Too Much of a Good
Thing -- Carrot Juice Overload
About Liz
Applegate, Ph.D. | Nutrition and
Fitness Archive
Q: I have a friend who is "into juicing."
He consumes at least a half-gallon of carrot juice daily. His skin, mostly his
hands, has turned yellowish-orange. He thinks this is a sign of health; I
believe it signals excessive intake of carotene. What's the verdict? And does he
run the risk of any side effects with his carrot juice addiction?
A: Your assessment is correct. Your friend's
yellow-orange skin hue is a tell-tale sign of a beta carotene overdose from his
hefty carrot juice consumption. And whether this skin discoloration signals
health, as your friend insists, is questionable. But don't get me wrong. Beta
carotene -- along with other plant pigments generally called carotenes, found in
carrots and other colorful vegetables and fruits -- are a boost to your
health.
In fact, a diet rich in
carotenes helps ward off age-related degenerative diseases such as cancer, arthritis and heart disease. But your friend's "drinking" habit has
led to too much of a good thing. Let's take a look at how carotenes keep you
young, how much you need, what's too much and where to get these wondrous
nutrients.
First, meet the carotenes: An
entire family of colorful pigments in shades of yellow, orange and red abound in
fruits and vegetables. More than 500 different carotenes have been identified,
with beta carotene the most notable and most common carotene found in foods and
body tissues. Others from the carotene family include lycopene (giving a red hue
to tomatoes and watermelons), lutein and zeaxanthin (both stockpiled in greens
like spinach and kale), and cryptoxanthin (a reddish-orange carotene found in
red peppers, tangerines and
papayas).
Carotenes have several jobs.
Some, particularly beta carotene, are converted into vitamin A which keeps your skin, lungs, intestinal
track and immune system in working order. Carotenes also act as antioxidants
protecting against the oxidative damage caused by highly reactive substances
called free radicals. Exposure to sunlight, cigarette smoke and air pollution,
along with your body's everyday cellular activities, cause free radicals to
form. And it's free-radical havoc that scientists believe is pivotal in the
development of age-related, degenerative diseases such as cancer, cataracts, arthritis, heart disease and even asthma.
Studies
show that people who eat carotene-rich foods have lower risk for many of these
diseases. In a Swedish study involving women 50 years and up, those who ate
about one-half a carrot's worth of beta carotene daily had two-thirds lower risk
for breast cancer compared to women who skimped on their
carotene intake. Other studies show that a lycopene-rich diet protects against
prostate cancer in men. And research also shows lutein
and zeaxanthin, acting as antioxidants, protect the eyes from macular degeneration, a leading form of blindness in
the elderly. And still other studies suggest that carotenes cut heart disease
risk in both men and women.
The bottom line: Disease protection comes from getting the
entire family of carotenes by eating a variety of fruits and vegetables.
Researchers also theorize that the carotenes may team up with each other and
other compounds in foods, making beta carotene supplements of questionable
benefit.
So what's your carotene need?
Meeting your vitamin A requirement from beta carotene, 6 milligrams daily, is
easy: Eat a handful of baby carrots and you've done it! Six ounces of carrot
juice (made from two medium-sized carrots) supplies a whopping 28 mg. of beta
carotene. And your friend's 1/2 gallon-a-day habit of carrot juice equals 300
mg., or 50 times the requirement.
The
good thing about your friend's beta-carotene overdosing, is that the body
doesn't convert the excess to vitamin A. If this were the case, serious toxicity
problems, such as liver damage, would occur. Instead, the excess carotene
accumulates over a period of weeks in the skin, primarily on the palms of hands
and feet, lending a yellow-orange
hue.
The amount of carotene that causes
notable skin color changes varies, but one study showed that approximately 50
milligrams daily led to discoloration in about 10 days. The skin discoloration
is completely harmless, except perhaps to friends who may find this appearance
startling. So your friend's tainted skin color is easily
explained.
While his orange skin is not a
threat to his health, the over-emphasis on one source of beta carotene -- carrot
juice -- is a concern. Your friend is missing out on health benefits from the
family of carotenes and other phytochemicals by not eating a variety of
vegetables (such as tomatoes, kale, spinach, winter squashes, broccoli and
romaine lettuce) and fruits (including apricots, tangerines, watermelon,
cantaloupe and grapefruit). Suggest he try some of these in his juicer the next
time around for a dose of good health.
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