TYPES OF OILS FOR THE HAIR
Investigation of penetration abilities of various oils into human hair fibers.
TRI Princeton, Princeton, NJ 08542, USA.
In this work we have explored capillary adhesion between hair fibers treated with different types of oils. With coconut, olive, and sunflower oils the capillary adhesion was found to decrease with time, but not with mineral oil. Application of heat reduced the capillary adhesion further for coconut and sunflower oils. Again, this was not observed with mineral oil. Based on an earlier study, where coconut oil was found to penetrate hair while mineral oil was unable to do so, it was hypothesized that the reduction in capillary adhesion resulted from the penetration of oil into the fiber, leaving a thinner oil film on the surface. Such a reduction in capillary adhesion can be explained by changes in Laplace pressure and in the areas of liquid bridges formed between the fibers. The thinning of oil films on the surface of hair has been confirmed independently by goniophotometric measurements on single hair fibers treated with coconut, sunflower, and mineral oils. Thick films of oil (thicker than approximately 0.5 microm) are known to mask the scale structure. As the oil is absorbed into the hair, the film thins with time and application of heat, and the scale structure reappears. This change can be conveniently determined by measuring the scale angle, using the well established goniophotometric protocol. The agreement between the two methods supports the concept that the reduction in capillary adhesion between hair fibers is most likely due to thinning of oil films by absorption of oil into the hair.
Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage.
Research and Development Department, Nature Care Division, Marico Industries Ltd., Mumbai, India.
Previously published results showed that both in vitro and in vivo coconut oil (CNO) treatments prevented combing damage of various hair types. Using the same methodology, an attempt was made to study the properties of mineral oil and sunflower oil on hair. Mineral oil (MO) was selected because it is extensively used in hair oil formulations in India, because it is non-greasy in nature, and because it is cheaper than vegetable oils like coconut and sunflower oils. The study was extended to sunflower oil (SFO) because it is the second most utilized base oil in the hair oil industry on account of its non-freezing property and its odorlessness at ambient temperature. As the aim was to cover different treatments, and the effect of these treatments on various hair types using the above oils, the number of experiments to be conducted was a very high number and a technique termed as the Taguchi Design of Experimentation was used. The findings clearly indicate the strong impact that coconut oil application has to hair as compared to application of both sunflower and mineral oils. Among three oils, coconut oil was the only oil found to reduce the protein loss remarkably for both undamaged and damaged hair when used as a pre-wash and post-wash grooming product. Both sunflower and mineral oils do not help at all in reducing the protein loss from hair. This difference in results could arise from the composition of each of these oils. Coconut oil, being a triglyceride of lauric acid (principal fatty acid), has a high affinity for hair proteins and, because of its low molecular weight and straight linear chain, is able to penetrate inside the hair shaft. Mineral oil, being a hydrocarbon, has no affinity for proteins and therefore is not able to penetrate and yield better results. In the case of sunflower oil, although it is a triglyceride of linoleic acid, because of its bulky structure due to the presence of double bonds, it does not penetrate the fiber, consequently resulting in no favorable impact on protein loss.
Effect of oil films on moisture vapor absorption on human hair.
TRI/Princeton, Box 625, Princeton, NJ 08542, USA.
In this paper sorption and desorption of water vapor on hair fibers treated with various oils is investigated, using a dynamic vapor sorption (DVS) apparatus. Results show lower “equilibrium” sorption of moisture for various oil-treated samples compared to the untreated sample. Coconut oil-treated hair had a higher regain than mineral oil-treated hair. Although treating the hair samples with oil reduced moisture pickup, a considerable amount of moisture vapor was still able to penetrate into hair fibers. Calculated hysteresis plots show that the samples treated with different oils have slightly higher moisture retention at low relative humidities compared to that of the untreated sample, which suggests a beneficial effect. The calculated moisture diffusion coefficients for oil-treated samples were much lower compared to the untreated hair fibers, suggesting that surface oil films and penetrated oil molecules form a diffusion barrier. A moisture diffusion model is discussed in terms of the possible role of fiber swelling on restrictive narrowing of the cell membrane complexes (CMCs), which form the diffusion pathways in the fiber. The effect of film thickness on moisture absorption and the reverting of the sorption isotherm to that of the untreated hair after removal of the oil film shows that oil film is the main resistance to moisture diffusion. The lowering of the diffusion coefficient of water vapor by oil films will slow the loss of moisture, an effect similar to “moisturization” of hair.
