The Science of Skincare - Cleansers

Updated: May 4, 2020

This is where all skincare begins. On the outside anyway. Cleansing is responsible for removing dirt, makeup, sweat, pollution, and so much more that can clog pores, cause irritations and reactions, free radical damage, and premature aging. It prepares skin for absorbing ingredients from what we layer subsequently. But, this process can be harsh and disrupt the skin’s natural acid mantle, so the avoidance of this is exactly what we will be discussing today.

In the 1920s, German physicians Marchionini and Shahde identified the acidity of the skin and its hydrolipid film - a protective, slightly acidic film which acts as the barrier between you and the world, sitting on the outermost layer of the skin called the stratum corneum. If this barrier is removed:

  1. There is little to protect your skin from bacteria, pollutants, and chemicals, and your skin becomes more permeable to these things.

  2. Water is also able to leave your skin more easily, leading to dehydrated skin.

  3. Your skin is defenseless, easily aggravated, and this gives rise to irritations, acne, free radical damage, excess oil production, excess enzyme activity

Our skin naturally sits at a pH level of 4.5 - 6.5 - slightly acidic, and this is a perfect environment for the growth of our skin's bacterial flora which is necessary for skin health. This pH is also essential for the proper functioning of our skin's enzymes which help seal in hydration and exfoliate dead skin cells. Additionally, a slightly acidic stratum corneum is essential for the optimal functioning of the bactericidal qualities of our hydrolipid film. Bacteria have a hard time living there, and a shift in its natural pH predisposes the skin to inflammatory and infectious dermatoses, including acne vulgaris.

pH stands for potential of hydrogen, and only aqueous solutions, or solutions that are soluble in water, have pH values. It is a scale used to rank whether a substance is more acidic or more alkaline/basic based on the amount of hydrogen ion activity in that substance. The scale ranges from 0 to 14 - right in the middle is 7 which is neutral, and water falls into this category, it is neither acidic nor basic. Anything below 7 is acidic, like vinegar which is a 2, and of course the lower the pH, the stronger the acid. Anything above 7 is a base, like bleach, drain cleaner, and ammonia.

The Brownsted Lowry Acid-Base Theory explains that when water mixes with an acidic substance, the acidic substance sheds its hydrogen ions and when an alkaline substance mixes with water it accepts hydrogen ions.

At both ends of the spectrum, the most acidic and most basic substances are capable of doing the most damage to our bodies. Strong Acids are so eager to give off hydrogen ions and strong bases are so eager to accept them, that this reaction will destroy chemical structures, but in completely different ways.

  • With an acid - the proton donation will change the structure of the protein in our skin, in a process called denaturing. Protein is responsible for giving our skin structure and protection, while elastin and collagen keep our skin flexible. Denatured protein loses its shape and function, so the cells die but don’t disintegrate, and you’re left with a paler colored patch of dead skin. This process is called coagulative necrosis. The dead tissue, called coagulum, prevents the acid from reaching deeper tissues and keeps the burn more superficial.

  • With an alkaline substance, on the other hand, the burn will not create coagulum through coagulative necrosis but instead cause liquefaction - a process by which cells liquefy and dissolve, leaving you with pockets of melted tissue which allows for the chemicals to seep deeper into the skin. This happens because while alkalis denature proteins, they also break down fats in a process called saponification, and since the outermost barrier of cells is composed of fats, their breakdown causes the entire structure to fall apart, making alkali burns much worse than acid burns. 

Using a cleanser that is as close to natural pH is ideal, and reaching this neutral ground will solve a whole host of skin issues. So how do you find out if your skin is more alkaline or more acidic right now based on your health and the products you’re using?

  • If your skin is too acidic, it will feel consistently oily, it will quickly feel greasy with moisturizer, prone to irritation, sensitive to products.

  • Skin that is too alkaline tends to feel tight, you’ll feel the need to moisturize multiple times a day, it tends to feel scaly and look dull, with more fine lines and wrinkles, and can sting when products are applied.

So our job is to move away from being too acidic or too alkaline and come within the 4.5-6.5 normal skin pH.

There are 2 types of cleansers you can use - water-soluble, or oil-soluble. Water-soluble means they dissolve in water, while oil-soluble cleansers are not able to do so - notice how in mixing oil and water there is always a separation!

Remember, we discussed the acid-base theory earlier and said that when water mixes with either of those, it either accepts or donates a hydrogen ion or one charge unit. This happens because water is a polar molecule, meaning one side of the molecule has a positive charge and the other has a negative charge, like a battery, and water wants to become a non-polar molecule, in that its charges are balanced. Like dissolves like, so polar, imbalanced molecules will mix with other polar molecules, to find balance. And non-polar molecules will mix with others bc they do not disturb each other.

Applying this to your skin -

  • Water-soluble cleansers will mix with the acidity of your skin and disturb its natural state because these are polar, imbalanced, and looking to exchange their hydrogen ions with another substance.

