain a stronger
heart and support longevity.
Antioxidants
What
are antioxidants?
Antioxidants
include the vitamins A, C and E, and yellow-coloured carotenoids,
such as beta-carotene. Antioxidants help to counter the
detrimental effects of oxygen free radicals which form naturally
during normal metabolism, and by external factors such as x-rays,
ultra-violet radiation and pollution. Oxygen free radicals have
been implicated in the development of several diseases including
cancer and heart disease, highlighting the need to consider
antioxidant levels as part of preventative medicine.
Where will I find antioxidants?
There
are a number of naturally occurring substances in food, such as
vitamins and phenolic compounds which are large molecules
comprised of a number of ring structures which have antioxidant
properties. It is also possible to purchase antioxidant vitamin
supplement tablets (containing vitamins E & C, and
beta-carotene).
What are the benefits of antioxidants?
Recent
research has estimated that the risk of cancer and heart disease
is considerably lower in people who consume 5-7 serves of
antioxidant-rich fruit and vegetables. Other studies have shown
that after three months the level of protection against heart
disease provided by a vitamin supplement was 27% better than
normal; after six months the level of protection had risen to 35%
better than normal.
It has been proposed that extra health benefits may derive from
above-average intake of these compounds. This is supported by the
extensive medical studies which indicate that diets high in
antioxidant rich foods, such as fruit and vegetables, offer
significant protection against general degenerative diseases.
More research is needed however, to substantiate this further, and
to also consider the importance of non-nutrient antioxidants in
the diet, as well as other protective plant substances in foods
which may not be antioxidants. At present it appears that the wide
mix of antioxidants obtained from plant foods work more
effectively in the body that single supplements with pure
antioxidants in tablet form although these may be of value in some
circumstances.
What more do we need to know?
More
information is needed concerning the relative antioxidant
potencies of non-nutrient antioxidants and conventional
antioxidants in food. We also need to know more about the
distribution and function of antioxidants in cells in the body,
and the potential to influence this distribution by dietary means.
Current research is evaluating the importance of lesser known
antioxidants in plant foods as anti-cancer agents. Levels of
intake of the known nutrient antioxidants needed to protect cells
against naturally occurring and induced damage to genes (elements
in the structure of our hereditary material), and the associated
risks of cancer, also need to be established.
Antioxidants
and Coronary Heart Disease
Coronary heart
disease (or ischaemic heart disease) results from blockages of the
coronary arteries by atherosclerotic plaques which are essentially
complex cholesterol deposits. Coronary heart disease has been
extensively studied and the main risk factors for its development
have been identified. These risk factors include: hyperlipidemia
(high blood fats), obesity, hypertension, diabetes mellitus and
lack of physical activity.
What are antioxidants?
There have been
some observational studies which indicate that antioxidants in the
diet may have a protective effect on coronary heart disease.
Antioxidants include the vitamins A, C and E, and beta-carotene.
Antioxidants help to counter the detrimental effects of oxygen
free radicals which form naturally during normal metabolism. Free
radicals are thought to play a role in coronary heart disease,
cancer and inflammatory conditions. At this stage, without a
complete understanding of how free radicals work, large doses of
antioxidants are not recommended. However eating a variety of
foods which contain natural antioxidants, such as fruit,
vegetables and wholegrain products may have a beneficial effect.
How might antioxidants help reduce coronary heart disease?
Antioxidants in
food prevent oxygen from making the food rancid, or causing
discolouration or loss of flavour. In the body antioxidants appear
to work by preventing the "bad" LDL-cholesterol (Low
Density Lipoprotein cholesterol) from being oxidised and producing
"foam" cells which form fatty streaks in the walls of
blood vessels. Eventually these produce atherosclerosis and
arterial narrowing and an increased risk of angina, heart attacks
and strokes.
Research has shown that the antioxidants beta-carotene and vitamin
E are found in the core of the LDL particle and it is known that
giving large doses of vitamin E can prevent oxidation in vitro.