published 2005 study titled the Investigation of penetration abilities of various oils into the human hair fibers. In this study, various types of oils were applied to hair samples in order to observe and measure “the capillary adhesion resulting from the penetration of oil into the fiber.” So what they did was measure the thickness of the oil film on the hair strand after some time elapsed. They also did the same observation with the use of heat on the strand. The theory was that the thickness of the oil film on the hair would diminish with time and heat as the oil was absorbed into the hair. Those oils that left a film thicker than a certain amount, actually masked that hair as it remained on the surface. During the study, a measurement tool was also used to view the hair’s surface. Strands with the “non-absorbing” oils would appear to have a thicker film covering and masking the scale structure of the hair for extending periods of time even with the use of heat (blow dryer). Basically, this would mean the oil was just idly sitting there.
The oils used in this particular study were coconut oil, sunflower seed oil, mineral oil, sesame, rice brand, mustard, and olive oil. Scientists measure the “capillary adhesion,” or amount of penetration of mineral, coconut, and sunflower with the use of heat. The higher the adhesion, the less the oil was able to penetrate the strand. It’s no surprise that absorption levels of mineral oil was pretty much non-existent, even with the use of heat. The study found that coconut oil treated hair (with heat) looked close to untreated hair after 24 hours. That speaks to the high absorption rate of the oil. To further prove this theory, a second assessment was made on the hair fibers by studying the interior of the hair fiber with a specialized tool. Mineral oil was not detected in the hair’s cross section. Coconut oil, however, “was found to penetrate partially or completely.”
As mentioned earlier, other oils were also analyzed during this study. Unfortunately, the other oils tested did not demonstrate the high level of penetrability of coconut oil. Some of the oils partially penetrated through the cuticle layer but the scientists weren’t able to determine if the penetration went down into the hair’s cortex. The general consensus of the study was that monounsaturated oils penetrate or “diffuse” into the hair much more effectively than polyunsaturate oils.
I, for one, am excited about seeing this for myself in black and white. I’ve used coconut oil forever. You could see me using it during my pre-poo steam treatment video. It’s even an ingredient in Gleau. Now that we’ve discussed, what I want each one of you to do is scour your hair product closest looking for anything with the word mineral oil on it. If you happen to find such a product, I’d like for you to immediately chuck it into the nearest trash can and never look back.
explains Corey. So use a thick, tight shower cap to minimize the mess.
Fine Hair-Pomegranate seed oil
“Pomegranate seed oil is a favorite of mine because it has a lot of punicic acid, which revitalizes dull strands and increases flexibility,” says Corey. “I mix it with olive oil to thin down its texture for clients with finer hair.”
Thin Hair-Rosemary oil
“Rosemary oil is great for mixing with other natural oils because it stimulates the hair follicles,” says Corey. High in iron, calcium, and vitamin B, the oil acts as an anti-aging agent, helps boost color, shine, thickness, and prevents hair loss.
Wavy Hair-Sweet almond oil
Like most nut oils, sweet almond has high contents of vitamins A, B, and E. “The oil heals split ends, improves circulation in the scalp to produce stronger hair, and can add luster and shine to dull hair,” says Dr. Shamban. Adds Corey: “The fatty acids add UV protection by reflecting harmful rays.”
Coarse Hair-Avocado oil
“Avocado oil is excellent for the hair because it is rich in proteins and amino acids, and it has high levels of vitamins A, D, and E,” says Dr. Shamban. “The proteins help fill in all the crevices in your hair’s cuticles, so each strand is stronger and better protected from future breakage,” adds Corey. “Since it’s a thicker oil, it works best on medium- to coarse-textured hair.”
Thick Hair-Olive oil
Need a deep-conditioning treatment? “Olive oil contains monounsaturated fat, which has been used for years as a holistic, natural remedy to alleviate dryness,” says Dr. Shamban. Not only is olive oil ultra-hydrating but it is packed with nourishing antioxidants and omega-3 fatty acids that improve elasticity and restore strength and shine. “Olive oil is very heavy and works well with thicker, coarser hair,” says Corey.All hair types
Two other oils Corey swears by? Rice bran and hemp seed. “Rice bran contains vitamin E and creates a harder shell around the cuticle so your strands have less breakage,” says Corey. “You can hardly smell the oil, and it works for any type of hair! But I also love hemp seed oil because it is packed with amino acids, omega-3 fatty acids, proteins, and minerals that make hair stronger and healthier overall.” SEE NEXT ARTICLE BELOW-
Mineral Oil Versus Coconut Oil: Which is better?
