Water. We know that it is vital for our health and wellbeing. Doctors have been telling us for decades about the importance of drinking enough water throughout the day. We know that adequate hydration promotes optimal organ health, kidney function, good digestion and healthier skin. However, did you know that water is also crucial for good spine health? When you don’t drink enough water and become even mildly dehydrated, it can cause impairments in your spine, some of which are painful.
Firstly, we need to understand how the spine is constructed in order to understand the importance of good hydration. Our spine is a column made up of vertebra that are connected to each other by small joints. Between each vertebra is a fluid-filled disc. These discs act like shock absorbers. They cushion the vertebra so that they don’t rub against each other, provide flexibility to the spine and enable the spine to support weight. Each disc is made up of two parts. The centre of the disc is called the nucleus pulposis and is what protects the bones. The tough outer ring is called the annulus fibrosis and this protects the disc.
How Does Dehydration Cause Back Pain?
The spinal discs consist of up to 85% water. Most of this water is found in the nucleus pulposis. The high water content of the discs is what makes them capable of shock absorption. When you are sitting, standing, running, jumping etc., the discs absorb the shock caused by these movements and are compressed. This causes some of the water to be squeezed out of the disc. Research has shown that spinal discs in the lumbar spine (lower back) lose around 20% of water throughout the day. If you were to measure your height at the beginning of the day and then again at the of the day, you’d notice that you may lose around 2-3cm in height strictly due to the discs being compressed. At the end of the day when you lie down, most of the load on the discs is removed and water slowly flows back into them. For this to happen, however, the body has to be adequately hydrated. It is important to continuously rehydrate the spinal discs in order to provide adequate cushion to the spine. This significantly lowers the risk of deterioration and spinal injury/pain.
If the body is dehydrated it will not be able to replenish the disc with enough water. This will cause the disc to remain compressed and compromises its ability to adequately cushion and support the spine, making it is less flexible and more susceptible to injury. If the discs do not contain enough water, they can no longer function properly. This can increase the risk of spinal degeneration, osteoarthritis, disc injuries and muscular injuries.
How Much Water Should You Drink?
It is advised that men should drink 3-4L of water daily while women should be drinking 2-3L of water daily. However, these numbers are variable. How much water you should drink depends entirely on your activity levels during the day and how much you weigh. A good measure to start with is to drink 1 cup of water for every 9kgs of bodyweight. So an 80kg person who doesn’t exercise or live in a hot climate should be drinking about 9 cups of water daily. This should increase if the weather is hot or they are physically active.
The water content found in tea or coffee is not hydrating. The caffeine in these products do the opposite and will dehydrate you. The same goes for soft-drinks as they are filled with artificial sweeteners and caffeine.
Some people wait until they feel thirsty to drink, but we encourage you to drink consistently before this sensation kicks in for optimal maintenance.
Written by Nicholas Dimos (Physiotherapist)