IN THIS ISSUE:
Ironing out the "math gap" in teen girls
Spotlight on iron – am I getting enough?
RECIPE: Mango Tango Black Bean Salsa
How Active and Fit Are Teens?
NEWS IN BRIEF:
Does breastfeeding reduce the risk of becoming overweight?
Nutrition and Academic Achievement
Science for Kids

The girls with the low iron stores were more than twice as likely to struggle in math than the girls who had normal iron status.

The most recent DRI report from the National Academy of Sciences recommends that vegetarians consume twice as much iron to meet their daily requirement due to the reduced absorption of iron from plant foods.

Ironing out the "math gap" in teen girls

MEMO TO GIRLS: If you're struggling to pass algebra, you may want to take a closer look at what you're eating.

Dr. Jill S. Halterman from the University of Rochester's Children's Hospital in Rochester, New York, conducted a study on adolescent girls, iron status and math achievement. She found that the more deficient the iron level, the lower the score on a mathematics achievement test.

In her study, Dr. Halterman found that 8.7% of the teen girls were iron deficient, with 1.5% diagnosed as having full-blown iron-deficiency anemia. The girls with the low iron stores were more than twice as likely to struggle in math than the girls who had normal iron status.

While a lack of interest in math and other social/cultural factors have been blamed for poor math performance in many adolescent girls, this study adds a nutritional factor to the equation. The decline in math performance for many teen girls corresponds to the onset of menstruation at around age 12. It's long been known that monthly blood losses associated with menstruation place girls and women at risk of iron-deficiency anemia.

The study findings make sense when you consider the role of iron in the body. Iron functions as a component of hemoglobin, the oxygen carrier in red blood cells that transports oxygen to tissues throughout the body. In iron-deficiency anemia, the red blood cells contain less hemoglobin, resulting in a reduced capacity to carry oxygen. A shortage of oxygen results in fatigue, apathy, pale skin and the inability to concentrate. A simple blood test that measures the amount of hemoglobin in the blood can detect iron-deficiency anemia. (There are also more complex tests that can detect iron depletion in the early stages).

GETTING ENOUGH IRON
Adolescent females and women in their childbearing years require 18 milligrams daily, according to the most recent Dietary Reference Intakes (DRI). In contrast, the requirement for males and post-menopausal women is a mere 8 milligrams per day.

The best food sources of iron are lean meat, fish and poultry. They contain a form of iron known as heme iron, which is easily absorbed by the body. Non-heme sources of iron are found in soybeans, lima beans, almonds, peanut butter, dried apricots, raisins, spinach, potato, peas, winter squash, and fortified cereals. Vitamin C enhances the absorption of non-heme iron. To get the most iron from plant-based foods, include a vitamin C source such as citrus, broccoli, kiwi, strawberries, peppers or potatoes with meals.

The most recent DRI report from the National Academy of Sciences recommends that vegetarians consume twice as much iron to meet their daily requirement due to the reduced absorption of iron from plant foods. (The full report can be found at http://www.nap.edu/books/0309072794/html/ )

The worksheet below is a useful tool for helping teen girls make diet changes to boost their iron intake. Teen girls, particularly those who eat few animal sources of protein, may also want to consider taking an iron-containing vitamin/mineral supplement.

Spotlight on iron — am I getting enough?

Iron is not an equal opportunity mineral. In spite of a lower caloric need, females have to pack over twice as much iron into their diets compared to males. Because the average U.S. diet provides only 5-6 milligrams of iron per 1000 calories, few females actually reach the daily goal of 18 milligrams. This exercise will monitor how much iron you consume in a typical day.

YOUR DAILY INTAKE:

1. Keep a record of everything you eat and drink for 3-7 days. Circle all of the foods (including the amounts) that contain iron, including eggs, meat, fish, poultry, legumes, grains, fruits, and vegetables.

2. Calculate the milligrams of iron in your daily diet using one or more of the following methods:

• Nutrition Facts food label information (for iron, multiply % Daily Value times .18 to get the number of milligrams)
• A computer-based nutrition database (such as the USDA nutrient database located at http://www.nal.usda.gov/fnic/foodcomp/Data/ )
• The chart below :

IRON CONTENT OF COMMON FOODS (in milligrams):
3 oz. halibut, salmon, or tuna -- 1.0 mg
3 oz. shrimp or sardines --2.5 mg
3 oz. liver, raw clams, or oysters -- 6.0 mg
3 oz. other meat or poultry --2.0 mg
3/4 c. legumes, cooked -- 3.0 mg
1 egg -- 1.0 mg
4 oz. tofu -- 2.5 mg
1 serving of fruit (average) -- 0.5 mg
1/4 c. dried fruit -- 1.5 mg
1 cup iron-rich vegetables*-- 2.0 mg
1/2 cup other vegetables (average) -- 0.5 mg
1 slice bread, 1/2 cup rice or pasta -- 0.5 mg
1 serving fortified breakfast cereal (read label)

*Dark-green leafy vegetables, broccoli, asparagus, lima beans, black-eyed peas, Brussels sprouts, corn, peas, winter squash, tomato juice, mixed frozen vegetables.

