Posted in January 2012

Jan 31 2012
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Q + A

Is a thicker cream more moisturizing?

The Question

Is a thicker product, like a body butter, more moisturizing?

The Answer

What Are Lotions Anyways…?

Lotions and creams are emulsions, which means that they’re a mix of two or more things that do to not mix. Like water and oil.

Ingredients that dissolve in water, like ascorbic acid (vitamin C) are dissolved in to the water portion of the product and ingredients that dissolve in oil like ceramides are dissolved in to the oil portion. The two are then mixed together with the addition of an emulsifier. An emulsifier is a surfactant, it helps break down the globules of oil and water in to smaller “bubbles” and helps to keep them from seperating.

Early generation creams and lotions actually used traditional saponified oil soap and detergents like sodium lauryl sulfate to keep them emulsified. But this raised problems as detergents like sodium lauryl sulfate are irritants, and traditional saponified oil soap has a high pH.

Emulsifiers are needed in a lotion or cream, usually in small amounts…without them the product would separate!

Now these emulsions (the water and oil mixed with an emulsifier) aren’t very thick, an oil-in-water emulsion (where the oil is inside water bubbles) will have the thickness of milk. A water-in-oil emulsion, mayonaisse is an example, will be thicker, but feel greasy on the skin. Most commercial products these days are oil-in-water emulsions. You can usually tell when a product is a water-in-oil emulsion when the oil is listed higher up than water on the ingredient list. It also won’t “absorb” in to the skin as well as an oil-in-water emulsion.

So in order to make an oil-in-water emulsion product easier to apply, and to create a pleasing texture, thickeners are added . This not only has the benefit of making the product look more like what we’re used to, but it also helps keep the product stable. Emulsions won’t stay mixed forever, making the product thicker makes it harder for the oil and water to break apart.

These thickeners can range from basic things like corn starch to more elegant solutions like carbomer. Carbomer is a powder thickener that turns water in to a thick and clear gel, it was actually designed specifically for cosmetics!

Thickeners are generally used in low amounts, ranging between 0.01% to 1%.

Some thickeners can act as humectants and emollients, like stearic acid, but the majority of the moisturizing effect is going to come from the other ingredients in the product .

A Study Tells Us…

A study actually examined the moisturizing effects of 12 similar moisturizing creams, they were all made exactly the same way except the level of thickener. They wanted to study, empirically, whether or not a thicker cream meant it was more moisturizing.

What they found was that changing the amount of thickener had no effect on how quickly water evaporated from the skin. Interestingly, they also found that people applied a similar amount of product, regardless of how thick or thin it was.

What Does That Mean To Us?

What that means is that you can’t judge whether a product will be moisturizing just because it’s thicker. It’s possible to create a lotion that contains 1% oil that is thicker than a lotion that contains 30% oil.

If you want a more moisturizing product you have to look at the ingredients list on the back, the higher up an oil or other emollient (like dimethicone) or humectant (like glycerin) is on the list the more likely the product will be moisturizing.

Most formulators know that a consumer expects a more moisturizing product when it’s thicker, so they formulate accordingly. So when you buy something that’s thick and creamy, it’s likely that it’s high in moisturizers…but you have to understand that it’s not moisturizing just because it’s thick! Moisturizers generally don’t make a product thick, and thickeners generally don’t make a product moisturizing.

So again, don’t let the thickness fool you! If a runny lotion contains a high amount of oil, it will be more moisturizing than a thick body butter that contains barely any.

 

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Jan 30 2012
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Q + A

What’s a gentle method to exfoliate sensitive skin?

The Question

Can you suggest a safe and gentle method to exfoliate for sensitive skin?

The Answer

Common Exfoliants

Glycolic, lactic and salicylic acid are the most common exfoliants found in products. Glycolic and lactic belong to a family of acids called alpha hydroxy acids, they are water soluble and help dissolve the bonds that keep dead skin cells “glued” to the surface of the skin.

