Fasting for Improved Immunity


Up until about 50 years ago, fasting was one of the foundations of medicine. Fasting, defined as not eating solid food, keeps proving its worth to maintain your health and vitality.

Today, there’s a substantial body of research showing the health benefits of fasting. They include:

  • Strengthens immunity—creates stem cells and destroys damaged cells
  • Detoxifies
  • Slows aging
  • Weight loss
  • Improves concentration and mental functions
  • Rests and recharges digestive system
  • Increases energy levels
  • Allergy relief

Sounds good, right? But in order to get these benefits, you need to fast correctly, in a way that supports the healing process.

While fasting, keep juice, water, herbal tea, or broth handy to sip throughout the time when you’re not eating. A fast typically lasts anywhere from one and three days.

Individual reactions vary. Some patients find fasting energizing, while others tell me that a few low-key days without food to fuss over is a pleasant break.

Do not fast longer than three days without medical supervision. If you experience nausea, vomiting, diarrhea, dizziness, or a change in your heart rate, stop fasting. To break the fast—whether it’s due to a bad reaction or not—have some fruit juice or a small piece of fruit every few hours. If your symptoms persist, see your health-care professional.

Intermittent fasts—usually two non-consecutive days out of the week—are another option. During this type of fast, you eat normally five days a week, then consume only juices, tea, and water on the fasting days.

“Eat normally” doesn’t mean indulge in bad food choices. Your non-fasting meals should focus on real, whole foods—vegetables, fruits, lean protein, whole grains, nuts, and seeds.

Choose days for fasting when there isn’t much happening. Avoid fasting during occasions that require high energy levels. If your grandchildren are coming to visit, for example, and you want to keep up with them, plan your fast for after their visit, when you can rest and relax.

Gather everything you’ll need before beginning the fast. In addition to a juicer, you should have the following on hand:

  • Fresh fruits and vegetables such as apples, beets, cabbage, carrot, celery, cilantro, cucumber, kale, and spinach.
  • Organic herbal teas

If you don’t have a juicer, use bottled juices from a grocery or health-food store. Read the labels carefully, though, to be sure the juice does not contain added sugars.

Never fasted before? Try it for one day first, to see what it’s like. In our food-centric culture, it can be challenging. But most people are surprised by how good they feel during a fast and adjust pretty easily.

When I recommended fasting to a friend I’ll call Connie, she was horrified. “I get so hungry just between lunch and dinner. How am I ever going to go for a whole day without any food?”

After I explained the health benefits, like how Connie’s immune system would be recharged so she wouldn’t be plagued by her usual neverending winter colds, she agreed to give it a try.

And according to Connie, the results were well worth it, especially the unexpected benefits.

Most of Connie’s medical problems stemmed from the fact that she had gained quite a bit of weight while taking antidepressants. She managed to get off those drugs with a combination of omega-3 essential fatty acids (EFAs), curcumin, and vitamin D supplements.

So Connie’s depression was gone. But she wanted to lose more weight, and get back to her normally high energy levels. And since toxins like pesticides and drugs are stored in fat, I thought her health would improve if she lost some of those stubborn pounds.

Here is what I recommended to Connie.

  1.  Do not fast on water alone. Remember, your body is releasing toxins, and with a water-only fast that process can occur so quickly it becomes overwhelming. Stick with raw juices, which make the process tolerable while providing you with loads of nutrients.
  2. Do drink plenty of water along with the juices. First thing in the morning, prepare a large container of fresh, filtered water.  Add a few slices of citrus, strawberries, or other favorite fruits, if you like.You should drink one ounce of water for every two pounds you weigh. If you weigh 180 pounds, you need to drink 90 ounces of water each day.
  3. Don’t be concerned if you feel exhausted, irritable, or develop a headache while fasting. Minor discomforts like these are normal during toxin release. Just keep yourself comfortable, spend your time doing things you enjoy, and hang in there.

The toxins and pollution in your body have been accumulating for years. They will not be magically eliminated in a day or two. Think of each fast as one more step toward a healthier you.

Connie proclaimed her first one-day fast as a success, since she not only survived but also noticed a difference. “I felt so much lighter, even though I didn’t lose weight,” she told me. “And my energy level was better than it’s been for years! I guess when you’re not using up all your energy digesting food, you have get-up-and-go to spare.”

A few weeks later, Connie embarked on a three-day fast, this time losing a few pounds in the process. Eventually, Connie took up intermittent fasting—also known as the 5:2 Diet or FastDiet—two days each week.

Her weight loss continued, her immune system kept her healthy all winter, and today she’s back to her old, high-energy self. “Wish I’d known about fasting a long time ago,” she told me during her last visit. “It’s the best weight-loss method I’ve ever tried.”

If you have a chronic health condition, like diabetes, or other ongoing health issue that requires medication, please talk to your doctor before fasting. Individuals who are weak, frail, and sick but have not been diagnosed yet should avoid fasting, as should anyone with an eating disorder, like bulimia or anorexia.


Last Updated: September 2, 2020
Originally Published: September 1, 2014