Sugar and the Immune System
Animal models have shown that increasing sucrose intake increases the neurotransmitter serotonin, important for mood balancing, suggesting that eating sugar can make us feel better when depressed.2 Although consuming sugar may result in enhanced mood, anyone who experiences this “sugar high” must pay a steep price. This is because numerous studies have shown that increased sugar intake dramatically decreases the immune response.
Short-term hyperglycemia (elevated blood sugar) affects all major components of innate immunity and impairs the ability of the individual to fight infection.3 The white blood cells are the primary mediators of the immune response. Neutrophils are a type of white blood cell that act as an important first-line-of-defense in the immune system by engulfing (phagocytizing) pathogens. Hyperglycemia has been shown to decrease neutrophil activity in numerous studies.4 One study showed that increased glucose levels decreased neutrophils’ ability to engulf several pathogens such as Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli.5 A similar study showed that poor blood sugar control in diabetic patients decreased neutrophil activity against Klebsiella pneumoniae.6 Specifically, neutrophils experienced a decrease in their movement and their ability to engulf and kill pathogens, an increase in leukocyte apoptosis (programmed cell death), and a reduction in lymph node retention capacity. Additionally, lowering of blood glucose has been shown to significantly improve neutrophil activity.7
Sugar’s harmful effect on the immune system was further demonstrated in a study that showed a significant decrease in neutrophil activity in blood samples from healthy adults at 30 and 60 minutes following ingestion of 75 grams of glucose.8 Another similar study examined the activity of neutrophils after a 100 gram dose of various simple carbohydrates including glucose, fructose, sucrose, honey, and orange juice in humans. The results indicated that all simple carbohydrates tested significantly decreased the capacity of neutrophils to engulf bacteria. The greatest effects occurred between 1 and 2 hours after ingestion of the carbohydrates, and the values were still significantly below the fasting control values five hours after glucose ingestion.9 Thus, increasing intake of sugary foods will have a profound impact on the immune response.
Stress and the Immune System
Around the holidays, not only do individuals increase their consumption of sugary foods, they also often experience increased stress levels. Stress, through the hypothalamic-pituitary-adrenal (HPA) axis, can modulate the immune system. Cortisol, released from the adrenal glands, is the primary hormone that mediates the stress response. Cortisol, in response to stress, suppresses the immune response.10 Research has shown that stress can affect the immune system in several ways such as reduced neutrophil activity, changes in types of chemical mediators (cytokines) produced by the white blood cells, and decreased cytotoxic T-lymphocytes and natural killer cell activities.11-12 Studies suggest that an elevated cortisol:DHEA ratio is a contributing factor to this reduced immunity, particularly in elderly patients. DHEA (dehydroepiandrosterone) is a steroid hormone secreted from the adrenal glands). More specifically, an elevated cortisol:DHEA ratio significantly decreases neutrophil activity.
One particularly interesting study evaluated the perceived life stress and risk of upper respiratory infections (URI). The study found that those individuals with high levels of negative life events and who showed high cortisol reactivity had increased numbers of URIs. Also this study showed that during times of increased perceived stress, lower reactivity of natural killer cells and CD8 T-lymphocytes were also correlated with increased URIs.13
In addition, studies have shown that anxiety affects immune function. Anxious subjects were found to have increased cortisol levels with impaired immune function and changes in cytokines released from the white blood cells.14
When Defenses are Down
EpiCor® is widely used for its ability to act as a potent immune system modulator. It has been shown to modulate the number and activity of immune cells known as lymphocytes including T-lymphocytes and natural killer cells, as well as antibody production.15 Additionally, EpiCor has been shown to significantly decrease the duration and number of reported symptoms in individuals suffering from colds and flu in a clinical trial.16 However, under times of increased vulnerability and decreased resistance to infection, such as during the holidays, pathogens may gain the upper hand. Consequently, even those individuals who regularly take Epicor for immune enhancement may need additional support this time of year. When defenses are down and the first signs of a cold or flu are felt, adding Fast Response™ can be a particularly powerful tool to enhance immunity.
