You Finished Treatment, Now What? Part Three*: Intermittent Fasting

Amy Rothenberg ND
Feb 11 · 4 min read

A Ten Part Series for Cancer Survivors/Thrivers from Your Licensed Naturopathic Doctor

Photo by Hannah Busing on Unsplash

In my last post I shared ideas about what to eat to regain and maintain health during or after cancer treatment. Here I will highlight when to eat, or in fact when to abstain, which as evidence mounts, is just as important.

Naturopathic doctors have long advocated for the role of fasting in disease reversal and health maintenance. There are many types of fasting from water fasting to juice fasting to alternate day fasting and other forms of periodic or intermittent fasting. The health impact of caloric restriction or having longer stretches of time without eating are numerous and research supports its broad and positive impact on health, including prevention of cardiovascular disease, inflammatory illness, obesity and cancer.

When I was in chemotherapy treatment, I did a restricted 500–800 caloric vegan affair two days before, the day of and the day after chemo. The idea was that healthy cells can go many days without ample nourishment where cancer cells cannot. By restricting intake, I would weaken any cancer cells that were around, hence making the chemo more effective. One side effect to this caloric restriction, which many of my patients also report, is fewer symptoms from the chemo: less nausea, fatigue and overall discomfort. Like all medicine, this approach is not for everyone and must be tailored to the individual. If you have a history of disordered eating or those who are already underweight or quite weak or who have blood counts in dangerously low levels, this would not be a direction to go during chemo.

And for those who have completed treatment or who are living well enough with cancer, intermittent fasting may well have the capacity to tune up the immune system and support pathways that help fight cancer. Studies show that elongated overnight fasting helps with both glucose regulation and with quality of sleep, two things important for good health. When we fast, our cells also initiate an inherent repair process including autophagy where older and less functional cells are removed.

Listed here are three fasting approaches my patients use after conventional care to optimize health and help prevent recurrence; for that matter I have many patients at risk for cancer, heart disease and/or diabetes who have adopted intermittent fasting as another important element of preventive care.

1. Some eat freely 5 days a week, but for 2 days a week, (no need to be consecutive,) you take in an 800 calorie day. This works well for people who are disciplined and don’t mind the restrictiveness and impact on social eating.

2. Others fast for 3–4 consecutive days, once a month, again in that 800 calorie range. Some people are able to carve out time like this, lighten their work load or family responsibilities and enjoy a more inward time of reflection and quiet.

3. Another option, which I have both recommended and done for years now, is eating all my food within an 8–10 hour period of the day, say 9am to 6pm or in my case more like 11am-7pm. In essence, I fast for 13-14 hours a day/night. Some push this to 16 hours, but research shows a 13- 14 hour overnight fast is adequate to achieve health benefits. Whenever I finish dinner or a nighttime snack, I look at the clock. I know I will have breakfast in 14 hours. I prefer patients not go to bed hungry, because that can interfere with deep, restorative sleep. I prefer a pattern where people delay breakfast. For those who feel they must eat first thing, I always say, try it for a week. Many report that by the end of the week they have adjusted and do not find it arduous. I know this flies in the face of what we’ve heard that breakfast is the most important meal. That may well be true, but no one said when you had to eat it! You can start with some consciousness raising, see how many hours you actually do fast overnight. If it’s usually 9–10 hours, see if you can stretch to 11 hours. And then each month add another 30–60 minutes.

Intermittent fasting enhances insulin sensitivity which in turn reduces inflammation which has anti-cancer impact. Research is mounting to support this effort and it adds zero cost with nary a side-effect, well except the many other benefits. Many people lose weight without trying. The total number of calories you eat in the day may well not be reduced but you make better use of the calories you do take in. Patients report feeling better self-control and self-agency which trickles over into other aspects of life, say getting regular exercise and insuring adequate sleep. I love when the positive spiral of health brings patients in a good direction.

Additional pieces in this series:

See here to read more about naturopathic medicine. To find an ND near you see here.

FieldNotes From Natural Medicine

Stories from the World of Natural Medicine

Amy Rothenberg ND

Written by

American Association of Naturopathic Physician’s 2017 Physician of the Year. Teacher, writer and advocate for healthy living.

FieldNotes From Natural Medicine

Stories from the World of Natural Medicine

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