Food as Medicine: Pecan (Carya illinoinensis, Juglandaceae)

Pecan (Carya illinoinensis) is a member of the Juglandaceae family, which also includes other economically important North American trees, such as hickory (Carya spp.) and walnut (Juglans spp.).1,2 Fossil records show that the pecan tree can live up to a thousand years, and its existence predates human settlements in North America.3 Pecan can grow to a height of 150 feet with a seven-foot diameter.2-4 The deciduous, lanceolate leaves are alternate and odd-pinnately compound and are typically made up of 9-17 leaflets.4In the spring, the tree produces both male and female inconspicuous flowers that are often wind-pollinated.5,6 During the summer, the “fruit” of the tree grows in clusters of 3-6 one-inch oblong brown-shelled nuts, called endocarps, that contain two seeds that are referred to and sold in the market as pecans.4,5

The pecan tree initially requires well-drained soil with an adequate water supply; however, once established, it is drought-tolerant.7 Pecan trees are native to North America, and typically grow in the southern and midwestern regions of the United States and in the northern regions of Mexico.2,8Eighty percent of the world’s supply of pecans is grown and produced in the United States,2 but other countries, such as Mexico, Brazil, Peru, Israel, China, South Africa, and Australia also produce pecans on a large commercial scale.4,7 In the United States, pecans are grown and harvested commercially in 14 states. More than 75% of US pecans come from Georgia, New Mexico, and Texas, which produced 76 million, 67 million, and 61 million pounds, respectively, in 2014.9,10

Among tree nut consumption in the United States, pecans rank third behind almonds (Prunus dulcis, Rosaceae) and English walnuts (Juglans regia, Juglandaceae), respectively.10 In 2014, the global pecan crop totaled 264.2 million pounds or 132,075 US tons and was valued at $517 million, a 12% increase from 2013. In terms of pecan exports, Hong Kong and Vietnam remain the primary markets for in-shell pecans from the United States. Canada and the Netherlands are the primary markets for shelled pecans from the United States.

Phytochemicals and Constituents

Pecans contain essential fatty acids, 17 different vitamins and minerals, and phenols and phytosterols.4They are calorie-dense and have a high-fat content.7 Of all culinary nuts (though the pecan nutmeat is botanically considered a drupe), pecans have the second-highest fat content after macadamia (Macadamiaspp., Proteaceae).11 Pecans are low in saturated fats but are a rich source of monounsaturated fatty acids (MUFAs), primarily oleic acid, and polyunsaturated fatty acids (PUFAs), predominantly linoleic acid (omega-6).4 Diets with higher intakes of MUFAs and PUFAs and lower intakes of saturated and trans fats correlate with a lower risk for cardiovascular disease (CVD).

Compared to other nuts, pecans have an especially high antioxidant content.12 Specifically, pecans contain bioactive compounds such as phenols, condensed tannins (e.g., proanthocyanidins, or PACs), hydrolyzable tannins (e.g., derivatives of gallic and ellagic acids), and tocopherol isomers that contribute to their antioxidant activity.12,13

Phenolic acids, such as gallic acid, may inhibit the growth of a variety of bacteria.14 PACs exhibit antimutagenic properties and antioxidant effects,1 specifically by inhibiting lipid oxidation in both foods and in human cells.15 A study that analyzed phenolic compounds from 18 different pecan cultivars in the United States found that the most abundant antioxidants present were PACs, as well as gallic and ellagic acids and their derivatives.12

Pecan shells have also been tested for bioactive compounds and reportedly contain higher amounts of phenolic compounds than the actual pecan nutmeat.13 Current research is exploring the use of teas prepared with pecan nut shells to treat liver damage in rat models, which may expand the role of pecans in the human diet.16 However, no human research has been conducted regarding the therapeutic use of pecan shells, so additional research is warranted to ensure safety.

Pecans are an excellent source of tocopherols, which are forms of lipid-soluble vitamin E, and exist as four different isomers: alpha, beta, gamma, and delta.4 Foods that are sources of vitamin E typically contain alpha-tocopherol and gamma-tocopherol. Pecans have unusually high gamma-tocopherol content: around 25 mg of gamma-tocopherol per 100 grams. Gamma-tocopherol has been observed to act as a stronger antioxidant in vivo than alpha-tocopherol.17 In addition, it has been suggested that gamma-tocopherol may also detoxify reactive nitrogen oxide species, and thus reduce inflammation in the body.

