Role of oat beta-glucan in lowering cholesterol

Abstract

Angie Jefferson reviews the role of oats and their constituent fibre beta-glucan in cholesterol reduction, and provides practical advice for supporting patients with dietary change

Full text

Clinical Focus nutrition
180 Practice Nursing 2009, Vol 20, No 4
nutrition
Cholesterol is the most common risk
factor for coronary heart disease
(CHD), being an important factor in
46% of all deaths from CHD, much higher
than the comparable figures for smoking
(19%) and lack of physical activity (37%)
(British Heart Foundation, 2008). With more
than two thirds of UK adults having higher than
ideal cholesterol levels, tackling cholesterol
remains a priority for all in health care.
Reducing the risk of heart disease by eating
a diet rich in high-fibre foods was first high-
lighted by Ancel Keys and colleagues in the
Journal of Nutrition in 1960. Almost 50 years
later, there is a growing body of evidence that
a key factor in decreasing CHD risk is the
cholesterol-lowering effect of viscous fibres
found in cereal foods, such as oats and barley
(Poppitt, 2007). This article reviews the evi-
dence for the role of oats and their constitu-
ent fibre beta-glucan in cholesterol reduction,
and their efficacy. Suggestions are made for
how often oats need to be included in a
healthy balanced diet, and how much to con-
sume. Practice nurses play an important role
in conducting heart health checks, helping to
assess and manage CHD risk, and giving evi-
dence-based advice to patients on dietary
change. This article provides practical advice
and tips to help patients achieve life-long
healthier dietary habits.
What is cholesterol?
Cholesterol is essential to life and has three
main functions in the body: as a structural
component of cell membranes, in the manu-
facture of steroid hormones and vitamin D,
and in the production of bile acids to aid the
digestion and absorption of fats. The current
British guidelines for recommended choles-
terol levels are shown in Table 1 and the
types of cholesterol explained in Table 2.
Although cholesterol is present in foods,
around 75% of blood cholesterol is produced
by the liver from saturated fats; an ability
which, for the majority, underlies the prob-
lem of high cholesterol levels (American
Heart Association, 2009). Saturated fat
intake in the UK remains high, with around
14% of food energy coming from this source
(Department for Environment, Food and
Rural Affairs (DEFRA), 2008). The signifi-
cance of raised cholesterol is evident if the
following facts are considered (British Heart
Foundation, 2008):
227 000 people suffer heart attacks each
year
Cholesterol is a key factor in nearly half
of all heart attacks
Cholesterol is directly related to CHD risk
CHD cost the NHS £3.2 billion in 2006
Over 75% of adults aged 45–65 years
have cholesterol levels >5 mmol/litre
8 out of 10 adults do not know they have
raised cholesterol
Diet and lifestyle changes can lower
cholesterol by up to 30%.
Around 110 000 people in the UK are
affected by familial hypercholesterolaemia, a
genetic condition leading to high blood cho-
lesterol levels. While diet and lifestyle inter-
vention continues to underpin treatment,
drug therapy or other specialist treatments
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Role of oat beta-glucan
in lowering cholesterol
Angie Jefferson is a freelance dietitian
running her own consultancy, based in
Berkshire
Submitted for peer review 6 January 2009
accepted for publication 24 February 2009
Key words: cholesterol; oats; beta-glucan;
soluble fibre
Angie Jefferson
reviews the role of
oats and their
constituent fibre
beta-glucan in
cholesterol
reduction, and
provides practical
advice for
supporting patients
with dietary change
Risk group Target UK average
Total cholesterol Individuals at risk of CVD <4 mmol/litre 5.4 mmol/litre
All others <5 mmol/litre
LDL cholesterol Individuals at risk of CVD <2 mmol/litre
All others <3 mmol/litre
HDL cholesterol Men >1 mmol/litre 1.3 mmol/litre
Women >1.2 mmol/litre 1.6 mmol/litre
CVD = cardiovascular disease; LDL = low-density lipoprotein; HDL = high-density lipoprotein
From: Wood et al, 2005.