Therefore work on the role of antioxidants in preventing heart
disease is being carried out in centres around the world,
including
Australia
.
Which foods contain antioxidants?
Fruit,
vegetables and wholegrain products contain antioxidants.
__________________________________________________
Vitamin C (milligrams per 100 grams of food)
Capsicum (231 mg)
Strawberries (58)
Blackcurrants (209)
Cabbage (56)
Broccoli, cooked (92)
Orange juice (49)
Brussels sprouts, cooked (83)
Mango (41)
Vitamin E (milligrams per 100 grams of food)
Sunflower oil (48.7 mg)
Wheatgerm (11.0)
Polyunsaturated margarine (25.0)
Tuna, canned (6.3)
Hazelnuts (21.0)
Peanuts (5.6)
Almonds (20.0)
Olive oil (5.1)
Beta-carotene
Found in deep yellow/orange vegetables and fruits and dark green
leafy vegetables
(eg. carrot, pumpkin, apricot, mango, spinach, broccoli, endive,
turnip, tomato).
Future Research
Although
considerable evidence shows that high levels of antioxidant
vitamins are associated with protection against LDL oxidation and
cardiovascular disease, the only randomised trial performed to
date has failed to show any benefit. A recent review * of research
papers about antioxidants and their impact on heart disease risk
has concluded that modest doses of antioxidants were used in most
studies and that higher doses may be required to show clinical
effects. Recommendations to take vitamin supplements should await
positive evidence.
Diet
and Cancer
The relationships between diet and cancer are still subjects of
scientific research. Enough is now known for some recommendations
to be made for reducing the risk of cancer.
INCREASE
THESE!!!!
Fruit
and vegetables
Eat more fruit and vegetables - they are full of vitamins and
minerals, and are a great source of fibre as well. Leafy green and
yellow vegetables are excellent. Aim for 3 serves of fruit and
four serves of vegetables every day. A serve is only half a cup
and these foods have been shown to afford a protective effect
against cancer.
Natural Oils
Eat more nuts, especially almonds. Use oils that are rich in
the Omegas (3,6&9)
REDUCE
THESE!!!!!
Reduce
your saturated fat intake
It is important to reduce the amount of saturated fat consumed. Do
this by choosing lean cuts of meat and trim the fat whenever
possible.
Reduce you
simple carb Intake
It is important
to stay away from simple carbs (pasta, white bread, pasties, etc.)
as they turn into sugar in the body and cause problems such a
diabeties, heart disease, etc. It is fine to consume a
moderate amount of complex carbs especially those produced from
whole wheat, barley, oat bran, tec.
Control
your body weight
Obesity may be a risk factor - reduce your weight to the middle
line. Be physically active and avoid overeating.
Limit some types of foods in your diet
It may help to limit some particular foods in your diet including
- burnt or charred foods (eg. charred bbq meat); mouldy or spoiled
food; cured, salt-cured, pickled or smoked foods (eg. bacon, hams,
sausages, cured fish or corned beef).
Limit alcohol intake
Remember - everything in moderation and alcohol is no exception.
Try not to have more than two drinks a day. This will help control
your weight too.
High
Blood Pressure - The Salt Story
One
of the most extensively debated nutritional issues is the need to
reduce our intake of sodium chloride, or common salt. Salt is an
important determinant of the texture and flavour of food and
traditionally it has played such a major role in our diet that
sectors of the medical profession, food industry and general
public alike have questioned the need to limit its use, even
though it is recognised that the average sodium content of Western
diets substantially exceeds basic physiological requirements.
A common argument against salt restriction is that only a small
proportion of people stand to benefit and the benefit itself is
too small to justify the effort. Whilst it is true that not
everybody will show a blood pressure response to lowering salt
intake, research conducted at our Division shows that the benefits
for those either with or at risk of developing high blood pressure
may be substantial.