YOUR ESTIMATED DAILY IRON INTAKE:

How does your estimated intake compare with the RDA of 18 milligrams per day?

 

List ways you can improve your iron intake:

Mango Tango Black Bean Salsa

The following recipe is a versatile and delicious recipe that can be used as a dip with baked tortilla chips, wrapped into a tortilla or even served as a cold salad. The corn and beans are iron-rich, and the mango provides a good source of vitamin C.

Ingredients:
1 can (15 ounces) black beans, rinsed and drained
1 can (7 ounces) whole kernel corn with peppers, drained
1 medium mango, peeled, seeded and cut into 3/4-inch
cubes
1/4 cup finely chopped onion
1/4 cup coarsely chopped fresh cilantro
2 tablespoons fresh lime juice
1 teaspoon garlic salt
1/4 teaspoon ground cumin

Preparation:
In medium bowl, combine all ingredients. Serve with baked tortilla chips, if desired.

Servings: 8 (about 1/3 cup each)
Nutritional Information Per Serving: 70 calories; 0 g fat; 0 mg cholesterol;589 mg sodium; 17 g carbohydrate; 4 g fiber; 3 g protein.
Recipe courtesy of the Canned Food Alliance

Source: The Centers for Disease Control and Prevention’s (CDC’s) Youth Risk Behavior Surveillance System (YRBSS) data for 1999.

How Active and Fit Are Teens?

American adolescents have notoriously poor eating habits and new data suggest that their exercise habits may not be much better. The following statistics compiled by the Centers for Disease Control and Prevention (CDC) offer a snapshot of the activity patterns of teens.

Of particular note – competitive sports may not be the solution for many children and teens. At around age 10, youth sports participation begins to decline, most likely due to the competitive and exclusive climate of many of today's youth sports leagues. Clearly, we need to encourage lifetime fitness activities, including basics such as walking, bicycle riding and fitness-oriented recreational activities.

• More than one in three (35%) do not participate regularly in vigorous physical activity.

• Regular participation in vigorous physical activity drops from 73% of 9th grade students to 61% of 12th grade students.

• Nearly half (45%) do not play on any sports teams during the year.

• Nearly half (44%) are not even enrolled in a physical education class; enrollment in physical education drops from 79% in 9th grade to 37% in 12th grade.

• Only 29% attend daily physical education classes, a dramatic decline from 1991, when 42% of high school students did so.

• National transportation surveys have found that walking and bicycling by children aged 5–15 dropped 40% between 1977 and 1995.

• Although an estimated 38 million young people participate in youth sports programs, participation declines substantially as children progress through adolescence. One study found that attrition from youth sports programs was occurring among 10-year-olds and peaked among 14–15-year-olds.

News in Brief

DOES BREASTFEEDING REDUCE THE RISK OF BECOMING OVERWEIGHT?
In the May 16, 2001 issue of the Journal of the American Medical Association, two separate groups of researchers report on a possible association between breastfeeding and later incidence of overweight among children and adolescents. The first study ( Hedinger, et al) looked at weight patterns in 3- to 5-year-olds and found inconclusive results. The second study (Gillman, et al) gleaned data from over 15,000 9- to 14-year-olds participating in the "Growing Up Today Study." Researchers found that infants who were fed breast milk more than infant formula, or who were breastfed for longer periods, had a lower risk of being overweight during older childhood and adolescence.

NUTRITION & ACADEMIC ACHIEVEMENT
In the current issue of Pediatrics, researchers report on the link between suboptimal nutrition and academic achievement. Six to eleven-year-old food-insufficient children had significantly lower arithmetic scores and were more likely to have repeated a grade, have seen a psychologist, and have had difficulty getting along with other children. Food-insufficient teenagers were more likely to have seen a psychologist, have been suspended from school, and have had difficulty getting along with other children.

Source: Food Insufficiency and American School-Aged Children's Cognitive, Academic, and Psychosocial Development, Alaimo K , Olson CM, Frongillo Jr, EA; PEDIATRICS Vol. 108 No. 1 July 2001, pp. 44-53 http://www.pediatrics.org/cgi/content/abstract/108/1/44

SCIENCE FOR KIDS
The Agricultural Research Service (ARS), the principal research agency of the US Department of Agriculture (USDA), has developed a wonderful educational website for children. Sci4Kids features an interactive approach to topics such as agriculture, nutrition, insects and the environment. There are also helpful resources for educators. Visit the Sci4Kids site at http://www.ars.usda.gov/is/kids/

The information contained in this newsletter is not intended as a substitute for medical and/or nutrition advice. See your physician and/or registered dietitian for individual health and/or dietary concerns.

©2001, by Connie Evers, All Rights Reserved. There is a modest reprint fee for reproducing the material in this newsletter in either print or electronic publications. Please send an email to reprint@nutritionforkids.com for details and rates.