Cholesterol Levels: Regaining Control
Dr Rod Panter
Science, Technology, Environment and Resources Group
5 June 2001
Contribution of dietary fats and oils to
Why is high cholesterol so common?
What should the cholesterol message be?
Who should deliver the cholesterol
Cholesterol-promoting foods; can they be
High blood cholesterol, that is, above about 5.5
millimoles per litre, is known to be one of the prime risk factors
for cardiovascular disease (heart attacks, stroke, atherosclerosis
and other circulatory disorders). Other risk factors include
obesity, high blood pressure, stress, diabetes, family tendencies,
age and smoking. In Australia, cardiovascular disease affects
nearly three million people nationwide and kills 50 000 each
There is some debate over a 2001-2002 Budget
decision to control access to taxpayer-subsidised
cholesterol-lowering drugs. The Federal Government is expressing
concern through the Budget over the increasing cost of this class
of drugs, known as statins. There are significant consequences of
high cholesterol in the Australian population apart from health;
between 1998-99 and 1999-2000 the cost of the statins subsidy rose
by more than $110 million and increased in volume by nearly two
million prescriptions. This class of drugs now tops the
Pharmaceutical Benefit Scheme (PBS) in cost, amounting to over half
a billion dollars in 2000 and rising by about 25 per cent each
year. As with many other drugs, statins are often prescribed for
the life of a patient, thus controlling rather than curing high
blood cholesterol. A key concern of the Government is whether
statins are being prescribed appropriately on all occasions.
Through changes to the wording of PBS guidelines, enhanced by
procedures to ensure that doctors adhere to the guidelines, plus
education of doctors and consumers, the Government expects to save
$103.9 million on statins over four years.
The debate over levels of blood cholesterol
appropriate for drug prescriptions will no doubt continue.
Recently, recommendations were made in the US which called for a
higher, not lower use of cholesterol-lowering drugs. Seemingly, the
Australian Government is moving away from such recommendations in
its Budget move. However, rather than discuss in detail the
cholesterol level at which drugs are appropriate, this short
paper's main emphasis is on prevention of cholesterol
buildup, including better dietary advice to the class of patient
previous offered statins more or less automatically. Whereas the
government appears to be relying on encouraging and educating
general practitioners to counsel patients on lifestyle matters,
there is much more that governments can do through preventive
measures to reduce the great social and actual costs of heart
disease promoted, at least in part, by high cholesterol.
Dietary advice in relation to reducing blood
cholesterol has changed considerably over the years. In 1984 the
(US) National Institutes of Health advocated reducing total fat in
the diet. In 1988 the US Surgeon-General issued a major report on
nutrition and health in which fat was declared to be the single
most unwholesome component of the American diet. It took eleven
years of dispute to cancel a further project by the Surgeon-General
on the dangers of dietary fat. The subject had become far too
complex for simple conclusions. In any case, it was known that
several comparatively healthy food cultures included high fat
intake. It is the type of fat, more than the quantity of
fat in the diet which is important. We are all familiar with more
specific advice to avoid saturated fats. But, to
complicate matters, some components of saturated fats raise
cholesterol much more than others. And not surprisingly,
cholesterol itself in the diet influences cholesterol levels in the
Why is there such a large Australian call on
cholesterol-lowering drugs? How can accumulated knowledge about
cholesterol and the diet be simplified for communication to the
public? Which group or groups should do the communicating? And,
once educated, is the public then able to choose those foods with
the least risk?
While the Australian population ages, and thus
increases the overall risk of heart-related disease, a special
concern is the increasing level of cholesterol in young
Australians. Indeed, for the entire population there is a danger of
moving backwards from the cholesterol-avoiding strategies of the
past. This may be due to food manufacturers' advertising, changing
habits in food purchasing, forgetfulness, ignorance or sheer
The following discussion briefly covers the
issue of both preventing and lowering cholesterol buildup in the
Australian population. Matters covered include the role of health
communicators and the practicality of suitable labels on all
Contribution of dietary fats and oils to
Dietary fats (solids and semisolids) and oils
(liquids) are triglycerides, being composed of three
fatty acid molecules strung onto a three-carbon backbone
A molecule of fat or oil
Fatty acids are important to this discussion in
that they influence blood cholesterol levels. Each fatty acid
molecule consists of a long chain of carbon atoms combined with
hydrogen atoms. Fatty acid names are derived from (i) the length of
the chain, and (ii) the number of 'double bonds' in the chain.
