Home / Therapies / Diet & Nutrition / Transcript: Intermittent Fasting: What is it? Recommend it? Part 2

Transcript: Intermittent Fasting: What is it? Recommend it? Part 2

Jan 30, 2016

This is part 2 of a 3-part video transcription.

Transcript Part 1 | Transcript Part 3


To view the video series, go here.

Steve Freed:               One of the things that I’ve noticed, which I think is comical, is we probably spend $50 billion to study that exercise is good for you. I mean I don’t think there’s ever been a study shown it was negative unless you – it’s a serious medical condition. But we spend all this money to find out that exercise, which we already knew, okay, is good for you.

Why is it that I haven’t seen anything even close when it comes to intermittent fasting? We’re talking about preventing disease, we’re talking about improving your health and living longer and feeling better, and yet it seems like you and maybe three other people are investigating it. Now obviously the money came from someplace, it wasn’t all NIH on exercise. Universities did a lot of those studies and why don’t we see more universities?

Dr. Mark Mattson:     Yeah, Steve, there will be. Just in the last few years with the help of a lot of interest from the lay public and a lot of communications by people like you there are many studies in progress.

So for example one area that’s now pretty quickly taking off is asking the question whether intermittent fasting in cancer patients when they’re being treated with chemotherapy or radiation therapy can improve the outcome, and there’s a really strong scientific rationale for that because cancer cells rely on glucose as an energy source, they cannot use ketones, and during fasting, as we talked about, glucose levels are down, ketone levels are up, so that’s bad if you’re a cancer cell. And the animal studies suggest that fasting makes the cancer cells much more vulnerable to being killed by chemo and radiation therapy.

So I know of at least three or four trials in various cancers – breast cancer, prostate, glioblastoma – I’m actually involved in one such trial.   But from the standpoint of disease prevention there are industries that if not necessarily actively suppressing research on intermittent fasting are certainly not encouraging it.

So the pharmaceutical industry, the food industry who don’t make any money from these kinds of approaches and in fact lose money if people are more healthy, they don’t need to take the drugs – diabetes is a good example – generally people go to their family practitioner, they’re overweight, their blood glucose is getting up, they’re starting to have insulin resistance, they come back the next year – the doctor gives them advice, “You need to eat less, exercise more,” that’s it, send them home, come back the next year, they’re heavier, more insulin resistant, come back the next year and now they have diabetes and the doctors will prescribe drugs.

So there’s a problem in medical education, the medical schools training curricula – there’s virtually nothing on preventative medicine. They learn about the diseases, – the current understanding of the pathogenesis of the diseases – and then they learn what drugs or surgical approaches are used to treat the disease. So there’s a systemic problem with the healthcare training of physicians and in healthcare practice where prescriptions for intermittent fasting and exercise – specific prescriptions – are not given and followed up on by physicians.

So for example one could – someone’s coming in, they’re pre-diabetic – the doctor could say, “Okay, I’m going to give you three different diet and lifestyle approaches that you can follow and if you could choose one and then I’m going to have my assistant followup with you over a period of a month or two to see how you’re doing and kind of monitor your progress.”

So they could say, “Okay, you can try this two days a week fasting, or if you think it would be easier for you to restrict your food intake to say six or eight hours a day we’ll go with that, and then I’d like you to start exercising three days a week. Just maybe start by walking.” It has to be some concerted effort of the experts that patients interact with and their staff and the system to help people change their bad habits.

And for many of them I think if – as I mentioned before – if they can get into a routine for a couple of months – particularly if they’re overweight and sedentary to start with – they’ll be feeling better and they may stick with it. As you know many people who exercise regularly if they stop exercising they almost have withdrawal symptoms because they know they feel better when they exercise and we think the same is true with intermittent fasting.


Steve Freed:               So do we have any results from studies that show that intermittent fasting can reduce the oxidative stress and reduce inflammation which can prevent cardiovascular disease? And if so why haven’t seen much dialogue .


Dr. Mark Mattson:     Yeah, well, the answer is yes: a huge amount of data in animals, but there are also data from humans. For example we did a study in asthma patients that we published in 2007. It was a small study with only 12 overweight asthma patients and – before we started them on an intermittent fasting diet we got a lot of data about their symptoms, their airway resistance, we measured their airflow, we took blood samples and measured markers of oxidative stress and inflammation.

So for example what are called proinflammatory cytokines and then we evaluated what we call markers of oxidative stress and molecules that have been damaged by free radicals.

Okay then we put the subjects on a diet where every other day they only ate about 500 to 600 calories and then we took blood and evaluated their symptoms and airflow at two weeks, one month, two months after being on the diet, and what we found is that during the first week there were some subtle changes in their symptoms and the markers of oxidative stress and inflammation, but then between two weeks and one month there were very clear highly significant improvements in their symptoms, airflow and reductions in oxidative stress and inflammation that continued to improve to two months. So that’s one example of a study with clear results.

