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Have you noticed joint aches and pains are worse during the winter months? Or how many niggling health complaints can fade or even completely disappear when the sun shines?

New research has discovered not only can the climate affect the amount of inflammatory chemicals travelling around your bloodstream, but it can also alter the way in which your DNA directs your body’s processes, including your immune system.

What is inflammation?

Inflammation is a necessary and helpful response by your body to injury and trauma. Think about a sprained ankle – it will become hot, red and swollen, blood will rush to the area, infection-fighting white blood cells will be sent to assist, and the process of healing will begin.

After a while, when the infection or trauma is resolved, the inflammation will die down. The body directs this process by means of several chemical messengers which travel around the body to where they’re needed.

However, problems occur when the body is in a state of constant and ongoing inflammation. Inflammatory messengers become numerous and tissues can be damaged. In fact, inflammation is now thought to be behind the development of most, if not all, chronic diseases and health conditions.

The weather and inflammation

The belief that aches and pains become worse in damp, winter weather is embedded in folklore (1). Some people even say they can predict the weather by how their joints feel.

Scientists in the UK have researched this phenomenon and discovered the connection between pain and weather is not all in the mind. They found that pain connected with inflammation increases when the weather is mild and humid.

Researchers used smartphone apps to track 2500 volunteers’ perceptions of pain for between one and 15 months. The pain suffered was from arthritis, fibromyalgia, migraine and neuralgia or nerve pain. This data of over 5 million pain reports was then compared with weather reports in the region where the user was on those days (2).

Specifically, damp and windy days with low pressure meant the volunteers were significantly more likely to experience pain. Pain was also worse on cold, damp days but it appeared to be the dampness rather than the temperature that had the greatest effect.

DNA and gene expression

We are all born with DNA inherited from our parents. DNA can be thought of as the instruction manual for your body, containing all the instructions on how you operate.

image of DNA and gene expression

(Image credit: News Medical Life Sciences)

DNA is found in every single cell of your body and contains many thousands of genes, which tell cells how to behave. For example, genes instruct an immune cell to behave like an immune cell. They also direct the functioning of proteins and enzymes throughout the body; enzymes are types of proteins which speed up the rate of chemical reactions within cells.

For many years it was thought we were at the mercy of our genetic inheritance, and the way genes directed our cells to behave was fixed throughout our life. However, new research into genetics has discovered outside influences can switch genes on and off as well as change the way they instruct cells to behave. This is known as gene expression, and it allows your DNA to respond to the environment.

We know there are several factors which can influence genes in this way, including food choices, stress levels and sleeping habits. But it now seems the changing of the seasons affects gene expression too.

The seasonality of genetics

In one study, scientists looked at thousands of blood samples of people from different countries, with diverse climates and seasons such as Germany, Australia, UK and the Gambia.

They identified over 5000 genes – 23% of those examined – which showed some sort of changes according to the season (3). These genes were primarily concerned with controlling inflammation.

In the winter, your genes change shape – they uncoil a little, and this means their genetic code is read slightly differently. The result is an increase in T-cells, white blood cells belonging to the immune system and providing part of your defence against infection. Scientists also noted an increase in inflammatory messenger chemicals. This means there are more immune cells in the blood in the winter than in the summer, creating a propensity towards increased inflammation.

So your body’s chemistry actually changes according to the season. In other words, during winter, the thresholds needed to trigger an immune response are lower than in the summer.

This makes sense, because in the winter we’re more susceptible to issues the immune system needs to protect us from. We’ve evolved with the bacteria and viruses which are more numerous at this time of the year. Interestingly, the blood samples from people living in the Gambia, where there’s no winter as such, showed increased inflammatory changes in the wet season, when diseases like malaria become more commonplace.

At the moment, science is not clear whether it’s the temperature, day length, lack of sunlight or food choices which are producing this effect, but it’s likely to be a combination of all these factors.

Inflammation and the seasons

In the modern indoor lifestyle, having a heightened level of inflammation and a super-primed immune system in the winter can be a problem, as it may predispose us towards auto-immune diseases, arthritis or cardiovascular events. Statistics reveal a higher incidence of these health issues during the winter.

For example, the likelihood of the inflammatory autoimmune disease rheumatoid arthritis progressing, is related to the season when the symptoms were first noted (4). Other autoimmune diseases such as Type 1 diabetes have seasonal trends in diagnosis.

This emphasises the importance of paying attention to lifestyle factors such as adequate exercise, sufficient sleep and eating plenty of colourful plant-based foods to counter inflammation, particularly in the winter.

A word about vitamin D

Vitamin D is important for immune function and to control inflammation. Deficiencies in this vitamin are linked with increased susceptibility to infection and with more frequent autoimmune diseases.

Receptors for vitamin D throughout the body can regulate genes which control the function of the immune system.

Although you can obtain some vitamin D from food, such as from fatty fish and eggs, the majority is made from exposure to sunlight. We know vitamin D levels are naturally lower during the winter, especially in late winter, when body stores will have been depleted and not replenished by sunshine (5).

It’s a good idea to take a supplement of vitamin D, especially in the winter months – it’s estimated at least one in five of us are deficient.

Takeaway

If you’ve noticed your joints ache a bit more, or your autoimmune disease flares up more frequently in the winter, then it seems you are not alone. Changes in your gene expression mean your body is wired to respond differently in winter than in summer. So, increasing your consumption of immune-supporting and anti-inflammatory plant-based foods is especially important at these times of the year.

If you would like one-to-one support on your journey towards optimal year round health, a consultation with an Amchara Personalised Health practitioner can support you every step of the way.

We’re dedicated to providing you with insightful information and evidence-based content, all orientated towards the Personalised Health approach.

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