Could E be for Immunity

Dietary Vitamin E May Protect Against Pneumonia in Aging Population

No one likes getting sick. A case of the flu might mean a few days in bed for some, but for others, infection can be fatal. Pneumonia, a lung infection, results in about 1.6 million deaths worldwide each year, and is a particular concern for the older population. As we age, our bodies’ immune systems weaken and we become more susceptible to disease. This is partially due to low-grade chronic inflammation and impaired immune responses that go hand-in-hand with aging.

Vitamin E, an antioxidant, has been shown to enhance specific components of the immune system that tend to weaken as people age. Knowing this, researchers from Tufts University decided to test if adding extra vitamin E to the diet might help older adults ward off pneumonia.

In the 2014 study, researchers infected a group of young and old mice with pneumonia bacteria. All mice had a little vitamin E in their diets, but some mice were also fed extra alpha-tocopherol, a form of vitamin E. These mice were given what would equate to about 200 IU/day vitamin E in humans over a period of 4 weeks, which is nearly 10 times the RDA of 22.5 IU but still considered safe.

Among mice not fed extra vitamin E, older mice were much more susceptible to infection than younger mice. After just 48 hours, less than half of the older mice were alive, while 90% of the younger mice survived. However, among mice fed extra vitamin E, this difference did not exist. In fact, older mice given extra vitamin E had 1,000 times fewer bacteria in their lungs and 2 times fewer white blood cells (neutrophils) after infection than older mice eating normal amounts of the vitamin. Furthermore, vitamin E appeared to help prevent brain damage and weight loss associated with pneumonia.

Researchers propose vitamin E helped reduce the lung inflammation associated with pneumonia, specifically by reducing the proinflammatory neutrophil (white blood cell) response to infection. Inflammation can hinder the clearance of bacteria from the body, so vitamin E may be a way to prevent harmful inflammation from occurring.

“Our present research is the first study to demonstrate that dietary vitamin E regulates neutrophil entry into the lungs in mice, and so dramatically reduces inflammation, and helps fight off infection by this common type of bacteria,” said first author Elsa N. Bou Ghanem, Ph.D.

Nuts, seeds, and vegetable oils provide some of the best sources of dietary alpha-tocopherol. Good sources include safflower oil, almonds, sunflower seeds, and peanut butter. Lots of fruits and vegetables pack vitamin E as well, including avocado, spinach, sweet potato, pumpkin, red pepper, kiwi, mango, asparagus, and broccoli. Try adding these foods to your diet to bump up your vitamin E and boost your immune system, especially if you are an older adult. Our Twice-Baked Sweet Potatoes Stuffed with Spinach delivers 20% of your daily vitamin E and a host of other health-promoting nutrients in just one serving.

BONUS: Want more tips to ramp up your immune system? In a 2011 study, David Nieman, PhD, scientist at the North Carolina Research Institute, found exercising five days a week and eating three servings of fruit per day was linked to fewer sick days.

Published March 1, 2015