Wednesday, October 28, 2009


Polyphenols are found in our oils in three major ways - flavonoids, lignans, and tannins. They are the structural backbone for most anti-oxidants found in plants, and we can use them in our creations to offer some awesome benefits. Polyphenols show up in most of the botanically based ingredients we use in lotion making - hydrosols, essential oils, carrier oils, butters, and so on - and they're what make essential oils essential!

As an aside, polyphenols are found in pretty much every fruit and vegetable out there. We'll take a look at various polyphenols in depth in the oil or extract specific posts.

There are over 4,000 identified flavonoids - you may see them as flavenols, flavones, isoflavones - and I'm not going into all of them on this blog! The ones containing ketones, like flavonoids and flavonals, are potent anti-oxidants with anti-allergic, anti-inflammatory, and anti-microbial benefits for your skin, and work as anti-oxidants for the purposes of preventing rancidity.

Flavonoids behave as anti-oxidants on our skin and in our bodies by scavenging the free radicals produced at our cell membranes. It is thought (meaning there aren't enough studies or nothing conclusive) the flavonoids offer anti-inflammatory benefits by inhibiting pro-inflammation mediators in our bodies, such as prostaglandins.

Catechins (a type of flavonoid) found in tea and chocolate can offer anti-biotic properties in our products as they disrupt a stage of bacterial DNA replication. This isn't to say you can use tea or chocolate (or extracts like cocoa butter or green tea butter) as a preservative for your lotions, but that's a nice thing in a lotion! A type of catechin found in green tea is being investigated for its role in preventing UV related skin damage.

Lignans behave as anti-oxidants and phytoestrogens in our body. We find the lignans in flax seed (0.3 grams per 100 grams), sesame seed (29 mg per 100 grams), pumpkin, and soy bean oil. The lignan sesamine found in sesame oil has been shown to be immuno-suppressive in lab tests, but not on humans.

As a note, isoflavones, like those found in soy bean products, can behave as phyto-estrogens as well. Neither the lignan nor the isoflavone phyto-estrogens behave this way when applied to skin - they have to be ingested to get that effect. (But who knows what science will discover next? Perhaps we're not applying them in high amounts?)

Tannins are water soluble phenolic compounds found in grapes, tea, and other botanical ingredients. They tend to be very astringent and produce "dry" oils like grapeseed, hazelnut, and camellia oil. (An astringent is defined as a substance that contracts the pores and tissues and makes them smaller). Witch hazel and green tea extract contain high levels of tannins, hence their notoriety for astringency.

The various polyphenols we use in skin care products are only just now being investigated in any great depth - this is why you're seeing the ingredient of the month touted by all the big companies and being good for x or wonderful for y! Polyphenols found in olive oil have been studied extensively, and they have been shown to help repair sun damaged skin. And studies coming out now about sea buckthorn oil show it may also have regenerative properties.

Polyphenols tend to lend a bitter taste to their fruits and vegetables - and in skin care products, they tend to produce oils that are "drier" than other oils and offer astringency. There tends to be a correlation between the amount of polyphenols and that slippery feeling in a lotion. Oils with high tannin levels - camellia oil, for instance - feel drier on our skin and can be more astringent. As a result, we might not want to use high polyphenolic oils as our primary oils if we want something glidy and slidy.

Join me tomorrow when we resume our posts on the oils - specifically, soy bean oil!


Anonymous said...

Hi, You state that "macadamia nut oil contains catechins". It is my understanding and after searching the literature that macadamia nuts do not contain any catechins! Likewise you state that "hazelnut oil contains catechins and tannins". Hazelnut meal contains catechins but there appears to be no reference that the the oil does! It does not follow that the respective oil contains all those compounds that are present in the original nut/ meal form! I would be obliged if you could share your source of reference(s) on these matters, as it is of considerable academic interest. As a consulting cosmetic chemist and a researcher of phytocosmetics I would appreciate your comments.

Grace said...

Hi there,

As a commercial producer of Macadamia nuts and oils, I would be very interested in where you obtain your information from.

It's one thing to state the makeup of a nut but another thing entirely to state the makeup of an oil. You appear to be placing both in the same basket as it were.

There are no catechins in macadamia nuts. I stake my profession on it.

This is a very basic aspect to have gotten wrong. It makes me wonder about the veracity of your other posts. Disappointing because I do enjoy what you have to say.

Susan Barclay-Nichols said...

Can you provide me with the information you have on macadamia nuts? I haven't been able to find any really good academic information on the nuts versus oils and I would really appreciate anything you can provide to me. I did ask the person who posted above you, but I didn't get any information from them. If you can provide me with links that I can read without a password or e-mailed attachments I'd be very grateful. (I did visit your link, but I didn't see anything on macadamia nut oil there. Your oils of Aloha link is broken.)

I use many references for the blog - textbooks, scholarly articles, manufacturers' and suppliers' data sheets - and I get it wrong some times. I can't tell you where I got this information as it was a very long time ago and I have many many notebooks, and I really don't have the time to go through every single notebook and find my source. (Normally I'd happily share my sources, including page number and link, if possible, but this really is asking a lot of me.)

What I don't get is the aggressive attitude with which you write. It's not necessary to come to my blog accusing me of writing false things. I make mistakes. When I'm wrong, I admit it and I write up a correction either in that post or in a new post with a link to the old post. You don't need to attack me personally and question my integrity. I'm not really sure why you'd do that?

What I think would be more effective is something like this - hey, I know a lot about macadamia nuts and I don't think this information is correct - then post a link or two to accurate information or offer to send me some information. Instead, you approach this as a challenge - what you know versus what I know - with the idea that somehow learning is about winning or losing.

I see learning as a process - we start in a position of ignorance and work to gather knowledge. It's not the teacher's job to mock, refuse to share information, and make ad hominem attacks: It's the teacher's job to create a safe place in which the student can take risks, make mistakes, and progress towards a state of knowing. If you want to teach me something - and if you want me to learn something - then provide me with information in a supportive way.

What I also find interesting is that you post this in a post on polyphenols instead of the post on macadamia nuts, just like the person above you. Nowhere in this post do I mention macadamia nuts - why choose here to make this comment? Just curious...

Tricia Miller said...

After seeing how you handled the above comments, I just wanted to say I love your attitude... I know this was a post from the distance past, but how refreshing! I hope you have maintained that attitude, Susan! Kudos to you! (and thank you for all this wonderful information!!)

A Fajardo said...

I had just read this page and the comment section struck me. I agree with Tricia Miller about how you handled the previous comments. Susan, I give you two thumbs up (since I only have two thumbs, but if toes are included, I give all my toes up as well!) on how excellently you have responded to the comments with a humble and transparent attitude. I love what you said about the teacher-student relationship. So much wisdom and I have learned from it (and took notes:). God bless you and hoping you continue to share your knowledge and humor to everyone who needs it. I support you 100% and I'm sure thousands of people do, too!