Post by livelonger on Sept 21, 2016 5:42:20 GMT -5
"Sugar + Stress = Vulnerability to Colds and Flu
By Nieske Zabriskie, ND
The strength of the immune response changes based on several variables such as diet, stress, and mood. Thus, around the holidays, when people are more prone to eat sugary foods and refined carbohydrates, there is a direct and unfavorable effect on immune function. In addition, the stress of the holiday season can also have detrimental effects on the immune response. Adults average 2-4 colds per year, with increased occurrence during the fall and winter when the air is colder with decreased humidity.1 Consequently, many people have an increased susceptibility to colds and flu during the holiday season.
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"
www.intelegen.com/holiday_immune_support.htm
By Nieske Zabriskie, ND
The strength of the immune response changes based on several variables such as diet, stress, and mood. Thus, around the holidays, when people are more prone to eat sugary foods and refined carbohydrates, there is a direct and unfavorable effect on immune function. In addition, the stress of the holiday season can also have detrimental effects on the immune response. Adults average 2-4 colds per year, with increased occurrence during the fall and winter when the air is colder with decreased humidity.1 Consequently, many people have an increased susceptibility to colds and flu during the holiday season.
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"
www.intelegen.com/holiday_immune_support.htm