BAS Health Series: Healthy Body Functions, Article 3 of 5
If your brain is the control center and your heart is the engine, your immune system is the security team — working 24/7 to protect everything you are. It’s your body’s most powerful internal defense, constantly identifying, targeting, and destroying threats before you ever feel a symptom.
Most people don’t realize the immune system is also one of the most important tools we have in the fight against the two biggest killers in America — cancer and heart disease. A strong immune system doesn’t just fight off colds; it identifies and removes damaged cells before they turn cancerous¹, and it helps control the inflammation that leads to heart disease². I’ve spent time in the top oncology clinics and chronic disease facilities in the US. I’ve realized that immune health is both vital to staying healthy and recovery … yet we rarely talk about it. Let’s learn about your immune system and provide the knowledge to keep that system strong for decades to come.
What Is Your Immune System and How Does It Work?
Your immune system is a complex army of cells, tissues, and organs — all coordinating to keep you healthy.
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Physical barriers: Your skin, mucous membranes, and gut lining act as walls to block invaders.
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Innate immunity: The rapid-response team. Cells like macrophages and neutrophils attack pathogens within minutes.
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Adaptive immunity: The intelligence unit. B-cells create antibodies that remember past infections, while T-cells coordinate attacks and destroy infected or abnormal cells³.
Did You Know? Your immune system produces around 100 billion new immune cells every day⁴, each one trained to recognize potential threats.
What Does It Mean to Improve Immune Health?
A strong immune system doesn’t mean you never get sick — it means your body responds quickly, efficiently, and without unnecessary inflammation.
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Faster recovery: White blood cells respond more efficiently.
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Lower inflammation: Prevents tissue damage that leads to chronic disease.
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Improved surveillance: Detects and eliminates precancerous or infected cells.
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Resilience with age: Maintains energy, mood, and overall vitality.
Issues and Diseases That Can Occur
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Autoimmune diseases: When the immune system mistakenly attacks the body’s own tissues.
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Allergies: An overreaction to harmless substances.
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Immunodeficiency: A weakened or underactive system.
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Chronic inflammation: When the immune system stays “on,” damaging healthy tissue and fueling diseases like diabetes, heart disease, and cancer⁵.
Important! Chronic inflammation contributes to nearly 50% of all deaths worldwide⁶, largely through cancer and cardiovascular disease.
The Immune System and Cancer
Your immune system constantly patrols for abnormal cells — including early cancer cells. Specialized natural killer (NK) cells and cytotoxic T-cells detect mutations, trigger cell death, and prevent tumors from developing⁷.
When this system weakens — due to stress, poor diet, lack of sleep, or aging — abnormal cells can slip through. This is known as immune evasion, one of cancer’s most powerful tricks⁸.
That’s why strengthening your immune system isn’t just about avoiding the flu — it’s cancer prevention at its most fundamental level.
People with strong immune surveillance have up to a 40% lower risk of developing certain cancers⁹.
The Immune System and Heart Disease
Most people think of heart disease as a plumbing problem — clogged arteries, bad cholesterol. But at its core, it’s also an immune and inflammation problem.
When LDL cholesterol oxidizes, the immune system sees it as an invader and sends macrophages to “clean it up.” Over time, these cells create plaque and inflammation inside artery walls¹⁰. If the immune system is balanced and well-regulated, this process slows dramatically.
Inflammation plays a role in up to 80% of heart attacks¹¹. Keeping your immune system balanced — not overactive, not underactive — is one of the best ways to protect your heart.
Simple Things You Can Do Every Day to Improve Immune Health
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Prioritize sleep: During deep sleep, your immune system releases cytokines — critical proteins for fighting infection and controlling inflammation. People who sleep fewer than 6 hours per night are 4x more likely to catch a cold¹².
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Eat nutrient-rich foods: Vitamins A, C, D, zinc, and antioxidants support immune cell growth and repair. Vitamin D deficiency increases respiratory infection risk by 64%¹³.
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Exercise moderately: Movement circulates immune cells and strengthens resistance to infection. Regular exercisers experience 50% fewer sick days each year¹⁴.
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Manage stress: Cortisol from chronic stress suppresses immune function and damages white blood cells. Prolonged stress can shrink the thymus — where T-cells mature¹⁵.