At least 350 volunteers, male and female, young or elderly, with
normal or high blood pressure, have taken part in
strictly-controlled dietary intervention trials to test the effect
of halving their salt intake. The results confirm that salt
restriction will lower blood pressure to a greater extent in the
elderly and in those with high blood pressure. They also reveal
that women are more likely to respond than men - a very
significant finding when one considers that blood pressure tends
to rise rapidly in postmenopausal women and that more than half
will reach a level requiring treatment.
Since elderly people often need to take several medications
continually, reducing salt intake may offer an attractive
alternative to drug treatment. Even for those whose blood pressure
is too high to be controlled by salt restriction alone, our
research confirms that the change of diet may still be worthwhile
because, depending on the particular type of blood pressure
lowering drug being taken, salt restriction can have an added
effect which may permit a reduction in the dose of drug needed to
maintain normal blood pressure.
The case for salt restriction has focused on blood pressure.
However, it is recognised that excessive salt can contribute to
the damage of cardiovascular organs, particularly the kidney,
which may occur in people with high blood pressure. Moreover,
recent research indicates that the degree of damage does not
necessarily depend on the extent to which salt affects blood
pressure. Thus, even those individuals whose blood pressure shows
little response to dietary salt restriction may still stand to
benefit through an overall reduction in cardiovascular risk.
Unfortunately, early attempts by the food industry to respond to a
perceived need for low salt alternatives to bread, cereals,
cheeses and other processed foods (our main sources of dietary
salt) were met with relative indifference by consumers. However,
when we supplied a range of low salt foods to the volunteers in
our intervention trials, they were well received. Increasing
awareness by both doctors and their patients of the value of a low
salt diet in the management of high blood pressure may be expected
to re-establish a market demand.
Fortunately, with the availability of new sodium chloride
substitutes for use in food manufacture, it should now be possible
to produce a wider range of palatable low salt products to satisfy
this market. Our Division expects to play a continuing role in
evaluating the cardiovascular health benefits to be derived from
this important dietary strategy.
Whey
Protein - new uses for an old waste
For
too long, whey, a by-product of cheesemaking, has been devalued
and even thrown away. Whey proteins represent the major proteins
in human (breast) milk, in contrast to that of cow's milk where
casein is the major protein. Dairy proteins represent one of the
richest sources of sulphur amino acids in the human diet, and it
is not uncommon for these amino acids to be deficient. We have
been examining the claim that it is the quantity of protein in the
diet, not the quality of protein, that is the important issue
where diet influences the risk of colon cancer.
Our recent experiment refutes this claim. We have shown that while
feeding a constant level of protein to the rat, we can vary the
incidence of intestinal cancer from 30 to 60% by substituting whey
protein for soybean protein, and with all other food components
being keep constant. Cysteine and methionine (sulphur amino acids)
were increased by 3.3 and 1.6 times respectively. There is
increasing evidence that these sulphur amino acids play a crucial
role in the protection of DNA by reducing the risk of mutation
(mutation being one of the steps towards increasing the risk of
cancer).
Other mechanisms also influenced by quality of protein in the diet
are glutathione concentration (an important cellular antioxidant),
immune status and the level and nature of fat in the hindgut which
can lead to toxic damage.
We are doing a detailed study of the mechanisms underlying colon
cancer. Besides helping to identify the important factors in diet
which can significantly alter the incidence and number of tumours
that occur in this region, we hope to be able to provide a better
understanding of why the incidence of cancer has increased in our
westernised culture. We now recognise that whey proteins, and
dairy proteins generally, are a valuable component of our diet and
may offer protection against colon cancer.
Whey proteins should not be wasted, but incorporated more
extensively into our diet. Ricotta cheese (which includes whey
proteins) and unprocessed milk products are examples of foods
which are most desirable, now that such dairy products are low in
fat and readily available.
