What is pine nut oil

Pine nut oil, also called pine seed oil or cedar nut oil, is a vegetable oil, extracted from the edible seeds of several species of pine. While the pine oil produced from the seeds of more common European [Pinus pinea, Pinus pinaster, Pinus cembra, Pinus mughus, Pinus nigra] and American pine [Pinus monophylla, Pinus cembroides] varieties is mostly used for culinary purposes ¹⁾, Siberian pines [Pinus sibirica, Pinus griffithii, Pinus sylvestris] (growing in Russia, Mongolia and Kazakhstan), as well as Korean pines [Pinus koraiensis] (growing mostly in China and North Korea) yield the seeds with the highest content of pinolenic acid, as well as antioxidants associated with medicinal uses ²⁾. Approximately 29 species of Pinus produce seeds, which have been used as a food item, at least by indigenous tribal cultures. Most of the edible nut bearing pines are haploxylon (soft) pines although several species are of the diploxylon (hard) pine group (Tables 1 and 2). The greatest number of pine species which bear edible nuts are found in North America, the largest group being the piñon pines of northern Mexico and south-western United States. These are a complex and highly variable group of small to medium sized trees that occur in localities with a semi-arid climate. About 13 species of piñon pines are known (Table 2). In Asia and the Near East, Pinus gerardiana, P. koraiensis , P. pumila and P. sibirica are important pine nut producing species. The nuts of Pinus sibirica and Pinus koraiensis are pressed commercially for the production of cooking oil. Pine nuts are rich in oil (31–68% by weight) and contain several unusual polymethylene-interrupted unsaturated fatty acids with a cis-5 ethylenic bond. These are the cis-5, cis-9 18:2; cis-5,cis-9,cis-12 18:3; cis-5,cis-11 20:2, and cis-5,cis-11,cis-14 20:3 acids, with a trace of cis-5,cis-9,cis-12,cis-15 18:4 acid. Their percentage relative to total fatty acids varies from a low of 3.1% (Pinus pinea) to a high of 30.3% (Pinus sylvestris), depending on the species. The major cis-5 double bond-containing acid is generally the cis-5,cis-9,cis-12 18:3 acid (pinolenic acid). In all species, linoleic acid represents approximately one-half the total fatty acids, whereas the content of oleic acid varies in the range 14–36% inversely to the sum of fatty acids containing a cis-5 ethylenic bond. Pinus koraiensis, a native plant of eastern Asia and commonly called the Korean pine nut, is one of the main types of commercial pine nuts. Pine nuts contain fatty acids with an unusual structure, e.g., Δ5-unsaturated polymethylene-interrupted fatty acids (delta5-UPIFAs) ³⁾. These fatty acids are the characteristic components of lipids obtained from conifer seeds and leaves ⁴⁾. Pinolenic acid (18:3, Δ5,9,12) is a major delta5-UPIFA present in pine nuts. Pinolenic acid (18:3, Δ5, 9, 12), which is an unusual omega-6 polyunsaturated fatty acids (PUFA) characterized by polymethylene-interrupted double bonds. The Korean pine (Pinus koraiensis) nuts have been used in Asia for various dishes. Lipid content of the Korean pine nut comprises 62% of the total weight of the nut ⁵⁾. The oil extracted from Korean pine nuts, also known as Korean pine nut oil, consists of 66% polyunsaturated fatty acids (PUFAs; 45% linoleic acid [C18:2, Δ9,12], 27% oleic acid [18:1, Δ9] and 15% pinolenic acid [C18:3]), 26% monounsaturated fatty acids (MUFAs; oleic acid [C18:1]), 5% palmitic acid (16:0), 2% stearic acid (18:0), 1% eicosenoic acid (20:1, Δ11) and 3% other Δ5-unsaturated polymethylene-interrupted fatty acids (delta5-UPIFAs) ⁶⁾, ⁷⁾.

