Show Hide image Science & Tech 22 December 2014 Why festive indulgence is good for you What should you do to stay happy and healthy this Christmas? You’ll like the first piece of advice: if you want to relax, you could try eating a big meal. Sign up for our weekly email * Print HTML Too often, the season of cheer and goodwill generates a lot of the opposite. There’s the high-pressure shopping and the overeating and its associated guilt. Routines of trips to the gym and exercise classes quickly become a distant memory. Then you have all those relatives to deal with. Fortunately, we also have science. No end of laboratory resources have been dedicated to figuring out what happens to our bodies in stressful situations and how those consequences can be defused. The first step is to know your enemy. Stress is devious. It makes it hard, for instance, to resist the temptation to overindulge in the sweet stuff. Experiments on rats have shown that their desire for sugar is amplified when stress hormones are high – they will work much harder than chilled-out rodents to get a sweet treat. Relaxation not only offers heightened immunity to temptation; it also gives you greater immunity to disease. The stress hormone cortisol impedes your immune response, making you more likely to succumb to winter bugs. Grandparents are particularly vulnerable here. In younger people, a hormone called DHEA counteracts cortisol’s effect on the immune system but the body produces much less DHEA once you are past 30. Those in their seventies are operating with about a fifth of the DHEA of their grandchildren – so kids should play nicely. The older generation is also more deeply affected by stress. Experiments on three-month-old and 24-month-old rats have shown that the same repeated stresses increased levels of stress hormones far more in the oldies. Brain scans showed a further consequence: not only were the senior rats much more anxious, they were also far less able to control their emotional state. So if grandma gets a bit teary, that’s only to be expected. What should you do to stay happy and healthy this Christmas? You’ll like the first piece of advice: if you want to relax, you could try eating a big meal. That nap you need after a turkey dinner is not your fault. Your impressive ingestion will give you raised blood glucose levels. This, it turns out, switches off the brain cells associated with alertness. If anyone challenges your need to rest your eyes for a few moments after your meal, tell them that evolution has equipped you with a switch that says, “It’s OK, everyone is full. All the hunter-gatherers should sleep now.” If you’re struggling to relax after last-minute Christmas shopping, try some chocolate. Not Roses or Quality Street, though: you need dark chocolate, packed full of flavonoids. These stimulate the body to release nitric oxide, which relaxes the arteries and veins, lowering blood pressure. The central message is: indulgence is good for you. For a start, smiling and laughing reduce the amount of cortisol in the bloodstream. But pleasure is its own tonic. Indulging in any pleasurable activity makes your cells release enkelytin, which will attack bacteria in your bloodstream. Meanwhile, if you’ve only got a few days to get into the holiday spirit, moments of meditation could be your ticket. A 2003 study showed that the practice of t’ai chi – meditation through movement – can boost cellular immune responses by up to 50 per cent. That requires a bit of expertise; however, a number of studies suggest that various forms of gentle, repetitive exercise or ritual will send your stress levels tumbling. Five days of a technique called “Integrated Body-Mind Training” (IBMT), for instance, put people in a better mood and enabled them to be more attentive to tasks than those given simple muscle relaxation training. When they were given mathematical puzzles to solve, the blood cortisol response – a stress measure – of IBMT trainees was lower, too. The guru of relaxation is a man called Herbert Benson who, in the 1960s and 1970s, performed game-changing experiments proving the efficacy of certain relaxation techniques. His basic prescription is ten to 20 minutes of deep, controlled breathing while sitting in a relaxed position. The result is the “relaxation response”, a physiological change that, according to the peer-reviewed literature, can help with hypertension, cardiac arrhythmia, insomnia, infertility and anxiety. Tempting as it might have been, Benson hasn’t just been chilling out since the 1970s. In 2012, he was part of a team that trialled the efficacy of relaxation gurus in virtual worlds such as Second Life. It turns out that they work, so if the holiday season gets too much, go online and find a relaxation tool for your phone to help you cope. Christmas? There’s an app for that. › Robert Webb: Peep Show has taught me we need to let women be idiots, too Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise. Subscribe This article first appeared in the 19 December 2014 issue of the New Statesman, Christmas Issue 2014 More Related articles Is air pollution damaging your mental health? The best days of the internet are over – now our privacy will suffer The Monzo question: should you ditch the high street and do all your banking on your phone?