Saturated fatty acids have no such bonds. In tissues, there is a
predominance of even-numbered chains in fatty acids. Some common
fatty acids are shown below.
||(12 carbon chain, no
||(14 carbon chain, no
||(16 carbon chain, no
||(18 carbon chain, no
Mono-unsaturated fatty acids
||(16 carbon chain, one
||(18 carbon chain, one
Poly-unsaturated fatty acids
||(18 carbon chain, two
||(18 carbon chain, three
Through experimentation, it has been found that
different fatty acids in the diet have different effects on blood
cholesterol. Myristic acid is especially notable since it promotes
cholesterol formation the most. Next in line is lauric acid and
third is palmitic acid. The latter is disputed as a cholesterol
promoter, not least because it occurs in palm oil, an
internationally traded edible oil. Australia's neighbours Malaysia
and Indonesia are major producers of palm oil. Some studies,
supported by producers, suggest that palmitic acid does not promote
cholesterol formation in low-cholesterol diets. A majority of
scientific opinion would argue that palmitic acid is indeed a
significant cholesterol promoter because there is much more of it
in most fats and oils than lauric and myristic acids. Stearic acid,
although fully saturated, is believed to have no effect on
cholesterol levels. The mono-unsaturated acids oleic and
palmitoleic are either neutral or have a slight cholesterol
reducing effect. Lastly, the polyunsaturated fatty acids have a
An individual fat or oil will have
characteristic proportions of various fatty acids within its basic
structure. Note that the three fatty acids in the triglyceride
molecule backbone (the fat molecule) are likely to be different.
Thus, in one type of fat or oil, it is possible to have a
cholesterol-promoting fatty acid and a cholesterol-damping fatty
acid present in comparable amounts. For example, the action of
cholesterol-neutral stearic acid present in meat fat and chocolate
is likely to be counteracted to some extent by other saturated
fatty acids (such as palmitic acid) which are present.
Simply on the basis of relative fatty acid
content, fats and oils should be able to be ranked in order of
cholesterol formation. The following list is a first approximation
along these lines, limited to six common fats and oils in the
Higher cholesterol forming
Lesser cholesterol forming
In this lineup, emphasis has been placed upon
myristic acid content; a very early study(4) suggested
that myristic acid controls more than two-thirds of the diet's
effect on blood cholesterol. An 'Atherogenic Index' devised in the
US to measure health effects of milk fat is a formula heavily
weighted towards myristic acid:
Atherogenic Index numerator = lauric + (4 x
myristic) + palmitic [proportions](5)
One would expect, therefore, that a diet heavily
laced with coconut oil would lead to high cholesterol-at least
under Western dietary conditions-while a diet concentrated on
canola oil should lower cholesterol.
Cholesterol present in foods is a contributor to
blood cholesterol. However, in recent years the National Heart
Foundation and others have advised that saturated fats in the diet
play a greater role. Nonetheless, a relatively recent development
in 'functional' foods has seen plant sterols added to margarines;
their function is to inhibit the absorption of dietary cholesterol
from the gastro-intestinal tract. Last year it was
reported(6) by one maker (Unilever) that levels of blood
cholesterol could be reduced by 10-15 per cent with sterol-enriched
spreads. CSIRO is reported to be examining the possibility of
adding plant sterols to other foods. This approach cannot by
itself sufficiently reduce high blood cholesterol or prevent
the same. Plant sterols are not able to prevent uptake of saturated
fats. Also, there are fears that the sterols may inhibit absorption
of some vitamins.
Trans fats are the result of
polyunsaturated fatty acids being 'hardened' or made more saturated
in nature through hydrogenation. The process is used to make solid
margarine out of vegetable oils or for stable frying oils.
Unfortunately, trans fats enhance cholesterol formation and
therefore are less benign than the polyunsaturated oils used as the
is high cholesterol so common?