Table 1. Pine species with edible nuts

Species	Natural Range	Remarks
Haploxylon (soft) pines
P. ayacahuite P. albicaulis P. cembra P. flexilis P. gerardiana P. koraiensis P. lambertianaP. monticola Piñon pines P. pumila P. sibirica P. strobiformis	Mexico, Central America Western Canada and United States Europe (Alps and Carpathian Mountains) Western Canada and United States E Afghanistan, Pakistan, N India E China, Japan, Korea, SE Siberia Western United States (California, Oregon) NW United States and adjoining Canada N Mexico, SW United StatesE Siberia, E China, Korea, N Japan Russia (Central Siberia), Mongolia N Mexico, SW United States	Traditional food for indigenous tribes Traditional food for indigenous tribes Locally important Traditional food for indigenous tribes Important in international trade Important in international trade Traditional food for indigenous tribes Traditional food for indigenous tribes A complex group of about 13 species. Many are important food sources (See Table 2) Locally important Nuts are ground into cooking oil Traditional food for indigenous tribes
Diploxylon (hard) pines
P. coulteri P. pinea P. ponderosa P. sabiniana P. roxburghii P. torreyana	United States (California) Mediterranean Europe and Near East W Canada and United States United States (California) India United States (California)	Traditional food for indigenous tribes Important in international trade Traditional food for indigenous tribes Traditional food for indigenous tribes Traditional food source Traditional food for indigenous tribes

[Source ⁸⁾]

Table 2. The pines of Mexico and the United States

Species	Natural Range	Remarks
P. catarinae	Mexico – Nuevo León	Seeds collected locally for food
P. cembroides	Mexico – Northern Sonora and Chihuahua south to Puebla	Nuts have very thick shells, sold in markets in Mexico
P. culminicola	Mexico – Nuevo León
P. discolor	Mexico – E Sonora, Chihuahua, Durango, San Luis Potosi USA – S Arizona, S New Mexico	Not sought after by humans because seed crops are generally small and seed coat is very hard
P. edulis	USA – Arizona, Colorado, New Mexico Mexico – NW Chihuahua	Important producer of pine nuts
P. quadrifolia	Mexico – Baja California Norte USA – S California	Locally important. Nuts have very thin seed coats
P. juarezensis	Mexico – Baja California Norte USA – Extreme S California	Seeds sold in markets along with seeds of P.edulis and P. monophylla
P. johannis	Mexico – Localized in Coahuila, N Zacatecas, S. Nuevo León	Seeds edible
P. lagunae	Mexico – Found only in a single restricted area in Baja California Sur
P. maximartinezii	Mexico – Isolated in the mountains of S Zacatecas, extremely rare	Large seeds; 20-25 mm long, unusually large, heavy cones
P. monophylla	Mexico – Baja California Norte USA – S California, Nevada, W Utah	Important producer of nuts. Only pine in the world with a single needle per fascicle
P. nelsonii	Mexico – Nuevo León, Tamaulipas, San Luis Potosi	Seeds collected with P. cembroides. Superior in flavour to P. cembroides
P. pinceana	Mexico – Coahuila, Hidalgo, Querétera, Zacatecas	Seeds collected for food
P. remota	Mexico – Chihuahua, Coahuila USA – W Texas	Common name is “papershell piñon.” Thin seed coat makes them especially attractive for human consumption

[Source ⁹⁾]

Table 3. Fatty acid composition of different the lipid sources

Fatty acids	Lard	Sunflower	Pinus pinaster
	g/100 total fat
Saturated
16:0	24.0	6.0	3.6
17:0	0.1	0.1	0.1
18:0	15.5	5.2	2.4
Monounsaturated
16:1	2.6	0.3	0.2
18:1	43.2	20.4	18.1
11- 20:1	0.7	0.8	1.0
Polyunsaturated
9,12- 18:2	11.6	64.1	55.9
9,12,15- 18:3	0.8	0.5	1.3
11,14- 20:2	n.d.1	n.d.	0.8
Δ5 olefinic acids
5,9- 18:2	n.d.	n.d.	0.7
5,9,12- 18:3	n.d.	n.d.	7.1
5,11- 20:2	n.d.	n.d.	0.8
5,11,14- 20:3	n.d.	n.d.	7.1
Others	1.5	2.6	0.9

[Source ¹⁰⁾]

