I
DIGEORGE SYNDROME
GOOD DIETARY HABITS
Eat fresh rather than preserved,
packaged, or convenience foods.
Eat plenty ofvegetables and at least five
portions of fruit every day. When raw or
lightly cooked, they retain a higher
nutritional value.
Eatwhole-grain products, including
wholemeal bread.
Cutdown consumption of red meat;
instead, eat fish, poultry, and pulses.
Keep the fat content of your diet low and
use polyunsaturated fats and vegetable
oils rather than saturated fats.
Cutdown on sugar and saltin allfoods.
When choosing filling foods, eat
potatoes in their skins, pasta, or rice.
In affluent countries, diseases due to
deficiency are rare, occurring only in
certain groups of people (such as alco-
holics). Instead, many disorders are due
at least partly to overconsumption of
food. Overeating causes weight gain
and, in severe cases,
obesity
.
The latter
condition places a person at increased
risk of disorders such as
diabetes melli-
tus
,
stroke
,
coronary artery disease
,
and
osteoarthritis
.
Diets causing weight gain
tend to be high in fats and sugar, but
may be low in valuable components
such as fibre and vitamins.
FATS
A diet that is high in fats, particularly
saturated fats (see
fats and oils
) ,
may
contribute to
atherosclerosis
(narrowing
of the arteries due to accumulation of
fatty deposits on the arterial walls);
this, in turn, may lead to cardiovascular
diseases such as coronary artery disease,
stroke, and peripheral vascular disease.
A high-fat diet has also been linked
with cancer of the bowel (see
colon,
cancer of
)
and
breast cancer
.
ALCOHOL
Overconsumption of
alcohol
can lead to
alcohol-related disorders
.
In the digestive
system, it may cause
cirrhosis
of the
liver,
pancreatitis
,
and oesophageal cancer
(see
oesophagus, cancer of
) ;
in addition,
people who are dependent on alcohol
often become malnourished. Drinking
too much alcohol may cause cardiovas-
cular
problems
such
as
hypertension
(high blood pressure) and
heart failure
;
neurological
disorders
such
as
Wer-
nicke-Korsakoff syndrome
;
and mental or
behavioural problems such as
depres-
sion
or violence.
SALT
A high salt intake may predispose a
person to hypertension.
FIBRE
Fibre, found in fruit, vegetables, and
grains, provides bulk, w hich helps the
passage of food through the intestine
and also aids the absorption of nutri-
ents (see
fibre, dietary
) .
A lack of fibre is
thought to be a contributory factor in
digestive disorders such as
diverticular
disease
(a condition in w hich abnormal
pouches form in the colon), chronic
constipation
,
and
haemorrhoids
.
VITAMINS
Many people’s diets contain too few
natural vitamins; to remedy this prob-
lem, it is better to eat vitam in-rich
foods than
to
take vitamin
supple-
ments. Women w ho are planning a
pregnancy need to increase their intake
of
folic acid
in order to reduce the risk
of
neural tube defects
in the baby
FOOD ALLERGIES
Many illnesses are commonly ascribed
to
food allergy
,
but it is only rarely that a
definite link is proved. Nut allergies,
w hich may cause the life-threatening
reaction
anaphylaxis
,
and
coeliac disease
(a reaction to the protein gluten, w hich
is found in wheat and other cereals) are
examples
of genuine
food allergies.
(See also
nutritional disorders
. )
dietary amenorrhoea
A form of
amenorrhoea
(cessation of
menstruation) caused by major weight
loss, although not necessarily by a lack
of food. In some cases, the weight loss
is deliberate and severe (see
anorexia
nervosa
) .
Absence of menstrual periods
occurs because the loss of body fat dis-
rupts
the
levels
of the
female
sex
hormone
oestrogen
.
dietary fibre
See
fibre, dietary.
dietetics
The application of nutritional science
to maintain or restore health. Dietetics
involves not only a knowledge of the
composition of foods, the effects of
cooking and processing various foods,
and dietary requirements, but also of
psychological aspects of diet, such as
eating habits (see
nutrition
) .
diethylstilbestrol
A synthetic form of the female sex hor-
mone
oestrogen
,
occasionally used to
treat prostate cancer (see
prostate, cancer
of
)
and,
in
postmenopausal
women
only, to treat
breast cancer
.
Common
adverse effects include nausea,
oedema
(fluid retention)
and breast enlarge-
ment
(
gynaecomastia
)
in men.
differential diagnosis
One of two or more different disorders
that could be the cause of a patient’s
symptoms. If certain symptoms, such as
abdominal pain, might be caused by
various disorders, a doctor w ill carry
out further tests, observe the patient’s
response to particular treatments, or
monitor the course of the disease in
order to arrive at the true diagnosis.
differentiation
The process by w hich the cells of the
early
embryo
,
w hich are almost identical
and have not yet taken on any particular
function, gradually diversify to form
the distinct tissues and organs of the
more developed embryo.
The word “ differentiation” is also
used in the assessment of cancer; it
means the degree to w hich the m icro-
scopic appearance of cancerous tissue
resembles normal tissue.
diffusion
The spread of a substance (by move-
ment of its molecules) in a fluid from
an area of high concentration to one of
lower concentration, thus producing a
uniform concentration throughout.
diflunisal
A
nonsteroidal
anti-inflammatory
drug
(NSAID) used to relieve joint pain and
stiffness in types of
arthritis
.T h e
drug is
also given for back pain, sprains, and
strains.
Side
effects
include
nausea,
diarrhoea, and a rash.
DiGeorge syndrome
An
immunodeficiency disorder
that results
in a failure of the
immune system’s
cells
to fight infection. The disorder is here-
ditary and congenital (present at birth).
In
DiGeorge
syndrome,
the
thymus
gland is absent or fails to develop nor-
mally. The thymus is a key part of the
immune system, so its absence may
allow persistent, serious infections to
develop. Children with DiGeorge syn-
drome are susceptible to
opportunistic
infections
,
such as
candidiasis
(thrush),
D
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