B

bilberry A plant (Vaccinium myrtillus) whose
berries, stems, and leaves are rich in antioxidants
(notably anthocyanosides) and tannins. Even pre-
serves made from the blue-colored berries of this
bush contain high enough levels of these sub-
stances 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 nutri-
ent/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
MOUTHand THROAT, plus gastrointestinal upset.
Many ophthalmologists recommend that peo-
ple 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 pro-
tect 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
RETINOPATHYof DIABETES

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

PAINor 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 RATEis 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 PAINsyndromes

HYPERTENSION migraine HEADACHE

MUSCLEtension headache PALPITATIONS

RAYNAUD’S SYNDROME RETINOPATHYof DIABETES

SEIZURE DISORDERS stress

STROKErecovery URINARY INCONTINENCE

Though the most common application of

biofeedback is stress relief, people who have

chronic health conditions also can use it to man-

age pain and other symptoms. Numerous clinical

studies over the past 25 years have supported the

effectiveness of biofeedback, especially for reliev-

ing pain and stress. There are few risks with

biofeedback, as it is noninvasive. Because biofeed-

back can alter body chemistry, it can change med-

ication needs for chronic conditions such as

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