Intermittent fasting, time restricted eating and more

Fasting has been part of pretty well every culture in the past but features much less so nowadays. I’ve heard about the possible benefits to cancer but because of my low body weight I’ve not investigated further. Indeed my naturopath has advised against it in the past. A couple of years ago I read Chris Woollams who shared research that shows little or no benefit from ’Intermittent Fasting’, where people extend their overnight fast to miss an evening meal or breakfast (i). The study he quotes found; "mild caloric restriction and weight loss, without calorie counting. It may also offer clinical benefits by reducing blood pressure."(ii).

Chris went on to argue that the benefits from fasting come after about 24 hours without food. As I wasn’t ready to fast longer I dismissed the idea of shorter fasts. It is certainly true there is lots and growing evidence about longer fasting. I’ll come to that in a mo but I am also not so dismissive of the shorter 12-16 hour fasts. Although as with so many aspects of health it is hard to unpick what folks are staying - not least as there are so many versions of ‘intermittent fasting’ and of course we are all so different.

A 2016 study looked at over 2,000 women with early stage breast cancer and looked at the role prolonged night time fasting might play in breast cancer recurrence (iii). Women who had a short duration of nightly fasting (less than 13 hours between the evening meal and breakfast) were 36% more likely to experience a breast cancer recurrence than those who had a nighttime fasting duration of more than 13 hours. However the increased risk of recurrence was not associated with increased mortality from breast cancer or overall mortality. The researchers suggest that longer periods of follow-up might reveal an association. But hey this is just one piece of research….

Fasting and nutrition

A lot of the Intermittent fasting research does not seem to say much about our choices of food. Yet we know what we eat is critical. Dr. Valter Longo, Professor of the USC School of Gerontology has done loads of work in this area and written the ground-breaking book, ”The Longevity Diet”. He describes in the book his everyday diet, based in part on research including studies of centenarians and long-lived populations around the world. It is mainly plant-based, low in protein and rich in unsaturated fats and complex carbohydrates. Some fish is allowed once or twice a week - see more at: https://www.createcures.org/cancer/ Interestingly for over 65s there is some relaxation of the diet: https://www.createcures.org/longevity-diet-for-adults/

And of course following any diet should be done with the knowledge of your doctors. This is even more so when we talk below about fasting as it can have many unforeseen consequences and indeed can be very dangerous.

Longo is clear that we need to look for quality in food and not demonise any particular food group. He says in an interview in an article (Feb 2019) (iv): "The truth is fats are good and bad. Carbs are good and bad. Proteins are good and bad. Fats like olive oil, nuts, salmon are actually associated with positive effects. It is saturated fats and trans fats that are associated with a lot of problems. You hear a lot about low-carb or no-carb diets, but the right carbohydrates, including legumes, vegetables and whole grains, are very good for you. In fact, all the populations who have record longevity have a high carbohydrate diet. All of them. No exceptions. It may seem easier to label foods as good or bad, but in the long run this leads to problems”.

So yes to intermittent fasting?

In his book he clearly recommends a form of intermittent fasting - time-restricted eating - and this is in addition to his ’Longevity Diet' and the periodic five day Fasting-Mimicking Diet. In the article where Longo is quoted above, he is asked specifically about the timing of when we eat. His response is: "It turns out that it is important is to stick very close to 12 hours of feeding and 12 hours of fasting. If you eat 15 hours a day or more, that starts to be associated with metabolic problems, sleep disorders, etc. This is a new habit. If you ask centenarians, it is almost unheard of in these groups. But also, if you fast for longer than 12 or 13 hours, that starts to be associated with problems like gallstone formation, and we also know that longer fasts can lead people to skip breakfast. There are a number of studies, and we have our own data supporting this, showing that skipping breakfast is associated with increased risk for overall mortality and cardiovascular disease. So not only is it not good, it is bad for you”.

So daily 12 hours fasting looks good - or as Longo calls it “time-restricted eating” - and he also recommends not eating 3-4 hours before bed. 


Ayurveda and a Nobel prize

This leads me onto a workshop that Dr Sam Watts, a leading Ayurvedic Consultant, ran on Facebook this week on Intermittent Fasting. In that excellent session he shared that in 2016 the Nobel Prize was won by Japanese cell biologist Yoshinori Ohsumi (v). This confirmed what the Ayurvedic tradition has been saying for many hundreds of years. Fasting can be very good for us. Indeed fasting for more than 12 or 24 hours hours triggers autophagy - this is when cells destroy viruses and bacteria and get rid of damaged structures (see film here to explain autophagy) (vi). The word autophagy comes from the Greek for "self" and "phagein", which means "to eat” - and it’s key for the health of our cells and indeed our survival. This links to the reasons that fasting is associated with longevity. 

Granddaughter pic of me rebounding

There is research that that shows benefits to fasting like better blood sugar balance, reduced inflammation, loss of weight loss, and better brain function. Oshumi has now provided some of the understanding about how this happens. What I found very interesting was that exercise also does this - it can cause autophagy so that cells repair and renew (vii). I’ve already noted many times the importance of exercise but this understanding helps me ensure I still exercise when perhaps I don’t feel so like it!