In addition, pecans contain phytosterols, also known as plant sterols, primarily in the forms of beta-sitosterol and stigmasterol, which may help lower cholesterol levels.12,18 In the small intestine, phytosterols compete with cholesterol for absorption and thus inhibit the body’s uptake and reuptake of cholesterol in the bloodstream. This can improve serum cholesterol levels and may reduce low-density lipoprotein (LDL) cholesterol by up to 10-14%.4 Different cultivars and the degree of ripening in pecans yield varying quantities of phytosterols, but all varieties provide these plant sterols.19

Historical and Commercial Uses

The word “pecan” likely comes from an Algonquian language. French traders recorded the word as pacanesor pecanes, which later evolved into its current common name.8 Native Americans consumed and stored pecans, but also traded them for furs and other goods.2 The low-water and high-calorie contents of pecans help them survive long storage.20 A historical record from the mid-1500s by the Spanish explorer Álvar Núñez Cabeza de Vaca revealed that Native Americans in south Texas would gather pecans in autumn and then grind them and soak them in water to make a milky beverage to sustain them throughout the winter.4This liquid also formed the base of a fermented beverage called powcohicora. Native Americans also used ground pecan meal to thicken stews and roasted the pecans for sustenance on long journeys.3

In addition to using the pecan nuts as a food source, the Kiowa tribe of the Great Plains area of the United States used decoctions of the tree bark to treat tuberculosis.21 The Comanche Nation used a poultice of pulverized pecan tree leaves as a topical treatment for ringworm-infected skin.

Although it can be used as a source of wood,3 the pecan tree is primarily grown and commercialized for its nuts. In order to reduce waste, different uses for pecan shells are being researched more extensively. Pecan shell mulch is available in areas that produce pecans commercially; however, its high tannin content may inhibit the growth of certain plant species. In addition, pecan shells can be used like wood chips to smoke and barbeque meats.

Due to its wide distribution throughout the state and long history of cultivation, the pecan tree became the official state tree of Texas in 1919.3 Texas also officially recognized pecan as its state health nut in 2001, and named pecan pie as the state pie in 2013.22

Modern Research

Currently, most research conducted on pecan consists of epidemiological or population-based studies that analyze correlations between nut consumption and lowered risk of CVD.23 However, there have been some in vitro and clinical research studies that have investigated the effects of pecan consumption in regards to antioxidant capacity.

Cardiovascular Health

Nut consumption has been linked to lowered risk of cardiovascular events such as heart attacks.4,23Epidemiological studies suggest a 37% decreased risk for coronary heart disease when nuts are consumed at least four times a week compared to infrequent or no nut consumption.24 A systematic review and meta-analysis of 61 trials confirmed that increased intake of tree nuts was associated with lower total cholesterol, LDL cholesterol, apolipoprotein B (Apo B, the main protein constituent of LDL cholesterol), and triglyceride levels.25 The review also found that nut consumption correlated with markedly lower Apo B levels in patients with diabetes versus patients without diabetes. Because people with diabetes are at an increased risk for CVD, this finding is significant and should be explored further.

In a crossover study, participants were randomly assigned to consume either a pecan-enriched diet or the National Cholesterol Education Program Step 1 diet for four weeks. The participants switched diets for the following four weeks. When consuming the pecan-rich diet, participants demonstrated a decrease in concentrations of Apo B and an increase in Apo A1, which stimulates an uptake of high-density lipoprotein (HDL) cholesterol, beyond the values observed in the Step 1 diet.26 Decreased LDL and increased HDL cholesterol levels were also observed in participants while consuming the pecan diet. In addition, the pecan-enriched diet resulted in decreased plasma triglycerides.

A study assessed postprandial (post-meal) plasma antioxidant capacity in human subjects after pecan consumption, and found that participants who consumed 90 grams (about three servings) of whole pecans or pecans blended with water had significantly higher hydrophilic and lipophilic plasma oxygen radical absorbance capacity (ORAC; which measures antioxidant capability in blood), decreased LDL oxidation, and increased plasma catechin concentrations, compared to the control meal that matched the pecans in caloric, fluid, and macronutrient contents.27 This demonstrates the bioavailability and potential antioxidant action in humans after consuming pecans.