Last month’s article delved into the chemistry and properties of mineral oil, as well as some of its benefits and drawbacks when used as an ingredient in hair products or as a topical treatment. This month, I would love to expand on that topic a bit and dig a little deeper into the similarities and differences of petroleum-derived mineral oil and plant-derived oils, specifically coconut oil. Both types of oils are found in various hair care products, and coconut oil is quite often used in homemade treatments, as well. The superior properties of natural oils are frequently lauded, so it should be interesting to review a few scientific comparisons backed by data.
Water in – water out
Several published studies have summarized experiments done to evaluate and compare the emollient properties of mineral oil, coconut oil, and to a lesser extent, olive oil and safflower oil. In one paper, researchers reported using an analytical technique (dynamic vapor sorption, for those curious) to measure and determine the moisture diffusion coefficient for mineral oil, coconut oil, and other oils when applied to hair. They were interested in finding out was how much water vapor can penetrate into or diffuse out of hair that has been coated with oil.
The data obtained in the experiments revealed that both coconut oil and mineral oil form a protective barrier that effectively prevents the diffusion of moisture out of the hair in low-humidity environments, thereby improving moisture retention and minimizing dry, fly-away hair. All of the oil-treated hair samples showed this effect, whereas the untreated control remained unchanged.
It was noted that for coconut oil, the moisture-retention effects dissipated significantly over time. This is credible evidence that coconut oil absorbs into the hair shaft while mineral oil remains on the exterior surface. (Remember this—it will be important later).
All of the treated hair fibers showed a reduction in absorption of moisture vapor from the atmosphere in damp conditions. This is advantageous in an anti-humectant topical treatment, as it provides some protection from frizz that often occurs in high relative humidity. However, this effect was not total, and each sample was found to absorb significant amounts of water over time. Extremely hydrophobic mineral oil performed the best in terms of its ability to seal water out of hair, while the more polar fatty acids such as coconut oil allowed greater transport of moisture through the cuticle and into the hair shaft. This can certainly be an undesirable attribute if frizz and the tell-tale halo are not qualities you prefer in your hair.
Curl Formation and Clumping
Both coconut oil and mineral oil enhance clumping of adjacent hair strands. This mechanism aids in curl formation, definition of curl pattern, and curl retention. Capillary adhesion, the mechanism by which this is possible, occurs when oils form sufficiently thick films on the surfaces of hair strands and capillary forces between adjacent hairs attract them to one another, effectively binding them into clumps.
Researchers found that capillary adhesion between hair fibers remains constant with mineral oil, but is found to decrease over time with coconut oil, olive oil, and sunflower oil. The reason for this is that the very non-polar mineral oil molecules remain on the surface of the cuticle of the hair. In contrast, the saturated or mono-unsaturated fruit and vegetable oils in this study slowly penetrate into the cell membrane complex (CMC) and are transported into the hair shaft. As this diffusion occurs, the film thickness on the surface of the hair gradually decreases, which diminishes capillary forces. As a result the cuticle scale structure begins to dominate the behavior of the surface of the hair once more, and subsequent tangling and frizz can occur.
A Closer Look at the Penetration Behaviors of Mineral Oil and Coconut Oil
As you have probably ascertained from this article, many of the behaviors and performance of oils and moisturizers on the hair are affected by whether they remain on the surface or are absorbed into the hair. To get a more quantitative understanding of this, scientists performed direct study of the penetration behaviors of coconut oil and mineral oil on hair via spectrometry (secondary ion mass spec (SIMS) plus time-of-flight mass spec (TOF-MS). The results showed definitively that coconut oil does indeed penetrate the hair shaft, while mineral oil remains on the surface of the air.
Both mineral oil and coconut oil have pretty compact structures which should physically permit diffusion through the porous external layer of the hair shaft. So why does coconut oil do so, while mineral oil does not?
