It's simple: Poor nutritional status leads to poor health and susceptibility to infections. When you're ill with an infection, it's even more difficult to eat well. Older adults are especially vulnerable to this compounding problem: They're more likely to be deficient in certain vitamins and minerals—also known as micronutrients—and aging comes with a decline in immune function. It stands to reason that improving nutritional status would improve the ability to stay well.

According to a study in the September 2012 Journal of the American Geriatrics Society, boosting intake of micronutrients, especially those associated with immune function—zinc, selenium, carotenoids and vitamins C and E—can help fight illnesses like respiratory tract infections.

The researchers found that the benefit was seen only among the participant group who ate nutrient-rich foods; taking nutritional supplements didn't do it. Furthermore, although improving dietary intake didn't reduce the incidence of infections among participants, it significantly reduced their impact, resulting in far fewer days of illness that affected daily activities.

The research method

The study involved 217 people ages 65 to 85 randomly assigned to one of three groups. For three months, one group ate a diet geared to increase micronutrient intake. A second group took a daily supplement containing a level of micronutrients that mimicked the intake of the diet group. A third group took a placebo. All participants kept a diary in which they noted any days they didn't feel well, their symptoms, whether a fever was present and whether the illness had any effect on daily activity.

After six months, the dietary group enjoyed significantly fewer weeks in which infection symptoms were reported over the other two groups and had far fewer doctor or hospital visits than the placebo group. The study participants in the diet group enjoyed other health benefits, too. They showed significant improvements in social functioning and emotional health in a part of the study that measured quality of life.

What you can do

The diet the study participants followed was designed to boost levels of zinc, selenium, carotenoids and vitamins C and E. Here's how you can do the same:

  • Strive for at least five servings of fruits and vegetables a day. This long-standing recommendation is backed by another recent study that associated eating fruits and vegetables with a boost in the immune process. Reporting in The American Journal of Clinical Nutrition, British researchers found that older adults who upped their daily fruit and vegetable intake to five servings measured better antibody response when they received the vaccination to prevent pneumonia and other infections caused by the Streptococcus pneumoniae bacteria. Fruits and vegetables are rich in carotenoids, folate, potassium, fiber and vitamins A, C and K. Opt for bright, deeply colored produce like red peppers, carrots, sweet potatoes, cantaloupe, watermelon, kale, spinach and blueberries.
  • Choose more whole grains. Study participants were directed to eat only whole-grain bread. Whole-grain foods are a good source of selenium, magnesium, zinc, iron, B vitamins and fiber. Go beyond bread and include in your diet whole-wheat pastas and crackers, brown or wild rice, bran cereals, oatmeal, barley, quinoa, millet and popcorn.
  • Eat fish twice a week. Both shellfish and regular varieties offer selenium, zinc, protein and omega-3 fats.
  • Munch on nuts once a week. Almonds, pecans, walnuts, hazelnuts, pistachio nuts and peanuts are good sources of selenium (especially Brazil nuts), vitamin E, zinc and omega-3s.

Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at

Published: 29 Jul 2103

Last Modified: 28 Sep 2015