Similarly, a randomized controlled, crossover trial assessed the impact of the addition of pecans to the diet on cholesterol levels and antioxidant capacity. Twenty-four healthy participants were assigned to either a control diet with no pecans or a pecan-enriched diet for four weeks, and then switched diets for another four weeks.15 The results showed that during the consumption of the pecan-enriched diet, participants significantly increased serum gamma-tocopherol (normalized to total cholesterol) while decreasing plasma LDL levels and inhibiting lipid peroxidation and degradation. Total antioxidant activity was not significantly different between groups.

Type 2 Diabetes

Though the mechanism of action is not fully understood, an inverse relationship has been observed between nut consumption and risk for developing type 2 diabetes.28 The Nurse’s Health Study suggested that a higher intake of MUFAs and PUFAs may contribute to improved insulin sensitivity.

For individuals with type 2 diabetes, it appears that nut consumption has a neutral impact on blood glucose and insulin levels.28 This makes nuts a healthy option for people with diabetes looking to lower their risk of CVD while having minimal impact on their blood glucose levels. Though the caloric intake associated with adding nuts to the diet is a concern, especially for those with, or at risk for, type 2 diabetes, the evidence that increased nut intake is associated with weight gain is inconclusive. Some studies show slight weight gain and others show weight maintenance or even loss with the addition of nuts to a calorie-controlled diet.28,29

Consumer Considerations

Like many other nuts, pecans contain phytic acid, which can block or reduce absorption of important minerals, including calcium, magnesium, iron, and zinc.4 The process of soaking or drying the pecans prior to consumption can reduce the phytic acid content. Pecans are also high in oxalates, so individuals with a history of calcium oxalate kidney stones should consider limiting intake of pecans to prevent complications.

Pecans are in the class of tree nuts, which are fairly common food allergens. It is estimated that about 1% of the population (about three million people) in the United States suffers from tree nut and/or peanut (Arachis hypogaea, Fabaceae) allergies.4 These allergies can cause severe reactions, such as life-threatening anaphylaxis. Individuals with tree nut allergies should, therefore, avoid consumption of or exposure to pecans, and always read food ingredient labels to determine if there is any possible contamination from the processing facility.

Although more common in peanuts and Brazil nuts (Bertholletia excelsa, Lecythidaceae), nuts like pecans are susceptible to contamination with a mold called Aspergillus flavus, which produces aflatoxins, which are among the most carcinogenic substances known, and also have the potential to lead to mental impairment in children.4 To avoid this mold, it is important to purchase high-quality nuts from reputable grocery stores that keep them in a dry, cool environment. Because of their high-fat content, shelled pecans have a shorter shelf life than pecans in the shell and become rancid easily, so it is best to consume them soon after shelling or properly store them in the refrigerator or freezer.4,11 Purchasing them in the shell and roasting them at home can also safeguard against this fungal growth.11

Nutrient Profile30

Macronutrient Profile: (Per 1 ounce [approx. 28.4 grams])

196 calories
2.6 g protein
3.9 g carbohydrate
20.4 g fat

Secondary Metabolites: (Per 1 ounce [approx. 28.4 grams])

Excellent source of:

Manganese: 1.3 mg (65% DV)
Vitamin E: 7.6 mg (36.7% DV)

Very good source of:

Thiamin: 0.2 mg (13.3% DV)
Dietary Fiber: 2.7 g (10.8% DV)

Good source of:

Magnesium: 34 mg (8.5% DV)
Phosphorus: 79 mg (7.9% DV)

Also provides:

Iron: 0.7 mg (3.9% DV)
Potassium: 116 mg (3.3% DV)
Vitamin B6: 0.06 mg (3% DV)
Riboflavin: 0.04 mg (2.4% DV)
Calcium: 20 mg (2% DV)
Niacin: 0.3 mg (1.5% DV)
Folate: 6 mcg (1.5% DV)
Vitamin K: 1 mcg (1.3% DV)

Trace amounts:

Vitamin C: 0.3 mg (0.5% DV)
Vitamin A: 16 IU (0.3% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000-calorie diet.

Recipe: Pecan Pie Energy Bites

Courtesy of Gluten Free Vegan Pantry31

Ingredients:

  • 2 cups Medjool dates, pitted
  • 1 1/2 cups pecans
  • 1/2 cup rolled oats
  • 1 teaspoon cinnamon
  • 2 tablespoons maple syrup

Directions:

  1. Process dates in a food processor on high for about 45 seconds, or until a date ball begins to form.

  2. Add pecans and process for another 1-2 minutes.

  3. Add remaining ingredients, scraping down the sides of the processor bowl if necessary, and process for another 1-2 minutes.

