The human body is approximately 60% water. When it gets severely dehydrated, all organs and systems begin to shut down.
Every biological function – for example, respiration, blood circulation, digestion, excretion, concentration, memory, metabolism, joint lubrication – depends on a continuous supply of water.
Water plays a part in our metabolism, breaking down fats and converting them to energy. At a time when we’re generally eating more and exercising less, it’s easy to put on weight. In wintertime, it’s particularly important that our metabolism is on form.
For many of us, hydration in wintertime isn’t something we’re inclined to bother too much about. During the warm summer weather, copious sweating and raging thirsts are constant reminders that we need to drink. Shouldn’t we just go by our instincts?
The hypothalamus is a small and vital part of the brain, essential for multiple biological functions, including regulation of water levels.
Detection of a fall in blood volume or blood pressure triggers the release of a hormone called vasopressin, which stimulates the desire to drink. However, in cold weather, when blood flow to the peripheries is restricted in order to boost flow to the core, the body can give a false reading of water levels! With adequate blood volume and pressure in the core, no signal is given for the release of vasopressin, even though the total level of hydration might be under par.
For this reason, the thirst reflex is often suppressed in cold weather.
So, let’s have a look at:
In wintertime, you can’t always rely on an instinct to drink. In fact, it’s thought that the thirst reflex can be suppressed by as much as 40%. Without the desire to drink, it’s easy to become dehydrated.
Therefore, we should maybe look at fluid intake from a more calculated point of view. If we’re aware of how much fluid we need, and what we’re actually consuming, we can contrive to maintain a healthy level of hydration. So, how about a drinking programme …
What? Of course it’s fun!
An hourly drink – of something you like, of course – will not only keep you hydrated, but will also break up the day nicely.
Dietary and medical professionals tell us we should be consuming approximately two litres of water a day. Roughly 20% of this water will be in our food, so the remaining 80% must be consumed in drinks. Even coffee will have an overall positive hydrating effect, as the diuretic properties of caffeine won’t outweigh the hydrating benefits of the fluid.
So, in the wintertime, make drinking a discipline. Keep a cup handy and refill it every hour. Even if you’re not thirsty.
A warming breakfast of porridge will provide you with 200-300 ml of milk or water, or a combination of the two. And how about hot milk on your Weetabix? It’s a whole new taste!
Traditional British winter dishes such as stews and casseroles are characterised by a rich gravy, bulked out by root vegetables; potato, parsnip, carrot, turnip, and swede are all more than 80% water. The water content of soup is also very high. A mixed vegetable soup or a creamy tomato soup provides a huge proportion of your vitamins and fibre, along with a good amount of water.
There’s a lot of water in fresh fruit and vegetables. All of the following foods comprise at least 90% water: swede, grapefruit, radish, watercress, cabbage, cauliflower, tomato, celery, watermelon, cucumber, spinach. Among the diverse vitamins and minerals in these foods, there’s one vitamin that’s present in every one of them. The antioxidant, vitamin C, is great for the immune system, tissue repair, and the production of some neurotransmitters.
All fresh fruit and vegetables contain a large amount of water. Apples, pears, and oranges are about 85% water; grapes are around 82%; and, surprisingly, even bananas are 75% water!
Because 80% of our water intake is through drinking, it’s important to focus on how much we’re drinking and how often.
Some people just love hot drinks and will choose a cup of tea or hot water even in summer. Others prefers a glass of something chilled, and there are some wild thrill-seekers who can’t get enough fizz! Most people mix and match, varying their choice of drink according to the weather, the situation, and the mood of the moment.
In the wintertime, it’s lovely to drink a comforting milky coffee or creamy hot chocolate. Milk is around 87% water, so these drinks will hydrate you – just not as much as an equal volume of watery drink. But if we’re going to drink the recommended two litres every day, it won’t do us any good if our drinks are all loaded with fat and sugar.
Tea contains a lot less caffeine than coffee. But there are also zero-caffeine options, such as boiling water infused with a slice of lemon or a herbal tea.
Herbal tea – also known as a tisane – is an infusion of caffeine-free plant material; it doesn’t have to be a herb, and it doesn’t have to be the cured leaves of Camellia sinensis (tea). The wide variety of infused leaves, roots, flowers, seeds, or fruits offer very diverse flavours and health benefits.
Sparkling water – also known as carbonated water – is just as good for you as still water. In fact, there’s evidence to suggest that it’s even better for the digestive system than still water. Sparkling water adds that extra je ne sais quoi to fruit juice or squash, and by itself, it has the faintly bitter taste of carbonic acid, which many people love.
For some, though, it has to be the delicious tastelessness of pure water.