The answer lies in the atoms. While the chemical structure of the molecules present in mineral oil is purely carbon and hydrogen, rendering them very non-polar, triglycerides such as those found in plant-derived oils contain carboxylic acid groups, which lend a little polarity to the molecules. This polarity confers an affinity to these oils for other polar molecules, such as the various keratinous proteins of which hair is comprised. Thus, it is this inherent attraction to other polar molecules, coupled with the relatively simple structure of coconut oil that enables it to diffuse through the cell membrane cortex of the hair and penetrate into the central cortex. Mineral oil has no such affinity for proteins, and remains on the more hydrophobic exterior surface of the hair.
Coconut oil and improved resistance to wash-wear
The presence of coconut oil inside the cortex of hair provides multiple benefits. It acts as a plasticizer to soften the hair and provide more flexibility and toughness. Coconut oil also increases retention of keratin molecules within the hair shaft, which reduces protein erosion that normally occurs during wash cycles. Continuous loss of protein over time from routine washing damages hair and can result in color fading, split ends, and breakage, so anything that can moderate this phenomenon is beneficial.
An additional advantage to coconut oil inside the hair shaft is that it decreases the amount of swelling of the hair shaft that normally occurs when immersed in water. Normally, when hair is saturated with water during the washing process, it absorbs up to 30% or more of its weight in water. This causes each strand to swell considerably, which can lead to several undesirable effects. Increasing the diameter of the hair shaft causes the outer covering of cuticle scales to lift and separate, which increases tangling and breakage. But, perhaps more subtle, is the damage done over time from many cycles of expansion and contraction.
Hair is a highly complex biomaterial composed of layers of differing materials, ranging from varying types of keratin structures to pigment molecules to fatty acids. When it is saturated with water and swells and then subsequently dries via natural or thermal means, it undergoes what is known as differential drying and differential deformation (because each separate type of molecule within the overall structure dries and deforms at differing rates). This leads to moisture-induced stress on the hair, which can lead to delamination (cuticle layer stripping off), breakage, fiber fatigue, and rupture (split ends). This whole phenomenon is referred to as hygral fatigue. So, anything that reduces hygral fatigue is great for the health of your hair in the long term.
Which is the winner?
Well, both water insoluble oils have some distinct advantages for curly hair. By improving moisture retention within the hair shaft, they each can minimize drying and frizz which may occur in arid climates. Both enhance curl formation and clumping. However, in both of these things, mineral oil does the job better and for a longer time. On the other hand, coconut oil appears to have some real potential for improving the health and long-term vitality of hair, especially when it comes to wash-wear, whereas mineral oil is more of a topical treatment that is effective until it is washed away. Those with very porous hair may find that coconut oil penetrates too much into the interior of the hair, which can cause its own set of problems such as frizz, greasiness, and limp hair. So, adding either coconut oil or mineral oil to your hair care regimen may prove to be beneficial, but proceed with caution and see what works best for your own locks.
ABC of carrier oils
Vegetable and carrier oils have a plethora of fine uses which include acting as a carrier for therapeutic applications, as an excellent addition to your culinary creations, as a lathering agent for soap, and a binding medium for cosmetics. It is hard to imagine where we would be with our creations, if it were not for the goodness and substance that pure oil provides. There are so many varieties, however, that it is easy to get overwhelmed. Here is a list of the most commonly used carrier oils!
Almond oil – This is one of the most useful, practical, and comonly used oils. It is great for all skin types as an acting emollient and is best known for its ability to soften, soothe, and re-condition the skin. It is truly marvelous as a carrier oil and is equally superb for addition to body care products.
Apricot kernel oil – A wonderful oil similar to Sweet Almond, but more suitable for sensitive and prematurely aged skin.It can be used liberally in most body care recipes.
Argan oil – This rare and exquisite oil is meticulously pressed from the fruit kernels of the Moroccan Argan tree. Argan oil is rich in natural tocopherols (vitamin E) and phenols, carotenes, squalene and fatty acids, making it a truly luxurious oil. Argan oil absorbs quickly and is often used in skin, nail and hair treatments to deliver deep hydration, strengthen brittle hair and nails, and prevent/reduce stretch marks.