  4. Using a small ice cream scoop or 1-tablespoon measure, portion

    out

    the mixture and roll into balls. Place on a parchment paper-lined baking sheet and place in the refrigerator for 15-20 minutes.

  5. Store in an airtight container in the refrigerator for up to a week.

References

  1. Villarreal-Lozoya JE, Lombardini L, Cisneros-Zevallos L. Phytochemical constituents and antioxidant capacity of different pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars. Food Chemistry. 2007;102:1241-1249.
  2. National Geographic Society. Edible: An Illustrated Guide to the World’s Food Plants. Lane Cove, Australia: Global Book Publishing; 2008.
  3. Pecan Tree: Texas State Tree. State Symbols USA website. Available at: www.statesymbolsusa.org/symbol-official-item/texas/state-tree/pecan-tree. Accessed October 16, 2017.
  4. Murray M. The Encyclopedia of Healing Foods. New York, NY: Atria Books; 2005.
  5. Plants Profile for Carya illinoinensis (pecan). United States Department of Agriculture website. Available at: http://plants.usda.gov/core/profile?symbol=cail2. Accessed October 16, 2017.
  6. Cheatham S, Johnston MC, Marshall L. The Useful Wild Plants of Texas, the Southeastern United States, the Southern Plains, and Northern Mexico. Volume 3. Austin, TX: Useful Wild Plants, Inc; 2009.
  7. Van Wyk B-E. Food Plants of the World. Portland, OR: Timber Press; 2006.
  8. Hall GD. Pecan food potential in prehistoric North America. Economic Botany. 2000;54(1):103-112.
  9. Lillywhite J, Simonsen J, Heerema R. US consumer purchases and nutritional knowledge of pecans. Horttechnology. 2014;24(2):222-230.
  10. Pecans. Agricultural Marketing Resource Center website. August 2015. Available at: www.agmrc.org/commodities-products/nuts/pecans/. Accessed October 16, 2017.
  11. Wood R. The New Whole Foods Encyclopedia. New York, NY: Penguin Books; 1999.
  12. Robbins K, Gong Y, Wells M, et al. Investigation of the antioxidant capacity and phenolic constituents of US pecans. Journal of Functional Foods. 2015;15:11-22.
  13. de la Rosa L, Vazquez-Flores A, Pedraza-Chaverri J, et al. Content of major classes of polyphenolic compounds, antioxidant, antiproliferative, and cell protective activity of pecan crude extracts and their fractions. Journal of Functional Foods. 2014;7:219-228.
  14. Prado A, Aragao A, Fett R, et al. Phenolic compounds and antioxidant activity of pecan (Carya illinoinensis (Wangenh.) K. Koch) kernel cake extracts. Grasas Y Aceites (España). 2009;(5):458.
  15. Haddad E, Jambazian P, Karunia M, et al. A pecan-enriched diet increases γ-tocopherol/cholesterol and decreases thiobarbituric acid reactive substances in plasma of adults. Nutrition Research. 2006;26:397-402.
  16. Müller L, Pase C, Burger M, et al. Hepatoprotective effects of pecan nut shells on ethanol-induced liver damage. Experimental and Toxicologic Pathology: Official Journal of the Gesellschaft Für Toxikologische Pathologie. 2013;65(1-2):165-171.
  17. Christen S, Woodall AA, Shigenaga MK, et al. γ-tocopherol traps mutagenic electrophiles such as NOx and complements α-tocopherol: Physiological implications. Proceedings of the National Academy of Sciences of the United States of America.1997;94:3217–3222.
  18. Alasalvar C, Bolling BW. Review of nut phytochemicals, fat-soluble bioactives, antioxidant components and health effects. British Journal of Nutrition. 2015;113 Suppl 2:S68-S78.
  19. Bouali I, Trabelsi H, Berdeaux O, et al. Analysis of pecan nut (Carya illinoinensis) unsaponifiable fraction. Effect of ripening stage on phytosterols and phytostanols composition. Food Chemistry. 2014;164:309-316.
  20. Pecan. Texas Texas Beyond History website. Available at: www.texasbeyondhistory.net/st-plains/nature/images/pecan.html. Accessed October 16, 2017.
  21. Moerman D. Native American Ethnobotany. Portland, OR: Timber Press; 1998.
  22. Texas State Symbols. Texas State Library and Archives Commission website. August 30, 2017. Available at: www.tsl.texas.gov/ref/abouttx/symbols.html. Accessed November 9, 2017.
  23. O’Neil C, Keast D, Fulgon V, Nicklas T. Tree nut consumption improves nutrient intake and diet quality in US adults: an analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2004. Asia Pacific Journal of Clinical Nutrition. 2010;19(2):142-150.
  24. Kelly J, Sabaté J. Nuts and coronary heart disease: an epidemiological perspective. British Journal of Nutrition. 2006;96 Suppl 2:S61-S67.
  25. Del Gobbo L, Falk M, Feldman R, et al. Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials. American Journal of Clinical Nutrition. 2015;102(6):1347-1356.
  26. Rajaram S, Burke K, Connell B, et al. A monounsaturated fatty acid-rich pecan-enriched diet favorably alters the serum lipid profile of healthy men and women. Journal of Nutrition. 2001;131(9):2275-2279.
  27. Hudthagosol C, Haddad E, McCarthy K, et al. Pecans acutely increase plasma postprandial antioxidant capacity and catechins and decrease LDL oxidation in humans. Journal of Nutrition. 2011;141(1):56-62.
  28. Lovejoy J. The impact of nuts on diabetes and diabetes risk. Current Diabetes Reports. 2005;5(5):379-384.
  29. Morgan W, Clayshulte B. Pecans lower low density lipoprotein cholesterol in people with normal lipid levels. Journal of the American Dietetic Association. 2000;100:312-318.
  30. Basic Report: 12142, Nuts, pecans. National Nutrient Database for Standard Reference Release 28. United States Department of Agriculture Agricultural Research Service. Available at: https://ndb.nal.usda.gov/ndb/foods/show/3681. Accessed October 16, 2017.
  31. Pecan pie energy bites – vegan + gluten free. Gluten Free Vegan Pantry website. April 24, 2015. Available at: www.glutenfreeveganpantry.com/pecan-pie-energy-bites-vegan-gluten-free/. Accessed October 19, 2017.

