April is the month when you can feel the soft spring breeze on your cheeks and when the grass and trees begin to sprout. It is a time when your life and rhythm change drastically, both in your private and public life, with new school years, new jobs, and personnel transfers. Although spring is in full swing, there is a lot of pollen and yellow sand flying around, and along with the changes in the environment, it can also be said that this is a time when your skin condition changes. So, how will you spend this April?
April. What are the environmental stresses unique to the start of spring?
1. Fluctuations in the external environment (external stress)
Looking back at the weather data for Tokyo last year in 2022, we can see that the weather conditions for the skin in April, when spring was in full swing, were quite variable.
<Temperature stress>
April 2022 saw the highest temperature difference of the year. Temperature differences can cause skin stress and lead to temperature difference allergies and temperature difference fatigue.
<Sunlight stress>
In April 2022, Tokyo saw rainfall on 15 days, half of the 30 days, making it a month with few sunny days for April. As a result, April had relatively few hours of sunshine and total solar radiation, but this is usually a month of sunlight stress similar to May, which records the maximum hours of sunshine in the year. Therefore, even if there is a lot of rain, we recommend that you take measures against sunlight stress.
<Stress caused by airborne particles such as pollen and yellow sand>
Pollen stress peaks around mid-April, but yellow sand also peaks in April and May, so the skin is hit by a double layer of airborne stress. For people who are already suffering from skin problems or troubles due to other factors, the stress caused by these airborne substances will be a further blow to their already sensitive skin.
2. Fluctuations due to changes in daily rhythm (internal stress)
One of the internal stresses unique to April is the change in daily rhythm. For new students and new members of the workforce, commuting to school or work brings about a major change in daily rhythm. Many people will change their bedtime and wake-up times to suit their daily rhythm. For those who have changed jobs or responsibilities due to personnel transfers, they will have to get used to their new workplace and environment, which can be stressful. These changes in daily rhythm can lead to psychological stress and may trigger various skin problems.
Freedom from mask life?
As of March 13th, wearing a mask has become a personal decision. This is the first step towards freedom from three years of wearing a mask, but Japanese people, who tend to be self-conscious of others around them, seem to be finding it difficult to take off their masks. In light of the current spread of COVID-19, perhaps more and more people will gradually take off their masks?
In preparation for being free from masks, let's be conscious of skin care that will condition the skin that tends to become sensitive due to the roughness and humidity caused by masks. Specifically, it is important to "moisturize" and "strengthen the barrier function."
After gentle cleansing and washing your face without over-washing, care for your skin with a highly moisturizing lotion and serum, and finish off with a gel or cream to enhance your skin's barrier function.
About the skin's own "barrier function"
1. Mechanism of barrier function
The barrier function of the skin is provided by two layers: the "stratum corneum" that is the outermost layer of the skin's epidermis, and the "sebum film" that is secreted from the sebaceous glands and covers the stratum corneum. Specifically, it has the following two major functions:
① Protects the skin by blocking external stimuli and stress such as flying particles and ultraviolet rays. ② Prevents moisture loss from the inside of the skin and maintains moisture.
2. Barrier function components of the stratum corneum [NMF]
NMF is a moisturizing ingredient whose main components are amino acids and their derivatives present in keratinocytes, and is known as a natural moisturizing factor. It plays a role in retaining moisture and keeping skin moisturized, but it has been reported that the amount of NMF produced in the human body decreases with age. It has also been confirmed that NMF levels are reduced in people with dry skin or senile xerosis. In that sense, it is clear that it is useful to supplement moisturizing ingredients from the outside with cosmetics.
3. Ceramide: A barrier function component of the stratum corneum
Ceramide, which fills the gaps between keratinocytes in the stratum corneum and binds moisture between the keratinocytes, also functions to maintain moisture and hydration in the stratum corneum, just like NMF. Unfortunately, it is known that ceramide also decreases with age.
NMF in the keratinocytes and ceramide between the keratinocytes work together to maintain the moisture and hydration of the stratum corneum itself while also suppressing moisture evaporation. When these two components decrease and the skin becomes dry, not only is it unable to prevent moisture evaporation, but it also leads to a decrease in the skin's ability to block external stress and protect itself.
4. The skin's final defense: the "sebum film"
The sebum film is a slightly acidic emulsion with a pH of 4 to 6 that is a mixture of sebum secreted from the sebaceous glands, sweat secreted from the sweat glands, decomposition products resulting from turnover (keratin metabolism), and externally attached dust.
Because it covers the surface of the skin, it not only prevents moisture from evaporating from the skin, but because it is weakly acidic, it also inhibits the growth of bacteria and neutralizes acids and alkaline substances that come into contact with the skin, relieving irritation. Because of these roles, the sebum film is described as the "last line of defense for the skin."
On the other hand, too much sebum secretion can have negative effects on the skin, such as stickiness and the tendency for external substances to adhere to the skin. The important thing is to control the amount of sebum on the skin surface by not removing too much sebum when cleansing or washing your face. The amount of sebum secreted is influenced by sex hormones and cannot be controlled by yourself, but it is important to be mindful of not disrupting your overall lifestyle, including your diet!
The skin's barrier function is achieved by three elements: natural moisturizing factors (NMF), ceramides, and the sebum film. Cosmetics such as moisturizing gels, milky lotions, and creams further supplement this barrier function.
"Be careful of environmental fluctuations!" What do you think?
As we move forward with our new lifestyle, it's important to take proper precautions during this season when your skin is prone to sensitivity.
The next topic will be "Skin care in the best season: May."
