Age, stress, and poor nutrition can sap our immune system of its effectiveness. Influenza provides one example; during young adulthood, when the body can mount a robust immune response to this common virus, influenza is rarely fatal. Among the elderly, however, the virus is associated with significant rates of death and hospitalization.1
The impact of aging on the immune system is profound. As people age, a number of critical immune system components including cellular response, antibody production, and response to vaccines are reduced or slowed.
At the same time, susceptibility to infection and cancer is increased. Some of this increased susceptibility to disease is linked to chronic inflammation, which is associated with many disorders of aging.2-4
Age, however, is not the sole culprit in reduced immune function. There is no question that exercise, stress, and nutritional status play an important role in maintaining a healthy immune system. Consider the following research findings:
• Dietary deficiencies and malabsorption alter metabolism and exacerbate chronic disorders.5
• Malnutrition causes a decline in immune function and increases susceptibility to infection. Likewise, a vitamin or mineral deficiency can suppress immune system function.6
• Psychological health influences the immune system and the course of many diseases. Depression, stress, and anxiety increase the production of pro-inflammatory chemicals in the blood, which in turn can compromise, depress, or suppress the immune system.7-12
• Chronic stress can provoke long-term increases in pro-inflammatory chemicals. For example, caregiving for a relative with a serious medical condition results in long-term immune suppression among women.13
• Chronic stress from persistent marital problems, burnout at work, and lengthy unemployment can lead to immune alterations that persist for years.14
Aging people should take action to bolster their immune systems. This includes reducing negative psychological stress; following a physician-approved, moderate, long-term exercise program; and following a healthy diet.
But with age, accomplishing all of that is often not enough. Supplementing with immune-specific nutrients is often required to reverse the signs of an aging immune system. Let’s take a look at some of these key nutrients.
Optimize Your Immunity with Vitamin D
Adults with higher vitamin D levels contract substantially fewer colds, flus, and other viral infections.15-17 Vitamin D down regulates the expression of pro-inflammatory cytokines while upregulating the expression of antimicrobial peptides in immune cells. This biological mechanism explains why Vitamin D confers such dramatic protection against common illnesses.
DHEA Improves Immune Function
Dehydroepiandrosterone (DHEA) is produced by the adrenal glands. DHEA has over 100 metabolites and is used by the body for estrogen and testosterone production.
Blood levels of DHEA rise until they peak in the third decade of life, then rapidly decline. Endocrinologists and anti-aging researchers have been focusing on this decrease in DHEA, which in turn produces a decline in other steroidal hormones.
Animal experiments suggest that DHEA has many biological effects, including anticancer, immune-enhancing, neurotrophic, and general anti-aging effects.18
Lower DHEA levels are associated with decreased production of IL-2 and an increase in the presence of IL-6, which is a pro-inflammatory cytokine.19 A study was performed on younger and older men to compare DHEA blood levels and a kind of immune cell, called a peripheral blood mononuclear cells (PBMCs).
The results showed significant changes in sex steroid metabolism by human PBMCs with aging, which may represent a link to age-associated changes in the immune system.19
Immunomodulatory effects of DHEA in various autoimmune diseases have been studied. Relative reductions in DHEA have been noted in patients with rheumatoid arthritis, systemic lupus erythematosus, HIV and AIDS, sepsis, and trauma.20
Overall, DHEA blood levels have been used as diagnostic factors in evaluating the impact of aging on the immune system. Supplemental DHEA has been clinically valuable when used to restore youthful hormonal blood levels in aging, stressed, and immune-compromised individuals.
Remove Immune Suppression with 7-keto DHEA
One of DHEA's metabolites, 7-keto DHEA, has also been studied for its ability to support the immune system. A study found that four weeks of 7-keto DHEA supplementation improved immune function in elderly men and women.
In this randomized, double-blind, placebo-controlled study, 22 women and 20 men over the age of 65 took either 100 mg of 7-keto twice daily or a placebo. The 7-keto group had a significant decrease in immune suppressor cells and a significant increase in immune helper cells.21
The 7-keto group also saw reductions in diastolic blood pressure and an increase in neutrophils, the first white blood cells to respond to infection.21
Probiotics Prevent Infections
The gastrointestinal tract relies on live bacteria to help support a robust immune response. These probiotic bacteria help prevent foreign bacteria and allergens from passing through the intestinal wall and are important to the overall health of the intestinal immune system.
Probiotics are found in foods such as yogurt and kefir, which enhance the microflora in the gut by providing additional probiotic bacteria. The most commonly used probiotic bacteria are lactobacillus and bifidobacterium, found in yogurts.
Probiotics also strengthen the intestinal immunological barrier. Lactobacillus stimulates natural immunity by improving a type of frontline immune cell called a natural killer cell.22
Grape Seed Extract
Compounds in grape seeds known as proanthocyanidins have potent antioxidant and immune-boosting properties. First, they increase the activity of internal antioxidants such as glutathione and SOD.23 Antioxidants such as these protect immune cells from free-radical damage, allowing a longer lifespan of infection fighting cells.
Interestingly, the antioxidants in grape seed extract are twice as potent as vitamin E and four times as potent as vitamin C.24,25 The powerful antioxidant of proanthocyanidins helps to increase the activity of natural killer cells, those frontline immune cells.
Lactoferrin – An Immune Booster from Mother’s Milk
Lactoferrin is one of the transferrin proteins that transfer iron to the cells and control the level of free iron in the blood and external secretions. Though human colostrum (“first milk”) has the highest concentration, followed by human milk, then cow’s milk, lactoferrin is found throughout the human body and plays an important immune strengthening role.26,27
Published studies examining lactoferrin as a supplement and its beneficial effects on immunity have been quite promising. For starters, lactoferrin helps maintain a proper level of “good” bacteria in the intestinal tract, while controlling the number of “bad” bacteria.28
Additionally, lactoferrin is concentrated in oral cavities where it will come in direct contact with pathogens and kills or greatly suppresses these pathogens through a variety of different mechanisms.
Exactly how lactoferrin exerts all of its immune-modulating or immune-enhancing functions is not entirely clear, but it is known to enhance the immune response both directly and indirectly (passively) in response to a wide range of immune challenges.
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