Intermittent fasting could help tackle diabetes – here’s the science

By Alison Major, on 29 August 2017

Today’s guest post is by Nicholas Lesica, Wellcome Trust Senior Research Fellow at UCL and author of A Conversation about Healthy Eating. This article was originally published on The Conversation. Read the original article.File 20170810 27661 18ax5ba
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Nick Lesica, UCL

Intermittent fasting is currently all the rage. But don’t be fooled: it’s much more than just the latest fad. Recent studies of this kind of fasting – with restricted eating part of the time, but not all of the time – have produced a number of successes, but the latest involving diabetes might be the most impressive yet.

The idea of intermittent fasting arose after scientists were wowed by the effects of constant calorie restriction. A number of studies in many different animals have shown that restricted eating throughout adulthood leads to dramatic improvements in lifespan and general health.

The reasons for these improvements aren’t yet clear. Part of it seems to be that going without food gives cells in the body a much needed break to perform maintenance and repair. But the lack of food also forces cells to resort to alternative sources of energy. Some of these, such as ketones – molecules created in the liver from recycled fat – appear to be beneficial.

‘Fasting’ without fasting

The problem is that constant calorie restriction isn’t practical: it’s easy for scientists to impose upon lab animals, but hard for humans to impose upon themselves in the real world. Fortunately, we’ve learned that constant calorie restriction isn’t really necessary. Intermittent fasting seems to have many of the same benefits.

There are two main types of intermittent fasting. One type, known as “time restricted feeding”, requires eating only during a few hours of the day – say between 10am and 6pm. This approach gives the body a long break from food each night, and also reinforces beneficial circadian rhythms.

The other type of intermittent fasting – made popular by the 5:2 diet – is known as “periodic fasting”. This approach involves alternating between long periods of unrestricted eating and short periods of eating very little (five days of eating normally, two days of eating restricted calories).

It isn’t yet clear whether one type of intermittent fasting is better than the other. But the data so far suggest that both types can work.

Tackling diabetes in mice and men

The recent studies of the effects of intermittent fasting on diabetes have focused on periodic fasting in particular. As a first step, researchers led by Valter Longo at the University of Southern California, began by testing whether periodic fasting could cure diabetes in mice. They used mutant mice that lack the fat hormone leptin to regulate their food intake. These mice constantly overeat and become obese and diabetic in early adulthood.

The researchers found that after just a few months of periodic fasting – alternating seven unrestricted eating days with four restricted days – the diabetes was cured. This is an amazing result. But what’s even more amazing is the reason behind it.

The mice lost weight during the periodic fasting, which helped of course. But that wasn’t the whole story. Periodic fasting actually solved the problem directly at one of its sources: the pancreas.

Diabetes is a disease characterised by excess blood “sugar”, which really means excess blood glucose. It’s largely an insulin problem. Normally, insulin causes cells in the body to take in glucose from the blood. But with diabetes, glucose stays in the blood because cells no longer take it in. This is partly because many cells lose their sensitivity to insulin, but also because the pancreas stops making it.


Glucose meter, healthy lifestyles and nutrition.
ratmaner/shutterstock

It turns out that the periodic fasting made the pancreas start producing insulin again. The days of restricted eating gave the pancreas a break that allowed it to remove and recycle many of its cells. Then, when the mice started eating again, new cells that were capable of producing insulin emerged.

So the pancreas actually shrunk during the four restricted eating days, and regrew during the seven unrestricted eating days. After several such cycles of shrinking, recycling, and regrowing, the pancreas was nearly as good as new.

The big question, of course, it whether intermittent fasting will have the same effects in humans. The answer is not yet clear, but the initial indications from a recently published phase two clinical trial, again led by Longo, are promising.

In this study, 100 people went through a series of 30-day cycles of periodic fasting, each with 25 days of unrestricted eating and five days of restricted eating. After only three cycles, those subjects who started the trial with high blood sugar saw big improvements. And, importantly, none of the subjects in the trial experienced any harmful effects.

So the evidence in support of intermittent fasting keeps growing. Does that mean that we should all be doing it? Not necessarily.

