Peanuts and peanut butter and peanut oil are energy and nutrient dense. Peanut oil's unsaturated lipid profile resembles that of olive oil.

All figures given are per 100g serving¹

• Energy values:                                                              

• Peanuts differ from other legumes by having a high oil content. 
• The high oil content of peanuts is composed of over 75% unsaturated fatty acids. Primarily oleic acid (monounsaturated fatty acid C18:1) and linoleic acid (polyunsaturated fatty acid C18:2).
• Peanut oil is nutritionally similar to olive oil in the proportions of fatty acids it contains, being high in monounsaturates and low in saturates (SFA), with monounsaturated oleic acid (C18:1) predominating:
  
  
  

  	SFA	MUFA	PUFA	MUFA +  PUFA
  Olive Oil	14.0	69.7	11.2	80.9
  Peanut Oil	18.8	47.8	28.5	76.3

  
  
• Both monounsaturated and polyunsaturated fat have been shown to decrease total and LDL-cholesterol levels when substituted for saturated fat, reducing the risk of coronary heart disease. Unsaturated fats have also generally been shown to help lower blood cholesterol levels^2,3,4.
  
• Peanuts contain no cholesterol.
• It is generally accepted that the majority of fats consumed should be unsaturated and that reducing the intake of saturated fats is the key dietary factor in reducing the risk of cardiovascular disease^5.  Replacing saturated fats with monounsaturated and polyunsaturated fats is more effective in preventing coronary heart disease in women than reducing overall fat intake⁶.
  This accords with the view that the "Mediterranean diet", in which monounsaturated fatty acids obtained from olive oil predominate and there are also high intakes of vegetables and fruit, is associated with lower rates of coronary heart disease⁷.
• Fatty acid fractions:

    * Calculated from total fat, minus non-fatty acid material present.

• The polyunsaturated linoleic acid in peanuts is also a source of "essential fatty acids", which the body cannot make sufficiently for itself and which must be present in dietary sources⁸. Ensuring adequate intakes of polyunsaturated fatty acids is a good way to encourage antioxidant vitamin E intake.
  
• The favourable fatty acid profile of peanuts means they can contribute to a mixed diet which reduces total fat and saturated fatty acid intakes overall. The DASH - Dietary Approaches to Stop Hypertension - Diet developed at Harvard University is one example⁹. 
   
  

1. Fruit and Nuts ed. B Holland, ID Unwin and DH Buss (1st Supplement to the 5th Edition of McCance and Widdowson's 
    The Composition of Foods ). Royal Society of Chemistry and Ministry of Agriculture, Fisheries and Food, Cambridge 1992.
2. MB Katan, SM Grundy and WC Willett "Should a Low-fat, High-carbohydrate Diet Be Recommended for Everyone? Beyond 
     Low-fat Diets" New England Journal of Medicine 1997; 337: 563-6, 567.
3. FB Hu, MJ Stampfer, JE Manson et al. "Dietary Fat Intake and the Risk of Coronary Heart Disease in Women" 
    New England Journal of Medicine 1997; 337: 491-9.
4. DJ O'Byrne, DA Knauft & RB Shireman "Low-fat Monounsaturated Rich Diets Containing High-oleic Peanuts Improve
    Serum Lipoprotein Profiles" Lipids 1997; 32(7): 687-95.
5. Scientific  Basis of Nutrition Education: A Synopsis of Dietary Reference Values Health Education Authority, London 1992.
6. See footnote 3.
7. LH Kushi, EB Lemart, WC Willett "Health Implications of Mediterranean Diets in Light of Contemporary Knowledge.
    1. Plant  Foods and Dairy Products" American Journal of Clinical Nutrition 1995; 61(suppl): 1470S-15S.
8. Unsaturated Fatty Acids: Nutritional and Physiological Significance British Nutrition Foundation, Chapman and Hall,
     London 1992.
9. LJ Appel, TJ Moore, E Obarzanek et al. "A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure"
    New England Journal of Medicine 1997; 336: 1117-24. 


 

Peanuts and peanut butter contain non-starch polysaccharides, both soluble and insoluble types.

All figures given are per 100g serving¹

• Diets high in non-starch polysaccharides have been shown to decrease and prevent the incidence of a number of illnesses including coronary heart disease, cancer of the colon and diabetes².
• NSP comprises:
  - water soluble fibre: found in oats, fruit and vegetables and legumes may have a role in reducing cholesterol  levels
  - water insoluble fibre: found in cereals - helps prevent constipation
• Both soluble and insoluble fibre are found in peanuts and peanut butter. Non-starch polysaccharides:

* figures have been rounded

• NSP levels in peanut butter are comparable to those found in many types of dried fruit, while the levels in raw and roasted peanuts are higher than common dried fruits such as prunes (5.7g/100g) and raisins (2.0g/100g).

