Peanut (Arachis hypogaea L.) is a plant belonging to the Leguminaceae family that grows up to 60 cm in height and its pods are born and grow in the earth.
It is an important crop for the production of oil (25-28%) and protein (43-55%) (1).
The major peanut producers are China and India with a production that represents about 2 thirds of the world, followed by the USA.
Some peanut species:
- Arachis duradensis
- Arachis ipaensis
- Arachis thaliana
- Arachis porphyrocalix
Studies
Peanut consumption was associated with a lower relative risk of chronic diseases (2) and subjects who consumed peanuts 2+ times a week had a relative risk of coronary heart disease of 0.66 (CI: 0.46-0.94) (3).
In this study carried out on obese men, the consumption of 85 grams of peanuts during the meal favorably influenced the endothelial and triglycerine response (4).
Phenolic compounds
The phenolic content (mg / kg) of cinnamic acid, epicatechin, catechin, caffeic acid, p-coumaric acid, rutin, isoquercitrin, transferulic acid, resveratrol, luteolin, quercetin ranged from ND to 3.9, from 17.0 to 32 , 1 from 22.0 to 41.0, from ND to 1.2, from 0.6 to 57.9, from 2.3 to 5.4, from 0.0 to 0.4, from ND to 1.4, from ND to 0.8, from ND to 0.7, from ND to 6.5 and from ND to 0.9, respectively (5).
Arachis hypogaea has abundant amounts of anthocyanins and flavonols in the skin (6).
Safety
Peanuts can cause allergic reactions or intolerance in some people.
Peanut studies
References__________________________________________________
(1) Pandey MK, Wang H, Khera P, Vishwakarma MK, Kale SM, Culbreath AK, Holbrook CC, Wang X, Varshney RK, Guo B. Genetic Dissection of Novel QTLs for Resistance to Leaf Spots and Tomato Spotted Wilt Virus in Peanut (Arachis hypogaea L.). Front Plant Sci. 2017 Jan 31;8:25. doi: 10.3389/fpls.2017.00025. PMID: 28197153; PMCID: PMC5281592.
Abstract. Peanut is an important crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to map the quantitative trait loci (QTLs) for resistance to leaf spots and TSWV in one recombinant inbred line (RIL) mapping population of "Tifrunner × GT-C20" for identification of linked markers for marker-assisted breeding. Here, we report the improved genetic linkage map with 418 marker loci with a marker density of 5.3 cM/loci and QTLs associated with multi-year (2010-2013) field phenotypes of foliar disease traits, including early leaf spot (ELS), late leaf spot (LLS), and TSWV. A total of 42 QTLs were identified with phenotypic variation explained (PVE) from 6.36 to 15.6%. There were nine QTLs for resistance to ELS, 22 QTLs for LLS, and 11 QTLs for TSWV, including six, five, and one major QTLs with PVE higher than 10% for resistance to each disease, respectively. Of the total 42 QTLs, 34 were mapped on the A sub-genome and eight mapped on the B sub-genome suggesting that the A sub-genome harbors more resistance genes than the B sub-genome. This genetic linkage map was also compared with two diploid peanut physical maps, and the overall co-linearity was 48.4% with an average co-linearity of 51.7% for the A sub-genome and 46.4% for the B sub-genome. The identified QTLs associated markers and potential candidate genes will be studied further for possible application in molecular breeding in peanut genetic improvement for disease resistance.
(2) Hu FB, Stampfer MJ, Manson JE, Rimm EB, Colditz GA, Rosner BA, Speizer FE, Hennekens CH, Willett WC. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. BMJ. 1998 Nov 14;317(7169):1341-5. doi: 10.1136/bmj.317.7169.1341.
Abstract. Objective: To examine the relation between nut consumption and risk of coronary heart disease in a cohort of women from the Nurses' Health Study....Conclusions: Frequent nut consumption was associated with a reduced risk of both fatal coronary heart disease and non-fatal myocardial infarction. These data, and those from other epidemiological and clinical studies, support a role for nuts in reducing the risk of coronary heart disease.
