Take a look at the multitude of celebrity advertisements and outrageous claims for shampoos on TV and in magazines and it is easy to lose sight of the simple truth: the main function of a shampoo is to clean the hair.
Its function is so simple – so boring even – that manufacturers have to work doubly hard to make it sound more complicated and exciting than it actually is. Thus, if the ads are to be believed, using a particular brand brings with it the promise of harmony, lust for life, nourishment and adoration by members of the opposite sex. Some shampoos are apparently so remarkable that they not only clean your hair, but also give you an orgasm.
Underneath all the puffery, however, a shampoo is just a bottle of highly coloured, highly perfumed detergent, and – in spite of ‘scientific’ claims for specific ingredients such as pro-vitamins – the difference between an own-brand bargain bottle and a designer shampoo is usually only the price.
Because around 90 per cent of us already buy shampoos regularly, the shampoo market is not exactly a growth market. What more can the manufacturers sell us, after all? How many bottles of shampoo does a person need all at once? Nevertheless manufacturers continue to jostle for market share and work extra hard to catch the consumer’s attention by segmenting the market – that is, creating smaller and smaller niches to be filled up with specialist shampoos. As a result, in a bid to persuade consumers to keep more than one bottle of shampoo on hand, ‘problem-solving’ shampoos have become a popular addition to basic ranges.
This process of segmentation has now reached such heights that consumers can walk into a supermarket and buy a haircare range that is (apparently) appropriate to the type, colour and even age of their hair. The UK shampoo market is worth around £316 million a year. Head and Shoulders, made by Procter & Gamble (P&G), is the number-one-selling shampoo. In a bid to keep it in the top spot, P&G recently relaunched Head & Shoulders shampoo with modern new packaging and a campaign to emphasise the product’s cosmetic value as well as its antidandruff properties.
In fact, shampoos belonging to the P&G stable occupy the top three spots, with Pantene and Herbal Essences being the second and third most popular shampoos in the UK respectively. Together, these three account for approximately 30 per cent of the UK shampoo market place.
Dandruff shampoos are made with detergents to which anti-flaking agents, such as coal tar, zinc pyrithizone, salicylic acid and selenium sulphide, are added. While they can relieve itching and decrease flaking, none can control dandruff completely.
Sulphur and salicylic acid work by breaking flakes into smaller, less noticeable pieces. It is thought that coal tar, selenium sulphide and zinc pyrithizone can slow the production of flakes; beyond this, little is known about exactly how anti-dandruff shampoos work. Of all the anti-flaking agents, zinc pyrithizone, contained in Head & Shoulders, and coal tar are considered to be the most effective in controlling dandruff.
All anti-flaking agents have some side effects. They can be irritating both to skin and eyes. Salicylic acid, in particular – an ingredient of aspirin – can be severely irritating, and is a poison if swallowed. Coal tar is a known carcinogen and can also be an irritant when inhaled or when it comes into contact with skin. Most anti-dandruff shampoos amount to a kind of chemical warfare on your scalp, when a more natural approach might do just as well. Dandruff appears to be related to the fungus Pityrosporum ovale. Tea tree oil has antifungal properties with activity against P. ovale and may be useful in the treatment of dandruff.
Studies have shown that a shampoo containing at least five per cent tea tree oil can be an effective way to tackle flakes. Effective as they may be, most of the shampoos that you can find online and in your health store don’t come with the big advertising budget of a multinational behind them, so most of us never hear of them and never think to try a simpler alternative.
Ingredients with adverse effects
Sodium laureth sulphate (SLES)
Purpose: Detergent
Adverse effects: Skin dryness, eye irritation, penetration enhancer. Laureth compounds can be contaminated with 1,4-dioxane, a carcinogen linked to breast cancer.
Sodium lauryl sulphate (SLS)
Purpose: Detergent and foaming agent
Adverse effects: SLS is a harsh cleanser often used as an engine de-greaser. It’s added to toothpaste to make it foam, but is not necessary to clean your teeth. Irritating to the mucous membranes in the mouth, can cause mouth ulcers, canker sores and contact eczema.
Cocamide MEA
Purpose: Detergent
Adverse effects: Skin, eye and lung irritation, contact allergies. Animal studies show damage to immune system and organs. Can react with formaldehyde releasing ingredients to form carcinogenic nitrosamines (see Sodium polynaphthalenesulfonate).
Zinc pyrithione
Purpose: Anti-dandruff
Adverse effects: Skin irritant. Animal studies show damage to immune system and organs. Persistent and bioaccumulative in the environment.