Salicylic acid is part of the beta hydroxy acid family. Beta hydroxy acids are lipid and fat soluble, meaning they can dissolve in to the skin’s sebum, working further in to pores.

Salicylic acid and lactic acid are generally better tolerated by sensitive skin than glycolic acid. However it’s the concentration and pH of the product that matters the most. For a product to be effective the pH just needs to be below the pH of the skin, which is about 6.5. The lower the pH of a product is the more effective it will be at removing dead skin cells, but it will also be more irritating.

A study found that the addition of strontium nitrate reduced the irritation and burning sensation of topically applied exfoliating acids.

Poly-hydroxy Acids

Poly-hydroxy acids are a newer family of exfoliating acids. They include: Lactobionic acid, gluconolactone, gluconic acid, and galactose.

They function in a similar way to alpha hydroxy acids, but they have a larger molecular structure. This larger structure means they don’t penetrate the skin as deeply, which reduces the potential for them to be irritating.

A study found that not only were poly-hydroxy acids better tolerated than alpha hydroxy acids, they had better anti-aging effects as well.

Physical Scrubs

While physical scrubs feel very effective, they’re not. Because of the small bead size, they’re not able to effectively exfoliate all of the skin in a consistent and even manner. For a person to rub the exfoliating beads over the entirety of the skin would mean that you would have to cover some spots more than once, which will increase irritation.

Exfoliating scrubs also have environmental downsides, plastic beads (which are better for the skin due to the spherical shape) are commonly made out of polyethelyne. These polyethelyne beads don’t break down in water, and can pass through filtration plants and wash out to our oceans. There in the oceans, small organisms can confuse the beads for food. Microplastic (plastic pieces smaller than 1 millimetre) is a growing source of pollution in our oceans.

Naturally sourced exfoliants, while better for our environment, can be damaging to the skin. The non uniformity of their surface means that they often have jagged or sharp edges which can cause small tears in the skin. These small tears can allow bacteria to enter the skin causing infections.

Baking soda is a common homemade scrub for the face, but the pH of a sodium bicarbonate (baking soda) and water paste may be too high for the skin. 10 grams of baking soda dissolved in one litre of water will produce a pH of 11.7 – and this only increases as the ratio of baking soda:water goes up. So if you do choose to use a baking soda scrub on the face, make sure you use an acidic toner afterwards to help restore the skin’s pH and acid mantle.

A gently applied wash cloth or muslin cloth can also do the job without the environmental impact. Just make sure you replace the cloth or disinfect it after use to prevent bacterial growth.

If you do choose to use a physical exfoliant try not to apply too much pressure (think along the lines of brushing a butterfly’s wings) and not to do it for too long.

Shaving

Believe it or not, but shaving will actually exfoliate the skin as well! When you shave you’re not only cutting off hair, but you take off a thin layer of skin.

It’s similar to a medical procedure known as dermaplaning, where a surgical blade is used at a 45 degree angle to remove layers of the skin. Dermaplaning has been used a treatment for acne scarring.

Now, I’m definitely not recommending you dermaplane your own face, but shaving will remove a thin layer of the top layer of dead skin.

Because of this, you might not need to exfoliate areas that you shave.

Tape

Cellophane tape is commonly used in studies to remove the stratum corneum or the layer of dead skin. It’s actually a very effective method of removing dead skin from the surface of the skin, but again over-doing it can cause irritation.

The more sticky a tape is the more skin it will remove, and the more irritating it will be. As well, applying pressure for longer periods of time will remove more skin, as will removing the tape faster.

A study found that tape applied to an area 20 times removed about 60% of the stratum corneum, whereas tape applied 50 times removed about 95% of it.

If you do try this method, make sure the tape is non-toxic and to wash off any glue residue after.

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Jan 30 2012
3 Comments
Food, Q + A

Does eating chocolate cause acne?

The Question

I’ve heard that foods like chocolate and milk can worsen acne. But I’ve also heard that it’s just a myth? Is it true? Can eating chocolate cause acne?