Intermittent fasting seems to be most beneficial for those who are already overweight and unhealthy. While it does also seem to have some benefits for lean and healthy lab animals, it’s not yet clear whether the same is true for humans.

The ConversationA much larger phase three trial of intermittent fasting in humans that will clarify a lot of things is set to begin soon. The results will no doubt be very exciting.

Win a copy of A Conversation about Healthy Eating with Goodreads!

By Alison Major, on 10 August 2017

To the launch of A Conversation about Healthy Eating, we’ve teamed up with Goodreads to offer avid readers the opportunity to win one of five copies! To enter, use the line below [free membership required].

Goodreads Book Giveaway

A conversation about Healthy Eating by Nicholas Lesica

A Conversation about Healthy Eating

by Nicholas Lesica

Giveaway ends September 19, 2017.

See the giveaway details
at Goodreads.

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Losing weight without a diet: manipulating a type of brain cell gets results in mice

By Alison Major, on 2 August 2017

Today’s guest post is by Nicholas Lesica, Wellcome Trust Senior Research Fellow at UCL and author of A Conversation about Healthy Eating. This article was originally published on The Conversation. Read the original article.

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Evidence for a link between obesity and brain inflammation is getting stronger.
Suzanne Tucker/Shutterstock

Nicholas A Lesica, UCL

A new study has found something remarkable: the activation of a particular type of immune cell in the brain can, on its own, lead to obesity in mice. This striking result provides the strongest demonstration yet that brain inflammation may be a cause, rather than a consequence, of obesity. It also provides promising leads for new anti-obesity therapies.

The evidence linking brain inflammation to obesity has been building for some time. Consistent overeating causes stress and damage to cells in the body and brain. This damage results in a response from the immune system that has a wide range of effects.

Some of these effects help to reduce the problems caused by overeating, but others seem to make things worse. For example, in the hypothalamus – the part of the brain that controls, among other things, eating and activity – inflammation causes problems such as leptin resistance that interfere with the regulation of body weight.

Computer Hope
The hypothalamus controls eating and physical activity.
stefan3andrei/Shutterstock

Leptin is a hormone that is released by fat cells and provides the brain with information about the amount of energy stored as body fat. Normally, neurons in the hypothalamus that are sensitive to leptin will use this information to regulate eating and activity as needed to maintain body fat within some desired range.

In obesity, however, these neurons become insensitive to leptin. As a result, they no longer trigger the decrease in hunger and increase in energy expenditure that are necessary to lose excess weight. This is why the vast majority of attempts by obese people to lose weight fail– inflammation causes the brain to fight against it every step of the way.

So brain inflammation clearly plays an important role in sustaining obesity. But could it also be one of the primary causes of obesity in the first place? The onset of brain inflammation coincides with the other changes that take place in the body and brain as a result of overeating and weight gain. But whether brain inflammation actually causes the development of obesity is not yet clear. The results of the new study, however, demonstrate that the activation of a particular type of brain immune cell, microglia, initiates a cascade of events that do indeed lead directly to obesity.

Manipulating microglia in mice

In the study, researchers at the University of California, San Francisco and the University of Washington performed experiments on mice. They found that altering the activity of microglia in the hypothalamus allowed them to control the body weight of the mice independent of diet.

The researchers began by testing the effects of reducing either the number of microglia or their level of activity. They found that both manipulations cut the weight gain that resulted from putting the mice on high-fat diet in half.

They then tested the effects of increasing the activity of microglia. They found that this manipulation caused obesity even in mice that were on a normal diet. This latter result is particularly surprising. The fact that obesity can be induced through microglia – rather than directly through neurons themselves – is an indication of how strongly the brain’s supporting cells can exert control over its primary functions.

Computer Hope
Obesity can be induced by manipulating microglia.
Janson George/Shutterstock

So artificial brain inflammation can cause obesity in mice. Of course, that doesn’t mean that natural, diet-induced brain inflammation does cause obesity in humans. But these new results suggest that this idea is worth taking seriously, particularly given that fact that potential solutions to the obesity crisis are in short supply.

