A vegetarian diet is known to confer a wide
range of health benefits. Research has shown
vegetarians to suffer less heart disease,
hypertension, obesity, diabetes, various
cancers, diverticular disease, bowel
disorders, gall stones, kidney stones, and
osteoporosis (Dwyer, 1988). Vegetarian diets
have also been used in the treatment of
various illnesses, including rheumatoid
arthritis and nephrotic syndrome.
Dickerson & Davies (1986) studied matched
pairs of vegetarians and non-vegetarians with
regard to their general health. It was found
that the vegetarians made 22% of the visits
to hospital out-patients of non-vegetarians,
and spent a similarly reduced proportion of
time in hospital.
A Healthy Vegetarian Diet
A typical vegetarian diet closely matches
expert dietary recommendations for healthy
eating, being low in saturated fat and high
in fibre, complex carbohydrates, and fresh
fruit and vegetables.
The 1983 NACNE Report (National Advisory
Committee on Nutrition Education) in the UK
recommended a reduction in fat intake,
particularly saturated fat, and an increased
dietary proportion of polyunsaturated fats to
saturated fats. An increased intake of
complex carbohydrates and fibre and a
decreased intake of sugar and salt were also
recommended.
The World Health Organisation (1990) has
similarly recommended a reduced intake of fat
and increased consumption of complex
carbohydrates. Increased consumption of
fruit, vegetables, cereals and pulses is also
recommended.
The nutritional guidelines from the World
Health Organisation, the NACNE Report and
other expert bodies form the basis of advice
given on healthy eating by health
professionals today.
Vegetarian diets tend to be lower in total
fat. Taber & Cook (1980) found lacto-ovo
vegetarians to consume an average of 35% of
energy as fat, compared to omnivores
consuming over 40% of energy as fat. A study
of the diets of a group of French vegetarians
found they had a daily intake of 25% less fat
than non-vegetarians (Millet, 1989).
Vegetarians also tend to eat proportionally
more polyunsaturated fat to saturated fat
compared with non-vegetarians. Animal
products are the major sources of dietary
saturated fat.
The best dietary sources of complex
carbohydrates and fibre (also called
non-starch polysaccharides or NSP's) include
wholegrain cereals, vegetables and pulses and
so vegetarian diets tend to be high in these
nutrients. Animal products contain no fibre
or complex carbohydrate.
Recent research has demonstrated the
importance of protective antioxidant
nutrients in the diet found in fresh fruit
and vegetables. These antioxidant nutrients
include the beta-carotene form of vitamin A,
vitamin C and E. Many researchers now believe
that these nutrients play a major role in
reducing the risk of chronic diseases such as
heart disease and cancer. A high consumption
of fresh fruit and vegetables is a benefit of
vegetarian diets.
All these factors contribute to the proven
health of vegetarians although it is
difficult to account for the exact
contribution of each nutrient. All vegetarian
diets are not necessarily healthy, for
example if too high a proportion of high fat
dairy products are consumed.
Myths and facts about vegetarianism
by Dr. D. P. Atukorale, M. D.
Many laymen and professionals in Sri Lanka
have various misconceptions about
vegetarianism and the proteins. One such
misconception is that vegetarians don’t get
sufficient
quantity of high quality proteins. Other
misconception is that vegetable proteins are
inferior in
quality when compared to animal proteins.
Whenever I tell my friends and relations that
I am a vegetarian their first reaction is
“how doyou get enough proteins?” Vegetarians
need not worry about proteins and it is
almost
impossible for a vegetarian to be protein
deficient. It is common knowledge that
protein is of
primary importance to good health as it plays
a crucial role in every cell of our body. All
enzymes are proteins. Antibodies, many
hormones and bones all contain proteins.
Proteins are
capable of yielding some dietary energy (4
Kcal/gm), help to transport fats and vitamins
and
help to control body’s self-regulatory system
(homeostasis).
When calories are adequate protein deficiency
is virtually non-existent. This is because
goodquality proteins with all the essential
amino-acids (EAA) are abundant in grains,
vegetables, beans, nuts and seeds. It is true
that in the under developed countries
sometimes you come across protein calorie
malnutrition. This is not due to
vegetarianism but due to lack of adequate
amount of food.