Are
Chemical Residues in Food a Worry ?
The foods we
eat, even unprocessed foods, contain an array of chemicals. Some,
such as proteins, sugars and fats are organic human nutrients
while others such as potassium, calcium and sodium are inorganic
nutrients. Vitamins and trace elements are important micro
nutrients. In addition plant and animal products contain various
quantities of chemicals, some of which occur naturally at various
concentrations. Others have been introduced by man. Farming land
is treated to increase the yield of crops or pastures, usually due
to a natural deficiency of elements in the soil. Such use of
supplements or fertilizer does not necessarily increase the level
of particular elements above that which occurs naturally under
adequate conditions. Other treatments aim to increase yield by way
of the removal of exotic "invaders" in the form of
insects, fungi or other plants which restrict production. These
treatments come under the general heading of
"pesticides", all invaders being considered pests. More
specifically, pesticides such as insecticides, fungicides and
herbicides are used in addition to other chemicals in order to
kill a wide range of organisms.
Because the active ingredients of some pesticides have been shown
to have cancer causing properties, and because some do not degrade
in the natural environment or indeed in the human body, there is a
fear by the general public of the risk to human health and,
accordingly, a view that these compounds should not be used in
agriculture. Another factor that has raised the profile of the
residues of pesticides is the fact that analytical chemists are
now able to detect minute amounts of these compounds in foods.
Because of their toxic properties some pesticides have now been
withdrawn from sale and government regulations limit the quantity
of residue permitted in farm produce. The number of times that
these limits have been exceeded in recent years has been limited
to less than 1%, and the consumption of pesticide residues in food
is minimal.
Nevertheless, partly because long term dietary exposure has not
been examined closely and partly because of public concern, the
CSIRO Division of Human Nutrition has studied the effects of
consumption of a number of the most common pesticides used in
South Australia
. Four pesticides were fed for a period of three months to rodents
(equivalent to five years in humans) at a level considered
non-toxic in acute poisoning terms. Substances capable of causing
cancer can show chromosomal damage in body cells but in the case
of two insecticides and two fungicides frequently and intensively
used in the production of garden vegetables, fruit and cereals, no
chromosomal aberrations could be detected in three of the
pesticides (which included an organo-chlorine insecticide, and an
organo-phosphate insecticide and fungicide). There was a slight
tendency for chromosomal damage in the case of the carbamate-based
fungicide. This general lack of effect of commonly used pesticides
is not to say that some highly sensitive people might not show
some reaction to pesticides in food. For trade, ecological and
general environmental health reasons, there are moves to lessen
the quantities of pesticides in food products. If used correctly
it appears that residues of the pesticides that are in use are not
likely to be a measurable cause of cancer in the Australian
community.
Fear
of Frying?
It
has been well established that diets rich in saturated fat
increase plasma total and low density lipoprotein (LDL)
cholesterol which in turn is causally related to the development
of coronary heart disease (CHD). Surveys in
Australia
of the fats used in foods of the fried takeaway variety show a
very high proportion of saturated fat. Up to one third of the fat
Australians eat is derived from commercially prepared foods and
therefore fried foods are likely to contribute a significant
proportion of this.
There is good evidence to suggest that this contribution is likely
to rise with upward trends in an increase in expenditure in snacks
and takeaway foods in the last ten years.
A major use of cooking fats is in deep fat frying where it
functions as a heat transfer medium and contributes desirable
flavour and texture to fried foods. Functionally, such oils need
to be stable at the high temperature and moisture exposure which
is characteristic of commercial usage where oils are used
repeatedly and frying may occur over several hours. During
heating, poly-unsaturated fatty acids (PUFA) polymerize, creating
changes in the oil which can result in a greasy product.
Furthermore, as in the case of stored snack items, the stability
of the fat will determine shelf-life. The more saturated the oil,
the more stable it is to oxidative and hydrolytic breakdown, and
the less likely it is to polymerize.
