Broad beans are a beautiful looking, highly companionable veg stuffed with protein

• Rosie Sykes's broad beans with pearl barley and feta recipe

With their verdant sheen and kidney-shaped curves, few vegetables rival broad beans in the looks department. True, a little effort in the form of double podding is needed to show them off. First you liberate the beans from their outer jackets (a doddle). Next, you immerse the beans in boiling water for two minutes, refresh them in cold, and drain them. Then by squeezing them gently, you can slip the seductive green beans out of their grey, papery skins.

Broad beans are most definitely not fast food, but when you bite through their silky exterior into their sweetly leguminous floury centre, you'll remember why they are worth the bother. They're best when they are relatively small and new; they become duller tasting and more like dried pulses with age. Mint, crispy bacon and pecorino all make perfect companions.

Why are broad beans good for me?

Broad beans are an excellent vegetable source of protein and fibre. This may be a winning combination for weight loss. A study published in the European Journal of Clinical Nutrition in 2010 found that overweight women on a high-protein, high-fibre diet lost more weight than those on the standard high-carbohydrate, low-fat regime that currently forms the basis of government "healthy eating" advice. Broad beans are also rich in both folate and B vitamins, which we need for nerve and blood cell development, cognitive function and energy.

Where to buy and what to pay

Reasonably disease-resistant and easy to cultivate, broad beans are one of the more reliable seasonal highlights of late spring/early summer. You'll find them particularly nice and fresh at farmers' markets or in organic vegetable boxes. Guide price: £6/kg.

Joanna Blythman is the author of What To Eat (Fourth Estate, £9.99). To order a copy for £7.99 with free UK p&p, go to guardianbookshop.co.uk

Broad beans with pearl barley and feta

At the beginning of the season, when the broad beans are small and tender, I tend not to pop them out of their skins in this recipe, but with the bigger, slightly tougher ones it's really worth the slightly painstaking effort. If you are using skinned broad beans, just add them at the end to heat through.

Serves 4
1 tbsp olive oil
30g butter
1 bunch spring onions, trimmed and sliced into 1cm pieces
2 garlic cloves, peeled and crushed
400g pearl barley, washed thoroughly and left to soak for 20 minutes
800g broad beans, podded and, if large, blanched and popped out of their skins
200ml white wine
1 litre vegetable stock
A couple of sprigs of mint, chopped
A small handful of parsley, chopped
100g feta, crumbled

1 Heat the oil and half the butter in a large, heavy-based pan and add the spring onions and garlic. Cook gently until soft, about 5 minutes, then stir in the pearl barley.

2 Cook for a minute or so, then add the broad beans and, soon after, the white wine. Cook until it has been absorbed then add the stock.

3 Simmer, stirring often, until the barley is tender. This will take about 30 minutes; top up with hot water if the stock is absorbed before the barley turns soft.

4 Take off the heat and stir in the rest of the butter, then season to taste, bearing in mind you will be finishing the dish with some salty cheese.

5 Leave to sit, covered, for 5 minutes then stir in the herbs and feta. Serve.

Rosie Sykes is head chef of Fitzbillies and co-author of The Kitchen Revolution (Ebury Press, £27.50). To order a copy for £19.99 with free UK p&p, go to guardianbookshop.co.uk

Michael Pollan, the American food writer and campaigner, says eating together round the table every night is the way children learn best how to get along in the wider world

What's for dinner? Where will you eat it? And who will eat it with you? Michael Pollan reckons that the answers to these questions could determine our survival as a species. In his own case, the answers are: meatballs, round the table, with his family.

An internationally successful food writer and campaigner, he's just got home after a tour to promote his new book, Cooked: A Natural History Of Transformation. Now he just wants to unpack and do some cooking. "I've found this terrific new recipe using ricotta," he says. "It's so light."

He won't be serving it on trays, in front of the television because sitting round a table is so important. "It's where we teach our children the manners they need to get along in society. We teach them how to share. To take turns. To argue without fighting and insulting other people. They learn the art of adult conversation. The family meal is the nursery of democracy."

But the family meal, or "primary eating", is in decline – down to 67 minutes a day, Pollan says. Secondary eating (while you're doing other things) now takes 78 minutes per person per day. Astoundingly, 20% of food intake in America is now eaten in the car, says Pollan. It's unlikely to be nutritious. "I'm sure that some people are sitting in there eating organic baby carrots, but on balance what they're eating is likely to be crap."

