Hemp Seed Oil, The Wonder Oil for the New Millennium

By Kristin Speiser, Michael Pobeda and Laurent Sousselier, Happi, June 1999, ppg. 106-109

Summary

This perfectly balanced oil has an impressive list of proven benefits to the consumer. The product’s ideal balance as a cosmetic oil and as a fashionable ingredient meets the demands of the millennium’s market.

What’s old is new again. Hemp seed oil has been used for centuries for its medicinal and nutritional properties. Now the cosmetics industry is rediscovering this wonder oil. Not only is hemp seed oil new on the cosmetics scene, but it is a trendy product. Today’s emphasis on environmentally-sound products calls for a multipurpose ingredient such as hemp seed oil. It is a perfectly balanced oil with an impressive list of proven benefits to the consumer. The product’s ideal balance as a cosmetic oil and as a fashionable ingredient meets the demands of the millennium’s market.

Across the globe, hemp products are renowned for their versatility. This popular material is used in clothing, accessories, home furnishings and even automobiles. Hemp is no longer confused as a “cannabis” product but is relished for its own reputation.

Four thousand years ago, China’s Emperor Sheng Nung used hemp for rheumatism and constipation treatments. Buddha supposedly ate one hemp seed per day while fasting. Romans used hemp fibers in their ropes and sails. Gutenberg’s Bible, the American Constitution and the Declaration of Independence were all printed on hemp paper. France’s Nîmes weavers used hemp in manufacturing the first denim (De Nîmes). Since hemp made up the very first jeans, contemporary fashion has turned to hemp fiber. Hemp is not a trend that any industry can afford to miss. Armani, Calvin Klein and Ralph Lauren all use hemp in their fashion lines. “I believe that hemp is going to be the fiber of choice for the millennium,” said Calvin Klein.

Botanical Aspects

This “choice” plant is actually a tall weed that grows worldwide. It has many applications, aside from its excellent use in hemp seed oil form. The plant itself grows rapidly (four times faster than trees). Hemp has been highlighted lately for its environmental soundness. A renewable biomass, hemp is grown without fertilizer or pesticides. In fact, the plant is a fertilizer itself. Therefore, without involving costly and potentially environmentally-damaging chemicals, hemp is a hardy, cost-efficient botanical that grows without damaging either the wallet or the environment.

It's no wonder that hemp is so widely used these days. Not only is the fiber used in paper, textiles and other products, but its hardiness makes it ideal for the building industry. Hemp is also edible and may even be found in modern food products; the nutritious oil helps reduce LDL cholesterol content.

Clearly, hemp has many beneficial uses but its full potential is realized in the form of hemp seed oil. The oil is edible, pleasing to the touch and perfectly balanced. cosmetic industry leaders recognize the desirability of high essential fatty acid contents. Hemp seed oil contains one of the highest levels of essential fatty acids: 76%.

Essential Fatty Acids and the Skin

EFAs (essential fatty acids) are very important in cell membranes. The more saturated the fatty acid, the less fluid the membrane. PUFA (poly-unsaturated fatty acids) are incorporated in the 2 position of the phospholipids constituting cell membrane. Afluid membrane is crucial for proper cell function. EFAs and their importance to the skin have been the subject of many studies.

Horrobin (J. Am. Acad. Dermatol. 1989 20 1045-1053) and later Wright (Br. J. Dermatol. 1991 125 503-515) have reviewed Essential Fatty Acid Deficiency (EFAD) consequences on the skin. They found that EFAD can lead to:

• Scaly epidermis;
  
• Hypertrophy of the sebaceous glands and hyperkeratosis of sebaceous ducts;
  
• Weakened cutaneous capillaries;
  
• Increased transepidermal water loss (TEWL) and
  
• Thin, discolored hair, or hair loss
  

Furthermore, EFAD plays a role in atopic eczema, acne and psoriasis.

Nutgeren, et. al. (Biochim. Biophis. Acta. 1985 834 429-436) proved that EFAs are absolutely necessary for maintaining the proper skin condition of water barrier in the skin. Direct topical application on linoleic acid (LA) to the skin restores the barrier in animals with EFAD. It as been shown that radiolabeled LA is incorporated mostly in an acyl ceramide (ceramide 1) in which LA was esterified to the end position of a very long chain unsaturated omega fatty acid. In EFAD, LA is replaced by oleic acid in the ceramide, which is unable to form a normal water barrier.

