Life Extension Magazine

Life Extension Magazine March 2014

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Getting Back To Basics...How Low-Cost Zinc Helps Combat Deadly Immunosenescence

By Heath Ramsey

Support Your Body’s Anti-Cancer Surveillance System

Whether you realize it or not, every one of us experiences dozens of pre-cancerous cell changes daily. The reason we don’t all develop malignancies every day is thanks to the aggressive anti-cancer surveillance by the body’s immune system, particularly the aggressive “natural killer” cells that seek out and destroy abnormal cells.36

Zinc is absolutely essential for this anti-cancer surveillance system to function properly. That’s why, when zinc levels drop, we see a substantially higher rate of cancer, especially in the mouth, esophagus, and stomach.37 The tissues of your digestive tract are particularly vulnerable because they’re more exposed to the outside toxins that we ingest.

Restoring your body’s levels of zinc prevents loss of natural killer cell function, reduces the inflammation that promotes cancer, and reduces cancer cells’ ability to grow new blood vessels.36,38-40 As a result, zinc supplementation has been associated with a reduced incidence and/or progression of tongue, esophageal, stomach, and colon cancer in animals with zinc deficiencies.8,37,41-45

Zinc offers additional protection against cancer by starving tumors of the glucose they need to grow and spread. Cancer cells take up glucose at a very high rate compared with non-malignant tissues; that’s presumably because the rapidly-growing tumors have exceptionally high energy requirements.46 Zinc supplements appear to reduce glucose uptake in malignant cells, thus reducing the availability of energy cancer cells need to replicate and progress.46

Zinc is important in cancers outside of the digestive tract as well. The risk of non-Hodgkin’s lymphoma, a common blood cancer, is 42% lower in people with higher levels of zinc compared to those with lower levels.47 And among patients with head and neck cancers, nearly 65% were found to be zinc deficient.39

Prostate cancer is also sensitive to zinc. Normally the prostate contains tenfold the amount of zinc found in other soft tissues, but zinc accumulation in prostate tissue decreases shortly after prostate cancer begins.48 Supplementation restores normal prostate zinc levels and reduces levels of a promoter of tumor growth (IGF-1).48 Supplementation also supports natural antioxidant enzymes in the prostate; those enzymes are impaired as the result of high oxidant stresses imposed by growing malignancies.49

Even if your zinc levels are adequate, supplementing with zinc could offer additional protection against cancer. In animals with normal zinc levels, the number of experimentally-induced tumors was 28% lower when the animals were given a modest zinc supplement.8

Dietary Sources Of Zinc10
Dietary Sources Of Zinc

Food

Mg of zinc per serving

Oysters

74.0

Beef chuck roast

7.0

Lobster

3.4

Pork loin

2.9

Baked beans

2.9

Chicken

2.4

Yogurt

1.7

Cashews

1.6

  • Minimum RDA of zinc is 15 mg according to the government. Optimal supplemental doses for aging humans may be five times higher—up to 80 mg daily.86
  • Although it’s possible to get zinc from plant sources, your body can’t utilize it as well because molecules found in breads, cereals, and legumes can bind the zinc and prevent your body from absorbing it.10

Diabetes And Obesity

The science demonstrating zinc’s importance in preventing diabetes and its consequences is so strong that zinc has become widely accepted as an important supplement for those at risk for—and even those already suffering from—diabetes.

In addition, zinc is involved in the synthesis, storage, and release of insulin. Zinc deficiency is associated with insulin resistance, impaired glucose tolerance, and obesity. In a study of obese individuals supplemented with 30 mg zinc for one month, researchers found significant reductions in body weight, body mass index (BMI), and triglycerides.50

Studies show that supplementation with zinc lowers both fasting and after-meal glucose levels and reduces the long-term measure of blood glucose called hemoglobin A1c.51-55 Zinc supplementation also improves insulin sensitivity and lowers insulin levels, a major factor in people with “pre-diabetes” (impaired fasting glucose).56-58

Higher blood levels of zinc are associated with the following:

  • 10 to 15% decrease in the risk of diabetes.
  • 34 to 43% lower risk of glucose intolerance.
  • 12 to 13% reduction in central obesity.
  • 23 to 43% reduction in coronary artery disease.59

In another study, body weight and body mass index decreased following supplementation with 20 mg of zinc.58 That’s particularly important because of the relationships between obesity, high insulin levels, and cancer. Zinc supplementation also markedly improves nerve conduction velocity, a measure of diabetic nerve damage.52

Zinc and Copper: A Balancing Act
Zinc and Copper: A Balancing Act

Research has shown that higher dosing of supplemental zinc has produced significant benefit.86 However, long-term supplementation of zinc at doses above around 50 mg can interfere with copper bioavailability and result in deficiency of copper.87 High intake of zinc induces the intestinal synthesis of a copper-binding protein called metallothionein.87 Metallothionein traps copper within intestinal cells and prevents its systemic absorption. Copper deficiency can lead to clinical manifestations such as anemia, low levels of neutrophils (the most abundant type of white blood cell), and bone abnormalities, including fractures.88 Low levels of copper can also lead to increased concentration of total cholesterol and LDL cholesterol, reduction of HDL cholesterol, diminished glucose tolerance, and altered cardiac rhythm.88 Individuals supplementing with more than 50 mg of zinc on a chronic basis should consider supplementing with 2 mg of copper daily to address the risk of copper deficiency associated with high zinc ingestion. Short term supplementation of high doses of zinc is unlikely to affect copper distribution in the body.87

Summary

Immunosenescence, the aging of the immune system, is a major contributor to the higher rates of serious infections and cancers seen in older adults. Although immunosenescence was previously thought of as a natural effect of aging, scientists now believe that it could be caused in part by a deficiency in zinc.

That means that something as simple as supplementing with zinc could slow or reverse immunosenescence. Studies show that supplementing with zinc reduces the risk of serious infections such as pneumonia and influenza. Lab studies also demonstrate a remarkable cancer-preventive effect of supplementary zinc. Even the twin scourges of obesity and diabetes show signs of yielding to zinc therapy, with improved measures of blood glucose and reduced body mass, as well as fewer diabetic complications such as nerve and kidney damage.

If you are not taking a zinc supplement today, you should consider it to minimize the impact of immuno-senescence on your body.

If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.

TABLE: Zinc And Your Health10

Health Concern

Impact of Insufficient Zinc

Immune Function

Increased susceptibility to pneumonia and other infections28

Wound Healing

Slow or incomplete wound healing84

Gastrointestinal
Health

Worsening of inflammatory bowel diseases and increased production of inflammatory cytokines85

Vision

Increased risk of age-related macular degeneration (AMD)78-83

Cardiovascular Health

Increased plasma lipids, markers of atherosclerosis62

Cancer

Diminished immune surveillance against cancer cells39

Diabetes

Decreased blood sugar control55

Neurological
and Mental Health

Increased risk of depression; decreased cognitive performance9,77