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25 health factors that lower immunity

By Dr. Sharon Stills, NMD

Months into the Covid-19 pandemic, the myth persists that it’s only the elderly who are at high risk for death or serious side effects. Can we please finally put this dangerous misconception to rest? The truth is, about half of all Americans have some level of suppressed immune function.

A woman with a list of 25 factors for lowered immunity

To help you understand your personal risk , we’ve compiled a list of 25 factors that impair your immune system.

Do you have family or friends who don’t take their own risk as seriously as you’d like? Or who put you at risk? Be sure to share this list with them too. It’s a great way for us to protect one another. After all, we’re in this together.

25 health factors that impair immune function

1. Pregnancy Yes, pregnancy is normal — it’s not a health problem. But the immune system changes during pregnancy, in part so that it doesn’t attack the fetus as “other.” These changes can make pregnant women more vulnerable to serious complications from infections like influenza. Are you or someone you know pregnant? In addition to standard precautions of hand washing and wearing a mask, pregnant women may do well to avoid contact with persons outside their household and “friend/work bubble” and crowds that make social distancing difficult.

2. Lack of sleep When we sleep, different parts of our immune systems are believed to engage in “cross-talk” with each other, leading to better outcomes during illness if we get enough sleep. Conversely, lack of sleep leads to inflammation and also leaves us more vulnerable to illness. If you’re one of the tens of millions who struggle with insomnia, try some natural sleep practices that make it easier to drift off. Insomnia in women can be related to adrenal stress, so it’s also a good idea to explore if your adrenal function needs added support.

3. Poor diet Not taking in enough protein is problematic for immune function and regeneration of immune cells, but deficiencies in certain vitamins and micronutrients also put immune function at risk. For example, zinc deficiency is associated with lymphoid atrophy and reduced lymphocyte response, whereas copper deficiency may impair T-cell responses.The good news? There are so many foods that boost immune support. Zinc-rich foods include oysters, red meat, poultry, chickpeas, and nuts. Taking a high quality multivitamin can help fill in any nutritional gaps and provide added support.

4. Diabetes and pre-diabetes  High blood sugars found in diabetes are believed to interfere with the immune response, leading people with diabetes to be more vulnerable to infections. High blood sugar also leads to inflammation, which can make the damage to the pancreas even worse. If you have diabetes or insulin resistance/borderline diabetes, now is the time to make the changes needed to bring your blood sugar back into balance.

5. Obesity Obesity is a prime risk factor for immunity-hampering conditions like diabetes. But that’s not the whole story. One of the hormonal effects associated with obesity is an imbalance of the metabolic hormone leptin. Leptin is an important factor in weight regulation, but leptin is also needed to activate immune responses. In obese people with “leptin resistance,” immune function can be slowed and the risk for infection increases.Almost 40% of adults in the U.S. are obese. If you are struggling with hormone-driven weight gain that is common in perimenopause and menopause, addressing any underlying hormonal issues first is often the key to finally unlocking weight loss.

6. Antibiotics — current, recent, or prolonged use Many people associate antibiotics with protection from pathogens. But antibiotics kill most bacteria in their paths, not just the dangerous ones. When antibiotics kill the “good bacteria” of our own microbiomes, this leaves our immune system (more than 70% of which resides in the lining of the gut) unprotected. That gives pathogens a chance to flourish. Antibiotics should only be used when necessary and under a provider’s supervision. If you have taken an antibiotic recently, follow up with a quality probiotic and eat probiotic-rich foods to start replenishing beneficial flora.

7. Being male In studies of immune response of men vs. women, women generally have more activity associated with adaptive (B and T) immune cells than men, giving them a possible edge in staving off infection. Men tend to have higher innate (including inflammatory) immune cell activity, which is good for launching general responses but not specific immune responses. This might help explain why men are more prone to infections, especially over the age of 65 (when this activity intensifies). You can’t change this factor (not easily!), but you can compensate by increasing immune support in other ways. And you should.

8. Autoimmune disease People with autoimmune diseases by definition have an immune system that doesn’t self-regulate properly. Instead of a temporary inflammatory response, in autoimmune diseases the immune response comes on and stays on, eventually attacking the body’s own cells and organs. In measuring immune function, we don’t just look for power — we want the immune system to aim its responses accurately and dial itself down as appropriate. When that doesn’t happen, the immune system is inefficient and compromised when a new pathogen shows up.In addition, the usual medications for autoimmune disease suppress immune function to limit the damage to your body. This vulnerability is a special concern for women, since women represent 80% of all cases of autoimmune disease and are 16 times more likely than men to be diagnosed with an autoimmune issue. Not surprisingly, the problem works in reverse as well: when sufferers of autoimmune disease get a new infection, their AD often flares up as well.

