Eat dinner at 6pm (and other winter health boosters)

“I always get my clients to eat earlier,” says Laura Southern, a nutritionist at London Food Therapy. “With more dark, cold nights on the sofa, we often struggle to expend the energy from our evening meal. Plus, the closer we eat to bed, the worse our sleep quality is. The gut needs time to repair and rest, otherwise it can have a negative impact on our immune system.”

The nutritionist Laura Thomas, author of Just Eat It, advises paying attention to when you start to feel hungry (rather than waiting until your stomach is gnawing to eat) but cautions against rigorously following strict rules. “With a better understanding of our hunger signals, I find people tend to naturally eat earlier and we tend to feel better when we eat in alignment with our circadian rhythm,” she says. “But I’m not sure it’s helpful to say, ‘No eating after 7pm,’ as fluctuations in appetite are normal with illness, tiredness, hormonal shifts and so on. If we second-guess ourselves, we feel guilty and stressed.”

Book a winter holiday

On the one hand, we’re told that sunlight during the winter months can help us get enough vitamin D. On the other, we’re advised to protect ourselves from the sun’s rays to avoid skin cancer. So … Caribbean winter break or not?

While the evidence isn’t conclusive, a growing body of research suggests the health benefits of sunlight may go further than we have acknowledged. Analysis by the University of Edinburgh last year, which studied medical data from 395,000 pale-skinned Brits, concluded that while the risks of UV exposure are real, it may also make us less likely to die from cardiovascular disease and cancer, possibly thanks to the role vitamin D plays in bolstering our immune systems and bone health.

All things considered, Professor Richard Weller, a dermatologist at the university who co-led the study, thinks a winter break somewhere sunny is a good idea. “Sunlight has benefits on overall health, independent of vitamin D,” he says. “Sunlight does increase your risk of developing skin cancer but this needs to be balanced against other health benefits, including reductions in blood pressure and deaths from heart disease.”

Britain’s health watchdog, the National Institute for Health and Care Excellence (Nice), hasn’t changed its guidance on taking precautions in direct sunlight just yet. But a winter break, with adequate suncream slapped on, just got a whole lot less guilt-inducing.

Can’t afford a winter break? Take vitamin D

Our skin usually manufactures its own vitamin D when exposed to sunlight — not so easy during the winter. It’s stored in our adipose tissue (or body fat), meaning we have some surplus with which to temporarily top up our daily intake, but it is generally not enough at this time of year. Between October and March about one in six adults in the UK have lower levels of vitamin D than officially recommended. And at this time of year “Vitamin D is important for your immune health”, says Daniel Davis, professor of immunology at Imperial College London and author of Self Defence: A Myth-Busting Guide to Immune Health.

So if you can’t book a holiday (which may not adequately top up your reserves in any case), eat plenty of vitamin D-rich foods — Davis suggests oily fish and eggs — and consider taking a supplement. A big analysis in the British Medical Journal in 2017 found that doing so can protect against developing acute respiratory tract infections. “The bottom line,” Davis says, “is that during the winter months most people do need to top up their vitamin D levels with supplements.”

Sleep differently

Research by German academics in 2023 found that we might need up to 30 minutes more deep REM sleep — linked directly to the circadian clock — during the dark winter months. So how can we get it?

Counterintuitively, Guy Leschziner, professor of neurology and sleep medicine at King’s College London and author of The Secret World of Sleep, says the best thing we can do for our sleep in the winter months is to focus on getting enough daylight.

“A lack of exposure to bright light can weaken your circadian rhythm and therefore your sleep,” he says. “It’s important to make sure that you’re getting a good dose of outdoor light — not easy when we’re going to work in the dark and coming home in the dark. So go outside at lunchtime, ideally for at least an hour.”

If that’s impossible, invest in a sun lamp for your desk. And make sure your bedroom isn’t too hot or cold at night — about 18C is ideal. A drop in your core body temperature is one of the physiological processes needed to send us to sleep, so if you’re too cosy it might stop you from drifting off or wake you up.

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“For some people their bedroom is hotter in winter than in the summer because they put the heating on and that may result in worsening sleep,” Leschziner says. A dehumidifier, which reduces moisture in the air, lessening damp or mould, may also help.

Hibernate but don’t stagnate

It’s little wonder many of us feel like hibernating at this time of year. The lack of daylight can lead to a drop in our levels of the brain chemical serotonin, leaving us experiencing low mood, while an overproduction of melatonin — the hormone that manages our sleep-wake cycle — can make us feel sluggish and fatigued.