But again, as I mentioned, in order to – for the NIH, for example, to make recommendations they want to see a huge amount of data and replication and multiple studies. Our study, for example, what we really need to do – we didn’t have actually a group in that study where we had asthma patients who we did not subject to the intermittent fasting diet, so we need some randomized trials.

We’re doing a study now we just started where we’re taking subjects at risk for cognitive impairment because of their age and metabolic status, so people between the ages of 55 and 70 who are obese and have insulin resistance but are not being treated with drugs for diabetes, and we’re going to randomly assign them to either the two days a week fasting diet or a controlled diet where they’re just given advice for healthy eating.

And then before we start them on the diets we’re going to do a battery of cognitive tests to test their learning and memory abilities, we are going to do functional magnetic resonance imaging of their brains which we can look at neuronal network activity. We have some – well, the field has quite a bit of evidence that in what’s called mild cognitive impairment and Alzheimer’s disease there’s some very stereotypical changes in neural network activity that occur, and we have some reason to believe from our animal studies that the intermittent fasting could attenuate these abnormalities that are probably going to be apparent in these obese insulin resistant subjects.

We’re taking cerebral spinal fluid to measure levels of some of the neuro chemicals that we find change in beneficial ways in animals in their brains when they’re on an intermittent fasting diet.

And then we’re going to go two months on the diet and repeat all these tests. So that’s an example of an ongoing human study.


Steve Freed:               Well, I would think that intermittent fasting would be a lot easier to achieve than all the diets that require you to eat certain foods, not eat certain foods, you’ve got to read books to understand the diet. It’s easy to go off of one of those diets because it’s easy to stop doing it because there’s so many things involved with dieting, so I would think this would be a simple diet.

Has there been any books to explain this? And by the way when we say intermittent diet – intermittent fasting – we’re not saying that you shouldn’t eat anything. And I think that title – fasting – gives us wrong information because people think, “Yeah, I’m going to lose weight and feel better if I stop eating but I’ll be dead: I’ll have no energy to do anything.”


Dr. Mark Mattson:     And of course they’re wrong but they don’t know that yet. So, you know, you’re right, fasting implies not eating anything – the definition is eating nothing. And you know maybe we should switch the terminology to intermittent energy restriction or what – for example Dr. Panda, he calls time-restricted feeding – you know, restricting the time period each day or certain days a week that you eat food – so what you said is true but in terms of people’s perception of fasting it’s not starvation.

You know – and you’ve probably experienced this – you’ll go to say a all-you-can-eat food bar place and there will be a lot of overweight people there, obese people, and you know waiting to get in, many of them will comment that they’re starving. Well, they’re obviously not starving they’re just hungry.

And what we find with regards to the feeling of hunger is that during the first weeks of switching to intermittent energy restriction type diets people do have increased hunger but then that goes away.

And so you know if you’ve been eating three meals a day plus snacks then you miss a meal you’ll feel hungry. But if you start skipping breakfast every day and you do that for several weeks or months then you’re not going to be hungry in the morning anymore. It takes time for your neuroendocrine systems and the hormones – hormonal systems that regulate hunger and satiety to adjust to the new eating pattern.

And so a big issue is this getting over the hurdle of switching the diet that’s really kind of a critical aspect of this because there will be a short time period when hunger will be increased during this period when you’ve normally been eating and some people in our studies – so the five-two diet, for example, the days that they’re only eating 500 calories they may have like a mild headache – there is some evidence that drinking tea or coffee can ameliorate the headache or prevent it from happening.

I do this myself, – I mentioned that four or five days a week I skip breakfast and lunch: I’ll drink tea in the morning and I find that helps– we actually know that caffeine improves cognitive function too, so both fasting and a little caffeine in moderate amounts improve your cognitive function: there’s really strong evidence for that.


Steve Freed:               Do you ever recommend actually fasting – I mean because you’re a runner and obviously you need to have energy – and what’s the difference between 500 calories a day twice a week or zero calories twice a week? Is that dangerous or is it not…?


Dr. Mark Mattson:     No. Zero calories is not dangerous, you know, it’s probably a little bit better than 500 calories on those two days, although I should say that that specific study hasn’t been done in humans but based on the animal studies having no food would be better than having some food on those days.


Steve Freed:               And I certainly can say that if you were to do a presentation in front of the American Dietician Association they’d be throwing tomatoes at you because that’s their job is to give you all of this information on what you should eat and what you shouldn’t eat and fasting is –


Dr. Mark Mattson:     Well, that’s an interesting point that – not only would – you know, say all of the sudden a large portion of our population started eating more healthy eating patterns including some intermittent energy restriction approaches and exercise regularly, then not only the drug companies and some physicians will lose their jobs or shrink in size, but also the dieticians – we wouldn’t need dieticians so much would we?

Click here for part 3.