Avocado oil – This ultra rich organic oil is a delightful treasure containing high amounts of Vitamin A, B1, B2, D, and E. Also contains amino acids, sterols, pantothenic acid, lecithin, and other essential fatty acids. Highly prized to those with skin problems such as eczema, psoriasis, and other skin ailments, it also makes a lovely salad oil for dressings and condiments. Highly recommended to those with sensitive skin, problem skin, and other irritations that require vitamin rich oil.
Baobab oil – This exquisite oil is cold pressed from the seeds of Baobab fruit trees growing in Africa. The normal lifespan of a Baobab tree is 500 years, with the oldest trees reaching the age of 5,000 years and a height of 20 meters. Known to the locals in its natural habitat as “The Tree Of Life”, Baobab’s bark, leaves and fruit pulp are also used. Its lovely white flowers emit a smell of rotting meat, which attracts pollinating moths, flies and ants; however, the seed oil itself possesses a light, nutty, almost floral scent. Rich in vitamins A, E and F and sterols, baobab oil absorbs quickly and is a wonderful oil to use in dry skin treatments and products designed to moisturize dry hair.
Borage seed oil -Because of its extremely high levels of gamma linolenic acid, Borage Seed Oil has many potential uses. It has been widely studied for its ability to calm and reduce inflammation, and has been used successfully to alleviate the pain, swelling, and joint stiffness associated with rheumatoid arthritis. Borage Seed Oil has also been used with positive results for many different skin disorders, such as psoriasis, eczema, acne, rosacea, and prematurely matured skin. Furthermore, studies have begun to show that it may be able to be beneficial for treating and preventing a malady of conditions.
Castor oil – A natural source oil from castor beans. A hard and shiny oil found in most cosmetics that acts as a barrier agent and protective medium against harsh conditions and extremes. Very soothing to the skin when included into cosmetic applications.
Coconut oil – This is a great oil for general moisturizing and serves as a protective layer, helping to retain the moisture in your skin. It also acts as a mild oil suitable for those with inflamed and irritated skin, and those with skin sensitivities. Coconut oil is without a doubt the number one lather-producing agent used in soaps.
Grapeseed oil – Grapeseed oil has a mild green color with a pleasant odor, silken texture, and great absorbtion rate. Generally employed as a base oil for many creams, lotions and as a general carrier oil. Grapeseed is especially useful for skin types that do not absorb oils too well, and it does not leave a greasy feeling. Wonderful for those with skin sensitivities because of its natural non-allergenic properties.
Hazelnut oil – Hazelnut oil is known for its astringent qualities and because of this, it is best used for those who have oily skin but do not want to abstain from using oils.
Hemp seed oil – Exceptionally rich oil high in essential omega fatty acids and proteins. This oil has a pleasant nutty smell, deep green color, and absorbs well into the skin. It makes a marvelous cosmetic grade oil and because of its high nutritional value, it makes a superior quality dietary oil and one that can be used as a base ingredient for skin care recipes which require healing and regenerative ingredients.
Jojoba oil – Jojoba oil comes from the beans of the shrub like plant, simmondsia chinensis. It is bright and golden in color and is regarded as the most favored in the carrier oil family because of its advanced molecular stability. Also makes a great scalp cleanser for the hair, and is equally wonderful for the skin because it has absorption properties that are similar to our skin’s own sebum.
Kukui nut oil – The Kukui nut tree is the official tree of Hawaii and has been used by natives of this island for hundreds of years. They recognized the oil’s high penetrability and soothing properties and currently they put it to use in helping sooth sunburns and chapped skin. A fabulous ingredient for your cosmetics, or as a stand-alone application, Kukui nut oil contains very high levels of the essential fatty acids linoleic and alpha-linolenic. This oil is readily absorbed into the skin, providing tissues the essential elements that it needs and is particularly good for dry skin, psoriasis, acne and eczema.
Macadamia nut oil – This fine oil comes from the pressed nuts of the Macadamia tree. It is a priceless delight for the skin and has proven itself to be one of the best regenerative oils available. It is high in monounsaturated fatty acids, and closely resembles sebum (the oil naturally produced by one’s skin to help protect it). Macadamia oil is a fabulous, protective oil with a high absorption rate and has been successfully used as a healing oil for scars, sunburns, minor wounds and other irritations.
