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Stress and Immune Function

Posted Apr 15, 2019

Immunity and the Stress Response

When your patients experience any type of physical or emotional stress, their body’s physiological reaction is the same as that of early humans: an immediate, short-term response programmed to help them physically deal with the stressor. Their brain signals their adrenal glands to secrete hormones, such as adrenaline and cortisol, that prepare their body for action. These hormones cause the “fight or flight” response, in which every system in the body becomes primed to do one of two things: fight the stressor or escape.

The stress response increases heart rate and blood pressure to rush blood and nutrients to muscles, mobilizes sugar into the bloodstream where it can be used for energy, and focuses attention.  However, there are other important changes triggered by stress hormones that are not so readily apparent. One of the most important of these is the alteration in immune function.

Almost every immune cell in the body has receptor sites for either cortisol, adrenaline, or both. The acute fight or flight response set off by adrenaline can be pro-inflammatory and temporarily boosts certain aspects of innate, front-line immunity that help reduce the chance of infection from an injury sustained in the fight or flight. The accompanying elevated cortisol suppresses the deeper, adaptive aspects of immunity that protect the body over the long term from disease.

If facing a lion, the body will shift energy resources from less immediate threats (like fighting cancer or a cold) to help the person survive the critical danger in front of them. When stress is chronic or prolonged, both the increase in inflammation and the decrease in overall immune function can begin to adversely affect your patient’s health.

21st Century Stress Weakens Immunity

The stress response worked beautifully for primitive humans who usually dealt with their stressors through a relatively brief burst of physical activity. Cortisol and adrenaline allowed the body to surge into action to overcome the stressor and support immune function in case of injury. During this physical activity, the circulating stress hormones were dissipated and metabolism was able to return to normal. 21st century stressors, however, seldom require a physical response and tend to continue over longer periods of time. Historically, a stressor might be something along the lines of having to wrestle a large mammal to the ground for the week’s food.

Today’s stressor is more likely to be bumper to bumper traffic when you have an appointment across town in 15 minutes for a job you cannot afford to lose because your paycheck barely covers your current rent and you have a baby on the way. There is no effective way to physically overcome this type of modern stressor and little opportunity to dissipate the stress hormones it elicits. Because the stress continues, the brain keeps sending messages to produce more cortisol, and the multiple stressors become cumulative. This can wreak havoc on the immune system. If the adrenal glands are continually stressed, they may become fatigued and unable to produce sufficient hormone levels for effective immune stimulus.

Consequently, a heavy stress load can have a negative impact on immune activity with either adequate or inadequate adrenal function. In addition, when people are stressed, they often do a poorer job of taking care of themselves. They have a tendency to laugh less, smoke and drink more, get insufficient sleep and make less healthy dietary choices – all of which can affect the immune system for the worse.

The Cortisol/Immune Seesaw

Elevated cortisol, as is often associated with healthy adrenal glands responding to ongoing stress, is related to a net decrease in immune function, leaving the body more susceptible to colds, flu, acne flare ups, and other infections, and potentially making people more vulnerable to more serious illnesses and degenerative disease down the road. Chronic stress is also associated with the development of allergies and autoimmune disorders.

If stress continues over an extended period of time, the adrenals eventually may not be able to keep up with the continued demand and may, over time, actually produce too little cortisol. Among the other aspects of immunity that cortisol suppresses, it also affects inflammation. If the adrenals do not produce enough cortisol, inflammation in the body can worsen and inflammatory conditions can flare. Whether there is too much or too little cortisol, the body’s immune system can suffer from the effects of chronic 21st century stress.

Keeping Immune Balance Under Stress

Stress creates such an intricate web of interactions with the immune system that managing stress and supporting the HPA axis, especially the adrenal glands, can significantly enhance immunity and help your patients stay well.

Lifestyle and Dietary Tips

• Make a point of getting 7 or more hours of sleep each night – sleep deprivation and restriction disrupt immunity
• Wash your hands to prevent the spread of disease
• Reduce your consumption of sugar (including drinks like soda and your favorite Starbucks coffee) – sugar suppresses immune function
• Eat sufficient high quality protein – amino acids are the building blocks of your immune cells
• Practice yoga, meditation, and moderate exercise, each of which has been shown to help normalize cortisol levels and positively impact immune function
• Laugh! It has been shown to help modulate cortisol and boost immune function

Supplements For Immune Function Enhancement

Certain nutritional supplements and herbs have a long history of successful use and/or scientific support for enhancing immune function and promoting stress hardiness.

Probiotics for Immune Enhancement
– Lactobacillus bulgaricus, a probiotic, beneficially modulates the immune system by promoting front line immune cell activity in the lungs and intestines (1) and enhancing innate immunity (2)
– Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus rhamnosus, Lactobacillus salivarius, and Lactobacillus plantarum promote healthy intestinal microbial balance necessary for optimal frontline immune defenses in the digestive tract (3), and promote optimal bowel function (4)

Vitamins and Minerals for Immune Enhancement
– Vitamin C has been shown to enhance the production and function of white blood cells (5)
– Vitamin A is required for immune cell activation and survival (6)
– Zinc is essential for healthy immune function and has been shown to beneficially affect the duration and severity of the common cold (7)

Herbs for Immune Enhancement
– Echinacea and thuja have been shown to beneficially affect the duration of cold viruses in human subjects (8) and survival rate in mice with influenza (9)
– Ashwagandha has been shown to enhance macrophage and natural killer cell functions (10), and increase production of lymphocytes
– Cayenne has been shown to increase numbers of B cells and antibodies, and lymphocyte proliferation (11)
– Thuja has been shown to enhance cell-mediated immunity (12)

Defense against Pathogens
– L-lysine, an amino acid, interferes with the replication of certain viruses and has been shown to have a beneficial effect on stress-related viral outbreaks (13)
– Herbs such as grapefruit seed extract, cat’s claw, oregano, pau d’arco, thyme, and cayenne pepper have been shown to promote healthy microbial balance (14)
– Cell wall fractions from probiotic Lactobacillus bulgaricus have been shown to support immune system efficacy (15)
– Lomatium, an herb, has been shown to help mitigate the effects of rotavirus (one of the causes of the common cold) (16)

Adrenal Support

Vitamins and Minerals for Adrenal Support
– Vitamins A, C & E help modulate brain/adrenal gland interaction and related stress responses (17) (18)
– Copper, zinc, manganese, magnesium, vitamin C, vitamin E and bioflavonoids are important as antioxidants that help neutralize free radical damage that increases during stress (19)
– B vitamins and vitamin C are rapidly depleted under stress and must be replenished for the body to continue to handle stress (20)

Herbs for Adrenal Support
– Eleutherococcus has been shown to help moderate inflammation and curb excessive physiologic reactions to stress (21)
– Eleutherococcus, maca and ashwagandha have been shown to promote optimal brain and adrenal function under stress (21)


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