PUFA supplementation influences the rate of biosynthesis of EFA derivatives as it seems to depend on the size of the precursors pool. Supplementing gamma linoleic acid (GLA) results in an increase of the less inflammatory PGE2. Similarly long chain omega-3 acids supplementation induces a marked reduction in LA and arachidonic acid (AA) in membrane lipids and also result in local generation of the less inflammatory PGE3.

Also, dihomo gamma linoleic acid (DGLA) is converted in the skin to PGE1, which is known to raise the levels of cAMP which in turn inhibits PLA2 (what’s PLA2) and so exerts anti-inflammatory effects by keeping AA locked into the phospholipidic membrane. Thus access of free AA to cyclo-oxygenase is denied and pro-inflammatory PG2 level is reduced. This implies the necessity of a well balanced mix of PUFA in the diet and in topical application.

The Right Prostaglandins are Extremely Important

Larregue (Prostaglandines et thromboxanes Masson 1997) reviewed the importance of prostaglandin (PG) in skin. PGs are not stored but are synthesized on request after being stimulated. PG2 are synthesized from AA present in cell membranes.

PG2 is a powerful vasodilator and contributes to the characteristic edema related to inflammation. It must be noted that PG1 and PG3 are less pro-inflammatory. PGs are also immune modulators: PGE2 is a powerful inhibitor of cytotoxic T cells activity. In situ PG production happens simultaneously with UV erythema. Therefore omega-3 PUFA, by helping prevent PG2, has a photo-protective effect on skin.

Marshall, et. al. (Progr Lipid Res 1981 20 7312-734) demonstrate that nutritional balance between omega-3 and omega-6 EFA affects prostaglandin synthesis in the immune system improving certain skin inflammatory pathologies. This is due to the competitive inhibition of cyclo-oxygenase which does not release as much pro-inflammatory AA derived PG2, favoring the less active PG3. High LNA levels in the diet led to a decreased capacity for cyclo-oxygenase produced PGE syntheses in the thymus and spleen due to the preference of desaturase and elongase enzymes for the omega-3 EFA. This causes a larger decrease in AA than may be expected on the basis of dietary LA/LNA ratio.

Finally, Ziboh (Arch. Dermatol. 1989 125 241-245) has studied the accumulation in psoriasis lesions of leukotriene B4, the major pro-inflammatory metabolite of AA. He proved that GLA and EPA present in fish oil are potent inhibitors of leukotriene B4 generation. They seem to work by competitive inhibition of 5 lipoxygenase.

PUFA Metabolism in the Skin

The enzymes involved in PUFA metabolism are crucial. Unfortunately, the key enzyme, Æ6 desaturase enzymes and cannot convert LA to GLA nor DGLA to AA, but it can convert GLA to DGLA. The epidermis is therefore dependent on the continual formation of GLA and AA by the liver and on the transport to the skin by the blood.

Kassis et. al. (Arch. Dermatol. Res. 1983 275 9-13) proved that a person’s capacity to convert LA to GLA decreases with age, as do the levels of PGE1. Æ6 desaturase is inhibited by many exogenous factors such as diet, stress and aging. Therefore, a GLA deficit leads to: a lack of PG1, an off-balance PG1/PG2 ratio and various cutaneous problems related to aging, such as skin dryness, itching, erythema and skin thinning. A well-balanced oil has to be supplemented to counter this consequence of aging by circumventing the key Æ6 desaturase stage.

Benefits of Topical EFAs

Topical application studies proved that PUFA or preferably PUFA-rich vegetable oils (released by the skin esterase) are beneficial to the skin. Prottey et. al. (J. Invest. Dermatol. 1975 64 228-234) demonstrated that, after cutaneous application of sunflower seed oil, which is rich in LA, to the right forearm of EFAD volunteers for two weeks, the level of LA in their epidermal lipids was markedly increased, the rate of TEWL was significantly lowered and the scaly lesions had disappeared. No such changes were seen in the volunteers’ left forearms after cutaneous application of olive oil (containing nearly no LA (Chart 2).

Proksch et. al. (Br. J. Dermatol. 1993 128 473-482) demonstrated that disrupting the barrier function by topical acetone treatment results in an increase of free fatty acids, sphingolipids and cholesterol in the living layer of the epidermis, leading to barrier repair. DNA synthesis is also stimulated the same way as by occlusion. This is a possible second mechanism by which the epidermis repairs its barrier function of omega-6 PUFA limits DNA synthesis and helps restore the barrier function.