Neem oil – A magnificent oil with numerous benefits for both therapeutic and medicinal use. Among other properties, this certified organic oil is anti-septic, anti-viral, anti-bacterial, and anti-fungal. Used widely in creams, dental products, hair care products, and in gardens for natural pest control. Can be applied directly to the skin or included within skin care preparations that are designed specifically to treat problematic skin conditions. This oil is exceptionally rich, contains a heavy odor, and may be diluted accordingly.
Olive oil – Olive oil is by far the most universal oils used for a multitude of purposes including cosmetics, as a carrier oil, for hair care solutions, and in cooking. It has a rich, full bodied flavor with a strong aroma and is golden brown in color. It has a great conditioning effect in body care recipes and can be used in almost all applications because of its stable nature.
Palm kernel oil – Palm Kernel Oil is pressed from the fruit kernels of the palm tree Elaeis guineensis. It is most commonly found in handmade soap to increase its lather and hardness. It may also be used in a multitude of other cosmetic and bodycare products for its moisturizing properties.
Plum kernel oil – An incredibly rich and intoxicating oil which gracefully shares it benefits in numerous food and cosmetic applications throughout the world. Plum oil is a recent addition to the exotic oil scene and it has been incorporated into some of the finest food dishes in France and it can be found in some of the most exquisite cosmetics in Italy. Having a flavor and aroma similar to Apricot kernel oil with a fruity top note, this oil is sure to embellish itself well upon any creation you may choose. High in fatty acids and leaving virtually no residue on the skin, the potential of Plum kernel oil in body care applications is endless.
Pomegranate seed oil – A luxurious and deeply penetrating oil from the cold pressed organic seeds of pomegranate fruit. This highly prized oil which is naturally high in flavonoids and punicic acid is remarkable for the skin and has numerous dietary benefits as well. Deeply nourishing to the outer epidermal layer, Pomegranate seed oil provides powerful anti-oxidant benefits for numerous skin ailments including eczema, and psoriasis and gently challenges free radicals that damage and age the skin. A great ally to have in your cosmetic creations or as a stand alone product to help nourish and develop healthy skin cell regeneration.
Rosehip seed oil – A rich, amber colored organic oil from the ripened fruit of the famed Rosehip. This unique oil is extremely high in essential fatty acids and has carried much respect amongst professional journals and organizations as being a great agent in the fight against dry, weathered, and dehydrated skin. It works wonders on scars and is the predominant oil used for treating wrinkles and premature aging. Can be used in all fine skin care recipes.
Safflower oil – A highly moisturizing oil with an exceptionally high amount of Oleic acids. Deeply soothing and one of the first choices for skin care recipes requiring moisturizing benefits.
Shea nut oil – Shea oil is a byproduct of Shea butter production where the pressing of the seeds produces a fractionated oil. This oil leaves a smooth and healthy feel to the skin and offers benefits for numerous skin problems including dermatitis, eczema, burns, cutaneous dryness and other irritations. Highly recommended as a protective agent against harsh weather conditions where a mild barrier against the elements is desired.
Soybean oil -High in natural source lecitihin, sterolins, and vitamin E, this oil makes a great base for your products which are being created for outer epidermal healing. Soybean oil is easily absorbed and leaves a smooth sensation to the skin.
Sunflower oil – An oil wealthy in Oleic acids with high amounts of Vitamins A, D, and E, also has beneficial amounts of lecithin, and unsaturated fatty acids. Deeply nourishing and conditioning for the skin and it is highly recommended for recipes designed to treat dry, weathered, aged, and damaged skin.
Tamanu oil – The Oil of Tamanu offered by Mountain Rose Herbs is extracted by a cold pressed method from the whole organic nuts of the Polynesian Tamanu tree. Tamanu oil has been thoroughly researched, and the conclusive evidence on its ability to heal damaged skin is overwhelming. Its benefits are notable for the treatment for scarring, stretch marks, minor cuts and abrasions, rashes, sores and much more. Can be used directly on the skin or mixed within formulations.
Wheat germ oil – This ultra rich, unrefined Wheat Germ oil is a great ingredient high in natural source Vitamin E, A, D, proteins, Lecithin, and Squalene. Wheat germ has been applied externally for numerous irritations including roughness of the skin, cracking, chaffing and many crafters of cosmetics use it successfully to help reverse the effects of wrinkling. The first ingredient in quality skin care products.