9. Stress, depression and isolation  Can negative feelings lower immune function? The short answer is yes. There’s ample evidence to show how stress, depression and social isolation diminish immune responses by T cells. This effect is more pronounced if a person experiences these emotions over the long term. The mind-body connection is real, so if you are struggling with depression, reach out for help.

10. Kidney disease Kidney failure affects general immunity on a number of levels, causing dysfunction at the intestinal barrier, systemic inflammation and also immunodeficiency that can lead to infections.

11. HIV/AIDS Over a million people in the USA are living with HIV. The disease that results from HIV infection, AIDS (Acquired Immunodeficiency Syndrome ) leaves people with immune systems so vulnerable that they get “opportunistic infections” that are rarely seen in healthy people. This is because the HIV virus specifically attacks a kind of T lymphocyte called a CD4 cell or T-helper cell. CD4 cells help T cells and B cells to fight off infections. When CD4 cells are attacked by the HIV virus, they become HIV factories and can no longer perform their job.

12. Fatty liver disease and cirrhosis An incredible 25-30% of the US population, or over 80 million people, suffer from fatty liver disease. Over 600,000 people suffer from cirrhosis. Both conditions impair immune function by undermining the liver’s key role in immune function.

13. Recent measles Not only is measles potentially deadly on its own, researchers have found that measles illness can induce an after-effect called “immune amnesia.” For the first couple years after measles infection, people can be frequently ill, even with diseases they should already be immune to.

14. Radiation therapy (RT) + chemotherapy About 30% of cancer patients receive some form of radiation therapy (RT). Today RT comes in many forms and its adverse impact on immune function is welll-studied and minimized. Nevertheless, in many cases, the damage to immune cells and systems is severe and long-lasting. Chemotherapy can cause neutropenia, which is a severely diminished level of a white blood cell called neutrophils. Because neutrophils are needed to fight infection, people on chemotherapy are often very vulnerable to infections. These adverse effects can persist long after the therapy is completed.

15. Tumorous cancers If cancer invades the bone marrow or other tissues where immune systems are formed, the cancer cells can interfere with the production of protective immune cells. Similarly, if they invade areas like the lungs, fluid can build up around the cancer that interferes with getting rid of pathogens.

16. Leukemia and lymphomas These cancers directly attack components of the immune system, the lymphatic system and also the blood cell types. Because lymphomas interfere with the work of the lymphatic system, it cannot perform its immunological roles. With leukemia, blood cell lines are often impacted, leading to ineffective and immature cells, including impairment of the white blood cells that help fight disease.

17. Prescription + OTC medications Some of the most common prescription and OTC medications in U.S. come with immune suppressing side effects:

Proton pump inhibitors (PPIs) for acid reflux and GERD.

Gut health is part of immune health — over 70% of the body’s immune system reside in the linings of the intestines. Gut health issues can impair immunity — but so can the OTC medications sold to solve these problems! OTC PPIs for acid reflux and GERD, including Omeprazole (sold under the brand names Prilosec and Losec) can alter the gut flora and immune responses by altering your stomach’s pH levels. Altered pH can also affect nutrient absorption, reducing nourishment needed for healthy immune function. About 15 million people in the U.S. regularly use PPIs. If you’re relying on PPIs to keep your acid reflex in check, considering explore natural, non-medicated solutions for gut health.

Opioid pain medications

Opioid pain medications (oxycodone, hydrocodone, codeine and morphine) carry risk for addiction, but other side effects associated with long term use of opioids include the potential for lowered immunity. Opioids can harm the lining of the gut and intestines where the majority of the body’s immune cells reside, increasing the risk of infection.According to the CDC, 170 million prescriptions for opioids will be written in the U.S. this year; approximately two million American adults are addicted to opioids.

Anti-inflammatory corticoid medications

These medications are given to suppress a hyperactive immune system, such as in allergies, asthma or autoimmune diseases. Because they suppress the immune system, they can leave people more vulnerable to infections. Examples include the commonly prescribed drugs prednisone, cortisone and dexamethasone and methylprednisolone. For prednisone alone, over 25 million prescriptions are handed out each year.

18. Bone marrow transplants When people receive bone marrow transplants, their own defective bone marrow must be totally destroyed beforehand with chemotherapy and sometimes radiation. Because so many of our immune cells start their lives in our bone marrow, these patients are extremely vulnerable to all kinds of infections because these areas of production have been destroyed.