Table 1. Recommended cholesterol levels, UK Total cholesterol: includes all cholesterol fractions
LDL cholesterol: often termed ‘bad’ as this is the
type that builds up in arteries and blood vessels. It
is usually measured during fasting
HDL cholesterol: often termed ‘good’ as this
carries cholesterol back to the liver to be removed
from the body. It is usually measured during fasting
Triglycerides: also linked to atherosclerosis.
An ideal level is below 2 mmol/litre and is usually
measured during fasting
Table 2. Terminology

nutrition
nutrition
Practice Nursing 2009, Vol 20, No 4 181
are required for this condition. An effective
cholesterol-lowering intervention reduces
total and low-density lipoprotein (LDL) cho-
lesterol, while not decreasing (or, ideally,
increasing) high-density lipoprotein (HDL)
cholesterol levels.
The National Institute for Health and
Clinical Excellence (NICE) (2008) recom-
mends a systematic approach by primary care
to identifying those aged 40–75 years at risk
of cardiovascular disease (CVD). Modelling
of the total health gain from improving the
quality of care for patients with CVD in line
with the quality indicator targets in the
Quality and Outcomes Framework (QOF) of
the new GMS contract, has shown that the
greatest gain in health among those aged
between 45–84 years would come from reach-
ing cholesterol reduction targets (McElduff et
al, 2004).
Why oats?
It is believed that the cholesterol-lowering
effect of viscous or soluble fibre is one of the
key reasons why a high-fibre diet helps main-
tain a healthy heart. Soluble fibre is found in
many legumes (e.g. peas and beans), some
fruits (e.g. apples and pears) and the plantain
seed husk, psyllium. However, it is the beta-
glucan soluble fibre of cereals that has been
shown to be most effective in lowering cho-
lesterol (Poppitt, 2007).
Beta-glucan occurs naturally in the bran of
grasses such as barley, oats and rye. Barley
bran is 7% beta-glucan, oat bran 5%, and
rye bran 2%. However, the majority of
research has been carried out into the choles-
terol-lowering effect of oat beta-glucan, as
barley is less palatable than oats and eaten
less frequently in the diet. Although rye prod-
ucts are commonly eaten in Scandinavian
countries and Germany, this cereal is more
rarely consumed elsewhere.
How does oat beta-glucan work?
Beta-glucan is a soluble fibre, meaning that it
dissolves in the gut to form a thick gel-like
paste (not dissimilar to wallpaper paste).
During digestion beta-glucan is believed to
increase intestinal viscosity and bind the bile
acids and cholesterol from food, carrying
them out of the body in faeces. As a result the
liver must increase synthesis of bile acids,
requiring increased LDL cholesterol uptake
from the bloodstream and lowering blood
cholesterol levels as a result (Theuwissen and
Mensink, 2008).
Evidence
In 1963, De Groot et al were the first to
report that in healthy men, consumption of
bread containing rolled oats for 3 weeks
decreased total cholesterol by 11%. Since
then many other studies have shown oats and
beta-glucan to be effective in lowering blood
cholesterol levels. In 1992 Ripsin and col-
leagues conducted a meta-analysis of 20 trials
into the effects of oat products on cholesterol
and found a reduction of 0.13 mmol/litre.
Larger reductions were seen among patients
with initial cholesterol levels over 5.9 mmol/
litre, and particularly where 3 g of soluble
fibre (oat beta glucan) were consumed each
day. This was followed by a further meta-
analysis by Brown et al in 1999, who also
found that intakes of soluble fibre in the
region of 2–10 g per day had small significant
effects on total and LDL cholesterol levels.
A more recent review by Theuwissen and
Mensink in 2008 concluded that for each 1 g
increase in soluble fibre intake, total and LDL
cholesterol levels fell by 0.028 mmol/litre and
0.029 mmol/litre respectively. While these
cholesterol reductions may sound small,
according to Law et al (1994), for every 1%
fall in cholesterol levels, the risk of heart dis-
ease falls by 2–3%.