Pine oil uses and benefits

The health benefits of pine nut oil have been investigated in several studies. Asset et al. ¹¹⁾, ¹²⁾ reported that pine nut oil consumption lowered the total cholesterol and triglyceride levels when compared with the consumption of other lipids such as sunflower oil, coconut oil, or lard in mice. In a study by Sugano et al. ¹³⁾, consumption of pine nut oil (22% energy) alleviated high blood pressure in spontaneously hypertensive rats after five weeks of feeding. Hughes et al. ¹⁴⁾ showed that providing a pine nut oil capsule prior to an ad libitum buffet lunch resulted in reduced food intake in overweight female subjects. Pasman et al. ¹⁵⁾ observed that cholecystokinin (CCK-8) and glucagon-like peptide-I secretion were higher in subjects who received a pine nut oil capsule than in those who received a placebo, thereby supporting the findings by Hughes et al. ¹⁶⁾. Pine nut oil administration to overweight postmenopausal women has reported to produce a significant increase of cholecystokinin (CCK-8) and glucagon like peptide-1 (GLP-1) ¹⁷⁾. Cholecystokinin (CCK-8) that is released from duodenal enteroendocrine cells into the blood stream in response to fatty acids or protein ¹⁸⁾. Cholecystokinin (CCK-8) suppresses appetite, and higher concentrations of CCK-8 produce larger appetite-suppressing events ¹⁹⁾. Other hormones that are important are glucagon like peptide-1 (GLP-1), peptide YY (PYY) and ghrelin ²⁰⁾. GLP-1 and PYY are both produced in the ileum, induced by passing fatty acids and carbohydrates. Higher concentrations decrease appetite ²¹⁾. However, unlike the appetite suppressing results of previous study by Hughes et al. ²²⁾, a more recent study involving 39 healthy women aged 18-45 y with a BMI of 23-30 kg/m² who took 3 g or 6 gram “PinnoThin” Korean pine nuts oil compared to placebo milk fat ²³⁾ no appetite suppressing effect of “PinnoThin” Korean pine nuts oil was found.

Dietary fatty acids, especially polyunsaturated fatty acids (PUFAs), play a major role in regulating immune function by modulating the production of lipid mediators involved in a variety of signaling pathways. In general, omega-6 polyunsaturated fatty acids (PUFAs) are known to promote hyperactive immune responses by providing substrates for proinflammatory lipid mediators; whereas consumption of omega-3 polyunsaturated fatty acids (PUFAs) results in the alleviation of proinflammatory responses ²⁴⁾. However, γ-linolenic acid [Gamma-linolenic acid or GLA] (18:3, Δ6,9,12), which is an omega-6 PUFA, was reported to suppress chronic inflammation by increasing the cellular levels of dihomo-γ-linolenic acid (20:3, Δ8,11,14) ²⁵⁾. Dihomo-γ-linolenic acid can compete with arachidonic acid (20:4, Δ5,8,11,14) as a substrate for cyclooxygenase and lipoxygenase.

Pinolenic acid, which is the positional isomer of γ-linolenic acid [Gamma-linolenic acid or GLA], can also be taken up and elongated to form eicosatrienoic acid (20:3, Δ7,11,14) ²⁶⁾. Chuang et al. ²⁷⁾ reported that pinolenic acid, taken up by cells, modified the fatty acid composition of cellular phospholipids, resulting in a decreased production of proinflammatory eicosanoids in the murine macrophage cell line. In contrast to the in test tube results, the production of proinflammatory lipid mediators was elevated in animals that were fed with pine nut oil ²⁸⁾. In a study that examined the effects of a five-week pine nut oil diet (22% energy) on immune parameters ²⁹⁾, the relative proportion of splenic CD4+ T lymphocytes, the splenic production of immunoglobulin G and E, and the leukotriene B4 released from peritoneal exudate cells were higher in rats that were fed with pine nut oil compared with those fed with safflower oil (a source of linoleic acid; n-6, 18:2, Δ9,12) or evening primrose oil (a source of γ-linolenic acid; n-6, 18:3, Δ6,9,12). Therefore, pinolenic acid has the potential to modulate the immune response via a mechanism that may be different from that of other omega-6 PUFAs in vivo. However, information regarding the effect of pine nut oil on immune function is limited.

Obesity has been associated with impaired immune function. It was reported that obese patients had an increased risk of infection ³⁰⁾ and poor antibody response to vaccination ³¹⁾. It was suggested that altered levels of circulating hormones and nutrients, such as glucose and lipids, might contribute to dysregulation of the immune cells ³²⁾. Several studies showed that adequate weight reduction could correct the altered immune response ³³⁾, which suggests that immune response could be improved by weight reduction in obese subjects.