  • Oil-soluble cleansers will not disturb the acidity of your skin, because remember that only water-soluble solutions have pHs, therefore oil has no pH to disturb your skin with in the first place. The only pH you would expose your skin to is the water you wash the oil off with. And these work on the idea above of like attracts like. The oil will attract and dissolve your natural oils, the ones that stick onto grime and dirt from our environment, and can be pore-clogging so that you can wash them away. Makeup contains oil too, so oil-soluble cleansers will break down your makeup and make it easier to remove.

My recommendation is to take a look at the pH and ingredients in the cleansers that you are currently using and understand how they leave your skin feeling.

  • If they are leaving your skin feeling dry and tight - chances are they are too alkaline. You might also notice that after this dry/tight feeling your skin starts overproducing oil, and your acne flares up - this is still because your skincare is too alkaline. after all, your body is OVER producing oil to try and moisturize itself, and this oil is clogging your pores leading to acne.

  • If on the other hand, you find your skin is constantly red, inflamed, and irritated, feels greasy and oily despite cleansing - chances are your skincare is too acidic and is stripping your skin of its pH balance.

What I do at night to wash my skin is start with a makeup wipe - any brand will work sufficiently enough to at least remove some surface debris, it doesn’t have to do too thorough of a job since this is only the first step of our process. 

Then, I go in with an oil cleanser. My favorite one on the market is the Tatcha camellia cleansing oil.

  • I love using Camellia Oil (1) because it is suitable for sensitive skin, meaning it really could work for anyone. Camellia oil is rich in oleic acid and is a source of Omegas 3,6,9, and Vitamins A, B, D, E. The Tatcha cleanser mixes this oil with Uji green tea which is a powerful antioxidant to prevent premature aging, Mozuku Algae which helps the skin retain water, and Akita rice which is rich in essential proteins. (You could also use pure Camellia oil, found at any whole foods store or Amazon.

However, if you have specific skin concerns here are some other recommendations:

  • For oily skin - grapeseed (1) or pumpkin seed oil (2)

  • For acne-prone skin - jojoba (2), hemp seed (0), rosehip seed (1) or castor oil (1)

  • For dry skin - avocado (3), extra virgin olive (2), or almond oil (2).

  • Universally flattering - argan oil (0)

You may be wondering why I've included numbers adjacent to the oil names. These are rankings of each oil on the comedogenic scale - which is a system of ranking how likely it is that the ingredient will clog pores, on a scale of 0-5. 0 won’t clog pores at all, 1 has a very low likelihood, 2 is moderately low, 3 is moderate, 4 is fairly high, and 5 is a high likelihood of clogging pores.

People often use Coconut oil on their faces out of convenience but this ranks at a 4 on the comedogenic scale and is, therefore, a terrible idea if you are suffering from clogged pores or acne.

What I do with the oil is massage it onto my dry, just wiped skin (sometimes even non-wiped skin), without wetting my face or hands beforehand. I massage the oil over my face first and lastly over my eyes until I feel that everything on my skin has been adequately loosened from the surface. Then, I either wet my hands and massage my face one more time to turn the oil to a milky consistency before washing it all away, OR I give myself a small spa experience - I run hot water over a face cloth until I can see the cloth steaming. After wringing out as much of the water as possible, before the towel cools down, I tilt my head back and lay the towel over my face and press down to allow the heat to soothe my facial muscles and open my pores. Once the towel feels cool to the touch I wipe my face with it and finish with a splash of water to remove anything that remains.

Lastly, I go in really quickly with a water-soluble cleanser, just to be thorough. The way I see it, the makeup wipe has dusted away the real surface debris, the oil has then gone and cleansed whatever other debris was sitting on my face, but my SKIN underneath all that has not been treated - so this last step is to really cleanse your actual skin and not just move around all the things sitting on the surface.

I use the Drunk Elephant Juju Bar religiously - this bar is made up of thermal mud to tone and detox the skin, and bamboo powder for a soft exfoliation. The bar is fragrance-free, soap-free, vegan, and formulated with a pH of 6.3 so it is neither overly drying, nor overly stripping of the skin's natural protective acidity. It is a perfect way to end your day and prep your skin to absorb all the treatments you apply to it afterward, now that it is not only properly cleansed, but also exfoliated away of dead skin cells and open to accept any healing ingredients that follow. When people think of exfoliation they think it has to be rough and abrasive but your skin is fragile and doesn't like to be disturbed - a pretty good rule of thumb is that if YOU can feel harsh exfoliation, your SKIN is experiencing it 1000 fold with micro-tears that you cannot even see. but that is all for another post.

I'm going to leave it here for today, hopefully, this post brought you some insight on how your skincare may be benefitting or harming you, starting at the very first step. I admit the process I follow is thorough and sometimes tedious, but it has proven to keep my immensely sensitive skin calm and irritation-free, so I swear by it. Experiment with your routine rather than with too many products, and find out what works for you!

Disclaimer: This content is strictly the opinion of Dr. Mashal Khan and is for informational and educational purposes only.The information discussed is not intended to diagnose, treat, cure or prevent any specific disease or medical condition. It should not be used for or in the place of medical advice or treatment from a personal physician. All viewers of this content, especially those taking prescription or over-the-counter medications, are advised to consult their physicians before beginning any nutrition, supplement or lifestyle program and with specific health questions. Neither Dr. Khan nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content.

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