PERIANAL.The area surrounding the anus.PERIANAL ABSCESS.Abscess that can occur when
the tiny anal glands that open on the inside of the anus
become blocked and infected by bacteria. When pus
develops, an abscess forms.
PERIPHERAL VASCULAR DISEASE.Diseases of any
blood vessels except those that supply blood to the
heart.
PERISTALSIS.A sequence of muscle contractions
that progressively squeeze one small section of the
digestive tract and then the next to push food along
the tract, something like pushing toothpaste out of its
tube.
PEROXIDES.Peroxides are highly reactive free radi-
cal molecules, used as powerful bleaching agents and
as disinfectant. In the body, they form as intermediate
compounds, for example during the oxidation of
lipids, and may damage tissues.
PERSONAL TRAINER.An individual specializing in
diet and exercise who works with clients on an indivi-
dual basis.
PERVASIVE DEVELOPMENTAL DISORDER.An impair-
ment in the development of social skills.
PESCE/POLLO VEGETARIAN. A vegetarian who
avoids the use of red meat but will include fish (pesce
in Italian) or chicken (polloin Italian) in the diet.
PH.A measure of the acidity or alkalinity of a
solution. Solutions with a pH below 7 are considered
acidic while those above 7 are alkaline. A pH of
exactly 7 (pure water) is neutral.
PHARYNX.Part of the neck and throat that con-
nects the mouth to the esophagus.
PHENTERMINE.An anorectic drug sold under a
large number of brand names.
PHENYLALANINE.An essential amino acid that can-
not be consumed by people with a metabolic disease
known as phenylketonuria (PKU).
PHENYLKETONURIA (PKU).A rare inherited meta-
bolic disorder resulting in accumulation of phenylala-
nine, an amino acid, in the body. It can lead to mental
retardation and seizures. People with PKU should not
use products containing the artificial sweetener aspar-
tame because it is broken down into phenylalanine
(and other products) during digestion.
PHOSPHOLIPID.A type of fat used to build cell
membranes.
PHYCOCYANIN.A protein found in spirulina that
gives the alga its blue color. Phycocyanin has anti-
inflammatory effects.PHYTATE.Phytic acid; an acid in cereal grains that
interferes with the intestinal absorption of minerals
such as calcium and magnesium.PHYTOCHEMICALS.A nonnutritive bioactive plant
substance, such as a flavonoid or carotenoid, consid-
ered to have a beneficial effect on human health.PHYTOESTROGENS.Compounds that occur natu-
rally in plants and under certain circumstances can
have actions like human estrogen. When eaten they
bind to estrogen receptors and may act in a similar way
to oestrogen.
PITA.Pitta; pita bread; a round, double-layered or
pocket flatbread made from wheat and yeast.PITUITARY GLAND.A small gland at the base of the
brain that produces many regulating hormones.PLACEBO EFFECT.A termthat describesthe improve-
ment in symptoms that some patients experience when
they are given a placebo (sugar pill or other inert sub-
stancethatdoes notcontainany medication)aspartof a
clinical trial. Patients with functional dyspepsia show a
high rate of placebo effect in trials of new medications
for the disorder.PLAQUE.Material forming deposits on the surface
of the teeth, which may promote bacterial growth and
decay.PLASMA.The liquid part of the blood and lympha-
tic fluid, which makes up about half of its volume. It is
92% water, 7% protein and 1% minerals.POLAR.Containing regions of positive and nega-
tive charge; likely to be soluble in water.POLYCYSTIC OVARY SYNDROME.A condition in
which cysts in the ovary interfere with normal ovula-
tion and menstruation.POLYMORPHISM.A gene that exists in variant or
allelic forms.POLYOL.An alcohol containing more than two
hydroxyl (OH) groups, such as sugar alcohols,
inositol.POLYPEPTIDE.A molecule made up of a string of
amino acids. A protein is an example of a polypeptide.POLYSACCHARIDE. Any of a class of carbohy-
drates, such as starch, amylose, amylopectin and cel-
lulose, consisting of several monosaccharides.Glossary