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Stay hydrated: Lymphatic fluid, which carries immune cells, depends on proper hydration. Even mild dehydration slows lymph flow and weakens immunity¹⁶.
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Get vaccinated: Vaccines train your adaptive immune system to respond faster to future infections. Vaccines prevent an estimated 4 to 5 million deaths globally each year¹⁷.
Things You Should Avoid That Damage Your Immune System
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Chronic stress: Over time, cortisol reduces lymphocyte production and weakens defenses¹⁸.
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Poor diet: High-sugar and processed foods feed inflammation and disrupt gut microbiota — where 70% of your immune cells live¹⁹.
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Smoking: Damages white blood cells and impairs oxygen delivery²⁰.
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Excess alcohol: Weakens the intestinal barrier, allowing toxins to leak into the bloodstream²¹.
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Sedentary lifestyle: Slows circulation and immune cell transport.
When I manage stress, eat well, and stay active, I notice the difference — fewer colds, better energy, and a calm, clear sense of balance. The immune system rewards consistency.
Why This Matters
This article is really the genesis of this entire series. Over the past few years, I’ve spent time visiting some of the top oncology clinics in the country — and what I witnessed changed me. Again and again, I saw that patients with stronger immune systems not only responded better to treatment, but often lived longer, fuller lives.
It became crystal clear that the immune system isn’t just about avoiding a cold — it’s the foundation of everything. It determines how well we fight disease, how we recover, and how long we live. Whether it’s cancer, heart disease, or chronic inflammation, every one of these battles is won or lost on the strength of our immune system.
I’ve also seen the other side of that truth. I’ve personally experienced the impact of autoimmune conditions — cruel, confusing, and often invisible illnesses where the body turns on itself. It taught me humility, and it gave me a deep respect for how delicate, powerful, and vital this system really is.
Most people never really learn how their immune system works until something goes wrong. But that knowledge — that understanding — can literally save lives.
This is why I wrote this series. Educating yourself about your immune system isn’t optional; it’s essential. It’s one of the most overlooked aspects of health, yet it influences everything — energy, mood, aging, disease prevention, even longevity. The more we understand it, the more control we have over our own health stories.
If there’s one message I hope readers take away, it’s this: your immune system is your greatest ally. Protect it, feed it, and give it what it needs. Because when it’s strong — you’re strong.
Healthy Core Body Functions Series
By Ken York, President of Benefit Airship
At Benefit Airship, our passion is helping members get the best healthcare possible. We’re endlessly curious about what makes the body thrive—and we love uncovering insights that make health simpler to understand and easier to manage. Whenever we find something worth sharing, we share it to empower healthier, more informed lives.
This series will explore five essential body systems—the brain, heart, immune, gastrointestinal, and nervous systems—and offer practical tools for improving your overall well-being. I’ll share science, tips, and inspiration for taking small, meaningful steps toward a stronger, healthier you.
Sources
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National Cancer Institute, Immune System and Cancer Prevention
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Harvard Medical School, Inflammation, Immunity, and Heart Disease
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National Institutes of Health, How the Immune System Works
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British Society for Immunology, Immune Cell Production Facts
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Mayo Clinic, Chronic Inflammation and Disease
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Global Burden of Disease Study (2023), Inflammation-Linked Mortality
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Cancer Research UK, Natural Killer Cells and Cancer Immunity
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Nature Reviews Cancer, Mechanisms of Immune Evasion in Tumors
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Frontiers in Immunology, Immune Surveillance and Cancer Risk Reduction
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European Heart Journal, Immune Response in Atherosclerosis
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American Heart Association, Inflammation and Cardiovascular Events
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Archives of Internal Medicine, Sleep and Cold Susceptibility
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BMJ, Vitamin D and Respiratory Infection Risk
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British Journal of Sports Medicine, Exercise and Immune Function
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Psychoneuroendocrinology, Stress and Thymus Shrinkage
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European Journal of Nutrition, Hydration and Immune Transport
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World Health Organization, Vaccine Impact Report (2024)
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Nature Reviews Immunology, Cortisol and Immune Suppression
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Johns Hopkins Medicine, Gut Microbiome and Immunity
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CDC, Smoking and Immune Function
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National Institutes of Health, Alcohol and Immune Dysfunction