Pine nut oil has been reported to have favorable effects on lipid metabolism in rats ³⁴⁾, blood pressurein rats ³⁵⁾, appetite control ³⁶⁾, and eicosanoid production ³⁷⁾. A study by Ferramosca et al. ³⁸⁾ showed that pine nut oil consumption led to less weight gain in mice that were fed with a 29% energy fat diet containing pine nut oil (17% energy). In another study by Ferramosca et al. ³⁹⁾, it was shown that the combination of conjugated linoleic acid and pine-nut-oil prevented a conjugated linoleic acid-induced fatty liver and improved insulin sensitivity in mice.

This study ⁴⁰⁾, showed that hepatic triacylglycerol accumulation was attenuated by pine nut oil replacement in high-fat diet-fed mice. Mice in the high-fat diet group with 45% of the energy from fat with 35% from lard and 10% from soy bean oil showed 30% higher hepatic triacylglycerol concentrations compared to the control group (10% of the energy from fat from pine nut oil or soy bean oil), but mice in the high-fat diet group with 45% of the energy from fat with 35% from lard and 10% pine nut oil group maintained hepatic triacylglycerol concentrations at the level of lean mice. Non-alcoholic fatty liver disease (NAFLD) induced by feeding the mice a high-fat diet (45% of the energy from fat) for 12 weeks in this study seemed to remain in the initial stage of a simple steatotic condition. A hepatic triacylglycerol content over 5% of the liver weight, which is the criteria for a fatty liver ⁴¹⁾, was not observed overall. On pathological observation, inflammation and hepatocyte degeneration were mild even in the mice in the high-fat diet group with 45% of the energy from fat with 35% from lard and 10% from soy bean oil. Meanwhile, the hepatic cholesterol level was lower in high-fat diet-fed mice, and pine nut oil had no effect on the hepatic cholesterol level. In another study by the same authors ⁴²⁾, showed that the consumption of high-fat diet, partially substituted with pine nut oil for 12 weeks, led to reduced weight gain, which was mainly due to less white adipose tissue in the mice. However, splenocyte production of IL-1β was significantly higher in mice that were fed with pine nut oil than in mice fed with soy bean oil. IL-1β is a proinflammatory cytokine that facilitates T cell proliferation and activation ⁴³⁾. In another study by Matsuo et al. ⁴⁴⁾, consumption of pine nut oil (22% kcal) for five weeks resulted in higher leukotriene B4 release from rat peritoneal exudate cells when compared with other oil groups. These results suggest that pine nut oil might have an immune-activating effect by facilitating the inflammatory response, the importance of which will require further study and whether pine nut oil affects the production of other inflammatory markers also.

Earlier studies in rats showed that maritime pine seed oil ⁴⁵⁾ lowers triglycerides, VLDL-triglycerides and VLDL-cholesterol compared to a diet enriched in oleic acid ⁴⁶⁾. The latter findings indicated that pine seed oil may be useful in lipid-lowering diets. In another animal study to assess the lipid-lowering and antiatherogenic properties of pine seed oil in apolipoprotein E-deficient mice ⁴⁷⁾, it was found pine oil feeding had no significant preventive effect on atherosclerosis lesion formation in the apo E-deficient mice compared to lard or sunflower. These data indicate that pine oil does not protect against atherosclerosis in the absence of apolipoprotein E. In contrast, triglycerides and VLDL + IDL-triglycerides levels were higher in mice fed pine oil than sunflower oil or lard.

Pine essential oil

Pine needle, bark, and cone essential oils of Pinus roxburghii were obtained in 0.053%, 0.001%, and 0.012%, respectively ⁴⁸⁾. Chemical compositions of Pinus roxburghii cone, needle, and bark essential oils revealed a total of 117 components, of which 111 were identified. A total of 95.5% of the pine cone essential oil of Pinus roxburghii was identified with major components being (E)-caryophyllene (26.8%), terpinen-4-ol (16.2%), with smaller amounts of δ-3-carene (6.8%) and α-humulene (5.0%). Examination of the needle essential oil yielded 98.3% identified components, mostly comprised of (E)-caryophyllene (31.7%), terpinen-4-ol (30.1%), α-humulene (7.3%), and α-terpineol (5.0%) ⁴⁹⁾. A total of 38 components were identified in the bark essential oil accounting for 98.6% of the composition. The major components were (E)-caryophyllene (34.5%) and eugenol (11.4%), along with linalool (6.4%), α-humulene (5.7%), α-terpineol (4.9%), and terpinen-4-ol (4.1%) ⁵⁰⁾.

