Pumpkin and Yam, the top foods for beta-carotene

Beta-Carotene - How Foods Fight Cancer

Beta-carotene enters the cell membrane that surrounds each of your cells 
and protects the cell from free radical damage.


One of the best-known antioxidants is beta-carotene, the yellow-orange
pigment found in carrots, yams, and cantaloupes. Beta-carotene has long
been looked on kindly by nutritionists because it provides vitamin A, which
is important for good vision, among other functions. Beta-carotene is actually
two molecules of vitamin A joined together.

However, beta-carotene does more than simply provide vitamin A. It
enters the cell membrane that surrounds each of the cells that make up your
body and then waits there to fend off free radicals that might approach.

Beta-carotene also has a measurable immune-boosting effect with as
little as 30 milligrams of beta-carotene per day—the amount in two large
carrots.3,4 Dietary reference intakes are set for vitamin A, rather than its
precursor, beta-carotene. However, the Institute of Medicine holds that
3–6 milligrams of beta-carotene per day—equivalent to 800–1,700 IU
(240–510 retinol equivalents) of vitamin A—is sufficient to maintain
beta-carotene blood levels in the range associated
with a lower risk of chronic diseases.5

You’ll find beta-carotene not only in orangecolored
fruits and vegetables; it is also in dark
green leafy vegetables. You can’t see the orange
color because the green chlorophyll hides betacarotene
in the same way that chlorophyll in tree leaves hides the plants’
underlying orange, red, and brown colors until the green color fades in
autumn.

Although you can buy beta-carotene supplements, it is much better to
get beta-carotene from foods. In fact, studies testing beta-carotene’s cancer-
fighting power in smokers (a group selected because they are at particular
risk for cancer) showed that those whose diets were high in beta-carotene
had a measure of protection, but those who got beta-carotene from supplements
were actually more likely to develop cancer than were other smokers.

The reason is not entirely clear, but it may be that, since supplements deliver
high doses of only one antioxidant, they interfere with the absorption of
others. Moreover, vegetables and fruits that are rich in beta-carotene are
loaded with hundreds of additional antioxidants, vitamins, minerals, and
other protective compounds.

The moral of the story is that there is plenty of beta-carotene in vegetables
and fruits, and they are the best sources. Table 6 lists some top
foods for beta-carotene.

6 lists some top foods for beta-carotene.