Encyclopedia of Health and Medicine

B
bilberry A plant (Vaccinium myrtillus) whose
berries, stems, and leaves are rich in antioxidants
(notably anthocyanosides) and tannins. Even preserves
made from the blue-colored berries of this
bush contain high enough levels of these substances
to have noticeable effect. Anthocyanosides
have particular affinity for the walls of arteries,
especially arterioles, the tiny, almost microscopic
arteries deep within body tissues where nutrient/waste
exchanges takes place. Anthocyanosides
appear to keep the cells of these arterial walls
healthy and structurally intact. This action has
pronounced effects on the tiny blood vessels that
supply the RETINA, CORNEA, and other structures of
the EYE, protecting them from age-related damage
such as AGE-RELATED MACULAR DEGENERATION (ARMD)
and CATARACT. The tannins in bilberry seem to
help INFLAMMATION and INFECTION affecting the
MOUTH and THROAT, plus gastrointestinal upset.
Many ophthalmologists recommend that people
over age 50, who are entering the high-risk
period of life for conditions such as ARMD, night
blindness, and cataracts, take bilberry to help protect
their eyes and vision. Bilberry seems most
effective in combination with the amino acids
LUTEIN and ZEAXANTHIN, which also protect the
retina and cornea. There are no known side effects
or interactions with bilberry, and doctors consider
it safe for most people to take long-term.
BILBERRY (Vaccinium myrtillus)
Uses Risks/Side Effects Interactions
improve night vision none known none known
prevent or slow ARMD
prevent or slow growth
of cataracts
RETINOPATHY of DIABETES
60
See also ARTERY; CATARACT EXTRACTION AND LENS
REPLACEMENT; RETINOPATHY; VISION IMPAIRMENT.
biofeedback A method in which a person learns
to influence certain body responses, such as to
PAIN or stress. Biofeedback begins with learning
sessions that use electronic measuring devices to
report physiologic signs such as PULSE, BREATHING
rate, or SKIN temperature. The device sends a
visual or sound signal to help focus concentration
on the particular sign, for example the pulse. The
person then concentrates on slowing the rate of
the sound or visual cue, indicating that the body is
relaxing and the HEART RATE is slowing. Over the
course of 5 to 10 biofeedback sessions, the person
learns to “tune in” to the physiologic signs and no
longer needs the device. Once the person masters
the method of biofeedback, he or she can use it at
will.
CONDITIONS BIOFEEDBACK MAY HELP
ASTHMA
chronic PAIN syndromes
HYPERTENSION
migraine HEADACHE
MUSCLE tension headache
PALPITATIONS
RAYNAUD’S SYNDROME
RETINOPATHY of DIABETES
SEIZURE DISORDERS
stress
STROKE recovery
URINARY INCONTINENCE
Though the most common application of
biofeedback is stress relief, people who have
chronic health conditions also can use it to manage
pain and other symptoms. Numerous clinical
studies over the past 25 years have supported the
effectiveness of biofeedback, especially for relieving
pain and stress. There are few risks with
biofeedback, as it is noninvasive. Because biofeedback
can alter body chemistry, it can change medication
needs for chronic conditions such as