1.   Fruit and Nuts ed. B Holland, ID Unwin and DH Buss (1st Supplement to the 5th Edition of McCance and Widdowson's 
     The Composition of Foods). Royal Society of Chemistry and Ministry of Agriculture, Fisheries and Food, Cambridge 1992.
2.  Committee on Medical Aspects of Food Policy Nutritional Aspects of Cardiovascular Disease Department of Health, London 1994. 

Major minerals and trace elements are found in peanuts, which are naturally low in sodium.

All figures given are per 100g serving¹

Calcium (Ca) For bone and dental health:

Chloride (Cl) Major element balancing sodium and potassium in cells:

Iodine (I) Necessary for regulation of metabolic rate, cellular metabolism and maintenance of connective tissue:

Iron (Fe) Essential for haemoglobin formation in red blood cells. raw kernels:

Phosphorus (P) Role in metabolism of carbohydrates and fats and transport of fatty acids.

Potassium (K) Enables electrolyte balance and efficient neuromuscular activity.  Higher intakes of potassium have been recommended because of a possible beneficial effect on elevated blood pressure. Peanut kernels are a significant
source of dietary potassium².

Zinc (Zn) Key role in enzyme systems and may have role in immune responses.

1.  Fruit and Nuts ed. B Holland, ID Unwin and DH Buss (1st Supplement to the 5th Edition of McCance
     and Widdowson's The Composition of Foods). Royal Society of Chemistry and Ministry of Agriculture,
     Fisheries and Food, Cambridge 1992.
2.  PK Whelton et al. "Effects of Oral Potassium on Blood Pressure: Meta-analysis of Randomized 
    Controlled Trials" Journal of the American Medical Association 1997; 277: 1624-32.

Literally "chemicals in plants", phytochemicals are non-nutritive natural constituents of nuts, legumes, seeds, fruits and vegetables. Their beneficial effects, particularly as antioxidants and plant hormone sources, are attracting increasing attention from researchers. Two phytochemicals being studied in peanuts, in terms of reduced cardiovascular disease and cancer risks, are resveratrol and plant sterols (beta-sitosterol).



RESVERATROL AND PEANUTS

What is resveratrol?
A phytoalexin, resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring phenolic compound helping protect peanut plants from disease.

Where is resveratrol found?
Resveratrol is most widely known for its presence in grape skins and red wine. Peanuts have a significant amount of resveratrol content in both the kernel and skin¹. The average amount of resveratrol in one ounce of commonly eaten peanuts without the skin (15 whole kernels) is 73µg. In comparison, almost 6 cups of grapes contain about the same amount of resveratrol and red wine contains approximately 160µg/fluid ounce. Roasting peanuts slightly reduces their resveratrol content².

Resveratrol may protect against heart disease
Resveratrol's presence in red wine has been associated with reduced cardiovascular disease. It has been credited as a factor in the "French Paradox" (despite a high-fat diet, the French have a surprisingly low rate of heart disease). There may be two reasons for this.

Resveratrol may protect against atherosclerosis. It acts as an anti-inflammatory agent to prevent the oxidation of the low density lipoproteins (LDL) in the blood vessels^3,4. This oxidation of LDL starts the depositing of cholesterol in the walls of arteries.
Resveratrol may also prevent platelet aggregation in blood vessels, which can form a clot causing a heart attack or stroke by blocking the vessel^5,6.

Resveratrol may protect against cancer
Resveratrol may help prevent cancer by stopping the growth of damaged cells in the human body⁷.Recent research suggests that resveratrol works in the body by "turning off" a specific protein, called NF-kB, which enables tumour cells to grow and survive. If this protein can be blocked, then cancer cells are more susceptible to apoptosis, a process the body uses to kill cells it no longer needs. The presence of resveratrol in tumour cell cultures had this effect under experimental conditions⁸.

PHYTOSTEROLS AND PEANUTS

What are plant sterols?
Plant sterols (phytosterols) are naturally occurring chemicals in plants, which are the counterparts of cholesterol in animal products, but with different and potentially very beneficial effects on the human body in terms of heart disease and cancer prevention.

Where are phytosterols found?
Plants with a high fat content and the oils and other products derived from them are generally good phytosterol sources⁹.

