Almost 20 years ago, scientist Christopher P. Wild coined a term that would change the way we came to think about our health overall: the exposome. This groundbreaking idea refers to the sum of all the factors we’re exposed to daily and how they influence our bodies. It revolutionized science’s understanding of chronic diseases, revealing that almost 75% of their origin could be linked to interactions with our environment.
But how does this idea relate to your skin? The exposome has been gaining traction in multiple medical fields, especially dermatology. And at ISDIN, it’s a concept we hold near and dear to our innovative process.
Today, we dive into a conversation with renowned dermatologist Susana Puig Sardà, who, in collaboration with the International School of Derma (ISD), is leading one of the first global studies exploring how these environmental and lifestyle factors affect skin health.
Read on and find out how your skin mirrors the world around you and how you can better care for it.
Dr. Susana Puig
Head of Dermatology at Hospital Clínic Barcelona and Director of the UB-ISD Dermatological Innovation Chair
What is the exposome?
In the words of Dr. Puig, “The exposome is everything that influences our body that isn’t genetic. It’s all of the things that aren’t already defined by our DNA.” Think about the hundreds of little choices you make each day: what you eat, how many hours you sleep, or the amount of sun you get. Your lifestyle and the exposome are deeply interconnected.
For her, “the exposome factors are all intertwined — interacting, enhancing, or counteracting each other.” That’s why a holistic approach to healthcare, including skincare, is so important.
How does it affect your skin?
Dr. Puig reveals that, although our genetics set the foundation, it’s the external factors — such as sun exposure, pollution, diet, and stress — that shape how those genes are expressed.
This means that our lifestyle choices, as well as the environmental influences we’re subjected to, might have a much greater impact on our skin than we realize. Science has shown that environmental and lifestyle factors contribute to 80% of the visible signs of skin aging, and genetics only 20%.
Science has shown that environmental and lifestyle factors contribute to 80% of the visible signs of skin aging, and genetics only 20%.
But stalling the signs of aging isn’t the top priority. While on the subject of skin health, we also have to discuss the most common type of cancer in the U.S. “Although solar radiation is the most well-known risk factor for skin cancer, a growing body of evidence suggests that other exposome factors may also contribute,” Dr. Puig explains. The variables in play? “Dietary factors and even pollution.”
Fortunately, this means that there are more things in your control — more ways you can protect yourself and your skin every day. And learning about the exposome is the first step.
The main factors of the skin exposome
The seven factors that make up the skin exposome are solar radiation, smoking, pollution, diet, stress, sleep, and climate. And each plays its own role in your skin’s health and appearance:
Let’s see how each of them affects our skin and how we can fight back.
1. Sun exposure
How does the sun affect your skin? The solar spectrum is made up of different kinds of radiation which are grouped by their electromagnetic frequencies. And some of them affect your skin more than others, especially ultraviolet A radiation (UVA) and ultraviolet B radiation (UVB). The sun’s UVB rays cause sunburns and cumulative damage, while UVA rays penetrate even deeper into the skin and contribute to long-term health risks and photoaging.
Keep in mind that solar radiation isn’t just a seasonal concern. We’re still exposed to both types of radiation even on cloudy days. Additionally, UVA rays can pass through glass windows, meaning they can reach your skin while driving or sitting in your office.
What you can do:
Aim to use sunscreen every single day. Emphasizing the importance of daily protection, Dr. Puig says, “It’s the best strategy to help prevent skin aging, skin damage such as actinic keratosis, and skin cancer in general (melanoma in particular).” And that includes wearing a hat, using protective clothing, and seeking shade when the sun’s at its strongest.
Another point Dr. Puig is adamant about is that everyone should be wearing sunscreen. “All skin tones can benefit from UVA protection to help prevent skin aging, and lighter skin tones need more UVB protection to help combat sunburns and a higher risk of skin cancer,” she shares.
Get into the daily routine of applying a high SPF, broad spectrum facial sunscreen — meaning the formula protects against both UVA and UVB radiation.
Learn more about the sun and your skin
2. Smoking
Tobacco smoke contains more than 3,800 different harmful chemicals: nicotine, carbon monoxide, tar, ammonia — the list goes on. But what exactly do these toxins do to your skin, and why do they have such negative effects?