The Answer

The link between diet and acne isn’t as clear as we’d like it to be. Some studies have shown that diet can increase inflammatory chemicals in sebum which may lead to worsened acne and other studies have shown that diet has no effect on acne at all.

There have been a few studies on the consumption of chocolate and its effect on acne, but again the results were contradictory. When we look at the studies closely though, we begin to see that this might be explained by the type of chocolate being consumed.

Types of Chocolate

Chocolate is made from the cocoa bean. The cocoa bean contains two components, cocoa butter and cocoa solids. We’re familiar with cocoa butter as a moisturizing skin care ingredient. Cocoa solids on the other hand are commonly sold as cocoa powder, a baking ingredient. Cocoa liquor is a combination of roughly equal parts cocoa butter and cocoa solids.

Dark chocolate contains a higher proportion of cocoa solids, than milk chocolate. White chocolate contains no cocoa solids and is comprised of mostly cocoa butter.

Different countries have different designations of the types of chocolate, and they’re listed here on Wikipedia.

Chocolate and Acne

A study in 1969 found that there was no increase of acne related to the consumption of chocolate. The participants, with mild to moderate acne, ate a chocolate bar containing 46% chocolate liquor (22% cocoa solids) for a month. In another portion of the study, subjects (prisoners!) two of the chocolate bars each day. They also reported no increase in acne. In the end, they found that there was no increase in acne and no change in sebum composition, production, or comedogenicity (the likelihood of it clogging pores).

However, it is important to note that the testers only considered a worsening of acne if the acne lesions on the face increased by 30%. So it’s entirely possible that their acne worsened, but wasn’t included in the results of the study.

There’s another publication that looks at the shortcomings of this studies. Some of the things they point out are: the lack of age provided for some of the participants, the lack of definition of “mild to moderate acne”, the only 30% counts as worsening issue, acne was only counted at the end of the month, lack of data provided, and that the study was “made possible” by the Chocolate Manufacturers’ Association of the USA.

Another study found that about 1/3 of participants had worsened acne when consuming chocolate. Unfortunately I wasn’t able to find the full text online, so I don’t know the amount of cocoa solids in the test bars that were eaten.

A newer and smaller study found a link between consumption of 100% cocoa solids (as confirmed by Dr. Brian Berman) and acne. Participants ate up to three 4 ounce bars of 100% cocoa solid  and then were evaluated daily for week. The testers found significant increases in acne lesions on Day 4 and 7, with the most lesions on the 7th day. Lesions increased from a mean of 2.7 on the 1st day to 18.2 on the 7th day.

So looking at these studies, it seems that there is a relationship between the quantity of cocoa solids consumed and acne. In the studies that found no link between chocolate and acne participants were only eating about 26 grams of cocoa solids. In the study that did find a link, participants ate as much as 340 grams of cocoa solids.

It’s been suggested that theobromine, a chemical found in cocoa solids, may be responsible for the worsening of acne.

So Can I Eat Chocolate?

As are all things in life, it depends. If you’ve never suffered from acne, it’s likely that eating chocolate won’t cause a problem for you. If you do suffer, or have suffered from acne it’s probably best to actually stick to chocolates that contain less cocoa solids. These types of chocolate, such as milk chocolate, contain less cocoa solids and the possibly responsible chemical theobromine. However, you’ll know quite quickly (within the timeframe of a week) whether or not cocoa solids are an issue for you.

Personally, I’ve found this to be true. Eating low cocoa solid chocolate has no effect on my acne, whereas a consumption of 100% cocoa solid powder (as a dietary and skin supplement, as studies have shown there to be benefits) increased my acne lesions significantly, as soon as a day later.

Dutch-processed chocolate removes alkaloids, like theobromine, from chocolate. So these versions of chocolate may not cause problems if theobromine really is the culprit. Unfortunately the processing also removes many of the benefits of chocolate as well.

Since the antioxidant and health benefits of chocolate are associated with the cocoa solids, acne prone people may have to find their antioxidants elsewhere – like blueberries!

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