The most important immune supportive approaches are not supplements, but lifestyle modifications:
- Get adequate sleep
- Do at least 30 minutes/day of dedicated stress reduction
- Maximize your intake of nutrient dense foods (great article)
- Minimize toxic exposures
- Exercise (muscle mass building is more critical than aerobic-only)
Research shows that individuals sleeping 6 hours or less a night were more than 4 times more likely to catch a cold compared to those who get 7+ hours of sleep. With every hour of sleep lost, the risk of catching a cold continued to rise.
One study found that a single night of interrupted sleep decreased natural killer cell activity by 30%.
There are many proposed mechanisms for how sleep and immunity are linked:
- Sleep disruption, inadequate sleep and poor sleep quality causes stimulation of the hypothalamic pituitary axis (HPA), which produces immune suppressing stress hormones (i.e. cortisol, epinephrine)
- Excessive or chronically high stress hormone levels directly and indirectly suppress immune function.
- Direct suppression: stress hormones act directly on receptors on white blood cells and inhibit their immune activity
- Indirect suppression: stress hormones decrease the production of melatonin (which stimulates immune function), cause insulin resistance (higher blood sugar levels suppress immune function) and increase inflammatory cytokine production (which directly impair immune function)
Some scientists believe that cancer, in part, is the end result of chronically stressed-out brains sending stimulatory signals to adrenal glands to produce stress hormones (like cortisol and epinephrine). They believe this because long-term exposure to stress hormones are catastrophic. They are responsible for:
- Increased production of free radicals that cause DNA damage and impaired immune systems.
- Increased inflammation through the production of inflammatory proteins (cytokines) that further impair the immune function and promote cancer growth.
- The direct impairment of the immune cell function responsible for destroying tumor cells and other invaders.
- Reduced ability of abnormal cells to undergo DNA repair or apoptosis (cell death), which is a vital self-regulating anti-cancer mechanism.
- Stimulating the production of IGF-1 (insulin-like growth factor-1), VEGF (vascular endothelial growth factor), and other factors that can promote tumor cell growth.
The immune surveillance theory (also known as immunosurveillance) suggests that there are numerous pre-cancerous and malignant cells that have the potential to become a tumor if not detected and destroyed by the immune system. Fortunately, immune cells (e.g., white blood cells, natural killer cells, macrophages) in a healthy immune system protect people by detecting and eliminating them.
Healthy immune systems are also working to protect people from viruses that can cause cancer. These include: Epstein-Barr virus, human papilloma virus, hepatitis C virus, hepatitis B virus, human herpes virus 8 and human T-cell leukemia virus.
When immune systems are weakened or suppressed, pre-cancerous and cancer cells and cancer-causing viruses are better able to wreak havoc. This may eventually lead to the development of uncontrolled cancer cell growth.
Excessive exercise will tamp down our immune systems, opening us to pathogens and illness (i.e. studies show that marathon running increased the incidence of infection symptoms among runners in the days and weeks after the race) however low-to-moderate intensity or short bouts of high-intensity exercise boost immune function.
The following supplements are my top choices for immune support as it pertains to reducing upper respiratory viral infection risk, severity and duration:
Lipoic acid (1200-1800 mg/day) ref
Selenium (50-100 mcg/day) ref
Zinc (30-50 mg/day) ref
Glucosamine (>/=3000 mg/day) ref
Glutathione (500-1000 mg/day) ref
Vitamin C (1000 mg/day prevention, 3000-4000 mg/day during viral infection) ref
Querectin (200-1200 mg/day) ref
N-acetylcysteine (600 mg two-times/day) ref
Spirulina 15 g/day (or 100 mg PCB) ref
I recommend functional medicine assay testing
Testing can identify underlying issues that impair immunity. I assess the following variables:
- Nutrient levels
- Systemic inflammation
- Stress hormones
- Gut health
- Insulin sensitivity
- Innate immune response
If we identify any concerns, these should be addressed and optimized through individualized lifestyle modifications and other targeted approaches.