as the bioavailability of some drugs is affected by
fasting. In addition, grapefruit or pomegranate juice
shouldnotbe used for a juice fast because the juices of
these fruits may increase the blood levels of prescrip-
tion medications in the body.
Juice fasts should not be extended beyond three or
four days without medical supervision, as longer fasts
can lead to poor intakes of nutrients such asprotein
andcalciumand could lead to deficiencies. In addi-
tion, anyone who feels faint or dizzy, develops an
abnormal heart rhythm, feels nauseated or vomits, or
has signs of low blood pressure, should discontinue the
fast and consult their doctor at once.
On the economic side, juice fasting is a potentially
expensive form of dietary therapy. Readers interested in
juice fasts at home or in juicing as a dietary addition
should be prepared to pay between $60 and $200 for a
juicer or juice extractor—although some deluxe models
are marketed for as much as $2000. The chief difference
is that juice extractors remove the fruit or vegetable
pulp from the juice (and are difficult to clean) while
juicers generally leave the pulp in the juice. In addition
to the cost of the machine and the fruits or vegetables to
be juiced, people on a juice fast will usually need to
purchase laxatives or enemas for cleansing the bowel.
Colonics cost anywhere from $50 to $105 per treatment
(as of 2007), while a 5-day juice fast retreat at a spa costs
at least $1600 per person at double-occupancy rates.Risks
The major risks to health from juice fasts include
metabolic crises in patients with undiagnosed diabetes
or hypoglycemia; dizziness or fainting due to sudden
lowering of blood pressure; diarrhea, which may result
indehydrationand an imbalance ofelectrolytesin the
body; and protein or calcium deficiencies from unsu-
pervised long-term juice fasts.
Minor side effects include headaches, fatigue,
constipation, acne, bad breath, and increased body
odor.
Juice fasters who undergo colonics are at risk of
contracting an infection from improperly sterilized
colonic equipment; of serious illness or death from
electrolyte imbalances in the blood; or of serious ill-
ness or death resulting from perforation of the intesti-
nal wall by improperly inserted equipment. Colonics
can also worsen the symptoms of ulcerative colitis.Research and general acceptance
Juice fasts as a specific dietary practice have not
received much attention from mainstream medicalresearchers; however, they have received some evalua-
tion within clinical studies of Ayurveda and naturop-
athy as alternative medical systems. Part of the
difficulty is that Ayurveda and naturopathy do not
lend themselves easily to the standard clinical trial
protocol, which generally focuses on only one illness
or one medication at a time rather than on multimodal
therapies or the general lifestyle changes recom-
mended by Ayurvedic practitioners and naturopaths.
There have been two studies conducted in Ger-
many in 2005 and 2006 that have reported on the
benefits of juice fasting in general lifestyle adjustment
and in treating functional bowel disorders. In the
United States, the National Center for Complemen-
tary and Alternative Medicine (NCCAM) has carried
out clinical trials of two specific plants that are often
used in juice fasts, aloe vera (Aloe barbadensis) and
cranberry (Vaccinium macrocarpon). Cranberry juice
is still being studied as of 2007 for its possible useful-
ness in preventing urinary tract infections in women.
With regard to aloe vera, NCCAM warns that the gel
from the plant has a laxative effect that causes cramps
and diarrhea in some people, and may inhibit the
absorption of prescription drugs.
Juice fasts as a treatment for AIDS and other
severe diseases, however, have come in for severe
criticism from mainstream physicians. Jay Kordich,
t‘‘ the Juiceman,’’ has been attacked for his claims
that he was cured of cancer when he was 20 by drink-
ing 13 glasses of carrot/apple juice each day. In partic-
ular, Kordich’s claims that raw vegetable juices boost
the human immune system or improve digestion are
questionable. One physician summarizes his critique
of juicing by saying, ‘‘The enzymes in plants help
regulate the metabolic function of plants. When
ingested, they do not act as enzymes within theQUESTIONS TO ASK YOUR
DOCTOR What are the potential benefits, if any, for a
person of my age, sex, and lifestyle in taking a
periodic juice fast?
What are the potential health risks of a juice fast,
if any, for me as an individual?
What specific types of juices would you
recommend for a juice fast? Have you tried any
of them yourself?
Are there any specific types of juice that you
would not recommend, and why?Juice fasts