Strength of immune-system response may drive healthy aging
1 of 3 | Aging may be inevitable, but boosting immune health may impact how we age, according to researcher Dr. George A. Kuchel. Photo courtesy of the University of Connecticut
It may not be the mythical fountain of youth, but the strength of the body’s immune system could hold the key to a healthy, long life, experts told UPI.
The concept of so-called “immune resilience” has gained traction in recent years, particularly since the COVID-19 pandemic, which heightened awareness of the importance of a strong immune system, according to geriatrician Dr. George Kuchel, director of the Center on Aging at the University of Connecticut.
A resilient immune system is one that is strong and is able to minimize inflammation anywhere in the body — particularly in vital organs such as the heart, lungs and digestive tract — in response to disease-causing stressors, Kuchel told UPI in a phone interview.
Stressors include infectious diseases, or viruses such as COVID-19 or the flu, as well as certain cells that cause some types of cancer, he added.
A healthy immune system enables the body to effectively fight back against these stressors and slow the progression of aging and life-threatening health conditions, Kuchel said.
“Aging is inevitable, but how we age isn’t,” said Kuchel, who also is director of the Claude D. Pepper Older Americans Independence Center.
“In medicine, we talk about modifiable risk factors, things like diet, smoking — well, there are modifiable risk factors for aging, and one of those is a healthy immune system,” he said.
“Our immune system is the front line of defense in our body — it recognizes threats and mounts an appropriate response to harmful elements like virus or bacteria,” Jamie Justice, an expert in gerontology and geriatric medicine, added in an email interview.
Immune resilience and aging
With age, the body’s immune system experiences a decline in its ability to effectively respond to disease-causing pathogens, like the flu virus, according to Dr. Sunil K Ahuja, a professor of medicine at UT Health San Antonio, who has researched immune health and its effect on aging.
This natural decline, which begins to speed up around age 70, is called immunosenescence, and it can cause chronic inflammation, which accelerates aging, said Ahuja, who is also director of the Veterans Affairs Center for Personalized Medicine with the South Texas Veterans Health Care System in San Antonio.
Immunosenescence is why older adults are more susceptible to severe infections from the flu and COVID-19 and do not respond as well to vaccines designed to protect against them, he said.
“Immune resistance closely relates to resilience, which typically declines with advancing age,” said Justice, who is now an executive vice president with with XPrize Foundation.
“Older persons generally have greater susceptibility to infections than younger adults due to age-related changes in cell-mediated immunity, underlying chronic disease and geriatric syndromes,” she said.
The chronic inflammation that occurs with immunosenescence also contributes to declines in overall health and resilience, according to Ahuja.
“None of us can escape the biology of aging — it begins when we are born and continues until we die,” Ahuja told UPI in a video call.
For most of us, the immune system is “like a mote and that moat gets eroded” over time,” he said.
However, research conducted by Ahuja and his colleagues suggests that “some of us have the capacity to resist this erosion,” he said.
Now, he and his colleagues are trying to find out what characteristics people who experience less immunosenescence over time share, with the hope of identifying ways to maintain or even strengthen immune resilience, even with age.
“We know that people with good immunity have high levels of certain proteins, and vice versa, but we don’t yet know why,” Ahuja said.
“We also know that immune resilience as a trait is more common in women than men, and that people who preserve it have better health outcomes and longevity,” he said.
What the research says
In a study published last month by the journal Cell, Ahuja analyzed health data from 17,500 people of various ages whose records were collected as part of datasets for other research projects.
The analysis included people with HIV and tuberculosis, as well as those diagnosed with dementia and various forms of cancer and those who had undergone liver and kidney transplants. Some participants had no history of serious illness.
People with strong immune resilience at age 40 years had a 15.5-year survival advantage over those with low resilience at that age, the study found.
In addition, those who demonstrated strong immune resilience based on overall health between ages 40 and 70 years were nearly 70% less likely to die during this period compared with those who had poorer immune health, the researchers said.
Most of the study participants who demonstrated strong immune resilience throughout life had one thing in common, the researchers found — high levels of gene T-cell factor 7, which the body uses to manufacture and maintain immune cells.
It’s possible that drugs and other treatments designed to target this gene and boost its production could be used to strengthen immune health and thus slow aging, Ahuja said.
“This gene could give us a way to metricize or measure immune health,” he said. “That could one day enable us to predict and even prevent diseases.”
Boosting immune health now
Many existing prescription drugs enable medicine to “manufacture longevity” by controlling factors like blood pressure, heart rate, blood sugar, cholesterol and others linked with chronic illness, Ahuja said.
One of the biggest recent advances in this area has been the introduction of GLP-1 agonists like dulaglutide, or Trulicity, and semaglutide, or Ozempic.
These drugs work to lower blood sugar, but they can also control appetite and manage weight gain by making those taking them feel fuller after eating, UConn’s Kuchel said.
By helping people lose weight and manage Type 2 diabetes, GLP-1s can lower their risk for heart disease and other health conditions that shorten their lifespans, he said.
Meanwhile, research published last year suggests the immunosuppressant drug rapamycin, which is used to prevent organ rejection in transplant patients, as well as other conditions, may help slow aging by enhancing immune response, Kuchel said.
Similarly, the drug metformin, which has been used for decades to treat Type 2 diabetes, also may slow aging by boosting metabolic health, a study published earlier this month found.
Still, while research to understand the potential anti-aging benefits of these and other drugs is ongoing, Kuchel and Ahuja agree that none of them will replace lifestyle choices, such as limiting exposure to certain toxins by not smoking and eating a healthy diet, as well as engaging in regular exercise, to increase lifespan and quality of life.
“When we think about immunity, we typically think about virus-specific treatments and vaccines, which are critically needed,” said Justice, of the XPrize Foundation, which is researching the potential of existing and new drugs in anti-aging.
“But other complementary strategies are also needed to address the increased vulnerability to infections and stressors with aging, [and] this includes science-backed strategies … [and] basic general health solutions, like good sleep, a healthy diet and stress management,” she said.