Pollan has devoted years to attacking junk food, factory farming and agribusiness. He is also known for his advice on what we might eat, including the celebrated maxim, "Eat food, not too much, mostly plants." Now he would like to add to that pithy advice: "If you can, cook it yourself."

Cooking is what happens between farming and eating. It's a political act, he suggests, because by cooking we can improve our health, break our dependence on conglomerates, and build community. But like anything political, it can provoke fierce debate. Pollan courts criticism by suggesting that the modern-day reliance on convenience food, eaten in isolation, started with women going out to work. One American magazine writer said recently that she wants to "smack him with a spatula", and challenged readers with the question: Is Michael Pollan a sexist pig?

"For a man to criticise these developments will perhaps rankle," he concedes. "It sounds like I want to turn back the clock and return women to the kitchen. But that's not at all what I have in mind. I've come to think cooking is too important to be left to any one gender or member of the family. Men and children both need to be in the kitchen, too, not just for reasons of fairness but because they have so much to gain by being there."

His argument is not that feminism destroyed home cooking, rather that the food industry, eager to insinuate itself into the American kitchen, used feminist rhetoric to get there. "Feminism rightly demanded a renegotiation of the domestic division of labour, a very uncomfortable process for millions of us, and the industry seized the opportunity to say, 'Stop arguing! We've got you covered. We'll do the cooking so you don't have to argue about it any more.' And we all leapt at the 'solution'."

Pollan, 58, lives with his wife, Judith, 56, and their son Isaac, 20. Their kitchen is designed for "three people who like to hang out and cook together". Pollan calls it the family's centre of gravity. The dinner table dominates the room: a thick slab of elm with benches that tuck underneath.

In that kitchen, for the last three years or so, Pollan has been learning to "transform" food: to bake, braise, barbecue and brew. He has enjoyed roasting pigs and brewing beer with Isaac, and testing out recipes with Judith. "I like not using a recipe," says Pollan. "Using it for the first time and then throwing it out. Sometimes it goes off the track, but in general that evolution is good. You tend to figure out what's essential and what's not. We now have a nice rhythm. That's some of the best time we have together – in our kitchen."

He has also learned to cook with experts. "I was pinching myself that I was getting paid to learn the things I was learning," he says. "And I was working with people who wanted to work with me. I wasn't having to persuade feedlots [used in US and Canadian factory farming to intensively feed up animals before slaughter] to let me in, or ask Monsanto to have access to their scientists.

"This was a voluntary project. And the end result is more personal than anything I've written."

Pollan grew up loving food – he claims he could still pick out his mother's beloved blue casserole dish from a lineup. But despite writing a series of award-winning food books, he has never really cooked. "I wasn't a complete naif in the kitchen," says Pollan. "But I cooked in a pretty half-hearted way. Like a lot of people, I was divided when I came into the kitchen. None of us has to cook any more so when we get into the kitchen we're conflicted. There's always something else we could be doing that's more pleasurable. Or easier. Or more demanding."

Take onions. Pollan was always too impatient to chop them finely. He didn't see the point. When he put them in a pan to sauté he would wait 10 minutes before he tipped in the tomatoes. "The idea that I would wait 40 minutes for the onions to get really translucent and sweet? I was like, no, I'm not going to do that. But as I learned to cook, I changed. I just let myself be in the kitchen. I disconnected from my computer screens and took time to connect with my senses, my wife and my son. When chopping onions, just … chop … onions. It's a useful piece of life wisdom."

It may also sound time-consuming. But Pollan is good on how we have found other ways to waste time that would previously have been spent cooking. "We forget how much time it can take simply to avoid cooking: all that time spent driving to restaurants or waiting for our orders, none of which gets counted as 'food preparation'. And much of the half-hour saved by not cooking is spent watching screens."

In the book, Pollan writes about a "microwave night" in which he tested how much time is saved by ready meals: none. "That's because the microwave is an individualistic serial machine – it can only do one at a time so if you've got four people eating four different entrees, each has to be individually heated. So our microwave dinner, which was supposed to save us so much time, took about an hour to get to the table. And by the time the last entree got out, the first one needed to be renuked because it was cold. So I'm hard on the microwave. Without question."

