Well Nourished Women Have Rockin’ Immune Systems at Any Age

Healthy Diet Helps Preserve Immune Function  Mechanisms of Ageing and Development 1999;112:43-57.

Healthy diets may help women keep their immune systems youthful as they age, researchers at Pennsylvania State University report.

In a study of immune function in 75 well-nourished women aged 60 to 80, the investigators found that the women’s immune systems were nearly as strong as those of women aged 20 to 40. This stands in contrast to previous research suggesting that immune functionnormally declines with age — but many of these studies failed to take subjects’ nutritional status into account, according to Dr. Namanjeet Ahluwalia, an assistant professor of nutrition at Penn State in University Park, and colleagues.

Their findings, published in the current issue of the journal Mechanisms of Ageing and Development, suggest that healthy eating habits may offer a “natural means” to maintain the body’s ability to fight off infections and reduce illness in old age, Ahluwalia said in astatement. She and her colleagues note in their report that various vitamin and mineraldeficiencies may impair the immune system.

In the Penn State study, immune function in older women was compared with that in 35 women aged 20 to 40. All women in the study were screened for infections or chronic conditions that affect the immune system and for deficiencies in protein, iron, vitamin B12,and folic acid. Such deficiencies have been linked to impaired immune response. After determining that the women were well nourished, the researchers judged their immunefunction by examining particular immune-system cells in blood samples.

Ahluwalia’s team found that regardless of age, the women showed similar numbers of immune cells called T cells, including the “killer” T cells that are key to warding off invading pathogens. They also had comparable numbers of “natural killer” cells. When the researchers introduced two types of foreign substances, however, T cells in the older women did show a lesser response than those of the younger women.

Still, Ahluwalia and colleagues report, “most immune parameters were not compromised with aging in this (group) of apparently healthy, well-nourished women.” This, according to Ahluwalia, shows that “when nutritional and health status are maintained, the body’s ability to defend itself against viruses, bacteria, or tumor cells may not necessarily be affected with aging.”