The obvious disadvantage of high saturated fat cooking oils is
their plasma cholesterol-raising effect which represents a major
barrier to the future lowering of the national average cholesterol
level. In
Australia
, the most commonly used commercial frying fats are tallow and
palm oil, both of which are highly stable to oxidation and also
have good palatability and mouthfeel. However, they are also
highly saturated fats making them nutritionally undesirable in
countries that experience high rates of CHD.
Linolenic rich oils such as canola and soybean oils are
particularly susceptible to undesirable changes. Substantial
hydrogenation of these oils renders them more stable but results
in trans fatty acid (TFA) levels which may negate their lipid
lowering potential. Sunflower and safflower oils are also
unsuitable commercial frying oils because of their high PUFA
content. In contrast, oils high in monounsaturated fatty acids are
relatively resistant to oxidation.
Recently, a high oleic genetic variant of sunflower oil (Sunola -
TM) has been developed which has the stability and nutritionally
desirable characteristics required in a frying fat. We have tested
this oil in a group of 23 hypercholesterolaemic men and women and
compared it to a commonly used commercial frying oil, namely palm
oil. The oils made up over half the total fat intake and were
incorporated into margarines and baked products and consumed
daily. Everyone took both test oils in random order during the two
intervention periods lasting three weeks.
Our results showed that compared to palm oil, Sunola oil led to
significantly lower both total and LDL-Cholesterol. Total
cholesterol levels fell from 6.23mmol/l on palm oil to 5.72mmol/l
on Sunola which represents a drop of 8.4%. Most of this fall was
in LDL-Cholesterol which fell from 4.18 to 3.77 mmol/l . Subjects
with initially higher cholesterol levels experienced even greater
reductions in total cholesterol. It is of interest to note that
these changes were achieved on diets which contained 35% energy
from fat, similar to current eating patterns. This change in total
cholesterol represents at least a 17% reduction in cardiovascular
risk if extrapolated across the Australian population.
Economically, Sunola is somewhat more expensive than palm oil.
However, because of its stability to continuous deep frying, its
overall cost is reasonably competitive with current commercial
frying fats.
In conclusion, a change in fat profile can make a substantial
difference to plasma lipids. Mono-unsaturated oils such as Sunola
are clearly preferably to palm oil in the Australian food service
industry, in terms of cardiovascular risk.
We acknowledge that Sunola is a registered trademark (TM) of
Meadow Lea Foods.
Resistant
Starch - Closing the Carbohydrate Gap
The benefits to
large bowel health of an adequate intake of non-starch
polysaccharides (NSP; major components of dietary fibre) are
recognised extremely well. Common chronic degenerative bowel
disorders such as simple constipation, diverticular disease and
diarrhoea are relieved by greater consumption of fibre-rich foods.
These conditions are important causes of health-related
expenditure in
Australia
. Cancer of the colon and rectum are the single most important
cause of death from malignancies and it is believed that fibre may
be protective in this instance.
Non-starch polysaccharides are thought to be helpful in two ways.
Firstly, they are not digested by human gastrointestinal enzymes
so that their consumption leads to greater stool bulk which
stimulates colonic muscular activity. Secondly, many NSP are
fermented by colonic bacteria which leads to a greater bacterial
mass and at the same time generates short-chain fatty acids (SCFA).
These acids are now thought to be crucial to maintaining a healthy
colonic environment. They are fairly strong acids and so lower
colonic pH, inhibiting the growth of pathogenic microorganisms.
Two of the major acids have more specific benefits. Propionate is
believed to enhance colonic muscular activity which has obvious
implications for constipation and diverticular disease.
Experimental data support the view that butyrate assists in the
maintenance of a normal population of colonocytes through
suppressing the growth of malignant cells. Studies in humans with
ulcerative colitis show that infusion of butyrate into the colon
may lead to remission.