“We might not want to go out as much, but let’s not stagnate,” says Suzy Reading, a psychologist and author of Self-Care for Winter. “We’ve got to keep our bodies moving for our physical and mental health. If you don’t have the same energy to go to that HIIT class, just do some stretches at home — that’s better than being on the sofa for the next three months.”

“Moderate exercise is good for your immune system,” says Davis, and may help you fight off infection better. Cardiovascular training, for instance, increases the number of immune cells in your blood called neutrophils, which act as the immune system’s first line of defence. However, strenuous exercise, he warns, may put stress on the body. There is evidence, for example, that Olympic athletes might be more susceptible to respiratory infections after an event. It’s a no to that Ironman competition then.

Be more Danish

Naturally we can learn from the Danes. “For us, the dark months are hygge time,” says Meik Wiking, CEO of the Happiness Research Institute and author of several books on living Danishly. “We develop a survival strategy for winter. It’s lowering your expectations, appreciating the simple things and choosing to make it really cosy indoors when the weather is lousy.”

That might mean bringing out candles, making a stew, lighting a fire, watching the Lord of the Rings trilogy. But, crucially, you have to go outside first. A study from Denmark’s Aarhus University found that the number of depression diagnoses increased by 8 per cent the month after the start of winter — due to the lack of light, says Wiking, who realised the mood-boosting importance of daylight as a student selling Christmas trees outdoors. “When you come back inside, you feel as though you’ve earned the right to be there,” he says.

Don’t forget your friends

Hunkering down doesn’t mean forgetting your friends until the weather improves, tempting though it may be to avoid festive parties. Social isolation can increase during the winter months, especially around Christmas, reports the charity Linking Lives. “You can still socialise even though you’re hunkering down,” Wiking says. “Invite people over. I once had a cooking club where everybody would bring ingredients and cook a dish under a theme. We even made sausages from scratch once.” (Which may be the most Danish thing I’ve ever heard.)

“It’s fine if your social connection changes shape over the winter months, but we need to make sure that we’re still plugging in,” Reading says. “It might be a walk with a friend or exchanging voice notes. It could just be listening to podcasts or Ted talks. Anything to make you feel connected to something bigger than yourself.”

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Drink lots (but go easy on the booze)

The bad news? “There is quite a lot of evidence that alcohol is bad for immune health,” Davis says, “and it may change your eating and sleeping patterns.” But wait. “If you have wine with a meal, it could help you feel less stressed, in which case it would have some benefit.”

“We need to make a distinction between a crutch and something that genuinely helps us cope in the long run,” Reading says. “Alcohol, caffeine, sugar, online shopping — all these things might help in the moment but make tomorrow harder. We need a direct swap. It might be having a nonalcoholic beverage or a supportive phone call with a friend. It’s acknowledging that there is an underlying need and finding another coping mechanism that’s healthier in the long run.”

And don’t forget to stay hydrated. We are less aware of being thirsty during the winter, Reading says, but we’re often dehydrated with all the central heating and layers of clothing. “If you’re freezing, the last thing you feel like is a cold drink of water. So can you drink hot water with a slice of lemon? Herbal tea? You just need to make sure you’re meeting your fluid intake.”

Reduce your stress levels

The festive season can be emotionally fraught, with pressure around family gatherings, gifts and the existential crisis of another year passing (just me?)

“Long-term stress is definitely able to weaken your immune system,” Davis says. “But any stress at all will put your body into the fight-or-flight response, producing the stress hormones adrenaline and cortisol, which directly dampens your immune system.”

Oh good.

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“Anything you do that could lessen your stress levels will also help your immune system,” Davis says. “That will be different for every person — t’ai chi, being in nature, colouring books. Those kinds of activities can reduce cortisol levels in your blood and that has the effect of helping your immune system.”

Reading recommends a quick exercise — the “shrug and sigh” — to counteract the slumped posture many of us adopt in the cold weather and which can exacerbate low mood. Clench your upper body: make fists, squeeze your biceps and chest muscles, hunch your shoulders to your ears. Then breathe in and exhale, letting go of all the tension. “It shifts your nervous system out of the stress response into rest and digest mode,” she says.

Although, Davis says, “over Christmas people will be with their family and friends, which would hopefully reduce stress levels.” Perhaps hunkering down doesn’t sound so bad after all.