 

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Food as Medicine: Sesame (Sesamum indicum, Pedaliaceae)

Sesamum indicum (Pedaliaceae) is an annual flowering plant with fuzzy, slender, oblong leaves that are arranged opposite to one another on the stem. The plant reaches an average of two to four feet (0.6-1.2 meters) in height and produces small, bell-shaped pink, violet, or white flowers arranged closely to the stem. The plant produces oblong seed capsules that contain many small oval-shaped seeds.1 There are three color varieties of seeds: black, white, and red/brown. Sesamum indicum grows in well-drained soil in warm or hot climates and does not tolerate frost or poorly draining soil. It is, however, a robust plant that will grow in poor soil, drought, and high heat conditions where most other crops will not.

While the leaves of the plant are also edible, the sesame plant is grown primarily for its seeds, and the oil pressed from the seeds is an important commercial and medicinal product. Sesame seeds are possibly one of the oldest seed crops known to humankind. The exact origins of domestication are uncertain, but it is believed that sesame originated in Africa, and its cultivation and use spread to Egypt, India, the Middle East, and China. Currently, S. indicum is cultivated in dry tropical and subtropical regions of Asia, Africa, and South America.


Phytochemicals and Constituents

Although small in size, the sesame seed is densely packed with nutrients. Sesame seeds are rich in protein (approximately 20-25% by weight) and oil (approximately 50% by weight). Sesame additionally contains fiber, vitamin E, thiamine, riboflavin, niacin, and minerals, such as copper, zinc, magnesium, phosphorus, iron, and calcium. Sesame oil contains approximately 38% monounsaturated fat (MUFA) and approximately 44% polyunsaturated fat (PUFA). The unsaturated fatty acids oleic acid and linoleic acid account for the majority of the oil weight of the seed (more than 800 g/kg). Sesame seeds are low in saturated fat. PUFAs have anti-inflammatory, antithrombotic, antiarrhythmic, lipid-lowering, and vasodilatory properties.

Sesame seed may be of particular interest to those who follow vegetarian or vegan diets due to its amino acid and calcium contents. Unusual for a plant-based protein source, sesame has a mostly complete amino acid profile, missing only lysine. Sesame is rich in the amino acid methionine, which is often the missing amino acid in legume-based diets. Calcium is one of the predominant minerals found in sesame, along with manganese, phosphorus, and iron. One ounce (28 grams) of whole toasted sesame seeds contains approximately 28% of the daily value of calcium based on a 2,000-calorie diet. In comparison, one cup of nonfat dairy milk contains approximately 31% of the daily value of calcium. However, the bioavailability of the calcium content in plant foods is very different than that of animal-based products. Although the whole sesame seed contains a high amount of calcium, the degree to which the body is able to absorb this calcium is not well-studied.

