Immunity and Aging

How to Strengthen Defenses and Stay Healthy

Achoo!!! No one wants to sneeze—or be sneezed on! But it’s that time of year when cold and flu viruses abound in the cool, dry air that allows them to spread easily. And protecting ourselves from seasonal illnesses becomes even more important as we age. Assuming we are fully vaccinated according to our medical care provider’s recommendations, what else can we do to shore up our defenses?

What Exactly is Immunity?

The Cleveland Clinic tells us that our immune system is a network of organs, white blood cells, proteins, and chemical messengers working together to protect our bodies. Keeping viruses, bacteria, fungi, parasites, and cancer cells out of our bodies, removing them once they’re in, and limiting and repairing the damage they do are part of immune system functions.

A healthy immune system is characterized by an ability to differentiate healthy cells from “invading” cells and create antibodies, or protective proteins that remove unhealthy invaders, or antigens.

Two Systems of Immunity

The National Library of Medicine explains that our bodies have two types of immune systems: innate and adaptive.

Innate immunity, also called general immunity, is made up of skin, mucous membranes, specialized cells, and proteins that are the first line of defense against antigens.

The adaptive, or specialized, immune system kicks in when innate immunity systems can’t stop invading antigens. Comprised of T cells, B cells, and antibodies, or specialized proteins, the adaptive immune response is slower to react than innate immunity; however, it is able to recognize and target specific bacteria and other antigens. And because adaptive immunity response cells are able to “remember” antigens, they are better positioned to fight off germs they have previously encountered—meaning illnesses we have had before.

How Does the Aging Process Affect Immunity?

Unfortunately, older adults are generally more vulnerable to infection and disease. A February 2024 article by Dr. Peter Delves entitled Effects of Aging on the Immune System notes the following ways that our immune system changes as we age:

  • Greater difficulty distinguishing antigens from healthy cells
  • Fewer white blood cells to respond to antigens
  • Slower macrophage (type of white blood cell) response
  • Slower T-cells (bone marrow cells that recognize antigens) response
  • Production of fewer B and T cells
  • Fewer complement proteins, which work together to kill bacteria and neutralize viruses

The Importance of Reducing Inflammation

Researchers are pinpointing chronic inflammation associated with aging as a critical factor in why the immune system in older adults doesn’t function as well as it once did. An article in the journal Frontiers in Aging on current research in the field of aging and immunity notes the significant impact of low-grade, persistent inflammation called inflammaging.

The problem, according to the Mayo Clinic, is twofold: adaptive immune system T and B cells decrease in number at the same time innate immune system cell levels increase, releasing substances that cause inflammation. The result is chronic, low-level inflammation that can exhaust the immune system, leaving us with fewer resources available to fight infection and potentially causing damage to surrounding tissues.

The Challenge of Immunosenescence

Researchers have found that immunosenescence, or the age-related decline in immune system function, begins at age 20 and accelerates in the sixth decade of life. “The immune system is restructured with age. The immune system of a 60-year-old looks very different from the immune system of a 20-year-old,” explains Cornelia Weyand, MD, PhD and professor of Medicine and Immunology at the Mayo Alix School of Medicine and Stanford School of Medicine.

These age-related changes to the immune system are the result of inflammaging and lead to increased vulnerability to infections, viruses, and cancers and decreased efficacy of vaccines. The Mayo Clinic adds that these changes also result in longer recovery times from colds, flu, and other infections and increased risk of developing dementia, Parkinson’s, and osteoarthritis.

The Role of Exercise and Nutrition

A 2020 article in the journal Nutrients entitled Physical Activity and Diet Shape the Immune System During Aging explores the immunoprotective, anti-inflammatory benefits of exercise and nutrition. The authors note that “regular exercise training” has positive effects on both the innate and adaptive immune systems. “It is now widely accepted that physical activity has an anti-inflammatory effect and [positively] affects metabolic health in old age,” report the authors.

Specifically, regular exercise helps with weight control, and weight reduction improves immune system function and reduces inflammation. In addition, exercise has been shown to boost immune function at the cellular level, with skeletal muscles participating in the immune response. “Cyclic muscle contractions and increased muscular energy metabolism,” explain the authors, “lead to the production of anti-inflammatories.”