Fast Response supports the immune system using a combination of vitamins and minerals with traditional Chinese herbs. These ingredients modulate white blood cells including B-lymphocytes, T-lymphocytes, macrophages, and natural killer cells, as well as decrease inflammation, which causes many of the symptoms associated with colds and flu.
The traditional Chinese botanicals in Fast Response have shown efficacy in supporting immunity. Forsythia suspense has been shown to have anti-viral and anti-bacterial activity.17-18 Lonicera japonicus inhibits the pro-inflammatory cyclooxygenase (COX)-2 and 5-lipoxygenase (LOX) enzymes,19 which is important as infection with the cold virus increases the activity of these two inflammatory enzymes.20 In traditional Chinese medicine, Platycodon grandiflorum has been used for clearing the lungs, resolving phlegm, and soothing the throat,21 and research has shown that constituents of Platycodon stimulate macrophage proliferation and activity.22 Arctium lappa (Burdock) contains arctigenin, which has been shown to prolong the survival time of mice infected with influenza virus as well as inhibited lung consolidation in mice pneumonia caused by the influenza virus.23 Arctium lappa decreases coughing, and was equally active as some synthetic preparations in studies using animal models.24 Research indicates that both Arctium lappa and the essential oils of Mentha arvenis inhibit the growth of several strains of pathogenic bacteria.25-26 Constituents of Glycyrrhizae uralensis have anti-inflammatory properties,27 can activate macrophages,28 and have been shown to decrease replication of coronavirus from patients with severe acute respiratory syndrome (SARS).29 Schizonepeta tenuifolia has been shown to regulate inflammatory responses by modulating T-lymphocyte activity.30 This combination of nutrients and botanicals can provide the extra support needed during times of increased vulnerability to colds and flu.
Taking a formula that combines the above botanicals with immune-supporting vitamins and minerals can be a particularly effective approach. Vitamins A, C, B6 and the mineral zinc are critical for optimal immune function. Vitamin A is required for the growth and activation of B-lymphocytes, increases macrophage activity, and is important in maintaining a sufficient level of natural killer cells. Deficient levels of Vitamin A can reduce lymphocyte numbers, natural killer cells, immunoglobulin responses, and impair T-lymphocyte function.31 Vitamin C has been shown in multiple studies to significantly reduce the duration of episodes and the severity of common cold and flu symptoms.32 Vitamin B6 is important for normal immune function as deficiencies have been shown to alter lymphocyte differentiation and maturation and impair antibody production.33 Zinc is required for normal development and function of white blood cells such as neutrophils and natural killer cells, and zinc deficiency adversely affects T-lymphocyte function, B-lymphocyte development, antibody production, and macrophage activity.34 Clinical trials indicate that zinc supplementation can significantly shorten the time to complete resolution of symptoms in patients with the common cold.35
Adding a vitamin D3 supplement to the immune-boosting regimen above also is important during cold and flu season. Researchers have theorized that the reason why the cold and flu season occurs in winter is because vitamin D deficiency is widespread during this time of year when exposure to sunlight is minimal.36 One explanation for vitamin D’s role in immunity is that it up-regulates an important gene called cathelicidin, a naturally occurring broad-spectrum antibiotic.37
Stress and poor dietary habits such as increasing intake of sugary foods and refined carbohydrates increase susceptibility to infection, particularly this time of year. Supplements such as EpiCor (see source link below) are ideal for general immune support. However, under times of increased vulnerability and decreased resistance to infection, products such as Fast Response may be necessary for extra immune enhancement. Adding a vitamin D3 supplement to this regimen will further strengthen immunity and provide additional defense against colds and influenzas.
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22. Choi CY, Kim JY, Kim YS, et al. Augmentation of macrophage functions by an aqueous extract isolated from Platycodon grandiflorum. Cancer Lett. 2001 May 10;166(1):17-25.
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31. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002. Available at: www.nap.edu/books/0309072794/html/.
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