The primary culprit is oxidative stress. When you smoke, the toxins in cigarette smoke can trigger this bodily process and damage your skin cells. This series of events can cause inflammation and break down collagen, a protein essential for skin elasticity. The overall result? Wrinkles, sagging, and a dull complexion. And the more you smoke, the more it can leave a mark — studies show a clear connection between the number of cigarettes smoked and the severity of these signs.
But aging isn’t the main concern. Smoking constricts blood vessels, reducing blood flow to your skin. This can lead to a decrease in oxygen and nutrients, further contributing to damage. In her research, Dr. Puig also highlights the relationship between smoking and other skin health risks, such as keratoses and certain types of skin cancers.
What you can do:
We aren’t here to judge. But when it comes to improving your skin’s appearance and your overall health, quitting smoking is the way to go. And the sooner the better — research shows that stopping won’t automatically reverse the signs of aging. However, it’s never too late to start taking care of your skin.
3. Pollution
Sitting in traffic. Taking a stroll around the city. All of us are exposed to some level of pollution every day. Thankfully, your skin acts as a first layer of defense. But how does the pollution caused by smog, particulates, and other chemicals affect it?
First off, pollution microparticles suspended in the air around you adhere to your skin. Over time, this can cause cell damage via oxidative stress and lead to wrinkles or uneven pigmentation. The science shows that pollution, especially particulate matter, is a major cause of dark spots.
Another type of pollution to consider? Ozone. Dr. Puig’s research shows that high ozone levels (gases that are great at protecting the planet but harmful to your skin) can deplete the skin’s supply of vitamins C and E. The result? Again, oxidative stress and potential long-term damage.
What you can do:
The most important place to start? Washing your face. Cleanse your skin daily, especially at night, to get rid of any pollution particles sticking around. And it’s all the better if your cleanser contains some of the vitamins (like C and E) that pollution can zap from your skin. These nutrients work as antioxidants to help combat oxidative damage and its aging effects.
Another strategy? Reinforce your skin’s natural protector: the barrier function. Some studies suggest that skincare formulas that help support the barrier may help prevent pollutants from sinking in. Ingredients to look for include emollients like ceramides and humectants like hyaluronic acid found in targeted moisturizers.
Learn more about pollution and your skin
4. Diet
Food plays a major role in your life, and as it turns out, in your complexion, too. The good news? It’s one of the skin exposome factors in your direct control.
The first place to start — processed foods. Going overboard on fried goodies, sweets, and especially processed meat can be hard on your health and also contribute to the signs of skin aging. These foods can trigger a process called glycation, where certain molecules stick to skin’s proteins, weighing them down and causing sagging.
But there are also plenty of foods that help to keep your skin healthy. Commonly found in your favorite fruits and vegetables, vitamins C and E act like shields to neutralize harmful free radicals caused by the sun and other exposome factors. Niacinamide — a form of vitamin B3 found in fish, eggs, and nuts — takes a different approach. Dr. Puig’s research shows it can help prevent UV-induced immunosuppression, a process that weakens your skin’s natural defense system.
To sum things up? Your skin’s favorite diet is one rich in plant-based foods and healthy fats. One study even found that eating this way could help lower your risk of skin cancer.
What you can do:
A healthy diet can improve your energy level, mood, and body from the inside out — including your skin. So, try stocking up on superfoods, like seasonal fruits and vegetables, and cutting down on refined sugars to both look and feel your best.
5. Stress
Your not-so-favorite emotions such as worry and anxiety will inevitably pop up now and again — they’re simply a part of life. But did you know they can also be reflected in your skin? Stress can bring on some skin conditions such as acne, or worsen symptoms of existing issues such as seborrheic dermatitis or eczema. Science also suggests that chronic stress can contribute to your skin’s natural aging process.
Here’s how it works: When you’re stressed, your body releases certain hormones. That’s where cortisol comes in. Cortisol is one of the main hormones produced in response to stress.
While occasional stress can actually help your body to repair itself, high cortisol levels can dampen your immune system over time, causing inflammation, increasing oxidation, and impairing your skin’s barrier function. The result? Sustained stress may lead to skin discoloration, dehydration, sagging, and fine lines.