While much is known about the physiological effects of NSP,
anomalies remain. One of these is the so-called
'carbohydrate gap'. When fibre intakes are compared with stool
mass, the latter is consistently greater than would have been
predicted from the quantities of NSP ingested. The cause of the
difference is known now to be starch.
For many years it was assumed that all dietary starch was digested
completely in the human small intestine. Recently it has been
established that a significant fraction of starch escapes into the
large bowel where it is fermented by the colonic microflora in the
same way as NSP. This fraction is called resistant starch (RS) and
its presence explains not only the carbohydrate gap but also other
anomalies, one of which is the relationship between diet and risk
of colonic cancer.
Epidemiological studies have shown consistently that greater
consumption of dietary fat increases risk, while recent work has
shown that greater stool mass bulk is protective. It might have
been expected that dietary fibre also should lower risk but the
data show that while fibre is protective, the degree of protection
is surprisingly weak. More recent analysis of the data has shown
that total starch consumption is protective as is the intake of RS
+ NSP together.
A role for RS in bowel health is extremely important as is
understanding the factors which control starch digestion.
Resistant starch occurs for a wide range of reasons including the
presence of NSP which restricts the activity of amylases (hence
the carbohydrate gap).
Mastication also is important as a greater fraction of foods which
are chewed lightly escapes into the colon compared with those
which are chewed extensively. We have found in pigs that the
passage of starch into the large bowel is greater with finely
milled rice than with coarse rice. In some foods (eg legumes),
amylase inhibitors may be present which increase the passage of
undigested starch into the colon.
Another important factor is the type of starch which is present.
Maize starches which are high in amylose are of considerable
interest not only because this starch is resistant to a-amylase
attack but also because it is determined as fibre in the AOAC
procedure. Coupled with its functionality in food, this means that
the fibre content of low-fibre starchy foods can be increased.
We have found that in pigs, much more starch enters the large
bowel in animals fed a high amylose starch compared with other
starches. In a further study we found that the length of the large
bowel was greater in animals fed the high amylose starch. In fact,
there was a linear relationship between colon length and the
proportion of high amylose starch in the diet. This finding is of
some interest as it is thought that the greater colon development
is protective against those degenerative bowel conditions which
are encountered by a significant fraction of the population.
Functional
Foods - identification, substantiation and regulation
Functional
Foods are foods that have strong putative, metabolic and
regulatory (physiological) roles over and above those that are
used in a common range of foods and, more particularly, a class of
foods that achieve and define a therapeutic endpoint that can be
monitored.
There is a growing international interest and activity in this
area which focuses on the health potential of foods. These foods
can be naturally occurring, nutrient-fortified foods, as well as
ingredient-enriched foods. Examples of areas in which the health
potential of Functional Foods have been and are currently being
explored include specific fatty acids, antioxidants, probiotics
and macromolecules.
At national levels, an indication of the significance and
importance of this development can be seen in the establishment of
guidelines for foods that have a defined health end- point, or
that have strong metabolic roles. These are evident in
Japan
where a regulatory process, often referred to as FOSHU has been
implemented and, in the
United States
, where the FDA have outlined the relationships between specific
diets and health claims in their regulatory framework.
A common and critical theme running through all of these
developments is that of scientific substantiation and a need to
test these products, to ensure appropriate efficacy and safety to
the consumer. These tests may involve physiological and
pharmacological evidence that the product improves biological
function, or protects against the disease state. Similar tests are
conducted to determine the threshold amounts of Functional Foods
required to achieve the beneficial effects.
At the Division of Human Nutrition we have specialised in defining
scientific approaches to determine substantiation, efficacy and
pharmaco-kinetics of potential Functional Foods for Industry. In
their context, these studies are referred to as nutritional
pharmacology, an emerging discipline in the international setting,
and one with a major focus in
Australia
within the Nutritional Pharmacology Laboratories at the CSIRO in
Adelaide
.