The ConversationThis new study alone has already identified several possible targets for anti-obesity drugs. Intriguingly, one of the same drugs that was used in the study to decrease activity in microglia is also being tested in human cancer trials, so initial indications of its effects on body weight should be available soon. But either way, a deeper understanding of the role of brain inflammation will help to clarify the causes of obesity. And hopefully prompt ideas about how it can be avoided in the first place.

Nicholas A Lesica, Wellcome Trust Senior Research Fellow, UCL

This article was originally published on The Conversation. Read the original article.

An Interview with Robert Biel, author of Sustainable Food Systems: Role of the City

By Alison Major, on 21 February 2017

RBIEL78I’m intrigued about your pathway into this topic.

Well it converged from two directions. I’ve been an allotment holder for 15 years, experimenting with a low-input, high-productivity method where you work alongside natural systems, not against them.  That was a hobby, something I loved doing.  Professionally, I was teaching international relations theory, which is a lot about how order can emerge from within a system itself.

In the debate following my first book, The New Imperialism, I discovered general systems theory, which tries to identify what’s common to all systems: they have a capacity to self-regulate, but they can also go haywire.  So I began to understand that the ecological problem and the threats to human society are not two separate challenges which just happen to face us simultaneously; rather, we can study them – and look for answers – in an integrated way.

I addressed this in my 2012 book The Entropy of Capitalism, but at that more general level it was easier to write convincingly about all the bad stuff that was happening, than about solutions! The only way to get to grips with positive solutions was to take a very concrete topic and run with it.  With Sustainable Food Systems, this all came together.

Please tell us a bit about the process, from initial conception, to publication

Together with my colleague Yves Cabannes I started teaching a Masters module on Urban Agriculture, and there were also a few small community food-related action research projects.  This suggested a lot of ideas which I felt somehow needed to be written down.

But the project implies an unusual form of knowledge, drawing on both natural and social sciences.  While general systems theory was a help, I had to be respectful to the integrity of each specific discipline – soil science, anthropology etc. – even where I don’t have specialist training.  To ensure the research was solid, I embraced the peer-review process at several levels.  I started with a conference paper, delivered in Paris in 2012, and then split it into five journal articles and book chapters, all exploring different aspects of food-systems issues.  While I received much important feedback from the reviews on these papers, I was also myself doing quite a lot of peer-reviewing for journals.  And I could trust the peer-review system for the quality of research in the leading scientific journals which I was citing.

At the same time, the ‘new paradigm’, also implies deeper issues of fundamental world view.  In this sense, knowledge (or maybe we should say wisdom) should not be reduced to academic research.  The traditional/indigenous spirituality doesn’t see a distinction between nature and society anyway, it understands that our minds are part of nature, and correctly sees farming as intrinsically rooted in the wider ecosystemic context.  In this sense, visioning sustainable futures is also a return, to a more authentic way of apprehending the world and our place in it.Sustainable Food cover

Finally, the project implied a different publishing model.  Though there were enquiries from conventional publishing, I quickly rejected this when I realised that the form of publication must reflect the content: the book is about emergent order, self-organisation, commons regimes, peer-to-peer, grassroots research … therefore it had to be open-access.  I was delighted that UCL Press was thinking the same way.

What’s your take on organic food? Are you advocating it?

There are two issues here.  First, from a consumer angle, of course there are dangers from pesticides or loss of nutrients, which are rightly emphasised, but at the end of the day you might just say mainstream agriculture successfully feeds the world and the risk of changing it is too great.  So I would rather approach the question from the production angle: the main thing wrong with conventional farming is that it destroys the complex soil ecosystem and ultimately the soil itself, and therefore the risk of not changing it is too great.  We have a window of opportunity while there’s still enough food around.  That’s why the issue is urgent.

Secondly, ‘organic’ can often seem a negative definition, i.e. we limit ourselves by renouncing chemicals, which makes it seem like we’re farming with one hand tied behind our back.  I’d rather emphasise what we are opting into: a whole new world of biomimicry and self-organisation … that’s why I sometimes prefer a term like Natural Systems Agriculture.  Besides, the problem isn’t just chemicals, but a lot of other stuff: excessive ploughing, monocropping … Much of this is about how we face risk, because natural systems spontaneously evolve in response to shocks, and become stronger in doing so.