Pollan does still have a microwave, but doesn't use it to cook. It's there to defrost things and to reheat his coffee – several times a day. But he has little love for it. "When you compare a microwave with a real fire or a casserole – these things speak sharing. They draw people around them. The microwave doesn't. Nobody wants to get too close to a microwave. It gives them the willies because of the mysterious waves jumping round inside."

If Pollan sounds authoritative now, he wasn't always. His interest in food writing was partly sparked by his son, Isaac, who used to be a terrible eater. "From the age of three or four, he really only ate white food. I could make him a chicken breast [sandwich] without any crusts. But it was a seriously limited diet. If I'd had a more sensitive understanding of cooking I might have been able to feed him with more success. If we'd had a little more confidence as parents we would just have let him get really hungry. [We'd have said], 'He can take it or leave it. He's just jerking us around.'"

Pollan was quite clear about the food and drink he wanted in the house. "We never kept any soda. That's a key thing. If your kids aren't having soda every day, that's half the battle, in terms of weight and diabetes. Potato chips we seldom had around – maybe if people were coming over. We didn't have dessert every night. And we didn't fry too often. My wife is very fat-hostile. She doesn't like a lot of fat in her food. But we didn't really have to ban much."

That is probably why Isaac is still happy to bring friends home after college. "His friends will completely empty the refrigerator and pantry and take whatever crackers and snack foods they can find," says Pollan. "They will then go into the room where we have the TV and distribute the crumbs evenly over the floor and the couch. We're much more normal than you might suspect."

I expected Pollan to be pompous and self-righteous like every other food guru I've met. But he's not like that at all and, it transpires, not adverse to a junky snack or two. "We have a caramelised popcorn called Crackerjacks," he says. "If I'm in a gas station, that's what I'll go for. You could call it junk food I suppose. I prefer to think of it as a traditional native American treat …"

He's a funny man. But, sometimes, bearing the responsibilities of a nation's diet weighs him down. "I've become the food super-ego for a lot of people. And I find that uncomfortable. People like to confess their food crimes to me. I don't want to hear it. Eat what you want. That's not my role.

"My role, I think, is to make people eat with more consciousness. Eating thoughtlessly is the biggest problem we have. If we're not thinking, they can push our buttons and get us to eat all sorts of stuff. The more thoughtful we are, the healthier we'll be."

Pollan doesn't want to argue people into the kitchen. He wants to entice us – to show through his storytelling how rewarding cooking can be. "As good as restaurants are, they tend to throw a whole stick of butter in at the last minute just for the hell of it, plus put in more salt and sugar than the home cook would.

"Home cooking is good for you, and I eat out less. But that's the least of it. What has surprised me is how stimulating it is. How satisfying. You learn a lot about plants and animals. You begin to recognise your place in the world."

To learn these valuable lessons, he says, children do need to be taught about food. "There are few more important life skills we can give them. We already teach them about driving, alcohol and drugs, and safe sex in school, and it seems to me that teaching them to cook is just as important for their long-term health and happiness."

When Isaac was 13, Pollan says, he began to trust food. "Not fear it – because he saw how it was prepared. Kids can be very suspicious: 'Why are you hiding that food with sauce?'

"Once they start making it themselves, they are more likely to enjoy it."

Now, some years later, Isaac often does his work at the kitchen table while his parents cook: "We'll ask him to chop an onion. Or mince some garlic. And he'll offer unsolicited advice in the seasoning. Then, when we're almost done, he'll make a port reduction. The table really is the centre of our family."

• Michael Pollan will be taking part in a live chat at 3.30pm on Tuesday 28 May at guardian.co.uk/wordofmouth

Michael Pollan's food rules for the table

• Eat with others rather than while watching TV/working/driving by yourself – you will eat less.

• Decide how much sugar, salt and fat you want to eat – don't let a food corporation make that decision for you.

• Try to eat food cooked by humans rather than corporations – it will automatically be better for you.

• Don't use the microwave to heat up separate meals – sharing the same food at the same time is better for family life.

• Brew your own beer now and again – it's a great way to bond with teenage children.

• Cook your own meat – then you'll know what animal it really is.

• Enjoy watching cookery shows on TV – but don't let them put you off cooking. yourself and remember your children will learn to cook by watching you.

• Eat as cheaply as your grandmother did by cooking like her – use fresh ingredients and leftovers.

• When chopping onions, just chop onions – give cooking your full attention and you'll find you enjoy it more.

