Fasting, chemo and cancer: Hi everyone, I would... - My Ovacome

My Ovacome

15,886 members18,445 posts

Fasting, chemo and cancer

Itha profile image

Hi everyone, I would like to know if any of you have seriously tried fasting and if it was beneficial at all for you?

I regularly do intermittent fasting (almost every day for the past 2 years, when possible. Usually easier when at home) but I have not tried anything longer than that. I am willing to experiment with this though as I think there is enough evidence that fasting is good for us as human beings (if you are not diabetic of course).

My plan is to start with one day and then slowly work towards more days at a time.

I look forward to hearing your thoughts

54 years old, Stage 4B, Peritoneal, BRCA1+, diagnosed Oct 2020, chemo, debulking, chemo (completed May 2021), Avastin (15 cycles with last one on 6 Jan) and Lynparza (started in July)

So far all treatment is working for me (platinum sensitive, optimal debulking, consistent low CA125 - last one was 4.6 (my CA125 seems to be sensitive and a good indicator). My bloods are generally quite good on Lynparza.

I consider myself to be incredibly lucky and am very grateful for the treatment available and the fact that my body is responding so well.

I support the treatment by looking after myself so my body can deal with the side effects and my immune system and microbiome is as healthy as it possibly can be under the circumstances.

[Edited by moderator]

15 Replies

Hi Itha, Thanks for the vid. I’m v interested in fasting and I do believe it’s very good for you. But I haven’t yet. I have chemo every week and I think most effective fasting plans last a few days so I certainly can’t do that weekly. I was planning to try every two weeks around my chemo for about 2 1/2 days. However I don’t want to lose weight. I’ll try it once and see how I feel. I’ll be interested in other peoples experience. I’m so pleased your treatment has gone exactly to plan… I wish I could say the same for mine! Best of luck Charlotte x

Hi, I've had 2 cycles of paclitaxel / carboplatin so far for 1c3 clear cell ovarian cancer. I'm a medical doctor myself and have read as much as I can find about diets / fasting / supplements (& there's a lot out there). I follow a strict keto diet days -5 to -3 pre-chemo. Fast for 3 days on the day before, during & after chemo (less than 400 calories / day with broth & lots of fluids), then keto again days +2 to +4. I aim to take glutamine for 7 days beginning the day before chemo. The rest of the time I eat what I want. I also take daily vit E, omega 3 & multivitamins. I believe there's good theoretical evidence and some clinical evidence for all of this. Even if I'm wrong and it does no good, studies show no evidence of it causing harm.

I had horrific pain with my first cycle of chemo but thankfully not with the second. I was nauseous & really fatigued days 3-5 and horrible taste in the mouth. I find the chemo really really hard. The fasting is hard but not as hard as the chemo, and it helps me to think I'm doing what I can as the whole cancer thing is frightening.

Others should do whatever they feel comfortable with. Talking to your medical team is a good idea but many doctors will have limited if any knowledge of some of the issues.

Best Wishes to everyone x

As an alternative and for balance, I am not convinced by the idea of fasting. I used fasting at a time in my life when I was very gave me a feeling of control… but ultimately did not help. In our position, it is understandable that people want to feel that they can control outcomes but really none of us can. I eat a healthy diet but I don’t think that fasting is going to help my body stay strong.

Please be sceptical about things people claim on the web…there are so many people peddling falsehoods.

Whatever you decide, I wish you all the best xx

Hi. I do intermittent fasting, albeit 7 days per week. I fast from 7.30pm (sometimes 8pm), through to between 1 and 3 pm the next day, with the average being 2pm. I actually don't feel hungry, so need to ensure I do eat. I do have a coffee made with milk around 11amI have done this for several years. Not sure if it helps, but I am 5 years post diagnosis, stage 3C HGS. I am currently on my 5th line of treatment. Therese

I fasted before chemo every month and believe it helped alleviate the side effects. I did this for five days, on a severely restricted diet.If you look back on my last posts, you can read about this in more detail.


I should have added to my previous post, Valter Longo has done a lot of research on fasting too.


Have to say when I had the diagnosis at the end of 2019 and operation early in 2020 along with chemo I did ask the surgeon, oncologist etc apart from soft foods to help heal they said no diet need be followed, which is good as I had already decided the nature of the beast that is uninvited needs to enjoy what I eat, share in my alcohol ( flaming freeloader on this one I think 😂 ) and anything else I want to have. Have followed what my body wants in terms of eating and drinking, never have been into diets etc will eat in moderation hmm may be cept Christmas etc lol though even that is feat in itself...I enjoy life as it was in a culinary sense much as before, I don't think I have seen any evidence to support fasting or specific diets but I do believe each individual knows what there body wants or will tolerate etc and make that choice which helps them in their fight against ovarian cancer or any other cancers, hope my lil uninvited visitor is ready for some alcohol come New Year 😁