(3) Kris-Etherton PM, Hu FB, Ros E, Sabaté J. The role of tree nuts and peanuts in the prevention of coronary heart disease: multiple potential mechanisms. J Nutr. 2008 Sep;138(9):1746S-1751S. doi: 10.1093/jn/138.9.1746S.
Abstract. Epidemiologic and clinical trial evidence has demonstrated consistent benefits of nut and peanut consumption on coronary heart disease (CHD) risk and associated risk factors. The epidemiologic studies have reported various endpoints, including fatal CHD, total CHD death, total CHD, and nonfatal myocardial infarct. A pooled analysis of 4 U.S. epidemiologic studies showed that subjects in the highest intake group for nut consumption had an approximately 35% reduced risk of CHD incidence. The reduction in total CHD death was due primarily to a decrease in sudden cardiac death. Clinical studies have evaluated the effects of many different nuts and peanuts on lipids, lipoproteins, and various CHD risk factors, including oxidation, inflammation, and vascular reactivity. Evidence from these studies consistently shows a beneficial effect on these CHD risk factors. The LDL cholesterol-lowering response of nut and peanut studies is greater than expected on the basis of blood cholesterol-lowering equations that are derived from changes in the fatty acid profile of the diet. Thus, in addition to a favorable fatty acid profile, nuts and peanuts contain other bioactive compounds that explain their multiple cardiovascular benefits. Other macronutrients include plant protein and fiber; micronutrients including potassium, calcium, magnesium, and tocopherols; and phytochemicals such as phytosterols, phenolic compounds, resveratrol, and arginine. Nuts and peanuts are food sources that are a composite of numerous cardioprotective nutrients and if routinely incorporated in a healthy diet, population risk of CHD would therefore be expected to decrease markedly.
(4) Liu X, Hill AM, West SG, Gabauer RM, McCrea CE, Fleming JA, Kris-Etherton PM. Acute Peanut Consumption Alters Postprandial Lipids and Vascular Responses in Healthy Overweight or Obese Men. J Nutr. 2017 May;147(5):835-840. doi: 10.3945/jn.116.246785.
(5) Park SH, Do MH, Lee JH, Jeong M, Lim OK, Kim SY. Inhibitory Effect of Arachis hypogaea (Peanut) and Its Phenolics against Methylglyoxal-Derived Advanced Glycation End Product Toxicity. Nutrients. 2017 Nov 4;9(11):1214. doi: 10.3390/nu9111214.
Abstract. Methylglyoxal (MGO) is a highly reactive dicarbonyl compound that causes endothelial dysfunction and plays important roles in the development of diabetic complications. Peanuts are rich in energy, minerals, and antioxidants. Here, we report the potential beneficial effects of peanuts, and particularly the phenolic contents, against MGO-mediated cytotoxicity. Firstly, we optimized the extraction conditions for maximum yield of phenolics from peanuts by examining different processing methods and extraction solvents. To estimate the phenolic contents of peanut extracts, a simultaneous analysis method was developed and validated by ultra-high-performance liquid chromatography-tandem mass spectrometry. We found that roasted peanuts and their 80% methanol extracts showed the highest amount of total phenolics. Secondly, we evaluated the inhibitory effects of phenolics and peanut extracts against MGO-mediated cytotoxicity. Phenolics and peanut extracts were observed to inhibit advanced glycation end product (AGE) formation as well as to break preformed AGEs. Furthermore, pretreatment with peanut extracts significantly inhibited MGO-induced cell death and reactive oxygen species production in human umbilical vein endothelial cells. Peanut extracts prevented MGO-induced apoptosis by increasing Bcl-2 expression and decreasing Bax expression, and MGO-mediated activation of mitogen-activated protein kinases (MAPKs). In conclusion, the constituents of peanuts may prevent endothelial dysfunction and diabetic complications.
(6) Zhao Z, Wu M, Zhan Y, Zhan K, Chang X, Yang H, Li Z. Characterization and purification of anthocyanins from black peanut (Arachis hypogaea L.) skin by combined column chromatography. J Chromatogr A. 2017 Oct 13;1519:74-82. doi: 10.1016/j.chroma.2017.08.078.
Peanuts 
Luteolin
