March-April 2019: Building Resistance...tell those Bugs to Bug off!

Give your system a boost!

The idea of boosting your immunity is enticing, but the ability to do so has proven elusive for several reasons. The immune system is precisely that — a system, not a single entity. To function well, it requires balance and harmony. There is still much that researchers don't know about the intricacies and inter-connectedness of the immune response. For now, there links between lifestyle and enhanced immune function are tenuous at best, but there is a definite correlation.

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Increasingly, researchers are exploring the effects of diet, exercise, age, psychological stress, and other factors on the immune response, both in animals and in humans. In the meantime, general healthy-living strategies are a good way to start giving your immune system the upper hand.

Your first line of defense is to choose a healthy lifestyle. Following general good-health guidelines is the single best step you can take toward naturally keeping your immune system strong and healthy. Every part of your body, including your immune system, functions better when protected from environmental assaults and bolstered by healthy-living strategies such as these:

  • Don't smoke.

  • Eat a diet high in fruits and vegetables and low in added sugars and processed foods.

  • Exercise regularly.

  • Maintain a healthy weight.

  • If you drink alcohol, drink only in moderation.

  • Get adequate sleep.

  • Take steps to avoid infection, such as washing your hands frequently.

  • Try to minimize stress.

Immune system and age

As we age, our immune response capability becomes reduced, which in turn contributes to more infections and sometimes, a higher likelihood of cancer. The conclusion of many studies is that, compared with younger people, the elderly are more likely to contract infectious diseases and, even more importantly, more likely to die from them. Respiratory infections, influenza, and particularly pneumonia are a leading cause of death in people over 65 worldwide. No one knows for sure why this happens, but some scientists observe that this increased risk correlates with a decrease in T cells, cells that fight off infection.

In addition, there appears to be a connection between nutrition and immunity in the elderly. A form of malnutrition that is surprisingly common even in affluent countries is known as "micronutrient malnutrition". Micronutrient malnutrition, in which a person is deficient in some essential vitamins and trace minerals that are obtained from or supplemented by diet, can be common in the elderly since they often tend to eat less food and less variety of it. This is when dietary supplementation may be beneficial but should be discussed with their primary care physicians (1).

Diet and your immune system

Like any fighting force, the immune system warriors need good, regular nourishment. However, there are still relatively few studies of the effects of nutrition on the immune system of humans, and even fewer studies that tie the effects of nutrition directly to the development (versus the treatment) of diseases.


So what can you do? If you suspect your diet is not providing you with all your micronutrient needs — maybe, for instance, you don't eat enough vegetables — taking a daily multivitamin may bring other health benefits, beyond any possibly beneficial effects on the immune system. However, taking mega doses of a single vitamin does not, unless you are clinically deficient (like in the case of iron deficiency anemia). More is not necessarily better (2).

Improve immunity with herbs and supplements

Walk into a store, and you will find bottles of pills and herbal preparations that claim to "support or boost immunity". Although some preparations have been found to alter some components of immune function, thus far there is no evidence that herbal supplements actually bolster immunity. Scientists don't know, for example, whether an herb that seems to raise the levels of antibodies in the blood is actually doing anything beneficial for overall immunity (3).

Stress and immune function

Modern medicine has come to appreciate the closely linked relationship of mind and body. A wide variety of ailments, including stomach upset, hives, and even heart disease, are linked to the effects of emotional stress. Despite the challenges, scientists are actively studying the relationship between stress and immune function.

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For one thing, stress is difficult to define. What may appear to be a stressful situation for one person is not for another. When people are exposed to situations they regard as stressful, it is difficult for them to measure how much stress they feel, and difficult for the scientist to know if a person's subjective impression of the amount of stress is accurate. However, the literature shows that some scientists are investigating whether ongoing stress takes a toll on the immune system, and are making some progress (4, 5).

Does being cold give you a weak immune system?

Almost every parent or caregiver has said it: "Wear a jacket or you'll catch a cold!" Is he/she right? So far, researchers who are studying this question think that normal exposure to moderate cold doesn't increase your susceptibility to infection. Most health experts agree that the reason winter is "cold and flu season" is not that people are cold, but that they spend more time indoors, in closer contact with other people who can pass on their germs.

So, should you bundle up when it's cold outside? The answer is "yes" if you're uncomfortable, or if you're going to be outdoors for an extended period where such problems as frostbite and hypothermia are a risk. But don't worry about the cold compromising your immune health (6).

Exercise: Good or bad for immunity?

Regular exercise is one of the pillars of healthy living. But does it help to boost your immune system naturally and keep it healthy? Just like a healthy diet, exercise can contribute to general good health and therefore to a healthy immune system. It may contribute even more directly by promoting good circulation, which allows the cells and substances of the immune system to move through the body freely and do their job efficiently.

Some scientists are trying to take the next step to determine whether exercise directly affects a person's susceptibility to infection. For now, even though a direct beneficial link hasn't been established, it's reasonable to consider moderate regular exercise to be a potentially important means for keeping your immune system healthy along with the rest of your body.


  1. Causes, consequences and reversal of immune system aging. March 2013, Journal of Clinical Investigation.

  2. How your immune system is affected by diet, stress and exercise. March 2018. Cleveland Clinic.

  3. Three Vitamins that are best for boosting your immunity. Jan 2016, Cleveland Clinic.

  4. Stress and the Individual: Mechanisms leading to disease. Sept 27, 1993. JAMA Network, Internal Medicine.

  5. Current directions in stress and immune function. Science Direct, Oct 2015, Vol. 5. Current Opinion in Psychology.

  6. Can being cold make you sick? Feb 23, 2018. New York Times: Ask Well.