The authors also note the increased importance of nutrition as we age, adding that improvements in diet are superior to medical intervention as a means to improved aging and greater wellbeing. An article in the journal Aging and Disease similarly supports the connection between improved nutrition and prevention of senescence, or the deterioration of cell capability with age.

While researchers acknowledge the problem of “micronutrient malnutrition,” or deficiency in essential vitamins and trace minerals, they caution against the use of supplements without medical supervision. Supplements, such as probiotics for “gut health,” can improve one aspect of the aging process while simultaneously harming another.

Because older adults generally eat less, nutrition density and food variety are essential until the role of supplements in supporting the immune system is better understood.

Exercising to Boost Immunity

Regular exercise, explain the authors of the article Exercise and the Aging Immune System, provides a host of immune system benefits: better response to vaccinations, lower number of senescent (aging) T cells, increased number of productive T cells, and lower levels of inflammatory markers, among many other benefits.

An article on exercise and immunity from The University of Florida posits that physical activity helps cleanse the airways of bacteria and that the increase in body temperature may help inhibit the growth of bacteria in the body. Additional theories note the reduction in stress hormone levels following exercise, with fewer stress hormones in the body being immunoprotective. But because the connections among senescence, inflammaging, and exercise is an emerging field of research, finding proscriptive exercises specifically targeted for immune system benefits is difficult; however, researchers are able to identify exercises that are generally beneficial for older adults.

The National Council on Aging (NCOA) suggests a regular exercise routine that includes all three components of physical fitness: aerobic/cardio exercises, resistance/weight training, and stretching/flexibility exercises. Fit & Strong and SilverSneakers are programs mentioned by the NCOA because they are designed for adults over 65 and address the health and safety concerns of seniors.

Eating for Immune System Benefits

Both the Cleveland Clinic and Mayo Clinic note the importance of establishing a pattern of healthy eating because immunity is bolstered by the cumulative effect of excellent nutrition and adequate hydration. Healthful foods are superior to supplements because the body absorbs nutrients more efficiently from foods.

  • Vitamin C: a natural antioxidant and protectant against inflammation found in red peppers, oranges, kiwi, broccoli, strawberries
  • Vitamin B6: helps produce white blood and T cells, found in chickpeas, beef, salmon, tuna, potatoes, bananas, cottage cheese
  • Zinc: anti-inflammatory and antioxidant that aids immune cell function, found in lentils, beef, yogurt, pumpkin seeds, milk, shrimp, cheddar cheese
  • Vitamin E: helps T cells, fights infections, found in seeds, nuts, spinach, broccoli, tomatoes
  • Selenium: protects against chronic inflammation, found in Brazil and other nuts and seeds, tuna, cottage cheese, oatmeal, eggs

Jessica Lancaster, PhD, assistant professor of immunology and cancer biology at the Mayo Clinic, Arizona, also suggests a Vitamin D supplement to help protect the adaptive immune cells that decline with age.

Future Research into Strengthening the Aging Immune System

Researchers continue to investigate immune system changes on the cellular level, hoping for a more comprehensive understanding of immunity and aging. The Journal of Clinical Investigation notes the following areas for research:

  • Higher-concentration vaccines
  • Metabolism-altering treatments
  • Senylotics, or new drugs that destroy aging cells and prevent disease

As we await new discoveries and interventions, it’s important that we protect our immune system with what is known to be effective. As author and immunology expert Dr. Peter Delves reminds us: keep up with our immunizations and get booster shots as needed.

The Importance of Living in A Health-Conscious Community

Research-based data on the importance of proactive lifestyle choices reminds us that where and how we live are crucial to our wellbeing. A community that prioritizes fresh, healthy, nutrient-dense foods and provides opportunities for physical activity is helping us boost our immune system function—and live happier, healthier lives!

Come explore Plymouth Harbor and learn more about this extraordinary community where the health and wellbeing of residents is an everyday commitment. Call 941-361-7512 to schedule your private tour and discover why life truly is better on Sarasota Bay!