Like other affluent societies, the Australian
population may be said to be suffering from overnutrition. Apart
from a noticeable trend towards obesity and its hazards (Australia
is said to be on its way to becoming the fattest nation in the
world),(7) increasing total food intake and decreasing
physical activity will most likely stimulate cholesterol levels in
the population. Work pressures resulting from longer hours, job
insecurity and so on are encouraging workers' consumption of
high-calorie 'treats' between meals. The humble biscuit for morning
and afternoon break has been replaced by the monster lamington,
huge 'Danish pastry' or outsize 'muffin' (cupcake), that is, if the
Parliamentary staff cafeteria is any guide.
Manufacturers and restaurant owners know that
saturated fats are often tasty and have special textural and other
useful manufacturing characteristics not shared by healthier
vegetable oils. In 1998, 35 per cent of meals in Australia were
bought rather than being cooked by consumers.(8) Much of
this expenditure is in restaurants and fast food outlets where
there are endless opportunities for 'treats', and where there is no
health labelling. What are the fats in McDonalds 'fries' and
'shakes'? Very few people know or care. Regular restaurant
patronage has become almost a marker for high cholesterol.
Butter-soaked garlic bread followed by cream soup followed by rich
steak sauces and fried potato wedges plus the cream-filled cake or
ice cream for sweets adds up to a large serve of cholesterol
precursors. Popular Indian and Thai restaurants (and other
varieties) offer ghee-which is clarified butter-and coconut oil
laden food. Of course, the cholesterol precursors can be avoided,
but one might reasonably suspect that most patrons are not doing
When they are not eating out, Australians are
bringing home more and more packaged and pre-prepared food, that
is, if supermarket space for such foods is an indication. People
are eating unhealthy, hidden fats even though they would not
consider buying lard for frying or copha for cooking. While
nutrition labels are being improved under the new Food Code, there
is no existing requirement for informing customers of cholesterol
content, and certainly no indication of, say, the percentage of
myristic acid in contained fats. Familiar labels such as 'lite', or
'vegetable oil-contains no cholesterol', etc. have been misleading
because they do not give enough specific information to the
A declining awareness of cholesterol seems to be
underlined by newspaper articles telling us we can eat whatever we
like. 'Chocolate is good for you' is the commercially-inspired
message for Australians around Eastertime. Cholesterol-monitoring
kiosks in shopping malls seem to have disappeared. People are
simply not concerned about their cholesterol to the same extent. It
is probably seen by many as yesterday's fad.
One bright spot is the increasing popularity of
olive oil, which may create a significant Australian olive oil
industry. Epidemiological studies of the classic Mediterranean diet
indicate that liberal use of olive oil has a healthy outcome.
What should the cholesterol message be?
If it is accepted that there should be an
updated message for the general public in a preventive sense, what
should that message be? The list below could be a basis for a mass
marketing exercise (similar to the AIDS or anti-smoking
- cholesterol-lowering drugs are expensive and can be avoided in
many cases. Life-long dependence on drugs is not desirable and
there may be side effects for individuals.
- have your cholesterol level tested before drugs are
necessary. Monitor regularly.
- be aware, even curious about the types of fat and oil you are
- reduce intake of foods containing coconut oil and milk fat.
This includes full-fat cheese, butter, cream and ice-cream. Eat
low-fat milk products and other vegetable oil-based substitutes
(exceptions for infants and some adults). Trim meat fat.
- ask for butter-free and coconut oil-free food in restaurants.
Inquire as to the type of frying oil used (in a commercial kitchen,
stable mono-unsaturated Monola or Sunola is best, though still
- watch intake of high-calorie 'treats' at work. Many treats are
loaded with unhealthy fats.
- eat more fruit and vegetables (recognises the value of a
- stop smoking, exercise more, etc. (but cholesterol does not
quickly 'burn off' with exercise because it is not a primary energy
source for the body).
- there is some evidence that dietary fibre reduces blood
cholesterol (but not by much!).
As with anti-smoking advertisements, the above
advice needs to be accompanied by warnings of the personal
consequences of heart and circulatory disease.