Other constituents present in sesame include oxalic and phytic acids. These compounds may interfere with the absorption of certain nutrients. In addition, consuming high amounts of oxalates, which are derivatives of oxalic acid, may be problematic for individuals with a history of oxalate kidney stones.

While sesame has robust macronutrient and micronutrient profiles, other bioactive compounds present in the plant that have caught the attention of researchers. These compounds include phytosterols and a group of antioxidants known as lignans. Antioxidants are substances that can prevent or slow down the damage that reactive oxygen species (ROSs) can inflict on cells. Phytosterols possess similar chemical structures to cholesterol, which is not found in plants. When present in sufficient amounts in the diet, phytosterols have been shown to reduce cholesterol levels in the blood. The fat-soluble lignans (e.g., sesamin, sesaminol, sesamolinol, and sesamolin) are the most studied compounds in the sesame plant. Lignan glycosides, in which a sugar molecule is attached to a lignan, are also present in sesame, but are found only in the whole seed, and not in sesame oil. Although the lignan glycosides have no direct antioxidant role, these compounds within sesame seeds can be converted in the body to form sesaminol and thereby function as antioxidants.


Historical and Commercial Uses

The use of sesame as a food, medicine, and component of spiritual or ritual practices dates back more than 4,000 years in Egypt and the Middle East, spreading from these regions to India and Europe. In the Hindu tradition, the sesame seed represents immortality. In the Babylonian Empire (located in present-day Iraq; 18th century to 6th century BCE), sesame oil was used to make perfumes and medicine. Records reveal that ancient Egyptians also used sesame as a medicine, and the oil was used for ceremonial purification in 1500 BCE. Europeans first encountered sesame seeds when they were imported from India during the first century CE, and sesame seeds were brought to the United States from Africa in the 17th century.

Various preparations of the plant have been used for medicinal purposes. In Ayurveda, a traditional medicine system of India that has been practiced for millennia, powdered seeds were given orally in combination with a warm sitz bath containing a handful of bruised seeds for treatment of amenorrhea and dysmenorrhea. Topically, a poultice of seeds was applied to ulcers, burns, and scalds, and sesame seed paste was combined with ghee (clarified butter) to treat bleeding hemorrhoids. Sesame oil was commonly used as a base for perfume oils for anointing the body and hair and traditionally used as a hair wash to promote hair growth.

In traditional Chinese medicine, sesame is known as a yin tonic, which moistens dry tissues and increases body fluids. Due to these properties, the seeds were used to promote lactation in breastfeeding mothers. In Europe, the oil was rubbed onto eyelids or dropped into eyes for eye complaints and also used internally for treating gonorrhea. The leaves of the sesame plant were decocted and consumed to resolve bowel afflictions, such as dysentery and cholera.

In addition to its traditional medicinal uses, S. indicum continues to be an important food and lends itself to being prepared and used in a wide variety of ways. Grown predominately for sesame oil, the seeds themselves can be eaten raw or roasted.14When the seeds are hulled, they can be easily crushed into a flour or ground further into a paste. Hulled seeds are widely used in their ground form as a paste in Eastern Mediterranean and Middle Eastern cuisines. In Europe and North America, the seeds are mainly used for bakery products, such as sesame seed buns.

In most cultures, the seeds have traditionally been roasted or baked before consumption or prior to oil extraction, a practice that enhances the sweet, nutty flavor and aroma of the seed and produces darker-colored oil. Traditionally, the sesame seeds are cold-pressed for oil. In European and North American cultures, a hot-pressed and refined oil are more highly desired, since this creates a colorless and neutral oil, which is better suited for cooking and use in salad dressing. The young leaves of the plant can be eaten in stews, a practice seen in Africa today. In Korea, the leaves are used to make a kind of wrap eaten with meats and other vegetables. The sesame cake (leftover plant material after the oil has been removed from the seeds) is used for livestock feed and can serve as a subsistence food in times of scarcity. In African and Asian cuisines, the seeds are used in both sweet and savory dishes. With globalization, many cultural foods have traveled from their continents of origin to become commonly consumed in the United States and elsewhere. For example, tahini, or ground sesame seed paste, has emerged from the Middle Eastern culinary tradition as a familiar grocery store item in the United States.