It is true that vegetarians consume less
proteins than meat eaters. But they easily
meet their protein needs and protein
deficiency is extremely rare among
vegetarians. Vegetarians shoudl take variety
of plant foods and don’t need to consume
carefully planned food combinations at every
meal as was believed earlier.
Plant protein is healthier than animal
protein and excess animal proteins are
associated with increased heart diseases loss
of calcium from bones and poor kidney
function. In developing countries such as
Sri Lanka , the rise in standard of living is
often accompanied
by changes in lifestyle and dietary changes.
It is frequently seen that the “new rich” and
the
people who migrate to urban areas from
villages and who have never taken beef,
mutton, and
pork and eggs emulate the eating habits of
the “urban rich” and consume more
protein-rich
animal foods and this trend leads to chronic
diseases such as heart attacks, cancer,
kidney
diseases, hypertension diabetes and obesity.
Protein Chemistry
A protein molecule consists of long twisted
strands of aminoacids the building blocks of
protein. Every aminoacid contains nitrogen.
The food we consume contains about 20
different
aminoacids of which we can make 11 of them in
our body an these are called non-essential
aminoacids. The other 9 are called essential
aminoacids (EAA) and these we must get from
our food.
All proteins such as meat, milk, eggs, beans,
nuts and grains contain all EAA Gelatin is
theonly protein which is lacking in most of
the EAA some of the plant proteins do not
contain allthe EAA in sufficient quantities,
but as vegetarians take a variety of foods
they don’t get any deficiency of EAA. Protein
quality also depends on how well i.e. how
easily a particular
proteins is digested and broken down into its
individual amino-acids. Plant proteins are
about
85% digestible and those based on animal
proteins are about 95% digestible and that is
a small
difference.
How much proteins do we need ?
This depends on many factors such as age,
body size, climate, activity level and
overall
health. Number of calories in the diet also
affect protein needs. When calories are low,
body
burns proteins for energy and overall protein
requirement goes up.
Protein needs depend on the nitrogen balance.
Nitrogen balance studies tell us how much
protein we must consume to meet our nitrogen
needs. Nitrogen balance studies have been
used to establish the protein RDA
(recommended dietary allowance) RDA for
protein is 63 grams for an adult male and 50
grams for an adult female. These are American
figures and Sri Lankan figures should be very
much less. Protein requirements depend not on
the actual body weight but on the ideal body
weight. The more specific RDA for proteins is
0.8 grams for
every kilogram of ideal body weight.
Vegetarians and proteins
Vegetarians usually have diets that are lower
in proteins. As vegetable proteins contain
less proteins than animal proteins and as
they contain limiting aminoacids, vegetarians
have to
consume more proteins. A better RDA for
vegetarians (excluding lactovegetarians and
lacto-ovo-vegetarians whose protein needs are
like that of omnivores) is 1.0 gram of
protein
per kg of body weight compared to 0.8 grams
recommended for non-vegetarians.Vegans
(pure vegetarians) get about 11-12% of their
calories from protein whereas omnivores get
about 15-17% of calories from protein.
Surveys show that vegans get plenty of
proteins.
Vegetarians don’t have to do anything special
to meet their protein requirements. Just eat
enough calories, maintain your ideal weight
and include a variety of plant foods such as
soya,
lentils (Dhal) other legumes such as beans,
lima beans (mekaral) potatoes, spinach, tofu,
wheat bread, red rice and peas. Some of the
vegetarian foods such as broccoli are
superior to animal foods such as beef and are
more protein dense.
According to American Dietetic Association it
is not necessary that complementation of
aminoacid profiles be precise and at exactly
the same meal i.e. protein eaten at one meal
can combine with protein eaten at next meal
to improve the quality of the protein as our
body has a storage pool of essential
aminoacids.
Plant proteins prevent heart attacks and are
better for your bone health. Excess protein
is unhealthy for people with kidney disease.
Vegetarians unlike non-vegetarians don’t get
excess protein in their diet.
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