Varieties
Green asparagus is the most commonly seen type. White asparagus, which is grown underground
to prevent chlorophyll from developing and turning it green, has thicker, smoother spears.
It’s harder to find, but worth the effort. A less frequently seen variety is purple
asparagus, called viola, which actually turns green during cooking.
Buying and storing tips
Asparagus can be found in the produce section of most health food stores, specialty
markets, and supermarkets. When buying asparagus, choose firm, bright green (or pale ivory)
stalks with tight tips. Wider spears are from older plants, and slender spears from younger
ones; both are tender and flavorful. Store asparagus tightly wrapped in a plastic bag for up
to three days in the refrigerator. It may also be stored standing upright, with the stems
immersed in about an inch of water and the tops covered with plastic.
Preparation, uses, and tips
Because it’s grown in sandy soil, asparagus should be washed thoroughly to remove any
dirt or grit. Snap any tough ends off and immerse the stalks in boiling salted water. Reduce
heat, simmer, and remove after about five minutes, while still bright green. Toss with olive oil and serve hot. Asparagus is also
good in stir-fry dishes.
Nutritional Highlights
Asparagus, 3 medium spears of asparagus
(raw)
Calories: 11
Protein: 1.1g
Carbohydrate: 2.2g
Total Fat: 0.09g
Fiber: 1.0g
*Good source of: Vitamin C (6.3mg), and Folate (61mcg)
*Foods that are an “excellent source” of a particular
nutrient provide 20% or more of the Recommended Daily Value. Foods that are a “good
source” of a particular nutrient provide between 10 and 20% of the Recommended Daily
Value.
Health benefits and concerns
Asthma
Vitamin C, present in fruits and
vegetables, is a powerful antioxidant and
anti-inflammatory. This anti-inflammatory activity may influence the development of asthma
symptoms. A large preliminary study has shown that young children with asthma experience
significantly less wheezing if they eat a diet high in fruits rich in vitamin C.
Atherosclerosis
Diets high in insoluble fiber (found in some vegetables)
are associated with protection against heart disease in both men and women.
Bruising
Many Americans eat insufficient amounts of foods containing vitamin C; the disease caused
by vitamin C deficiency, scurvy, causes easy bruising. While very few people actually have
scurvy, even minor deficiencies of vitamin C can increase the incidence of bruising. People
who experience easy bruising may want to try eating more fruits and vegetables—common
dietary sources of vitamin C.
Cancer
The strong association between increased intake of
beta-carotene from food and a reduced risk of lung
cancer does not necessarily mean that supplementation with natural beta-carotene
supplements would reduce the risk of lung cancer. Dietary beta-carotene may be a marker for
diets high in certain fruits and vegetables that contain other anticancer substances that may
be responsible for the protective effects. Until more is known, some doctors advise smokers to
avoid all forms of beta-carotene supplementation—even natural beta-carotene.
Capillary
fragility
Eating plenty of flavonoid- and vitamin C-rich fruits
and vegetables helps to support the structure of capillaries.
Cataracts
Some but not all studies have reported that eating more foods rich in beta-carotene or
vitamin A was associated with a lower risk of cataracts. Synthetic beta-carotene
supplementation has not been found to reduce the risk of cataract formation. It remains
unclear whether natural beta-carotene from food or supplements would protect the eye or
whether beta-carotene in food is merely a marker for other protective factors in fruits and
vegetables high in beta-carotene.
High
homocysteine
A controlled trial showed that eating a diet high in fruits and vegetables containing folic acid, beta-carotene, and vitamin C effectively lowered
homocysteine levels. Healthy people were assigned to either a diet containing a pound of
fruits and vegetables per day, or to a diet containing 3 1/2 ounces (99g) of fruits and
vegetables per day. After four weeks, those eating the higher amount of fruits and vegetables
had an 11 percent lower homocysteine level compared to those eating the lower amount of fruits
and vegetables.
Macular
degeneration
People who eat plenty of fruits and vegetables high in beta-carotene appear to be at lower
risk for macular degeneration than people who do not eat these foods. However, another study
found no association between age-related macular degeneration and intake of antioxidants,
either from the diet, from supplements, or from both combined. More research is needed to
reconcile these differences. In the meantime, beta-carotene-rich vegetables continue to be
part of a healthful diet.
Multiple sclerosis
(MS)
In one survey, researchers gathered information from nearly 400 individuals (half with MS)
over three years. They found that consumption of vegetable protein, fruit juice, and foods rich in
vitamin C, thiamine, riboflavin, calcium, and potassium correlated with a decreased MS risk.
Health benefits and
concerns for vegetables
Many health benefits and concerns associated with this food are applicable to other
vegetables. Read about health benefits and concerns
for vegetables for a full description.