Note: the biochemistry of fat absorption,
storage, burn up, conversion to cellular structures, cholesterol
synthesis and so on is controlled by dozens of enzymes (protein
catalysts) and hormones. Because of personal differences in the
genes controlling these enzymes and hormones, there will be
individual differences in metabolising dietary fat. This could
explain stories about persons with extravagant eating habits living
to healthy old age. For some patients, an improved diet may not
result in sufficiently lowered blood cholesterol. Ideally, health
advice should be shaped to individual needs, but general advice
based on the above dot points could be very effective nationally if
should deliver the cholesterol message?
The 2001-2002 Budget Measures paper declares
The Government has decided to clarify and
improve the wording of the current Pharmaceutical Benefits Scheme
instructions to prescribers for the use of cholesterol lowering
medicines. This will help ensure that these medicines will be used
by those most likely to benefit from them.
The instructions presently advise that:
all patients should receive dietary therapy,
typically for six weeks, before resorting to drug treatment. For
obese patients, a longer dietary period should be considered. In
addition to dietary advice, specific advice should be provided
about lifestyle changes to modify risk factors such as smoking,
obesity, excessive alcohol intake and physical inactivity.
There may be difficulties in achieving the
Government's desired objectives. For example, busy doctors rarely
have the time to present adequate dietary advice to patients.
General practitioners may not have the necessary detailed knowledge
in any case. Vague messages about avoiding saturated fats can no
longer be considered sufficient. Thirdly, doctors are widely
perceived as prescribers of medicines rather than preventive health
advisors. It is infinitely preferable to deliver health messages
before an enforced and perhaps belated visit to the
doctor. Fourthly, many patients would not regard their GPs as
suitable role models for fitness and lifestyle. They are frequently
overworked and overstressed! Lastly, doctors should be referring
patients more frequently to dieticians; it follows that a
reassessment of Medicare support for such services is
If advice from doctors is insufficient, as
suggested by the arguments above, then who else can deliver a
truthful message on diets and lifestyle? There is of course the
National Heart Foundation, a private organisation. But there is no
government body with a strong independent public health voice on
nutrition issues. And this at a time when 'industry is widely
perceived to be gaining more control over food standards...and has
developed close links with many professional
organisations'.(9) One suspects that most players in the
food arena have either a direct commercial interest in what people
eat, or else are beholden to industry for funding. A good example
of increasing industry influence is within the CSIRO Division of
Health Sciences and Nutrition. The Division has been forced to turn
increasingly to industry in recent years for funding support. In
one sense, this makes CSIRO less isolated from industry and
prevents its research from becoming commercially irrelevant.
However, unless the Federal Government spends more on nutrition
research there is likely to be tension between consumer interests
and food industry interests within the Division. Even universities
appear less able to speak out independently, as they too are
becoming more reliant on external funding. Although the National
Health and Medical Research Council is expected to issue a new
draft of national dietary guidelines in July, the NH&MRC has no
formal advisory group on nutrition.
Another possible candidate for national advisor
on dietary matters is the Australia New Zealand Food Authority,
ANZFA (or its intended successor, Food Standards Australia New
Zealand, FSANZ). Through developing standards the Authority has had
plenty of opportunities to build up expertise in matters of diet
and health. During its short life, however, the Authority has
encountered resistance on key issues from powerful food
manufacturers and distributors. Commonwealth/State issues have also
complicated its affairs. Depending on the representative makeup of
its Board, to be laid down in the final version of the ANZFA
Amendment Bill 2001, there is still hope that the new FSANZ
can be both authoritative and influential. One of its roles could
be to send independent messages about diet-through its standards
and otherwise-to both the Australian and New Zealand
Cholesterol-promoting foods; can they be
While the new joint Australia New Zealand Food
Standards Code was being developed by ANZFA, there was much
discussion over food labelling. Some improvements in nutrition and
ingredient labelling will follow as a result. There has been major
opposition from the food industry over a requirement to label
genetically engineered foods. While the industry has insisted that
such foods are safe, adequate labels give the customer the freedom
to choose between genetically manipulated food or normal food.
Polls have shown overwhelming public support for the labels.
Similar choices will be made with labelling of irradiated
In a follow-up to the new Food Code, ANZFA is
currently proposing that additional items as follows
should be mentioned as quantities on a package of food whenever a
nutrition claim is made (Proposal P233):
- polyunsaturated fat
- mono-unsaturated fat
- trans fatty acids
- dietary fibre.