Surprise me with something unexpected you encountered in researching this book.

A couple of paradoxes, which are in fact closely linked:

[1] When looking for cutting-edge examples of the new paradigm in action – learning from nature, self-assembly and self-healing, not trying to control systems too much – I found them in areas like industrial design and materials science; farming in contrast, which you might expect to be our interface with nature, is still horribly conservative and stuck in the old ways. Wonderful research is being done, about soil systems for example, but translating this into an innovative, high-productivity, totally biomimicked farming practice: that’s not yet the mainstream, it’s still very peripheral.

[2] The countryside is so heavily depleted by herbicides, pesticides and monocropping, that cities are potentially havens for nature to regenerate itself: this has been beautifully demonstrated by green roofs, for example, and is potentially very encouraging for a programme of greening the city.  We might even pioneer the new paradigm here!

The book has an optimistic vibe, because it’s about solutions, and as you’ve said, some elements of ‘paradigm shift’ already underway.  So what’s blocking it?  And in particular, how do you interpret the recent Right-wing nationalist backlash.

In the book, I paraphrase a quote from Lenin, about the ruling system being dragged against its will into a new social order.  The shift in world politics towards the nationalist Right shows the system digging its heels in, frantically resisting the implications which its very own development has unleashed.  That’s the aspect internal to society.  But then there’s the environmental context: climate – plus soil-degradation and species-loss – forms the backdrop to everything.

So why is the nationalist Right addicted to climate denial? Because if we take climate seriously, we’d have to face up to the social conditions demanded by resilience: decentralised capacity, peer-to-peer networks, modularity, non-monetary exchange, commons regimes.  These are all evident in today’s food-related social movements – seed-sharing for example.  The issue is inevitably political: a new ‘order’ is a self-organised, emergent order.  That’s what scares the ruling interests.

So what about this term ‘food sovereignty’? That sounds nationalistic in a way…

I think it was always more about community autonomy.  But in a deeper sense, I take your point: we must dare to be normative, not just describe a movement like food sovereignty, but discover what it should be.  A lot about the ‘old’ food sovereignty was resisting the extreme neo-liberal agenda of ‘free’ trade and its disastrous implications for food, and that was all very necessary, but it was only a phase.  In the book I try to place this in a much broader historical context. You have millennia of resistance against exploitative agrarian systems, then against colonialism and imperialism, then against the ‘Green Revolution’ of the Cold War; at an English level, there is an unbroken legacy: the peasants’ revolt, the Diggers of 1649, early 19th century Chartists, the Land and Freedom movement of the 1970s, and some inspiring contemporary stuff. If the ruling agenda is today shifting away from ‘free’ trade, the enduring issues of commons and land rights haven’t changed.

At the same time, today’s food sovereignty must also face up to new challenges.  What has gone haywire (in society and its relations with nature) has been a narrowing, homogenisation, simplification.  Physically, this is seen in the shrinking variety of crops being cultivated, in the strains of each crop etc.; socio-politically this is seen in intolerance, xenophopia, the narrowing of discourses.  If that is permitted, we will have a system (in food, in society) which fractures and disintegrates in the face of shocks.

So if we are to respond to this threat, I would say – prolonging the book’s argument – that if political liberalism has in a sense destroyed itself by hitching itself to economic neo-liberalism, then the good things which used to be (very imperfectly) identified with liberalism must be regenerated on a new basis: tolerance, pluralism, what I’d call a ‘new cosmopolitanism’ … in essence a diverse system which can produce innovation from anywhere and which – when it faces shocks – will get stronger.

The movement over land and food can be a flagship for this.  Today, the academic and science community is trying to resist the attacks of obscurantism, but can’t do this alone: it needs mass allies.  This is precisely what the land/food-related struggles – of peasants, indigenous peoples, the urban masses – can supply; the academic world has important knowledge to offer, but it will also be itself transformed by discovering a new social relevance.

In these ways, researching the book, I got some kind of glimpse of a new world coming into being.  It’s exciting to feel part of this.

Sustainable Food Systems: The Role of the City is available to download for free here.