• Eat whatever you like as long as you cook it yourself.

Walking makes us healthy and happy, and there are plenty of ways to fit it into the day: walking to work, wandering book clubs or even training for a charity trek. Where do you walk?

"It felt like we were marching through a battlefield. People were gasping for breath and shouting for help. Lots didn't make it to the end, either collapsing from exhaustion or unable to take the pain any longer."

That is how one friend dramatically described the 24-hour, 100km charity walk from London to Brighton. What was I thinking when I signed up? But since making that rash decision last November, I've had little choice but to lace up my first ever pair of walking boots and take to the streets of London. It has been a refreshing – and blistering – experience.

A few years ago, walking was a hot topic, with charities and media commentators encouraging us to get a pedometer and walk 10,000 steps a day. But it seems we didn't listen: according to the historian Joe Moran, walking has declined by 25% in the past quarter of a century in the UK; a YouGov poll recently revealed that as many as a quarter of British adults walk for an hour or less a week – and that includes getting to the door of your car. Two-thirds of adults in the UK don't do nearly enough physical activity. The result is clear: sedentary Britain is facing a public health crisis.

At a recent TED lecture, the author Nilofer Merchant said sitting is the "new smoking of our generation". The phrase has been picked up by public health academics and experts, who warn of a worldwide pandemic of inactivity. Even going to the gym in the evening isn't enough to offset nine hours of sitting still in the office, according to studies. Walking needs to be part of everyday life – your commute to work, your journey home, your visit to the shops, your lunch break, and even the way you work.

Merchant has called for meetings to take place out of the boardroom and on foot, not only because it is healthier, but also because it encourages conversation and productivity. Aristotle would be pleased – apparently he loved to walk and talk, and would wander the Lyceum in Athens as he lectured to his followers. Sigmund Freud and Charles Dickens were also known to work on the move.

Perhaps the importance of combating our desire to sit still is spreading: estate agents in part of the US and Canada are starting to market homes according to their "walkability" rating. That is a measure of just how many places (pub, shops, post box, cinema, schools, offices and so on) you can reach by foot from your home. My home – in Finsbury Park, north London – is a "walker's paradise", according to the website walkscore.com. It makes sense. My surrounding streets are close together, with plenty of corners to bump into someone for a chat. If you head out to the countryside your walkscore goes down, because it's harder to cope without a car. People who live in walkable neighbourhoods are not only healthier and happier, but also 6-10lb (2.7-4.5kg) lighter, says Walkscore.

So although the idea of walking non-stop for 24 hours fills me with dread, it has propelled me on to the streets, forcing me to walk hundreds of miles along the pavements of London. What an eye-opener. In the last few months I've watched buildings being knocked down and built up, and witnessed things I would never have seen from the darkest depths of the tube. I've seen an entire theatre being built, and on walking past one evening to see its doors open to visitors, I decided to become a volunteer there. Walking has created a whole new connection with my community and provided me with hours of pleasing conversation with my walk-to-work buddy.

There are signs, too, that the decline in walking may be slowing or even reversing. Last week the UK Chartered Society of Physiotherapists said that despite the overall decline in activity, more and more people are ditching the train, bus, car or tube on their way to work. Over the past decade the number of "walking commuters" has risen by 9%. And it's not just walking to work that's becoming more popular. There's a walking book group, walk speed-dating events and walking therapy sessions. There's even a walking scheme being trialled in Berkshire which logs how far people walk using a system similar to the Transport for London Oyster card.

By this time on Saturday, I will hopefully be several miles into my epic 64-mile walk. I know there will be moments when it will seem far easier to sit down and stop. Maybe I'll be one of those people who described it as a battlefield. But whatever happens this weekend, the real challenge will be to keep on walking – not just to Brighton, but beyond. With a name like mine, I have no choice.

Sleep disturbances may be an early warning sign of Alzheimer's and other neurodegenerative diseases

The latest issue of Nature contains an Outlook supplement about the health impacts of poor sleep, including a feature I wrote about the link between sleep disturbances and neurodegenerative diseases, called "Amyloid awakenings". The title refers to a process called amyloidosis, by which mutated, abnormally folded proteins aggregate to form insoluble clumps in the brain.