(Note: saturated fats are already required)
One could well argue that these items deserve to
go on all packaged foods, not just those which make a nutritional
claim. While trans fatty acids are proposed to be listed, there is
no corresponding requirement for separately notifying myristic,
lauric and palmitic acid content. Listing the level of total
saturated fats is less precise, given the major differences in
cholesterol promotion by the various saturated fatty acids.
The more effective the label, the more pressure
is brought to bear on manufacturers to supply consumers with the
foods they want. Meanwhile, the food industry insists that
supplying consumer needs is one of its main aims. Both public
education and effective food labelling are needed for preventive
action on cholesterol.
With about one-third of all consumers' food
budgets going to restaurants and fast food outlets,(10)
it really is an anomaly that health labelling is not required where
food is served. This discrepancy has long been a complaint of the
Australian Food and Grocery Council. A relatively simple reform
could be to require fast food outlets to display a sign informing
customers of the type of frying oil being used. It would quickly
become known which fast food chains were using beef tallow,
hydrogenated cottonseed oil, palm oil or the more healthy Monola or
Sunola oils. For restaurants, the menu is the most obvious place
for health information. Just what form this could take is
debatable. Up until now, ANZFA seems to have regarded labelling at
food service outlets as 'too hard'. But authorities should no
longer ignore the accelerating trend away from home cooking and
towards restaurant meals.
- Given that cholesterol biochemistry is complex, and varies
between individuals, the characteristic fatty acid components of
fats and oils determine their cholesterol-forming potential.
- Myristic acid in saturated fats preferentially leads
to cholesterol in the blood. It is present in coconut oil, dairy
fat and beef fat (in descending order), but is virtually absent
from olive oil and most other vegetable oils. Other saturated fat
components promoting cholesterol buildup are palmitic acid
and lauric acid. By contrast, stearic acid,
although saturated, is believed to have no effect on blood
- The Federal Government intends to improve advice from doctors
to patients with high cholesterol, with the aim of reducing
cholesterol-lowering drug use. However, a strong anti-cholesterol
message should also be sent to the general public in order to
prevent an even larger national drug bill in future. Blood
cholesterol testing needs to be reinstated as a health priority.
Consideration should be given to appointing an independent
government body such as Food Standards Australia New Zealand to
advise the nation on dietary matters. Meanwhile, the nutrition
advisory work of the National Heart Foundation should be more
- In order that consumers can distinguish foods which can lead to
high cholesterol, more specific labelling is required on packaged
foods. Health labelling is required for restaurants and takeaway
- In recognition of the importance of diet to good health,
Medicare rebates on dieticians' fees should be considered.
- The National Heart Foundation and the Australian Institute of
Health and Welfare, 'Heart, Stroke and Vascular Diseases:
Australian Facts 2001'.
- Composition of Foods, Australia, Volume 4, 'Fats and Oils,
Processed Meat, Fruit and Vegetables, 1990.
- S. H. Ong, 'Nutritional aspects of palm oil: an introductory
review', Asia Pacific Journal of Clinical Nutrition (1994) 3, pp.
- D. M. Hegsted, R. B. McGandy, M. L. Myers and F. J. Stare,
'Quantitative effects of dietary fat on serum cholesterol in man',
American Journal of Clinical Nutrition, vol. 17, 1965,
- G. L. Lindberg and G. Bobe, 'Is milkfat from all cows
atherogenic?' 1997, Dairy report-Iowa State University,
- G. van Poppel, 'Foods and cardiovascular health: plant sterols
for lowering cholesterol', CSIRO Food Industry Conference,
Adelaide, September 2000.
- Caterson, quoted from a paper given to a Sydney conference,
Sydney Morning Herald, 12 December 2000, p. 3.
- L. Cobiac, 'The role of consumer science in marketing', CSIRO
Food Industry Conference, Adelaide, August 1999.
- M. Sweet, 'Recipe for confusion', The Bulletin, 22 May
2001, p. 31.
- I. Lindenmayer, 'The Food Regulatory System of Australia',
paper presented at the 7th ASEAN Food Conference,
Manila, November 2000.