So from this research it would seem the wonderful process of autophagy starts to kick in between 12 and 16 hours which maybe why the research noted above saw some benefits? And why Sam Watts recommends once or twice a week doing a 16 hour fast. This would perhaps then avoid the concerns Longo had around gallstones?


The five day Fasting-Mimicking Diet

Evidence is certainly mounting for the impact of fasting; reduced blood sugar and blood growth hormone (IGF-1), very low triglyceride and insulin levels, immune system regeneration and stopping cancer progression. And wow there are so many ways to fast - the internet is full of them from the 5:2 Diet (viii) to the Vedic way of 24 hour fasts on the 11th and 22nd days of the lunar cycle (ix). I started looking at possibilities ahead of my radiotherapy as it can help with that (x).

I can’t vouch for any of those fasting techniques but I do like the rigorous science behind the work of Dr Longo - in his book he gives a couple of weeks of food suggestions for his ’Longevity Diet’ and covers loads of the research to back his five day Fasting-Mimicking Diet - indeed it has been clinically demonstrated to provide huge beneficial effects on aging and disease risk factors. Of course as mentioned already don’t embark on this without doctor being involved - is is potentially dangerous for some conditions.

Longo has also shown that it looks like fasting significantly improves the performance of chemotherapy while reducing side-effects greatly. However fasting is not always possible on chemo which is why he has developed the Fasting-Mimicking Diet. Sadly this 5 day diet is only covered very briefly in his book - indeed to proceed safely it looks like you need to purchase food boxes at around $250 a time(xi)? And I don’t think these products are even organic or fresh? 

Interestingly new research from Longo is around using fasting as a groundbreaking method to avoid hormone therapy resistance in breast cancer - and I guess other cancers like prostate? I have had hormones twice in the past as part of my treatment so was very interested to hear about this (xii). You can listen to Longo being interviewed by Chris Wark here (xiii)

 

See also Longo's TedX talk: https://youtu.be/dVArDzYynYc

 

There is also an amazing opportunity to hear Longo and ask questions in the second 'Your LIfe and Cancer ' weekend: https://www.yourlifeandcancer.com/expanding-your-knowledge.

So where does that leave me?

1. Time-restricted eating. Eating in a 12 hour window where possible seems to make sense; this is possible but do have tottery and stop the need for nuts or something later in evening.

2.  16 hour fast. Try once or twice a week to go for a 16 hour fast; have done this a couple of times missing breakfast and surprisingly hard for me - I will persist and try missing dinner next time. I am also learning to fit it with the rhythm I mentioned in a recent blog - see here (xiv).

3. A longer Fast? I feel I still need to do some more research; just liquids carry there own challenges particularly when I am just on the bottom end of ideal weight - FMD also doesn’t feel the right place to start with a box sent from the states. Is there anyone who does that in this country?

 

Update 30th Sept 2020; just seen this blog on intermittent fasting by the wonderful Nasha Winters: https://www.drnasha.com/2020/09/14/intermittent-fasting-for-beginners-everything-you-need-to-know-to-get-started

and here's a useful Tedx talk on intermittent fasting: https://youtu.be/A6Dkt7zyImk 

Update 8th January 2021; I also just listened to this Dr Chatterjee podcast: https://drchatterjee.com/episode-21-circadian-rhythms-and-time-restricted-feeding-with-professor-satchin-panda-part-1/ and https://drchatterjee.com/episode-22-why-when-you-eat-matters-with-professor-satchin-panda-part-2/

Update 2.10.22: Must get around to a blog on chemo and fasting but in meantime see: https://nutritionfacts.org/video/fasting-mimicking-diet-before-and-after-chemotherapy/

Notes

(i) https://www.canceractive.com/article/Intermittent-fasting-is-basically-a-waste-of-time
(ii) https://pubmed.ncbi.nlm.nih.gov/29951594/
(iii) https://jamanetwork.com/journals/jamaoncology/fullarticle/2506710
(iv) https://news.usc.edu/135551/fasting-aging-dieting-and-when-you-should-eat-valter-longo/
(v) https://www.nature.com/articles/543S19a
(vi) https://www.bluezones.com/2018/10/fasting-for-health-and-longevity-nobel-prize-winning-research-on-cell-aging/
(vii) https://pubmed.ncbi.nlm.nih.gov/22258505/
(viii) https://thefastdiet.co.uk/
(ix) https://www.learnreligions.com/ekadasi-hindu-lunar-calendar-1770178
(x) https://myunexpectedguide.blogspot.com/2019/11/increasing-effectiveness-of.html
(xi) https://prolonfmd.com/
(xii) https://www.nature.com/articles/s41586-020-2502-7
(xiii) https://www.chrisbeatcancer.com/dr-valter-longo-fasting-mimicking-diet-improves-breast-cancer-treatment/ Also see more re Longo at: https://valterlongo.com/cancer/
(xiv) https://myunexpectedguide.blogspot.com/2020/07/getting-in-rhythm.html