Coupland (Active Ingredient Conference Paris 1997 195-201) described how damaged or inflamed skin can be treated with oils containing GLA and SDA due to a reduction in inflammatory metabolites: PG. Photo-damaged skin may also benefit from these natural oils by inhibiting the secretion of TNF∝. Morganti et. al. (J. Appl. Cosm. 1985 3 211-222) showed that EFA application improves skin’s hydration capacity and protects aged skin against environmental insults. A cream containing 3% EFA prevents much better skin atrophy induced by a cortisone like compound which accelerates the skin’s aging process (Chart 3).

All these data point out the great benefits of topical PUFA supplementation with the right balance of PUFA for helping:

• correct the consequences of dry skin (more by structural change than by occlusivity);
  
• contribute to skin aging prevention and
  
• provide relief for skin inflammatory condition.
  

The Wonder Oil

Hemp seed oil’s unique composition makes it the optimal active ingredient choice. It possess one of the highest PUFA contents but also has a perfect balance, providing the four essential fatty acids beneficial to the skin: LA, GLA, LNA, and SDA. Table II provides a comparison among the fatty acid profiles between many popular cosmetic oils.

No other oil provides the necessary EFAs with the right balance. Although any PUFA-containing oil is good, an oil such as hemp seed oil (with the right biological ratio between omega-3/omega-6) provides all the benefits. Hemp seeds oil’s fatty acid profile as well as some of the other valuable constitutes is illustrated in the pie chart above (Chart 4).

Hemp seed oil is pressed from a safe vegetable , hemp, which is a fiber-type weed of the Cannabis sativa species. The plant has dark green leaves and grows worldwide. Cannabis sativa can be separated into two categories:

• Hemp (drug type): the leaves are rich in THC (Δ9 tetrahydrocannabinol) do not contain its precursor CBD (cannabidiol), and is used for its psychotropic properties;
  
• Hemp (fiber type): contains very low levels of THC and does contain CBD.
  

In France, several hemp varieties are authorized for crops because they contain only traces of THC (less than 0.3%). It is very easy to check the quality of the seeds by chromatography. The seeds do not need to be sterilized, which allows the vitamin content to remain unchanged.

So even if hemp seed oil is described by its INCI name (Cannabis sativa seed oil) it contains only traces of THC (less than 10 ppm for selected oils) and is perfectly safe for nutritional and cosmetic use.

Dr. U. Erasmus’ book: Fats that Heal, Fats that Kill, (1993, Alive Books Canada), praises hemp seed oil for its nutritional benefits. Hemp seed oil helps:

• Reduce LDL cholesterol and lower blood pressure for cardiovascular disease prevention;
  
• Alleviate painful rheumatoid arthritis after a 12-week treatment;
  
• Relieve the symptoms of PNS and menopause with one teaspoon a day for three months and
  
• Improve health by sustaining the immune system.
  

Dr. Erasmus also recommends hemp seed oil as a salad oil for its pleasant nutty flavor. Two tablespoons a day provide the daily EFA requirements.

Hemp Seed Oil in Cosmetics

In addition to its outstanding composition, hemp seed oil’s unique texture imparts excellent skin feel. It is non-greasy, has high fluidity and lubricity and is absorbed quickly and efficiently in the skin. In fact, hemp seed oil is considered the “driest” vegetable oil.

Hemp seed oil's unique texture and activity on the skin (including the scalp) targets it toward many beneficial uses in cosmetic products. It is recommended in skin care formulas (up to 10%) that protect or provide anti-aging benefits, as well as dry-, mature- and sensitive skin products. It can be used at 3% in hand, foot or body creams. It can be used at 10% levels in after-sun products as well as lipsticks, lip balms and nail treatments. Hemp seed oil can also be used (3%) in cosmetic powders, liquid makeup and glossy hair conditioners that strengthen or prevent splitting and thinning. It is recommended for use (up to 10% for atopic eczema, acne and psoriasis treatment) and may be used at full strength for aromatherapy purposes and in body and massage oils.

Hemp seed oil is an excellent active ingredient in all of the above cosmetic applications. Structuring for maximum profit in the millennium means including the versatile, cost-efficient and trend-setting ingredients that today’s market demands. Hemp seed oil is the right choice. Not only is it fashionable, but it is the natural solution to the industry’s need for a rich oil that tests boundaries. Hemp seed oil is defined by unique properties that indulge the consumer in countless benefits. When used as an active ingredient, hemp seed oil follows a trend that you can bank on.

About the Authors
Kristin Speiser is a freelance public relations specialist from New York, NY. Michael Pobeda is a general manager of Teco Finance Export, a French manufacturer specialized in unique oils and butters. Laurent Sousselier is director of EX.A International - France and may be reached at + 33.1.4287.9698 or by e-mail at exacosm@club-internet.fr.