The Pinus roxburghii essential oil compositions in this present study are very different in comparison with previous reports from Egypt ⁵¹⁾ and Pakistan ⁵²⁾. The pine needle and cone essential oils from Egypt indicated a remarkably different chemotype led by δ-3-carene, comprising 26.3% and 45.87% of the needle and cone, respectively, as oppose to the Nepalese sample, which contained only 2.3% and 6.8% of needle and cone oil, respectively. In addition, the presence of α-pinene [29.3% in the needle ⁵³⁾ and 41.9% in the stem ⁵⁴⁾] in essential oils from Pakistan is in stark contrast to the trace amount found in the Pinus roxburghii samples from Nepal. Pinus roxburghii needle and stem oils from Pakistan were also rich in δ-3-carene (14.2% and 16.3%, respectively) and (E)-caryophyllene (21.9% and 12.3%, respectively).

Both, the needle and cone essential oils of Pinus roxburghii, were screened for anti-microbial activity. Neither of the oils exhibited anti-bacterial activity (MIC ≥625 μg/mL against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli). The major components (E)-caryophyllene and α-humulene had previously shown moderate anti-bacterial activity against Bacillus cereus and Staphylococcus aureus, while terpinen-4-ol was inactive ⁵⁵⁾. Both the needle and cone oils, on the other hand, were notably anti-fungal against Aspergillus niger (MIC=156 and 39 μg/mL, respectively), and α-humulene was previously shown to be anti-fungal against Aspergillus niger ⁵⁶⁾. Both the needle and bark oils also showed in-vitro cytotoxic activity against MCF-7 cells at 100 μg/mL concentrations (70.9 ± 1.4% and 100% kill, respectively). The cytotoxicities of these essential oils are likely due to the high concentrations of terpinen-4-ol, (E)-caryophyllene, and α-humulene, which have been shown to be cytotoxic on MCF-7 cells ⁵⁷⁾. Pinus roxburghii cone oil was toxic to Artemia salina with LC50=11.8 μg/mL. The biological activities of P. roxburghii oil in this study are consistent with previous literature reports ⁵⁸⁾ and are consistent with the traditional medicinal uses of this plant.

The essential oil of Pinus eldarica showed considerable cytotoxicity on the HeLa and MCF-7 tumor cells with IC50 (IC50 is a measure of the effectiveness of a substance in inhibiting a specific biological or biochemical function. It is commonly used as a measure of a drug’s potency) of 0.038 and 0.032 µg/mL, respectively ⁵⁹⁾. It has been shown that terpens play an important role in cytotoxicity of essential oils ⁶⁰⁾. Cytotoxic activity of pine needle and pine bark oils of Pinus roxburghii against MCF-7 tumor cells at 100 μg/mL concentrations indicated 70.9 ± 1.4% and 100% cell toxicity ⁶¹⁾. A study by Sarvmeili et al ⁶²⁾ showed that leaf essential oil of P. eldarica contained β-caryophyllene (14.81%), germacrene D (12.95%), α-terpinenyl acetate (8.15%), α–pinene (5.68%), and α-humulene (5.89%) that could be responsible for its cytotoxic activity. Several studies have shown that β-caryophyllene oxide, germacrene D, and α-humulene possess significant cytotoxic activity against various tumor cell lines ⁶³⁾.

According to these data, essential oil and extracts of Pinus. eldarica had more cytotoxic effect on HeLa than MCF-7 tumor cells. These differences in susceptibility of different cells have been shown by other studies ⁶⁴⁾. It can be calculated from the findings of this study ⁶⁵⁾ that essential oil of Pinus eldarica could be considered as a potential cytotoxic candidate for further studies to achieve antitumor agents.

The findings of this study ⁶⁶⁾ demonstrate the larvicidal potentials of the essential oils of Pinus sylvestris against the common mosquito vectors. The results as determined by gas chromatography–mass spectrometry showed that oil of Pinus sylvestris has 3-Cyclohexene-1-methanol, .alpha., .alpha.4-trimethyl (27.1%) as its dominant constituent. These locally sourced essential oil can therefore be incorporated in the mosquito control measures, mostly in local areas where access to health facilities is extremely difficult.

Summary

It can be concluded that to date there is no single well designed human clinical trials that can unequivocally support the purported benefits and uses of pine nut oil as appetite supressant or as an effective weight control product. Some of the animal experimental results reviewed above show potentially promising effects for pine oil. However, more data are needed in human studies.