The U.S. Centers for Disease Control (CDC) and Department of Health & Human Services (HHS) report that the flu epidemic currently sweeping the U.S. is striking older adults with weakened immune systems the hardest.
“Because your immune system weakens as you age, adults age 65 years and older are more susceptible to the flu,” HHS reports. In fact, “Ninety percent of flu-related deaths and more than half of flu-related hospitalizations occur in people age 65 and older,” according to HHS.
This has prompted many to ask whether there is anything a person can do to prevent or reverse the weakening of your immune system as you age, and to strengthen your immunity to bacteria and viruses in general.
A recent Special Health Report by Harvard Medical School, The Truth About Your Immune System, examines in detail medical scientists’ best current understanding of how the human immune system works, what happens when it fails, and how vaccines work, and then goes on to present practical information on what you can do to boost your immune system.
What Can You Do to Boost Your Immunity?
According to the Harvard Medical School Special Health Report, The Truth About Your Immune System, “Quite a number of researchers are exploring the effects of diet, exercise, age, psychological stress, herbal supplements, and other factors on the immune response, both in animals and in humans.”
“Although interesting results are emerging, thus far they can only be considered preliminary,” the Harvard authors caution. “That’s because researchers are still trying to understand how the immune system works and how to interpret measurements of immune function.”
However, Harvard’s report, prepared by Michael N. Starnbach, Ph.D., professor of Microbiology and Molecular Genetics at Harvard Medical School, in collaboration with editors at Harvard Medical School, goes on to state, “In the meantime, general healthy-living strategies are a good way to start giving your immune system the upper hand.”
“Your first line of defense is to choose a healthy lifestyle,” the Harvard authors advise.
“Following general good-health guidelines is the single best step you can take toward keeping your immune system strong and healthy. Every part of your body, including your immune system, functions better when protected from environmental assaults and bolstered by healthy-living strategies such as these:
- Don’t smoke.
- Eat a diet high in fruits, vegetables, and whole grains, and low in saturated fat.
- Exercise regularly.
- Maintain a healthy weight.
- Control your blood pressure.
- If you drink alcohol, drink only in moderation.
- Get adequate sleep.
- Take steps to avoid infection, such as washing your hands frequently and cooking meats thoroughly.
- Get regular medical screening tests for people in your age group and risk category.”
The Harvard authors, however, warn that one should be skeptical of the many products – supplements, herbs, and others – that claim to boost immunity. “At a time when we scientists are still trying to understand the basics of how the immune system works, product manufacturers have rushed to market everything from cereals to herbal teas that purport to support immunity with little evidence to back up those claims.”
“Keep this in mind when you are tempted to pay extra for one of these products: consuming a food or supplement that contains vitamins, antioxidants, or other substances intended to support immunity delivers no additional benefit beyond that of taking an ordinary multivitamin pill,” the Harvard authors advise.
“In fact, boosting the number of cells in your body — immune cells or others — is not necessarily a good thing,” Dr. Starnbach and his colleagues state. “[E]ven if it were possible to boost [your immune system] into high gear, that wouldn’t necessarily be a good thing. A hyperactive immune response is the underlying problem causing diseases such as lupus, rheumatoid arthritis, diabetes, and multiple sclerosis. These conditions, known as autoimmune diseases, occur when the immune system, instead of attacking outside invaders, attacks the body’s own cells,” the authors state.
The good news, however, is that “If that sounds discouraging, you might be cheered to know that your immune system doesn’t need support beyond the ordinary measures you would take to stay healthy. Although not invincible, your immune response works exceedingly well.”
Beyond living a healthy lifestyle, the best strategies, according to the Harvard authors, are to:
- Get immunized against the flu, and immunize your children against preventable diseases such as polio, diphtheria, whooping cough, and measles. “The one truly powerful way to boost immunity is immunization,” the Harvard authors state.
- Avoid contact with germs, by avoiding contact with sick people, and washing your hands frequently.
Immunity and Aging
According to the Harvard Medical School team, “While some people age healthily, the conclusion of many studies is that, compared with younger people, the elderly are far more likely to contract infectious diseases. Respiratory infections, influenza, and particularly pneumonia are a leading cause of death in people over 65 worldwide.”
“No one knows for sure why this happens,” the authors state, “but some scientists observe that this increased risk correlates with a decrease in T cells, possibly from the thymus atrophying with age and producing fewer T cells to fight off infection.” Other researchers are looking at other theories of why the immune system seems to weaken with age, they point out.
The reduction in immune response in older persons correlates with findings that their response to immunity-boosting vaccines is also lower in efficacy than in younger persons. “But despite the reduction in efficacy, vaccinations for influenza and S. pneumoniae have significantly lowered the rates of sickness and death in older people when compared with nonvaccination,” the Harvard authors state.
Other researchers are studying the effects of diet and malnutrition on immunity – especially in the elderly. “A form of malnutrition that is surprisingly common even in affluent countries is known as ‘micronutrient malnutrition.’ Micronutrient malnutrition, in which a person is deficient in some essential vitamins and trace minerals that are obtained from or supplemented by diet, can be common in the elderly,” Harvard reports.
“Older people tend to eat less and often have less variety in their diets. One important question is whether dietary supplements may help older people maintain a healthier immune system.” “Older people should discuss this question with a physician who is well versed in geriatric nutrition, because while some dietary supplementation may be beneficial for older people, even small changes can have serious repercussions in this age group,” Harvard advises.