Modern Research

Current research investigating the potential efficacy of S. indicum and its constituents covers a wide range of applications. Research on sesame’s lignan content and inherent antioxidant potential is most prolific, specifically on the synergy of action of the lignans in combination with vitamin E. Additionally, there were a number of studies on S. indicum published in 2016, adding to the body of evidence on the efficacy of therapeutic use and effective dosage.

Cardiovascular Disease Risk Factors and Serum Lipid Profile

Oxidative stress and inflammation play a large role in the development and progression of atherosclerosis. A cardioprotective diet and exercise are an important part of prevention and treatment. Two types of fats, polyunsaturated and monounsaturated fatty acids, are present in the sesame plant and have been reported to lower cholesterol. Other potential mechanisms for the cardioprotective effects of sesame have been described, and sesame oil may have multiple constituents that affect the atherogenic process in various ways.

The fat-soluble lignans in sesame may affect fat in the bloodstream and the ability of the liver to process fat, particularly triglycerides. A group of researchers cultivated a sesame variety that contained two times more sesamin and sesamolin than conventional sesame to observe the effect of these two compounds on health parameters. The results showed that consumption of these seeds compared to seeds of a conventional sesame variety effectively increased the activity of enzymes located in the liver and involved in fatty acid oxidation. This increase was correlated with a decrease in serum triglyceride levels. The researchers noted that it is unclear if these effects are solely a result of the difference in concentration in the fat-soluble lignans or if other compounds may be involved in the observed physiological activity of the seeds.

A 2016 systematic review examined scientific literature to discern the effect of dietary intake of sesame seed and its derivatives on the lipid profile and blood pressure of hypertensive and dyslipidemic individuals. Of the seven studies that fit the review criteria, most were not randomized, and those that were did not describe the blinding of participants or personnel. Five clinical trials on patients diagnosed with hypertension found significant results for the reduction in both systolic blood pressure (SBP) and/or diastolic blood pressure (DBP). Of the three studies that included a lipid profile, two found significant reductions in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) levels and one found a significant increase in high-density lipoprotein cholesterol (HDL-c) concentrations in the sesame treatment groups.

The dosage and administration of sesame to medicated hypertensive patients varied across studies. Positive outcomes for SBP (reduction by approximately 3%) and DBP (reduction by approximately 2%) were noted with as little as 7.6 grams per day of encapsulated black sesame flour, the use of sesame oil for 45-60 days, or 60 grams of encapsulated sesamin taken for four weeks.

Two studies examining the use of sesame flour in individuals with dyslipidemia found that it positively impacted lipid profiles. The exact mechanisms are still being studied. The reviewers noted, however, that further research with low risk of bias is necessary to obtain more conclusive results since the seven clinical trials reviewed contained a high risk of bias.

Both sesame seed and sesame oil have been studied for their cardioprotective benefits. Daily supplementation with sesame oil was shown to increase flow-mediated dilation levels, suggestive of an improvement in the vascular function, after meals when compared to supplementation with corn (Zea mays, Poaceae) or olive (Olea europaea, Oleaceae) oils in hypertensive men receiving medication. Furthermore, a randomized, double-blind, placebo-controlled trial showed supplementation with sesame paste ground from unhulled seeds improved lipid profiles and atherogenic lipid parameters in patients receiving treatment for type 2 diabetes. The researchers concluded that in addition to drug treatment, dietary modification using functional foods, such as sesame seeds, may have beneficial effects for the prevention of cardiovascular and diabetes complications. Additionally, a study using a substitution of 35 grams per day of sesame oil as the only edible oil for 45 days in hypertensive women resulted in significant decrease in serum TC, and SBP and DBP. However, this study was uncontrolled.

Neurodegenerative Conditions

While the underlying mechanisms remain unclear, sesame’s strong antioxidant capacity may be protective against neurodegenerative disorders. Antioxidant nutrients from food may play an important role in lessening the consequences of oxidative stress in cerebral ischemia (a type of stroke) and recirculation brain injury. Sesamin and sesamol have demonstrated the ability to elevate levels of alpha-tocopherol (a form of vitamin E) in the plasma, liver, and brain of rats, displaying an inhibitory effect on endogenous lipid peroxidation as well as oxidative DNA damage in rat plasma and liver and protective effects of hypoxia in neurons. Based on the strong antioxidant activities of sesame, it could be considered neuroprotective against cerebral ischemia and stroke, though further studies need to be conducted in support of this.


