How the 4 Seasons Affect our Metabolism
A lot of attention can be paid to the external affects the seasons can have on our bodies – our skin can feel drier or oilier, our hair can be drier or oilier, our predominant mood can change, our skin can be darker or lighter, and our waistlines can get larger or smaller. While some of these seasonal changes can be short and directly attributed to particular events (I’m thinking of you Christmas and my array of elastic waisted Boxing Day outfits!) the rest of these changes have a lot to do with our metabolism. We don’t always realise it but the changing seasons can affect us just as much as they affect the beautiful deciduous trees around our region, so as we head into a new season let’s take a look at this phenomenon a little…
Did you know that we develop a higher level of insulin resistance in winter1? Like other animals our body naturally adopts a higher insulin resistance to allow our bodies to be more fuel efficient and go for a longer period without food as food is generally more scarce in winter…or at least it used to be prior to modern day supermarkets! On an evoloutionary level our bodies are still very much in a pre-supermarket and even pre-farming timeframe. This natural occurrence happens within the body’s of all vertebrates over the colder months of the years and can make it that little bit easier to gain a little ‘winter weight’ if we don’t pay close attention to our food intake and activity levels. For many of us this annual cycle of insulin resistance reverses back to an insulin-sensitive state around late winter/early spring to get ready for summer and an abundance of food.
We now understand better that our Central Nervous System is in command and control of our peripheral fuel metabolism functions, such as liver glucose and lipid metabolism, adipose metabolism, muscle physiology, pancreatic insulin and glucagon secretion, as well as cardiovascular biology writes Betul Hatipoglu MD and it’s our fuel metabolism functions that determine how our body stores fuel. Interestingly, mainstream medical professionals are becoming more and more aware of the role the Central Nervous System (CNS) plays in maintaining a healthy and well-functioning body, something that Chiropractors have been communicating for the past 100 years. What needs to be understood here is that our metabolism itself isn’t truly slowing down, our body is processing things differently as a result of environmental changes.
While most people would tend to think our metabolism slows in colder weather, this technically isn’t true. Our Basal Metabolic Rate (BMR) usually stays on a pretty level plane thanks to the natural wisdom of our bodies intelligence. If anything, short bursts of cold will temporarily increase our BMR as our body works to warm us up. In summer our body will naturally try to slow down and conserve energy. The key thing to realise during summer and adjust is our hydration levels. While the soaring temperatures on their own won’t make a big difference, becoming dehydrated WILL make a difference2 and result in a slowing of the metabolism and general lethargy as well as possible headaches, fatigue, increased blood pressure, double vision, fainting….in fact a long list of possible negative side effects.
A recent Belgian study has found that the way our brains use energy and process mental tasks changes with the 4 seasons as well. The study took 28 adults being locked in a lab for 4 and a half days during each season and they were asked to complete a series of tests. Their test scores did not change at different times of the year, however the neural “cost” of that performance differed. In the summer, brain activity peaked on the attention tasks. During the winter, they used significantly less brain activity involved in attention. On the memory task, brain activity peaked in autumn and hit a low in the spring. So this is the first indication that brain activity levels can be seasonal as much as our levels of immunity and predominant moods are known to be3.
So, what are the key take away points here? The heading is really a little deceiving isn’t it? Because as we have discussed our BMR tends to stay pretty uniform throughout the year, however the way our body uses and stores fuel changes innately with the seasonal changes, and new science is also telling us that the way our brain functions changes with the seasons as well. Considering our brain and CNS are in control of every process within our bodies perhaps this new science isn’t too surprising, yet it certainly could change the way we look at and interact with the world around us in winter Vs summer or autumn Vs Spring. And this being the case, we need to put things into our body that will be beneficial for the seasons, so hydrating more in summer than in winter, eating fresh seasonal produce and eating bigger meals 3 times a day in winter while smaller more regular meals can help keep us ticking along when it’s warmer. As it turns out, the different seasons affect us in so many more ways than just the depth of our tan!