In 2007, a Cochrane systematic review was
carried out by Kelly et al to examine the rela-
tionship between wholegrain cereals and
CHD. Insufficient evidence was available to
draw any conclusions about wholegrain diets,
with the exception of oats. This review iden-
tified eight studies into the short-term effects
(4–8 weeks) of consuming oats on cholesterol
levels and concluded that including oats in
the diet may lower both total and LDL cho-
lesterol levels.
In all of these studies participants had at
least one risk factor for heart disease (Table 3).
When Andon and Anderson (2008) pooled
the results of these studies in a meta-analysis,
total cholesterol fell 0.19 mmol/litre and LDL
cholesterol by 0.18 mmol/litre following oat
intervention compared to refined cereal
grains. This was equivalent to a 4.9% fall in
LDL cholesterol levels, and hence a fall in
CHD risk of between 5–15%. No effects
were found on HDL cholesterol levels. The
authors concluded that:
There is enough evidence for wholegrain
oats to suggest that healthcare profession-
als could recommend oats as part of choles-
terol reduction programmes.

Clinical Focus
182 Practice Nursing 2009, Vol 20, No 4
Many patients with raised cholesterol lev-
els will need to lose weight, but weight-loss in
itself can lower cholesterol. Two randomized
controlled trials carried out by Saltzman et al
in 2001 and Berg et al in 2003 examined
whether the inclusion of oats in a weight-loss
programme further enhances cholesterol
reduction over weight-loss alone. They com-
pared calorie-restricted diets which included
oats with a matched diet containing no oats.
Total cholesterol and LDL cholesterol were
reduced in both the oat and non-oat groups;
however, the consumption of oats or oat bran
produced an additional total cholesterol
reduction of 4% and an LDL reduction of
12% beyond that resulting from weight loss.
Health claims for beta-glucan
Several countries across Europe have
approved health claims for use on foods that
contain oat beta-glucan, including most
recently France which approved a health
claim for oat bran and beta-glucan in July
2008. The UK health claim (Joint Health
Claims Initiative, 2004) states that:
The inclusion of oats as part of a diet low
in saturated fat and a healthy lifestyle can
help reduce blood cholesterol
Each food must contain 0.75 g beta-glucan
per serving in order to carry this claim.
Claims regarding the effect of oat beta-glucan
on cholesterol have now been submitted to
the European Food Safety Authority (EFSA)
for approval as part of the Europe-wide har-
monization of health and nutrition claims.
Dietary recommendations
In 2002, as part of their evidence-based
report on the detection, evaluation and treat-
ment of high cholesterol, the US National
Cholesterol Education Panel of Experts rec-
ommended the addition of soluble fibres,
including oats, to enhance LDL reduction as
part of the ‘therapeutic lifestyle changes’ diet
(National Cholesterol Education Programme,
2002). Heart UK recommends eating oats
daily as part of a total of 20 g of soluble fibre
per day from oats and oat bran, barley, beans
pulses and fruit, as part of the ‘portfolio’
Number
Authors Number of participants Intervention of weeks Outcome
Davidson et al, 1991 156 men and women aged Oatmeal or oat bran in doses 6 weeks Lowered total and LDL cholesterol
30–60 years with raised of 28 g, 56 g or 84 g LDL of 10% with 84 g oatmeal,
cholesterol 16% with 56 g oat bran,
12% with 84 g oat bran
Johnston et al, 1998 135 men and women aged 3 oz ready-to-eat oat cereal 6 weeks Lowered LDL cholesterol
40–70 years with raised vs 3 oz low-fibre ready-to-eat
cholesterol cereal
Karmally et al, 2005 152 men and women aged 45 g ready-to-eat oat cereal 6 weeks Lowered total and LDL cholesterol
30-70 years with raised vs low-fibre ready-to-eat cereal
cholesterol containing 3 g beta-glucan
Keenan et al, 2002 18 men and women aged Ready-to-eat oat cereal 6 weeks Lowered total (9%) and LDL (14%)
27–59 years with raised blood (5.52 g beta-glucan) vs low- cholesterol