I do like Bananasmoothie’s comments on this topic. This month I began 16-hour daily fast from 7:00 pm to 11:00 am the following day. An MD I know ( not an oncologist) told me he had a patient with cancer who went to MDAnderson for help and was advised they could not assist him. The man had lung cancer and decided to do intermittent fasting and was quite driven about it. He lived four more years with his lung cancer before passing. So I researched this and found a study that showed ovarian tumors shrank in mice put on intermittent fasting. The scans are pretty amazing. Mice responded in about a month. However, mice are not people and a month in mouse time is almost three years in people time. Still, I’m 70, stage four BRACA negative, with mets in liver and likely lung and I have nothing to lose by trying. BMI 31.5 so I have some pounds to play with. We’ll see. Here’s the link below to the study for those interested. I’m no MD, just a retired appellate lawyer who has handled many workers compensation matters and so over 35 years have reviewed medical records and discussed patient matters with doctors. I find such articles and studies fascinating. 🤔


I did short term light fasting with taxol and definitely curbed side effects

Thanks for sharing your experience. I feel encouraged to stick with it. The best in 2022 to you! Sashay

It was just published in Nature, a top science journal, that calorie restriction but not ketogenic diet helps reduce the size of tumor in mice. The reason is because when the total calorie intake is reduced, mono-unsaturated fatty acids are reduced, while saturated fatty acid levels increase. Ketogeneic diet involves a lot of fat consumption, so it didn't have any effect. So, although this study was done in mice, if time restricted fasting includes reducing your overall calorie intake, that should be helpful. I myself was on ketogenic diet right after surgery and the first line of chemo, but I ended up having a recurrence. So, I will try reducing my daily food consumption, although it is tough.

Here is the abstract from the Nature article for your view.

Dietary interventions can change metabolite levels in the tumour microenvironment,

which might then affect cancer cell metabolism to alter tumour growth1–5. Although

caloric restriction (CR) and a ketogenic diet (KD) are often thought to limit tumour

progression by lowering blood glucose and insulin levels6–8, we found that only CR

inhibits the growth of select tumour allografts in mice, suggesting that other

mechanisms contribute to tumour growth inhibition. A change in nutrient availability

observed with CR, but not with KD, is lower lipid levels in the plasma and tumours.

Upregulation of stearoyl-CoA desaturase (SCD), which synthesises monounsaturated

fatty acids, is required for cancer cells to proliferate in a lipid-depleted environment,

and CR also impairs tumour SCD activity to cause an imbalance between unsaturated

and saturated fatty acids to slow tumour growth. Enforcing cancer cell SCD

expression or raising circulating lipid levels through a higher-fat CR diet confers

resistance to the effects of CR. By contrast, although KD also impairs tumour SCD

activity, KD-driven increases in lipid availability maintain the unsaturated to saturated

fatty acid ratios in tumours, and changing the KD fat composition to increase tumour

saturated fatty acid levels cooperates with decreased tumour SCD activity to slow

tumour growth. These data suggest that diet-induced mismatches between tumour

fatty acid desaturation activity and the availability of specific fatty acid species

determine whether low glycaemic diets impair tumour growth.

Sashay2020 profile image
Sashay2020 in reply to soyoon

Thank you for sharing this information. Here is a link to Memorial Sloan Kettering Cancer Center’s article on topic. Anyone can see it.


soyoon profile image
soyoon in reply to Sashay2020

Thank you for alerting me to the article.

Sashay2020 profile image
Sashay2020 in reply to soyoon

You are welcome and may 2022 be good to you. Sashay

Thanks everyone for all the comments and sharing of additional reading and resources. I am exploring them all.See this summary of updated research by the American Institute for Cancer Research re diet and other factors that impacts cancer (increase/decrease risk) - their methodology is to review everything and continuously update this information as new research becomes available.

The key insight is that being overweight will increase your risk for any cancer thus paying attention to diet to manage your weight is beneficial for sure (and supported by the article about fat and how cancer cells love fat. This is also why breast cancer is such a high risk -due to the fatty tissue in breasts)

Also - alcohol is the one factor that almost consistently increases your risk for cancer as well.

Personally I am not "anal" about anything. I take a break every now and again and have a piece of cake or a glass of wine, but generally I prefer a nutritious rich diet with little diary and meat. I am lucky that I have access to good quality organic anti-biotic and hormone free products.

I generally feel much better when I eat better. I sleep better and my insides work better.

The initial video I shared had some key insights for me, such as the impact of what you eat when you do eat after fasting and what will extend the impact of the fast vs what takes away the benefits gained.

I don't believe fasting will cure cancer but I do think a healthier body and immune system has a far better chance to fight cancer and deal with side effects of the treatments we all have to endure which of course leads to a better quality life.

When I pay attention to what I feel like AFTER I ate something, it is very clear to me that I feel much better after eating something nutritious and healthy vs desert or cake (as much as I enjoy it while I am eating it, I never feel great afterwards and I often regret ordering it. What I tend to do is to just have a bit or two of my husband's cake to taste it and its enough).

Of course we are all different and at different stages in our journeys and our bodies have different needs. We just need to pay attention to our bodies and address the needs in the best possible way.

I think oncologist have a difficult job to keep up to date with ever single piece of research out there. Mine is open minded and love it when I share stuff with her as it helps her with how she can then assist other patients. If she doesn't think something will work, she will tell me. I do insist on evidence though as our oncologist are human beings and just like us, don't know everything and might have outdated information.

You may also like...