19. Organ transplants When people receive organ transplants, their own immune systems have to be severely suppressed with medications for life. If not, the transplant patient can reject the organ or bone marrow in a reaction called “Graft vs. Host”, which can be deadly. A couple of the medications given to prevent this are tacrolimus and mycophenolate. There are hundreds of thousands of organ transplant survivors in the USA

20. Recent surgery People are more vulnerable to infections after surgery, though the reasons are not entirely clear. The suppressive effect may be related to blood loss, antibiotics used, or the preoccupation of our immune system with healing and recovery from the procedure. Some experts feel that the anesthesia used in surgery might also play a role. There are over 100 million inpatient and outpatient surgeries per year in the USA.

21. Not having a spleen  The spleen is an organ where a lot of interactions happen between pathogens and immune cells like T cells and B cells. In the absence of a spleen (being “asplenic”), those cells aren’t present to kill many different pathogens and remove them from the blood, making the person more vulnerable to infections. Over 30,000 Americans have their spleen removed every year.

22. Certain genetic diseases  Some people are born with disorders that do not allow them to develop immunity to pathogens. This can be a severe combined lack of B lymphocytes and T lymphocytes like in Severe Combined Immunodeficiency Disorder (SCID), like the “boy in the bubble” had, or the disorder can be partial with the inability to produce only certain antibodies.

23. Iron deficiency anemia Iron appears to play a role in the maturation and differentiation of immune cells. People with iron-deficiency anemia might also have decreased T cell responses, making them more vulnerable to infection. Iron deficiencies are often seen in malnourished children and in women of childbearing age. But this doesn’t mean you should rush out and take an iron supplement; too much iron can be damaging in other ways. When is the last time you had your iron checked?

24. Being very young It takes several years for a child’s immune system to mature. When babies are born, they are born with some of their mother’s antibodies, but those fade. The window can be lengthened by breastfeeding, as some antibodies also come through breast milk. Please note: this does not appear to be a major risk factor in Covid-19; the evidence to date is that babies and young children rarely suffer severe cases of Covid infection. The exception to this — Multiple System Inflammatory Syndrome in Children, or MIS-C– is rare but life-threatening; its appearance seems related to immune dysfunction.

25. Being very old  Yes, being elderly is still on this list of factors for lowered immunity. It’s estimated that risk of death from a Covid-19 infection in someone age 20 is .03%. For an 80-year-old, that risk jumps to 7.8%. As we age, our immune responses are generally not as swift or as strong as they once were. We are also more prone to diseases and disorders that impact our immune systems. This is why infections like pneumonia are often the proximate cause of death among the elderly.

However, the elderly can still do a lot to protect and support their immune systems. And we can all do our part to protect everyone who may have lowered immunity.

Stay home if you feel sick. Wear a mask. Wash your hands.Whether or not we have a factor on this list, let’s all do our part to keep each other well.

Learn more: Best vitamins & nutrients to boost the immune system.

Pregnancy https://journals.physiology.org/doi/full/10.1152/physrev.00010.2018

Diabetes https://pubmed.ncbi.nlm.nih.gov/31657690/

Obesity https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5992476/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1779438/

Being Male https://www.jax.org/news-and-insights/2020/february/immune-system-changes-with-age-differ-between-men-and-women#

Stress, Depression Isolation https://www.apa.org/research/action/immune

Kidney Disease https://www.nature.com/articles/nri3523

Fatty Liver Disease https://reader.elsevier.com/reader/sd/pii/S0168827814005492?token=AEC9BF7158520B0D44903355606DCBE9923453C525B2F51BBDF2A558342EFD3AAEB1DC0D921D6B06D10A8E9D8D930419

Radiation Therapy https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/low-blood-counts/infections/why-people-with-cancer-are-at-risk.html

Chemotherapy https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/low-blood-counts/infections/why-people-with-cancer-are-at-risk.html

Cancerous Tumors https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/low-blood-counts/infections/why-people-with-cancer-are-at-risk.html

Opioid Pain Meds https://ghr.nlm.nih.gov/condition/opioid-addictionhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790459/

Anti-inflammatory medications https://ghr.nlm.nih.gov/condition/opioid-addictionhttps://www.belmarrahealth.com/7-common-habits-that-put-your-immune-system-at-risk/

Bone Marrow Transplantshttps://medlineplus.gov/bonemarrowtransplantation.html

Spleen https://www.immunodeficiencysearch.com/asplenia

Iron Deficiency Anemia https://academic.oup.com/ajcn/article/79/3/516/4690160 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134870/

About the immune system https://primaryimmune.org/immune-system-and-primary-immunodeficiency https://www.khanacademy.org/science/high-school-biology/hs-human-body-systems/hs-the-immune-system/a/hs-the-immune-system-review

Last Updated: January 7, 2022
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