Boosting your immune system
Do you always feel as if you have just recovered from one cold when another comes along? Luckily, according to Jenna Bell-Wilson, MS, RD, ID, media representative for the New Mexico dietetic association and doctoral student exercise physiology at the university of New Mexico, eating foods rich in four special nutrients can enhance your immune system.
1. Hooray for Vitamin A!
Vitamin is an immune system powerhouse! Studies have shown that vitamin A deficiency can lead to damage in the mucosal linings of the respiratory, gastrointestinal and genitourinary tracts. (These linings are essential to the body’s defense against foreign particles. When they are damaged, one is more likely to be infected.) Vitamin A deficiency has also been linked to an increased number of skin infections.
2. Keep your eye on Vitamin E
Also a mainstay of the immune system, vitamin E helps protect the body against cardiovascular disease and cancer. In a study reported in the British Journal of Nutrition, researchers evaluated the impact of three different amounts of vitamin E (65 times the minimum daily amount currently recommended for humans) were enhanced. Because of this finding, researchers believe that a diet rich in vitamin E may also help humans.
Immune System Helpers
Vitamin A & Beta-Carotene
(Daily value: 900 retinol equivalents [re])
85g beef liver: 9,124 re
½ cup sweet potato: 1,936 re
½ cup carrots: 1.584 re
½ cup cooked spinach: 739 re
½ cup mango: 320 re
3 apricots: 274 re
1 cup fortified milk: 150 re
(Daily value: 30 international units[iu])
¾ cup cereal: 35.2 iu
30g sunflower seeds (shelled): 22.6 iu
30g almonds: 11.8 iu
1 tbsp Margarine (hard, soybean oil): 7.3 iu
(Daily value: 15 milligrams [mg])
85g crab meat: 6.5 mg
85g roasted beef: 5.6 mg
½ cup dry roasted soybeans: 4 mg
¾ cup enriched cereal: 3.1 mg
1 cup plain yogurt: 2.2 mg
(Daily value: 18 milligrams [mg])
85g cooked clams: 24 mg
85g cooked oysters: 10 mg
1 cup corn flakes cereal: 9.3 mg
⅓ cup tofu (processed with calcium): 8.9 mg
3. The power of Zinc
Zinc aids the immune system in many ways. For example, it appears to help produce T cells, the small white blood cells essential to the adaptive immune system. (The adaptive immune system remembers how to respond to each new threat, e.g. if a person had a disease such as chicken pox as a child he/she will not get it again). It may also help produce phagocytes, the large white blood cells that patrol the body on ready alert. It may even help produce natural killer cells, which help destroy foreign substances in the body as well. Zinc deficiency sometimes contributes to death due to gastrointestinal or respiratory problems. Fortunately, zinc supplement can reduce such risks in people with low T cell counts, such as the elderly; those undergoing chemotherapy; and people suffering from HIV/AIDS, alcoholism, burns and more. However, because zinc can decrease the body’s absorption of copper, iron and calcium, zinc supplementation is not recommended for healthy adults.
4. The impact of iron
Iron deficiency, also called iron deficiency anemia, can weaken the immune system. You can correct this condition by eating plenty of iron-rich foods or, if necessary, taking iron supplements. However, zinc may limit the absorption of iron. If you take both zinc and iron supplements, also increase your daily consumption of iron-rich foods so the one nutrient doesn’t nullify the other.
This handout is a service if IDEA, the leading international membership association in the health and fitness industry.
IDEA PERSONAL TRAINER – February 2003