Our obsession with eating healthily may be preventing us from getting a good night’s sleep.
When insomnia strikes, it’s easy to blame our stressful lives and reach for the lavender oil or herbal tea. But what if the cause of our sleeplessness is our nice, clean, “healthy” diets? That’s the conclusion of Sophie Lamb, a former insomniac and medical herbalist who believes that low-carb, low-sugar diets are at the root of many of her patients’ sleep problems.
“We all get obsessed with sleep hygiene — buying expensive mattresses, having elaborate bedtime routines, trying desperately to eliminate all external stresses — but it’s often a huge red herring because people still wake up at 3 a.m. feeling wretched,” Lamb says. “I believe what’s happening inside our bodies is far more important — it’s physiology not psychology.”
She has set up a business called Done Counting Sheep and treats insomnia patients at her clinic in Tunbridge Wells, Kent. What she’s found is that people are not eating nearly enough carbohydrates to get a restful sleep. “They’ll typically be eating eggs for breakfast, a chicken salad for lunch, and meat with green veg for dinner,” she says. “For years they’ve viewed carbs as the enemy, and the recent demonization of sugar has meant they’ve cut right back on that too and are often even afraid to eat fruit.”
The problem with low-carb diets is that the brain runs on glucose.
She thinks that low-carb diets are so ubiquitous — especially among the middle-class, professional, health-conscious types she sees in her practice — that they are viewed as balanced and healthy when they are actually very restrictive. The problem with low-carb diets is that the brain runs on glucose, which it gets from converting the starchy carbs and sugars that are supposed to make up about half our intake. That’s fruits, root vegetables, oats, lentils, rice, milk, and honey.
“It’s basic physiology you can read in any textbook, yet we are all missing it,” Lamb says. “If the brain doesn’t have access to enough glucose in the form of glycogen, which is our body’s sugar store, then the body will scavenge for it elsewhere by converting body tissues to glucose instead. But it requires stress hormones to activate this process. Adrenaline and cortisol will fix the problem of supplying your brain with constant fuel, but their side effect is a lack of mental alertness. A body flooded with these ‘fight or flight’ hormones at night is, in my opinion, contributing to the huge insomnia epidemic we now have.”
That our cortisol levels can have an impact on sleep is widely recognized by experts. “We know that low-carb diets push up cortisol and that cortisol can affect sleep,” the eminent sleep researcher Dr Neil Stanley says. “This approach is putting those two pieces together.” He says that more research into the connection is needed to find out how much of a rise in cortisol is required to disturb sleep.
Lamb says that she made the connection in her mid-twenties, when she developed terrible insomnia. A “good” night’s sleep was five hours in two stretches; some nights she hardly slept at all. At first she blamed external stress factors, such as pressure at work and emotional upheavals. But even giving up her job and going traveling didn’t help.
Then, one day, a colleague suggested that she investigate the link with diet. “For years I’d been very careful with my food, eating a low-carb and low-sugar diet, which I thought was healthy,” she says. “I’d have eggs and tomato for breakfast, a salad for lunch, and a small evening meal, which I thought was balanced. But it wasn’t balanced in the sense that our grandparents would have recognized. I wasn’t eating enough carbs to feed my brain and lower my stress response.”
As a trial, she added carbs to each meal — not white bread, pasta, and cake, but natural starchy foods such as fruits, root vegetables, and oats, plus the natural sugars in honey and milk. “I added in small snacks of fruit and cheese or dates and oatcakes throughout the day, and I drank sweetened hot milk before bed,” she says. “The effect was instant — I slept a full eight hours that first night and have continued to sleep well in the seven years after that. On the nights I don’t, I can clearly identify what’s gone wrong during the day that’s caused it.”
I have patients who have dieted for so long that they see it as normal eating.
Lamb, 39, understands that insomnia is a complex issue and lots of factors can contribute — including too much evening light, external stresses, and worrying about insomnia, which perpetuates the problem. “But, fundamentally, if your stress hormones are running high into the night, your brain simply isn’t going to switch off and let you sleep, and food is the best way to start tackling that,” she says.
Lamb has been able to help the majority of her patients in transforming their sleep through dietary changes. “I have patients who have dieted for so long that they see it as normal eating,” she says. “One patient reeled off his daily diet, which sounded so thoughtful and so careful — eggs for breakfast, salad for lunch, and meat with green, non-starchy veg for dinner — but we worked out that was only 1,300 calories and hardly any carbs. Lots of my patients are eating only 50g to 80g of carbs a day when it should be more like 150g.”
Her advice to that patient was to add carbs to each meal and have a dessert of stewed apple with some ice cream and a hot milky drink before bed (the sugars in the milk dampen the stress response). “When he first came to see me he’d been made redundant, so obviously he was stressed, which he thought was causing his sleep problems,” she says. “After changing his diet, his sleep vastly improved — yet those external stresses remained the same. But because he’d gottenn his sleep back, he was better able to cope with the stress.”
As well as diet, Lamb sometimes prescribes adaptogen supplements — plants that reduce the body’s stress response — plus herbs to aid sleep. Occasionally she even tells patients to eat a bit more salt, which is enough to make most doctors gasp. Most of us eat too much salt, but she believes that some particularly health-conscious types who eat no processed food and don’t add salt to their cooking do not have enough of it. “If your salt intake is too low, that stimulates the stress hormone adrenaline,” she says. “And if you’re stressed, you actually need more salt, because you are losing more through sweat, and you also lose it when cortisol is released.”
“The bottom line is that sleep is a multifactorial problem — light matters, electronic screens matter, emotional factors matter,” Lamb says. “It’s a slew of factors, but diet is the one factor that’s never mentioned. If you’re stressed, not eating right is often the straw that breaks the camel’s back.”