Investigating Immunosenescence

A healthy immune system is vital for our survival against the daily onslaught of foreign organisms and pathogens. As we age, this system declines, leaving us with higher incidences of infections, autoimmune diseases, and cancers.

An understanding of our immune system and how our daily habits affect it may help us find our own fountain of youth.

The immune breakdown process

The study of immunosenescence, defined as the decline of the immune system with age, is complex and not yet completely understood, but it is evident that both the innate and the adaptive parts of our immune system become altered.

Innate immunity includes our natural physical and physiological barriers to pathogens. Adaptive immunity is developed as a result of prior exposure to pathogens and their antigens, which causes activation of a number of specialized immune cells.

With increasing age, the lymphocytes we produce from innate or adaptive immunity to combat infection become less vigorous and less effective. Our antibodies are fewer in number and the duration of their response is shorter.

Results of reduced immunity

As a result we may have less immunity to infections or viruses such as the flu. The immune system may also become less tolerant of the body’s own cells and produce auto antibodies that attack the body itself, leading to autoimmune diseases such as rheumatoid arthritis.

With aging there is also generally low-grade chronic inflammation, a decrease in the size of the thymus gland where we develop the important immune T-cells, as well as changes in our chromosomes. Ongoing investigation and study into these various aspects of immunosenescence is yielding promising information for those of us seeking a long, healthy lifespan.

The long and short of telomeres

Telomeres are DNA caps at the ends of chromosomes that help protect our genetic information. The length of telomeres is proposed as an indicator of biological aging because telomeres get shorter each time cells divide. When a critical shortness is reached where cells appear to stop dividing, they stop growing and die.

There is evidence that higher rates of oxidative stress and chronic inflammation may speed this attrition rate. A 2009 study presented in the American Journal of Clinical Nutrition found that women who regularly used multivitamins had longer telomere lengths than women who did not.

Other nutrients may also affect telomere length, as indicated in another study where researchers measured the serum vitamin D concentrations in 2,160 women aged 18 to 79. The researchers found that although increased age was associated with shorter telomere length, higher serum vitamin D concentrations were significantly associated with longer telomere length—even after adjusting for age. The difference in telomere length between the groups with the highest and the lowest levels of vitamin D was estimated to be the equivalent of five years of cellular aging.

Support your system

While aging is inevitable, there are definitely measures you can take to support your immune health and possibly slow immune decline.

10 tips for a strong immune system

1. Take a broad spectrum multivitamin/mineral daily. One study showed that 60 percent of healthy participants over 50 years of age had inadequate intake of vitamins D and E, folic acid, and calcium from food alone.
2. Ensure adequate vitamin D. Achieve this through supplementation or daily sun exposure of as much skin as possible for at least 15 minutes. The use of sunscreen will block the skin’s production of vitamin D, but be sure not to burn.
3. Eat your antioxidants. Consume at least five cups of deeply coloured vegetables and fruit per day. Plant chemicals known as bioflavonoids are very strong antioxidants that help reduce the cellular damage that ages the immune system.
4. Have protein at every meal. This will keep blood sugar balanced, promote sustained energy, and support all parts of the immune system including the formation of antibodies. Research indicates that although we may need fewer calories as we get older due to a slower metabolism, our need for protein actually stays the same.
5. Take a digestive enzyme that has protease activity with each meal. Or try 1 Tbsp (15 mL) of apple cider vinegar in 2 to 3 oz (60 to 90 mL) of water before each meal to help with protein digestion. Stomach acid declines with age but is crucial for the digestion and utilization of protein in the body.
6. Get enough vitamins B₁₂ and B₆. B₁₂ is crucial for red blood cell formation and antibody synthesis and B₆ is needed for cellular or innate immunity. The best food sources for both include oysters, clams, sardines, salmon, and turkey. B₁₂ needs intrinsic factor and therefore adequate stomach acid for its absorption.
7. Think zinc. A deficiency in zinc reduces production and response rate of immune cells, including lymphocytes and natural killer (NK) cells. The best food sources include oysters, turkey, crab, and baked beans.
8. Pump iron. Use appropriate weights in your workouts, and be sure there is enough iron in your diet. Iron levels are directly related to NK cell activities that help detect and destroy cancer cells. The best food sources include clams, soybeans, lentils, and spinach. It is proposed that through various mechanisms, including increased body temperature, increased circulation, and reduced stress, regular exercise also can improve the immune system.
9. Keep an eye on E. Vitamin E is an efficient antioxidant and modulator of the immune system. Low levels are associated with increased infections and tumour development. Include sunflower seeds, almonds, tomato paste, and spinach in your diet.
10. Add the A. Vitamin A is important for healthy mucous membranes that act as barriers
    to pathogens as well as playing a crucial role in the development and activity of immune cells. Add sweet potatoes, carrots, spinach, and collard greens.