Last week’s column was an overview of Dr. William Li’s new book “Eat to Beat Disease,” and the five body defense systems he talks about: immunity, angiogenesis, regeneration, the microbiome and DNA protection. Dr. Li is a practicing physician who is also on the cutting edge of medical research. The subtitle of his book is “The New Science of How Your Body Can Heal Itself.”
A column on immunity is timely, given the current COVID-19 pandemic. It’s interesting that with all the media attention, there has been minimal to no discussion about how each of us can improve our immunity while we’re waiting for a vaccine — which they say will be at least a year.
Our immune system has two parts: fast and slow, both of which protect against foreign invaders, such as bacteria, viruses, parasites and cancer cells. The fast — called the innate — immune system includes physical, chemical and cellular components. Our skin is an example of a physical barrier. An example of a chemical barrier are the secretions in our mouth, nose, and upper airways that contain enzymes that kill invaders. An example of cellular barriers are neutrophils and monocytes, that create an inflammatory response and remove harmful microbes and other invaders by consuming them.
The second, slower part of our immune system is called the adaptive immune system, which is more sophisticated than the innate system. It has a permanent memory of past invaders, and this is the system that immunizations engage. Adaptive immunity has two strategies: (1) It can attack invaders by using cells such as T and B cells to kill them; (2) it can use antibodies to attack intruders, which can take seven to 10 days (hence the term “slow system”).
Deficiency of the immune system causes many diseases. AIDS, caused by HIV — immune deficiency virus — is an example, and sufferers are at high risk for catastrophic infections and for cancers. Some immune deficient diseases are genetic. Cancers such as leukemia and multiple myeloma weaken your immune system, as does radiation and chemotherapy used to treat cancer. People with stress, poor sleep patterns, obesity, diabetes, malnutrition and alcoholism have weakened immunity. A sedentary lifestyle and a Western diet — high in animal fat, refined food, sugar, salt — cause weakened immune systems. Steroids (cortisone) and some of the new “biologics” such as Humira used to treat autoimmune diseases lower immunity. Immunity also diminishes after about age 65.
Immunotherapies are — according to Dr. Li — new medications that help the immune system locate and destroy cancer cells. They have led to breakthroughs in the treatment of many types of cancer (example: President Jimmy Carter was diagnosed a few years ago with metastatic melanoma, was treated with immunotherapy, and has no sign of remaining cancer).
Following are some examples of immune-boosting foods shown experimentally to strengthen immunity according to Dr. Li: mushrooms, aged garlic, broccoli sprouts, chestnuts, blackberries, black raspberries, walnuts, pomegranate, cranberries, grapes, blueberries and chile peppers.
In summary, here are some steps you can take to boost your immunity, which will help prevent cancer and infections such as the current COVID-19 (even if you follow all the currently recommended precautions to avoid contact with coronavirus, you still could come in contact with it):
• Eat primarily — if not totally — vegetables, fruit, nuts, seeds, and whole grains.
• Get 7-8 hours of sleep.
• Exercise at least 30 minutes a day, and the rest of the day move about frequently.
• Reduce stress — mindful meditation is one option.
• Keep your immunizations current — if you have one infection you are more likely to acquire a second one.
Next week’s column will be immunity part 2 — problems associated with an overactive immune system.
Greg Feinsinger, M.D. is a retired family physician who has a nonprofit: Prevention and Treatment of Disease Through Nutrition.