pressure and insulin levels fibre ready-to-eat cereal Reduced systolic and diastolic
blood pressure
Pins et al, 2002 88 men and women with 60 g oatmeal plus 77 g 12 weeks Lowered total and LDL cholesterol
raised blood pressure oat squares systolic and diastolic blood
pressure and blood glucose
Reynolds et al, 2000 46 men and women aged 2 x 42 g por tions ready-to-eat 4 weeks Lowered LDL cholesterol
27–68 years with raised oat cereal vs 2 x 42 g por tions
cholesterol low-fibre ready-to-eat cereal
Van Horn et al, 1988 236 men and women aged 56 g oatmeal substituted for 8 weeks Lowered total and LDL cholesterol
30–65 years with raised other foods
cholesterol
Van Horn et al, 1991 156 men and women aged 57 g oatmeal substituted for 8 weeks Lowered total and LDL cholesterol
22–76 years with raised other foods
cholesterol
LDL = low-density lipoprotein
Table 3. Brief overview of intervention trials using oats to lower cholesterol
Clinical Focus nutrition

approach to cholesterol management. Devised
by Jenkins et al (2003), the combination
approach of the portfolio diet recognizes that
cholesterol reductions of up to 30% (compa-
rable with a first-generation statin) can be
achieved by combining individual foods
known to help lower cholesterol (e.g. beta-
glucan and other soluble fibres, soya foods,
almonds and plant sterol spreads) within a
more traditional cholesterol-lowering diet.
The British Heart Foundation recommends
eating oats as part of a high-fibre diet for
cholesterol lowering (British Heart
Foundation, 2009). A few simple steps and
lifestyle changes which will help modify cho-
lesterol levels are outlined in Table 4.
How many oats do I need to eat?
To increase the benefits from oats and oat
bran products, they need to be eaten regu-
larly as part of the everyday diet. Ideally
products containing beta-glucan should be
consumed at least twice each day to achieve
best effect: the UK and USA health claims for
oat beta-glucan suggest an intake of 3 g beta-
glucan per day for cholesterol lowering and
foods carrying the claim must
contain at least 0.75 g beta-
glucan per serving. In order to
achieve this level of intake
this practically translates into
consumption of an oat-based
food at least twice a day, as
most oat-based foods contain
between 0.75 g–1.6 g beta-
glucan per serving.
A bowl of porridge oats
(45 g) contains around 1.8 g
of soluble fibre, of which 1.6 g
is beta-glucan. For some, por-
ridge is not palatable or
acceptable and conjures imag-
es of messy pans and time-
consuming breakfasts. For
this reason finding enjoyable
foods which are cholesterol
friendly is an important part
of sustainable behavioural
change. An increasing range
of ready-to-eat cereals made
with oat bran are available
which typically contain
Start the day with a bowl of beta-glucan-rich cereal
Replace butter spreads with a polyunsaturated or
monounsaturated spread or one containing plant sterols
or stanols
Eat at least 5 portions of fruit and vegetables every day
Include at least one oat-based snack each day, such as a
low-fat oat cereal bar or 2–3 oat cakes (but avoid high fat
snacks such as flapjacks)
Consume at least 2 portions of fish each week, including
at least 1 por tion of oily fish, such as mackerel, trout or
salmon
Cut down on processed meat products and replace these
with lean meats, poultry, nuts or soya protein
Choose low-fat dairy products and moderate cheese
intake
Eat more high-fibre foods, including wholemeal breads,
brown rice, skins on potatoes and fruit, beans and pulses
Aim to achieve a healthy weight
Be more active—everyone should be taking at least
30 minutes of moderate intensity physical activity on at
least 5 days each week.
Table 4. Simple steps to modify
cholesterol levels
The What’s Inside Guide – helping patients make healthy eating choices
Dr Sarah Jarvis, FRCGP
March 09
Tips for getting the most from
the label: -
1) Calorie GDA – the 2000 kcal value is the
amount for an average person. It is a useful
approximation, although patients need to be
aware their individual needs may vary
according to their size, gender and level of
physical activity.