How to fight back:
Take this as a sign to slow down. We know, easier said than done — but one of the best things you can do for your health (skin and otherwise) is to recharge your batteries. Make time for yourself with a few minutes each day to move your body or do something that brings you joy. Or carve out a quick self-care moment by turning your evening skincare routine into a calming ritual.
Learn more about stress and your skin
6. Sleep
Ever wondered why your skin actually looks tired after a few nights of poor sleep? At night, the skin conducts a natural repairing activity to try to reverse any damage suffered during the day. And when you skimp on sleep, this process is disrupted.
The outcome? A weakened skin barrier, increased sensitivity, and a dull, tired complexion. Science has shown that lack of sleep can even accelerate the signs of aging, such as wrinkles and fine lines. In fact, one study showed that participants who slept less than five hours a night noted increased signs of aging, diminished skin barrier function, and lower satisfaction with how their skin looked.
But it’s not all about appearance. Getting some rest helps your body produces hormones, such as melatonin, that help to protect it from damage. This means a good night’s sleep can help keep your skin healthy and hydrated.
What you can do:
Your skin is more permeable at night — meaning it’s also more receptive to skincare products. Try introducing antioxidant melatonin and renewing retinal into your nightly routine.
7. Climate
Your skin is the first barrier between you and the world. So, it makes sense that certain changes in the weather can affect it. Two seasonal factors make the most impact: temperature and humidity.
First off, warmer weather can play a role in various skin conditions, such as psoriasis. Why? When the temperature climbs, moisture evaporates more quickly, leaving the skin dry and stressed.
But above-average temperatures shouldn’t take all the heat. Eczema, an inflammatory skin condition, often flares up in fall and winter. How come? Cooler temperatures and lower humidity can also lead to dehydration, leaving the protective skin barrier vulnerable. And even if you don’t normally experience sensitivity or dryness, winter weather can still be harsh on your skin.
What you can do:
Get proactive with your skincare routine. Much like with the other exposome factors, do your best to properly cleanse, hydrate, and protect your skin. And just for good measure, here’s our favorite reminder: wear sunscreen every day, no matter the weather.
It’s all connected
Remember the words of Dr. Puig, “The exposome factors are all intertwined — interacting, enhancing, or counteracting each other.” That’s why taking care of your skin means much more than a simple product regimen — it means taking care of yourself.
Her expert advice? Focus on improving your daily experience with lifestyle exposome factors such as sleep, stress, and diet to prioritize your overall well-being. Then, do your best to protect your skin against environmental factors like the sun, pollution, and extreme weather. Healthy, happy, beautiful skin to follow.
References:
Molina-García M, Granger C, Trullàs C, Puig S. Exposome and Skin: Part 1. Bibliometric Analysis and Review of the Impact of Exposome Approaches on Dermatology. Dermatol Ther (Heidelb). 2022 Feb;12(2):345-359. doi: 10.1007/s13555-021-00680-z. Epub 2022 Feb 3. PMID: 35112325; PMCID: PMC8850514.Molina-García M, Malvehy J, Granger C, Garre A, Trullàs C, Puig S. Exposome and Skin. Part 2. The Influential Role of the Exposome, Beyond UVR, in Actinic Keratosis, Bowen's Disease and Squamous Cell Carcinoma: A Proposal. Dermatol Ther (Heidelb). 2022 Feb;12(2):361-380. doi: 10.1007/s13555-021-00644-3. Epub 2022 Feb 3. PMID: 35112326; PMCID: PMC8850498.
Krutmann, J., et al. (2017). The skin aging exposome. Journal of Dermatological Science, 95(3), 167-175. Krutmann, J., et al. (2017). https://www.jdsjournal.com/article/S0923-1811(16)30816-7/pdf
Khmaladze I, Leonardi M, Fabre S, Messaraa C, Mavon A. The Skin Interactome: A Holistic "Genome-Microbiome-Exposome" Approach to Understand and Modulate Skin Health and Aging. Clin Cosmet Investig Dermatol. 2020 Dec 24;13:1021-1040. doi: 10.2147/CCID.S239367
Lim, S. J., et al. (2021). Skin exposome science in practice: Current evidence on hair biomonitoring and future perspectives. ResearchGate.
Côte d'Azur University. (n.d.). Clinical and biological impact of the exposome on the skin.