Evidence Is Conflicting and We Simply Cannot Say
The Essential Info
Researchers have performed over a dozen studies that look at which season is worst for acne. The results of these studies are conflicting, and the answer is not yet definitive.
- Some studies show acne worsening in the summer
- Some show acne worsening in the winter
- Some studies show no seasonal pattern
Sometimes this is how it goes in science. You just gotta wait for more evidence to trickle in. Read the full article below if you’re curious about the hypotheses that scientists have put forward for why acne might worsen in the summer or the winter. But keep in mind as you read that nobody knows the real answer to this question.
- Study Limitations Make It Hard to Draw a Conclusion
- Why Acne Might Worsen During Summer
- Why Acne Might Improve During Winter
- Arguments Why Acne Might Improve During Summer
Study results on what season tends to coincide with more acne are a mixed bag:
- Five studies conclude that acne worsens during summer and improves in the winter1-5
- Four studies conclude the opposite–that acne worsens during winter and improves in the summer6-9
- Five studies conclude that there is no association between seasons and acne10-14
So, as we can see, it’s too early to confidently confirm any answer to which season is worst for acne.
Expand to read details of studies that show that acne may worsen in the summer
Expand to read details of studies that show that acne may worsen in the winter
Expand to read details of studies that show no association between seasons and acne
Study Limitations Make It Hard to Draw a Conclusion
The various studies listed above used participants with different genders, ages, and geographical locations. This variety makes it impossible to effectively compare the research in order to draw conclusions about which season is worst for acne. Therefore, we will need more carefully controlled research with what is called a “standard research population” in order to determine if acne worsens during a particular season.
If acne does in fact get worse in the summer or winter, why might this be so? Let’s start with arguments why acne might worsen during summer and improve during winter.
Why Acne Might Worsen During Summer
Summer tends to bring higher temperatures and increased humidity, so these are the two main suspects. Specifically, scientists speculate that humidity might increase acne by:
- Bacterial imbalance: Humidity might disturb the balance of bacteria in the skin, allowing acne bacteria to overgrow and making breakouts more likely.
- A weaker skin barrier: The skin barrier is the outer layer of skin which protects the deeper layers of skin from damage. Some evidence hints that humidity might weaken the barrier, making the skin more prone to breakouts.
- More sweat: When the air is humid, sweat evaporates more slowly and ends up staying on the skin. Although sweat by itself doesn’t cause acne, if your skin is already physically irritated (such as from rubbing or scratching), sweat can make this worse and potentially trigger more acne.15-18
- More chance of sunburn: The summer sun can cause sunburn unless the skin is properly protected with sunscreen or clothing. Sunburn is a type of skin irritation, and as the skin heals up from a burn, it often bites back with acne breakouts.
Why Acne Might Improve During Winter
Winter is typically a time of lower air temperatures, lower humidity, and less intense sunshine (although this will depend on your geographical location). Therefore, we might expect the opposite effects on the skin from what we see in the summer:
- Less bacterial imbalance: A balance of skin bacteria means that acne bacteria don’t have a chance to overgrow.
- A stronger skin barrier: A healthy skin barrier means the skin is less prone to breakouts.
- Less sweat: While sweat itself is not an acne trigger, sweat combined with skin irritation can spell more acne. Therefore, less sweating might potentially mean fewer breakouts as well.
- Less chance of sunburn: As we have seen, a sunburn leaves the skin irritated and susceptible to breakouts, so the less likely a sunburn is, the better for acne-prone skin.
However, as we have seen, some research finds the opposite, that acne might actually worsen in the winter and improve in the summer. Next, let’s look at the arguments why acne might worsen during winter and improve during summer. As you will see, there are still some puzzling inconsistencies.
Why Acne Might Worsen During Winter
- Skin hydration: To identify what might be the culprit in winter acne, scientists performed four studies between 2014 and 2015 and concluded that it may stem from changes in skin hydration. More specifically, patients in all four studies experienced a decrease in skin hydration during the winter season. Skin hydration is crucial for maintaining the healthy skin barrier, which is important in managing acne.13,19-22
- A weaker skin barrier: Additional research on the skin barrier function during winter has found one particular component of the skin barrier called ceramides, which can affect acne severity. Ceramides are found within skin cells and support the skin barrier function. Research has identified that acne patients typically possess lower levels of ceramides than patients with healthy skin, and that the levels of ceramides decrease during the winter season. In addition, research has shown that inside clogged pores is an imbalance of ceramides and other fats. This has led scientists to believe that a decrease in ceramides may partly explain the observation that in some people, acne worsens during the winter season.23-27
Arguments Why Acne Might Improve During Summer
Scientists have concluded in four separate studies that the UV radiation from the sun may explain acne clearing in some people during the summer months, specifically by:
- Decreasing inflammation: Research has shown that UV radiation may act as an anti-inflammatory agent. As inflammation is a major contributing factor to acne development, the researchers believe that UV light may decrease inflammation and help clear acne.
- Decreased acne bacteria: Additional research has shown that UV light may also help to reduce levels of the bacteria associated with acne called C. acnes.
The combination of anti-inflammatory light and a reduction in C. acnes could explain the observations that acne sometimes clears during the summer season. However, we will need more research to confirm these preliminary findings.1,6,27-29
There is not yet enough evidence to support the idea that acne worsens during a particular season. Scientists will need to perform more rigorous and controlled research before we can conclude anything definitively.
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