Does Olive Oil Protect Hair from Breakage and Heat Damage?'

Name: Kira

Question: I read that using a hair mask with olive oil in will protect your hair from damage from heat like hairdryers and hair straighteners is it true?

Answer: Hi, Kira. There is little scientific evidence to support this rumour, but we can tell you where it is likely to have come from.

Olive oil is often said to strengthen the hair and hair follicles, leaving it less prone to damage - in particular, hair breakage - when used as a conditioner or an intensive hair mask. This is, however, misleading.

Olive oil contains small amounts of vitamin E and vitamin K, but it's most beneficial properties for the hair and scalp are its moisturising monounsaturated fatty acids. Keeping the scalp clean and in good condition provides a solid environment for healthy hair growth - genetic and outside influences notwithstanding.

It can be helpful to hair health and scalp conditions when used correctly. If the hair is extremely over-processed, brittle and dry, applying lots of olive oil to dry hair will simply coat the hair and prevent moisture absorption, so this is a bad idea. If the hair is well-hydrated, for instance after a leave-in conditioner has been used or a scalp-steaming session, oil may be applied sparingly to coat the hair, helping it to retain moisture.

It can also provide some protection, helping to prevent split ends, as it reduces the friction of the hair cuticle when combing; it is worth noting that olive oil will not repair any existing split ends, however.

A 2015 review of previous studies, published in the International Journal of Trichology, suggested some oils - including olive oil - may help to protect the hair from heat damage by penetrating the shaft.

However, when olive oil was used for this purpose, it was noted "Although thick films of oil can mask the lifted scales of the cuticle, it may leave an oily and heavy look to the hair". Therefore, this suggests it is an unsuitable heat protector as using sufficient olive oil to prevent it from damaging the hair could cause the hair to look greasy and limp, which is not a particularly appealing proposition, especially when you add in the lingering smell.

Furthermore, the scale of this one study and information regarding the extent to which the hair was protected from heat damage, were not disclosed. As such, it is not something we would recommend.

When using heated styling devices, from a hair dryer to hair straighteners (flat irons) or curling tongs, it is advisable to use a good quality heat protector spray beforehand in order to help minimise heat damage. These sprays work by diffusing heat evenly across the hair - something olive oil will not do.

Ensuring tools are used on the appropriate temperature settings, and in the case of hair dryers, at the correct distance from the hair, is also wise.

Excessive and/or regular heat styling can cause damaged hair which becomes dry, and can appear thin, dull and frizzy due to hair breakage. This is something also seen in bleached or over-dyed hair so, if your hair is bleached, over-coloured and regularly heat-treated, you could be storing up trouble.

This type of damage is not hair loss per se as it does not affect the follicles, instead the hair snaps along the shaft due to its weakened state. Generally this can be repaired by having a hairdresser cut off the split ends and damaged strands - layering or 'dusting' techniques can be used to avoid losing too much length, where this is a concern - and using suitable intensive protein-based conditioners and other appropriate restorative hair care products.