Consumer Considerations

Although not common, there is the potential for an allergic reaction upon consumption of sesame seeds or sesame oil. Since allergic reactions are mainly due to a protein found in the seed, there may be no reaction or less of a reaction to the oil, with the exception of cold-pressed oil. Cold-pressed oil may still contain varying amounts of protein.

Individuals who are predisposed to kidney stones or are chronically undernourished in calcium, vitamin D and phosphorus may exercise caution and consider total dietary intake of foods high in oxalic acid. Sesame seeds contain 1-2% oxalic acid, which may interfere with calcium, magnesium, and protein absorption in the body. Additionally, certain types of kidney stones are composed of oxalic acid. It is important to note that the hull of the seed contains the highest amount of oxalic acid. The presence of oxalic acid can be reduced significantly through processing of the seeds and in particular through sprouting the seeds prior to consumption. Cooking and toasting the seeds before consumption or pressing the seed for oil also can reduce levels of oxalic acid and maximize the bioavailability of sesame’s beneficial constituents. Additionally, some bioactive constituents of sesame are found in highest amounts in sesame oil produced from toasted or otherwise heated sesame seeds.

Nutrient Profile

Macronutrient Profile: (Per 1 tablespoon [approx. 9 grams] sesame seeds)

52 calories

1.6 g protein

2.11 g carbohydrate

4.47 g fat

Secondary Metabolites: (Per 1 tablespoon [approx. 9 grams] sesame seeds)

Very good source of:

Manganese: 0.22 mg (11% DV)

Good source of:

Calcium: 88 mg (8.8% DV)

Magnesium: 32 mg (8% DV)

Iron: 1.31 mg (7.2% DV)

Phosphorus: 57 mg (5.7% DV)

Also, provides:

Thiamin: 0.07 mg (4.7% DV)

Dietary Fiber: 1.1 g (4.4% DV)

Molybdenum: 2.66 mcg (3.6% DV)

Vitamin B6: 0.07 mg (3.5% DV)

Niacin: 0.41 mg (2.1% DV)

Folate: 9 mcg (2.3% DV)

Potassium: 42 mg (1.2% DV)

Riboflavin: 0.02 mg (1.2% DV)

Trace Amounts

Vitamin E: 0.02 mg (0.1% DV)

Vitamin A: 1 IU (0.02% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000-calorie diet.

Recipe: Sticky Sesame Bars

Courtesy of Camilla V. Saulsbury

Ingredients:

Bars:

  • Coconut or vegetable oil for greasing
  • 2 cups nuts (e.g., cashews, peanuts, pistachios, pecans)
  • 1 cup sesame seeds
  • 1/2 cup chia seeds or poppy seeds
  • 1/2 cup agave nectar or honey
  • 1/3 cup natural, unsweetened nut or seed butter (e.g., tahini, sunflower, or peanut)
  • 2 tablespoons virgin coconut oil, warmed until melted (do not substitute with vegetable oil)
  • 1 teaspoons vanilla extract (optional)
  • 1/4 teaspoon fine sea salt

Chocolate Drizzle:

  • 2 tablespoons virgin coconut oil, warmed until melted
  • 2 tablespoons agave nectar or honey
  • 2 tablespoons unsweetened, natural cocoa powder (not Dutch-process)

Directions:

  1. Line an eight-inch square baking pan with foil or parchment paper and grease the pan with coconut oil or vegetable oil.
  2. Place the nuts, sesame seeds, and chia seeds in a food processor and process until finely chopped. Add the agave nectar, nut or seed butter, oil, vanilla, and salt. Process, using on/off pulses, until the mixture is blended and begins to stick together and clump on the sides of the bowl.
  3. Transfer the mixture to the prepared pan. Place a large piece of parchment paper, wax paper, or plastic wrap (lightly greased with coconut or vegetable oil) atop the bar mixture and use it to spread and flatten the mixture evenly in the pan; leave the paper or plastic wrap to cover. Place the mixture in the freezer for 30 minutes.
  4. To prepare the chocolate drizzle: Mix the oil, agave nectar, and cocoa powder in a small bowl until blended. Remove the bar mixture from the freezer, uncover, and decoratively drizzle or spread with the chocolate mixture. Refrigerate for at least four hours or place in the freezer for one hour until the mixture is firm.
  5. Using the liner, lift the mixture from the pan and transfer to a cutting board. Cut into 20 bars. Store wrapped in plastic in the refrigerator for one week or freezer for up to three months.