Antioxidants
-Their Role in Cancer
Antioxidants in
food, which include the micronutrients vitamins A,C,E and the
yellow-coloured carotenoids help to counter the detrimental
effects of oxygen free radicals, which are formed naturally as a
consequence of normal metabolism, and by external factors such as
x-rays, ultra violet radiation and pollution.
Increasingly, oxidative damage has been implicated in the
development of several degenerative diseases including cancer,
thus highlighting the need to ensure replete antioxidant status as
a central feature of preventive medicine. In addition however, it
has been proposed that extra health benefits may derive from
above-average intakes of these compounds. It is wise to look in to
body detoxification or drug detoxification to cleanse the
body which assists in nutritional supplement retention and
absorption.
While generally supported by laboratory studies, the hypothesis
has also gained credibility from extensive epidemiological
evidence which points to significant protection against general
degenerative diseases by high intakes of antioxidant-rich
foodstuffs such as fruits and vegetables. However, such
assumptions overlook the many other non-nutrient antioxidant and
protective substances in plant foods which are currently
attracting increasing research interest.
More information is clearly needed concerning the relative
antioxidant potencies of the non-nutrient antioxidants as well as
the different forms of conventional antioxidants. More also needs
to be known about their distribution and functionality within the
cell, and the potential which exists to influence this
distribution by dietary means. Such studies form a focus of the
research activity currently under way in the Cancer and Nutrition
Program of the CSIRO Division of Human Nutrition, where efforts
are being made to evaluate the importance of the lesser known
antioxidants in plant foods as anti-cancer agents, and to
establish the levels of intake of the established nutrient
antioxidants needed to protect cells against naturally occurring
and induced damage to genes and the attendant risk of cancer.
Prevention of overt deficiency disease is no longer the sole
nutritional objective as increasing interest is focussed on the
use of selected phytochemicals to ensure optimal health and
maximum protection against degenerative disease.
Antioxidants
and Cardiovascular Disease
High levels of
low density lipoproteins (LDL), the major cholesterol-carrying
particles in the blood, increase the risk of developing
cardiovascular disease. This risk is increased further if LDL are
damaged in the body by oxygen free radicals. Oxidised LDL are
taken up into the wall of the artery much more rapidly than
undamaged LDL, where they accumulate leading to the development of
atherosclerosis.
Dr Mavis Abbey, head of the Lipid Research Unit, is conducting
research to investigate factors which influence the extent of
oxidation damage to LDL. A recent human study in which subjects
consumed antioxidant vitamin tablets (vitamin E, vitamin C and
beta-carotene) for three months showed that their LDL was
protected from oxidative damage for a longer period than LDL from
subjects who did not consume the antioxidant vitamins.
Another human study showed LDL from subjects consuming a
poly-unsaturated fat-rich diet (eg. sunflower oil) oxidised faster
than LDL from subjects consuming a diet rich in mono-unsaturated
fat (eg. olive oil).
There are a number of naturally occurring compounds in foods which
have antioxidant properties (eg. vitamins and phenolic compounds).
Future antioxidant research in the Lipid Research Unit will be
conducted in line with food and agricultural industry needs.
Methods have been established which will enable foods or isolated
compounds to be tested for their effects on LDL oxidation in vitro
for clients in the food and agricultural industries.
Animal studies will allow the degree of atherosclerosis to be
determined in relation to administrat-ion of the test compounds,
and human dietary studies will enable the efficacy of the
compounds to be evaluated in relation to protection of LDL.
Food
and Nutrition
According to the United States
Department of Agriculture (USDA), thirty-one million Americans -
including 12 million children - live in households that experience
hunger or are at risk of hunger. These families frequently skip
meals or eat too little, sometimes going without food. Those who
have acess to some food often have lower quality diets or must
resort to seeking emergency food because they cannot always afford
the food they need. The USDA provides many programs to help meet
the nutritional needs of low income Americans.
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