By SUSAN CALLAHAN, Featured Columnist
Like an old-reliable car, your immune system just keep chugging along. For every day, 365 days a year, year in and year out, your immune system battles bacteria and viruses that dare enter the inner sanctum of your body.
But, like an old car, your immune needs maintenance to stay fit for purpose. It needs a regular tune-up. How can you re-invigorate your immune system? Are there things you can do to relieve some of the workload from your immune system?
1. Get At Least 7 Hours Sleep
To function properly, your immune system needs deep, restorative sleep. During sleep, your body down-regulates stress hormones ( cortisol and catecholamines) and stimulates cell growth, according to a 2012 study from the University of Tübingen, in Tübingen, Germany.
And a 2007 study from the University of Lübeck, in Germany found that, during sleep, your body produces more of the immune system cells, interleukin-7 (IL-7) and interleukin-15 (IL-15).
Going without sleep for a single night or shorting your sleep on rare occasions seems not to do much harm to your immune system. But chronic sleep deprivation is enormously harmful.
Losing sleep on a regular basis makes you more susceptible to colds and flu.
To support a healthy immune system, you should aim to sleep at least 7 hours per night. Eating salmon can help you to fall asleep more easily.
But don't overdo it. More and more is not better than less. Sleeping more than 9 hours appears to make matters worse, with some studies having found that over-sleeping triggers the inflammatory response.
2. Add Some Pork to Get Your Thiamine
Thiamin is also known as Vitamin B1. Most of us get enough thiamin from our foods but, if you find that you are feeling under the weather more than you'd like, consider boosting your thiamin levels a bit.
Thiamin plays a role in many different chemical reactions in your body. But among the most important is thiamin's role in reducing stress.
A 2011 study from Swinburne University of Technology, Hawthorn, in Victoria, Australia, examined the effect of giving thiamin to people experiencing work place stress.
In this study, thiamin supplements were given to 60 participants for 12 weeks.
At the end of the 12 weeks, those participants who took thiamin supplements reported " significantly lower personal strain and a reduction in confusion and depressed/dejected mood".
Pork contains 54% of the daily recommended amount of thiamin, the highest among all foods.
So, while too much pork can be disastrous for your heart and arteries, make room for a little pork in your weekly diet. Pork chop Thursdays, anyone?
3. You Get By With a Little Help from Vitamin E
Your lungs can easily be weakened by persistent colds and flu. In this weakened state, you become vulnerable to pneumonia.
Especially as you get older, pneumonia stalks your lungs. This is why pneumonia is one of the leading causes of death in the US and worldwide among people over the age of 50.
Vitamin E helps to protect aging lungs against the bacteria that causes pneumonia, a study from Tufts University has found. The study, conducted in 2014 by a team led by Dr. Elsa Bou Ghanem, examined how adding Vitamin E to the diets of older mice infected with the pneumonia bacteria would affect the mice's recovery.
Two groups of mice were infected with the pneumonia bacteria. One group was given the daily recommended amount of Vitamin E. The second group was given 10 times that amount of Vitamin E, about 200 IUs per day. This amount is still below the levels that would be toxic.
What the researchers discovered was that the lungs of the group of mice given the higher levels of Vitamin E actually resisted the pneumonia infection.
In fact, the mice which had been given the higher doses of Vitamin E had 1000 times fewer bacteria in the lungs.
It's hard to reach 200 IUs of Vitamin E from food alone. Sunflower seeds, one of the foods richest in Vitamin E, only contains 8.4 mg. A supplement is your best bet in this case.
4. Garlic Suppresses Inflammatory Immune Response
Garlic, whose technical name is "Allium sativum", helps to maintain the balance (homeostasis) of your immune system, according to a 2015 study led by of the Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, among others.
Garlic contains many compounds which interact with your immune system in ways not completely understood by scientists. This study, published in the Journal of Immunological Research, found that garlic appears to regulate the expression of certain immune system molecules, cytokines and chemokines.
The scientists observed that, when garlic is added to your blood stream, it significantly reduces the production of inflammatory cytokine cells.
Garlic, the study suggests, may be useful in fighting inflammatory diseases such as inflammatory bowel disease and malaria.
5. Yoga Improves the Immune System's Ability to Deal with Stress
Studies have found that people who practice yoga have more robust immune system.
For example, a 2012 study from Lady Hardinge Medical College, New Delhi, India examined 60 students undergoing examinations. The students were divided in to two groups. One group did not practice yoga. The other group practiced yoga with a trained yoga teacher for 12 weeks.
Levels of immune cells which are reactive to stress and hormones such as cortisol were taken before the study and compared to blood samples taken after the 12 weeks.
The group which practiced yoga experienced no elevation of cortisol or other stress markers, while the control group experienced elevated levels of stress-reactive immune cells.
6. Vitamin D Helps Is Critical to Maintaining a Healthy Immune System
Vitamin D deficiency is associated with a weakened immune system, according to a 2011 study from Feinstein Institute for Medical Research, Manhasset, N.Y.
The most efficient way to get your Vitamin D is throug exposure to the sun. As long as you limit your exposure during the intense sun to about half the time it takes for you to tan, you should get about 20 times the minimum amount of Vitamin D recommended by the Vitamin D Council.
For those winter months when sun is scarce, consider adding oily fish such as salmon or sardines to your diet or taking a Vitamin D3 supplement.
7. Eat Foods with Vitamin A or Get Sick
A Nobel Prize winning scientists summed up the importance of vitamins:
“A vitamin is a substance that makes you ill if you don’t eat it.” (Albert Szent-Gyorgyi, Nobel Prize in Physiology or Medicine, 1937).
In recent years, scientists have zeroed in on two Vitamins that are critical to your immune system. One, Vitamin D, we have already discussed.
The other Vitamin critical to your immune system is ...drum roll... Vitamin A.
According to a 2008 study from Massachusetts General Hospital, in affiliation with Harvard Medical School, several vitamins are needed to keep you healthy ---Vitamin C, the B vitamins-- but what makes Vitamins D and A different are two things.
First, Vitamins A and D, each have bioactive metabolites, retinoic acid and 1,25-dihydroxyvitamin D3 (1,25(OH)2VD3), which act like hormones.
Second, all other vitamins act in a general way interacting with many physiological systems. In contrast, Vitamins A and D act specifically upon your immune system.
The recommended daily amount of Vitamin A is 900 mcg for men over 50 and 700 mcg for women over 50.
A 3 ounce serving of beef liver gives you 6,582 mcg and a sweet potato with the skin gives you 1403 mcg of Vitamin A.