This process is a normal part of ageing, but happens faster in some people than others. Alzheimer's disease, for example, is characterised by insoluble clumps called plaques, which build up in the spaces around neurons in the brain, and neurofibrillary tangles, which accumulate inside the cells. The plaques are made of a mutated protein called amyloid-beta (Aβ), and the tangles of another called Tau. Most other neurodegenerative diseases involve the build-up of misfolded proteins (although each is associated with a different protein or proteins), so amyloidosis does not specifically refer to Aβ aggregation, but is a catch-all term for the process.

The feature grew out of two recent news stories I wrote: the first reported on research presented at the annual meeting of the Society for Neuroscience in New Orleans last October, showing that sleep disturbances may predict Alzheimer's, and the second describes a paper published earlier this year, showing that age-related deterioration of the prefrontal cortex disrupts sleep and impairs memory. Other research published over the past five years or so suggests that sleep disturbances could be an early warning sign of other neurodegenerative conditions, and the article summarises much of this work.

The research shows that people with Alzheimer's, Parkinson's and several other neurodegenerative conditions often experience sleep disturbances many decades before any symptoms appear, and that these disturbances are somehow linked to disruptions of the circadian rhythm. They include common sleeping difficulties such as insomnia, sleep apnoea, and daytime drowsiness, and some slightly more unusual ones. According to one small study published in 2011, for example, the early stages of Parkinson's disease are characterised by alterations in the content of dreams, particularly the presence of animals and increased aggressiveness.

It is still not clear how the sleep disturbances experienced by pre-symptomatic Alzheimer's patients differ from those who will go on to develop one of the other neurodegenerative conditions. Yet, all of the researchers I spoke to seem to agree that sleep disturbances may be the earliest manifestation of these diseases, and that detecting and treating them as early as possible may slow the neurodegenerative process, or even prevent it altogether.

They all agree, too, that the relationship between sleep and neurodegeneration is probably a two-way street. In other words, people with unhealthy sleeping habits earlier on in life may be predisposing themselves to these diseases.

Another new study, published earlier this month, shows that major depressive disorder involves disruption of the activity of hundreds of genes that are involved in regulating the circadian rhythm. Typically, these so-called "clock genes" exhibit regularly fluctuating expression patterns, so that their activity goes up and down with the daily rhythm of the body. As I discuss in my article, the sleep disturbances in patients who go on to develop neurodegenerative diseases are accompanied by a breakdown in the rhythmic expression of clock genes. This new paper is interesting because we now know that depression involves pathological changes similar to those seen in Alzheimer's, including shrinkage of the hippocampus, a part of the brain involved in learning and memory.

One thing I didn't mention in the article, due to space restrictions, is the relationship between protein aggregation and neurodegeneration. In some of these diseases, the misfolded proteins that build up in the brain are highly toxic, and lead directly to neuronal cell death. This is true of the motor neuron diseases and the prion diseases, which include "mad cow disease" and various human forms of it, such as variant Creutzfeldt-Jakob disease (vCJD). For the past few decades, researchers assumed that Aβ plaques cause Alzheimer's disease, and drug companies spent billions researching and developing drugs that block plaque formation or break down plaques that have already formed.

In animal studies, these drugs alleviate the memory impairments associated with Alzheimer's. In humans, however, they don't seem to work, and as a result several large drug companies have halted clinical trials in their late stages. Some researchers are sticking to their guns, arguing that the drugs have to be administered at the earliest stages of the disease to be effective.

It is also possible that plaque formation is a consequence of Alzheimer's disease, rather than its cause. According to one new school of thought, it's the soluble form of Aβ protein that is toxic, and the plaques may actually be protecting the brain by capturing these soluble protein particles and preventing them from causing damage. If this turns out to be the case, then blocking plaque formation may actually be harmful.

How does this come to bear on the link between sleep disturbances and neurodegeneration? In Alzheimer's, plaque formation seems to be closely related to the sleep-wake cycle. One study found that levels of soluble Aβ decrease at night and increase during the day, and are significantly elevated after sleep deprivation. Another showed that the sleep-wake cycle breaks down following plaque formation, but is restored when the plaques are eliminated.

It may mean that the protective mechanism is more active while we sleep than during waking hours, which is in keeping with the emerging view that sleeping well is important for good overall health. More research is needed to clarify exactly how all these factors are related, but this does not bear on the possibility that sleeping difficulties are early diagnostic markers of Alzheimer's and other neurodegenerative diseases.