Diet and Immunity
“There are still relatively few studies of the effects of nutrition on the immune system of humans, and even fewer studies that tie the effects of nutrition directly to the development (versus the treatment) of diseases,” the Harvard team states.
“There is some evidence that various micronutrient deficiencies — for example, deficiencies of zinc, selenium, iron, copper, folic acid, and vitamins A, B6, C, and E — alter immune responses in animals, as measured in the test tube. However, the impact of these immune system changes on the health of animals is less clear, and the effect of similar deficiencies on the human immune response has yet to be assessed.” “But the research at this stage is promising, at least for some of the micronutrients,” the authors report.
“So what can you do? If you suspect your diet is not providing you with all your micronutrient needs — maybe you don’t like vegetables or you choose white bread over whole grains — taking a daily multivitamin and mineral supplement brings health benefits of many types, beyond any possibly beneficial effects on the immune system,” the Harvard authors suggest.
However, “Taking megadoses of a single vitamin does not. More is not necessarily better. Researchers are investigating the immune boosting potential of a number of different nutrients.”
The Harvard Special Health Report, The Truth About Your Immune System, goes on to discuss the studies being done, and preliminary results, regarding a number of different vitamins and minerals, as well as certain herbs and other supplements.
Effects of Stress on Immunity
“Some scientists are investigating whether ongoing stress takes a toll on the immune system,” Harvard reports. Most of these studies are being done in animals, and face significant challenges, such as difficulties in defining precisely what is “stress” and in measuring scientifically its effects. Nevertheless, the authors cite a few examples of such ongoing studies on animals:
- “Experimentally created “stressful” situations delayed the production of antibodies in mice infected with influenza virus and suppressed the activity of T cells in animals inoculated with herpes simplex virus.
- Social stress can be even more damaging than physical stress. For example, some mice were put into a cage with a highly aggressive mouse two hours a day for six days and repeatedly threatened, but not injured, by the aggressive mouse — a “social stress.” Other mice were kept in tiny cages without food and water for long periods — a “physical stress.” Both groups of mice were exposed to a bacterial toxin, and the socially stressed animals were twice as likely to die. Isolation can also suppress immune function. Infant monkeys separated from their mothers, especially if they are caged alone rather than in groups, generate fewer lymphocytes in response to antigens and fewer antibodies in response to viruses.”
In addition, the authors cite examples of studies that have involved humans:
- “Elderly people caring for relatives with Alzheimer’s disease have higher than average levels of cortisol, a hormone secreted by the adrenal glands and, perhaps because of the higher levels of cortisol, make fewer antibodies in response to influenza vaccine.
- Some measures of T cell activity have been found to be lower in depressed patients compared with nondepressed patients, and in men who are separated or divorced compared with men who are married.
- In a year-long study of people caring for husbands or wives with Alzheimer’s disease, changes in T cell function were greatest in those who had the fewest friends and least outside help.
- Four months after the passage of Hurricane Andrew in Florida, people in the most heavily damaged neighborhoods showed reduced activity in several immune system measurements. Similar results were found in a study of hospital employees after an earthquake in Los Angeles.”
“In all of these studies, however, there was no proof that the immune system changes measured had any clear adverse effects on health in these individuals,” the Harvard authors caution.
Exercise and Immunity
“Regular exercise is one of the pillars of healthy living. It improves cardiovascular health, lowers blood pressure, helps control body weight, and protects against a variety of diseases,” the Harvard Medical School authors report.
“But does it help maintain a healthy immune system? Just like a healthy diet, exercise can contribute to general good health and therefore to a healthy immune system,” they state.
“It may contribute even more directly by promoting good circulation, which allows the cells and substances of the immune system to move through the body freely and do their job efficiently.”
Many studies are now underway seeking to understand the mechanisms through which exercise appears so effective in promoting good health, according to Dr. Starnbach and his team from Harvard Medical School.
See a report on Exercise and Immunity by Medline Plus, a service of the U.S. National Library of Medicine, part of the National Institutes of Health.
See also a recent report by the New York Times on Boosting Your Flu Shot Response With Exercise.
A report by the National Institute on Aging (NIA), part of the National Institutes of Aging, covers: IMMUNE SYSTEM: Can Your Immune System Still Defend You As You Age?
For more information on how the immune system works, see the website of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.
And, for a more detailed presentation, with pictorial slides, on the immune system and how it works, see the website of the National Cancer Institute.
See related HelpingYouCare® reports on:
For more information on healthy diet, exercise and other lifestyle factors that promote wellness and prevent diseases, see the HelpingYouCare® resource pages on Wellness/ Healthy Living for Seniors & Caregivers, including:
- Weight Loss/ Maintaining a Healthy Weight: Physical Wellness;
- Diet & Nutrition: Physical Wellness;
- Exercise: Physical Wellness;
- Sleep, Hygiene, Quit Smoking & Other Healthy Practices: Physical Wellness;
- Activities to Preserve Mental Acuity: Intellectual Wellness;
- Social Interaction & A Sense of Connection With Others: Social Wellness;
- Other Areas of Wellness: Emotional, Ethical/ Spiritual & Vocational Wellness; and
- Healthy Living: Stories of Inspiring Seniors.
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