Dimethicone
Purpose: Conditioner, film-former
Adverse effects: Skin irritant. Film-formers coat the hair to make it feel smooth, but confer no real moisturising properties.
Hydroxyisohexyl 3-cyclohexene carboxaldehyde
Purpose: Fragrance
Adverse effects: Also known as Lyral – can cause contact allergic reaction, especially in eczema sufferers.
Parfum
Purpose: Fragrance compound
Adverse effects: Central nervous system disruption (e.g. headache, mood swings, depression, forgetfulness); allergen; triggers asthmatic reactions; skin irritation. Some perfume ingredients, such as artificial musks and phthalates, are hormone-disrupting.
Sodium diethylenetriamine pentamethyl phosphonate
Purpose: Sequestrant
Adverse effects: Prevents metals in the mix having an adverse effect on product performance, appearance or stability by reacting with them. A common ingredient in liquid laundry detergents, where it acts to prevent/disperse soap scum. Effects in humans have not been studied.
Linalool, Hexyl cinnamal, Benzyl alcohol, Limonene, Citronellol
Purpose: Synthetic fragrances
Adverse effects: Must be listed on the label because they are severe allergens. Can also cause central nervous system disruption (thus their use in certain pesticides) and skin, eye and respiratory tract irritation. Can trigger asthma attacks.
Paraffinum liquidum
Purpose: Lubricant, emollient
Adverse effects: Aka mineral oil, this cheap ingredient produces a temporary moisturising effect. Penetration enhancer,can cause skin (scalp) dryness. Can be contaminated with polycyclic aromatic hydrocarbons (PAHs). Some PAHs are potential human carcinogens linked with an increased risk of breast cancer.
Sodium polynaphthalenesulfonate
Purpose: Emulsion stabiliser, surfactant
Adverse effects: Irritating to mucous membranes, can release low levels of formaldehyde, which react with DEA and DEA-containing ingredients (see Cocamide MEA) to form carcinogenic nitrosamines.
Methylchloroisothiazolinone, methylisothiazolinone
Purpose: Preservatives, together known as Kathon CG Adverse effects: Strong allergens, they bind quickly to the skin, remaining there long after use. Nerve damage; potential mutagen; a suspected carcinogen due to its corrosive action on the skin. Disodium EDTA,
Tetrasodium EDTA
Purpose: Preservatives
Adverse effects: Skin and eye irritation, contact dermatitis; penetration enhancer.
Environmentally persistent, binding with heavy metals in lakes and streams, aiding their re-entry into the food chain.
Ingredients
Aqua, Sodium laureth sulfate, Sodium lauryl sulfate, Cocamide MEA, Zinc carbonate, Glycol distearate, Sodium chloride, Zinc pyrithione, Dimethicone, Cetyl alcohol, Guar hydroxypropyltrimonium chloride, Parfum, Sodium xylenesulfonate, Magnesium sulfate, Sodium benzoate, Ammonium laureth sulfate, Butylphenyl Mothoxypropional, Linalool, Sodium diethylenetriamine pentamethyl phosphonate, Magnesium carbonate hydroxide, Hexyl cinnamal, Benzyl alcohol, Eitdronic acid, Hydroxyisohexyl 3-cyclohexene carboxaldehyde, Limonene, Citronellol, Paraffi num liquidum, Sodium polynaphthalenesulfonate, Methylchloroisothiazolinone, DMDM hydantoin, Disodium EDTA, Tetrasodium EDTA, Methylisothiazolinone, CI 42090, CI 60730
Alternative treatments
Because dandruff is caused by a fungus it is probably most effectively tackled from the inside out. Effective dietary measures include cutting out sugar and yeasty foods, supplementing with B-complex and probiotics (acidophilous and bifi dobacterium), and drinking plenty of water each day. Essential oils of tea tree, rosemary and thyme can also be applied topically (mixed with cider vinegar) at bedtime.
While it is almost impossible to make an ‘all-natural’ shampoo, consider these less unnatural alternatives for
dandruff control:
• Conditioning Dandruff Shampoo http://www.theorganicpharmacy.com
• Weleda Rosemary Shampoo www.weleda.co.uk
• Florame Purifying Anti-Dandruff Shampoo www.florame.co.uk
• Thursday Plantation Tea Tree Anti-Dandruff Shampoo www.auravita.com
• Nature’s Response Organic Anti-Dandruff Shampoo www.healthstore.uk.com
• Hope’s Relief Herbal Shampoo www.healthfoodonline.co.uk
This article first appeared in the Ecologist July 2008