2) It may not be necessary to consider all
GDAs. Patients may  nd it more feasible to
concentrate on one or two
3) Compare and contrast –patients can use
the GDA label to check nutrient levels,
compare similar products and choose the
one which best suits their needs.
4) Consistency counts –GDA labels are in the
same format across many food and drink
products, so patients can easily add up their
approximate daily intakes.
Despite a plethora of advice
from healthcare
professionals, our patients are
getting fatter at a super-size-me
rate.
The government has
increased spending on health
initiatives aimed at tackling
obesity, but only by getting
patients on board can we really
hope to make an enduring
di erence.
Fortunately, many food
manufacturers are playing their
part to increase consumer
education and awareness
about what’s in their food. More
than 80 companies have joined
forces to use the GDA label,
which now features on the front
of more than 20,000 product
lines across the UK – about 50%
of UK retail food and drink
packs.
The GDA label is based on
Guideline Daily Amounts*
which provide information on
Calories, sugars, fat, saturates
(saturated fat) and salt.
Nobody can expect
healthcare professionals to
police their patients’ eating.
Collaboration is the best that we
can hope for – but with the
medical consequences of
obesity proving so costly, we as
healthcare professionals should
take all the help we can get.
* GDAs are based on the
Committee on Medical Aspects
of Food Policy (COMA) report
on Dietary Reference Values.
Further information
To receive a copy of the GDA presenter, a toolkit designed to help explain
how to use GDA labels call: 020 7420 7128
What’s Inside Guide: www.whatsinsideguide.com
Untitled-1.indd 2 27/3/09 11:34:48
nutrition

Clinical Focus
184 Practice Nursing 2009, Vol 20, No 4
around 1 g beta-glucan per bowl and offer
quick, convenient and tasty ways to eat beta-
glucan. For example, Kellogg’s Optivita cere-
al contains 0.8–1 g beta-glucan per bowl
depending on the variety chosen (berry, raisin
or nut). In addition oats or oat bran can be
used in baking, added to thicken casseroles or
soups, added to crumble toppings or as a
crispy coating for fish or chicken.
Conclusions
Most people are creatures of habit so it is
easier to switch a food present in the diet to
a healthier version than change the foods that
are eaten, although this is sometimes required.
Starting with simple changes can help build
confidence and willingness to try something
new. Wherever possible ask the individual to
agree simple, clear goals for dietary change
and a timescale in which to achieve them.
Dietary changes generally take about 3 weeks
to become habits, so reassurance that perse-
verance will pay off is important.
Everyone should understand the need to
keep cholesterol levels low. Change need not
mean cutting out everything tasty from the
diet. Regular consumption of healthy foods
such as those rich in oat beta-glucan, cutting
back on saturated fats, and eating more fruit
and vegetables will, together with regular
exercise, give benefits that rapidly multiply to
reduce the risk of developing heart disease.
Conflict of interest: Angie Jefferson has received
support from the communications agency Munro &
Forster to write this article on behalf of Kellogg’s.
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KEY POINTS
Oats contain the soluble
fibre beta-glucan which
can help to actively
lower blood cholesterol
levels
Beta-glucan absorbs
cholesterol and
cholesterol-rich bile
acids in the gut
preventing their
absorption and lowering
total and LDL
cholesterol levels
Regular consumption of
oat beta-glucan can
lower LDL cholesterol by
up to 5%, equivalent to
a reduction in coronary
heart disease risk of
between 5–15%
Oats and oat beta-
glucan products should
be eaten regularly for
best effect
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Heart UK: The
cholesterol charity
Tel: 01628 628 638
www.heartuk.org.uk
British Heart Foundation
Tel: 08450 708 070
www.bhf.org.uk
Kellogg’s ‘Choose to Beat
Cholesterol’
www.choose-to-beat-
cholesterol.com
Further
information on
cholesterol or
heart disease
nutrition