Peanuts, peanut butter and peanut derivatives - such as flour and oil - contain plant sterols: campesterol, stigmasterol and, particularly, b-sitosterol (SIT). Research has found that roasted snack peanuts contain 48-94 mg SIT / 100g depending on the variety. Regular peanut butter contains almost 135mg SIT /100g, making it a good source of this phytosterol. Peanut flour and refined peanut oil contain about 46mg SIT/100g and 153mg SIT/100g respectively. Refined peanut oil contains more phytosterols, particularly b-sitosterol (SIT) than extra virgin olive oil (145mgSIT/100g). As whole foods which naturally contain plant sterols, consumption of peanuts and peanut products thus provide convenient ways of including these beneficial constituents into the everyday diet¹⁰.

Phytosterols may protect against heart disease
Phytosterols have been recognised for their ability to block the absorption of cholesterol, both dietary and cholesterol synthesised in the body, from the gut and thus to exert a cholesterol-lowering effect¹¹. To achieve this health benefit, some products such as cholesterol-lowering margarines available in Europe and the United States, contain added phytosterols, including the same type of sterols naturally found in peanuts¹².

Phytosterols may protect against cancer
The ability of some phytosterols to inhibit human cancer cell growth and spread is attracting increasing research attention. Recent animal research with human cancer cells has shown that SIT may offer protection in this way against certain types of cancer, in particular colon, prostate and breast cancer. Tumour size in animals fed phytosterols was 33% smaller and they had 20% fewer metastases (spreading of tumour cells to other organs) than controls. This may be partly explained by the effect of beta-sitosterol inhibiting the growth and inducing apoptosis in cancer cells¹³.

     1.   Sanders TH and McMichael RW. Occurrence of resveratrol in edible peanuts. Book of Abstracts. Las Vegas, NV: 
           American Chemical Society: Washington, DC, 1997; Abstr. AGFD 214:33
     2.   Sanders TH et al. Occurrence of resveratrol in edible peanuts. J Agric Food Chem 2000; 48: 1243-1246.
     3.   Belguendouz L et al. Resveratrol inhibits metal ion-dependent and independent peroxidation of porcine low-density 
           lipoproteins   Biochem Pharmacol 1997; 53(9): 1347-1355
     4.  Soleas GJ et al Resveratrol: a molecule who time has come? and gone? Clin Biochem 1997; 30(2): 91-113
     5.  Bertelli A et al Plasma and tissue resveratrol concentrations and pharmacological activity Drugs Exp Clin Res 1998; 24(3): 133-138
     6.  Pace-Asciak CR et al Wines and grape juices as modulators of platelet aggregation in healthy human subjects Clin Chem Acta 1996;
          246(1-2): 163-182 
     7.  Jang M et al Cancer chemopreventive activity of resveratrol: a natural product derived from grapes Science 1997; 275:218-220
     8.  Holmes-McNary M and Baldwin AS Chemopreventive properties of trans-resveratrol are associated with inhibition of activation of  
          the IkB kinase Cancer Res 2000; 60(13): 3477-3483 
     9.   Weihrauch JL and Gardner JMC Sterol content of foods of plant origin J Am Diet Assoc 1978; 73: 39-47
   10.  Awad AB et al Peanuts as a source of b-sitosterol: a sterol with anticancer properties Nutr Cancer 2000; 36(2): 238-241
    11.   Law M Plant sterol and stanol margarines and health B Med J 2000; 320: 861-864 
   12.   Hendriks HF et al Spreads enriched with three different levels of vegetable oil sterols and the degree of cholesterol lowering in  
          normocholesterolaemic and mildly hypercholesterolaemic subjects Eur J Clin Nutr 1999; 53(4): 319-327 
   13.   Awad AB et al Dietary phytosterol inhibits the growth and metastasis of MDA-MB-231 human breast cancer cells grown in
          SCID mice Anticancer Res 2000; 20: 821-824

Proteins made by the body from the amino acids in food are the major constituents of human tissues. They are essential for growth and repair, with any excess being utilised for energy.

Peanuts and peanut butter contain all nine essential amino acids* (Table_1)and when consumed with other protein sources, they provide a protein source of equivalent quality to animal protein. Around the world, it is common to find peanuts consumed with wheat (breads), rice, corn (maize), other legumes and products made from them (pasta, noodles, etc) and with lean meat, poultry and fish. This helps to reduce reliance on animal protein foods that contain higher levels of saturated fats than peanuts.

• Raw peanuts are 25.6% protein and peanut butter is 22.6% protein by weight, making these foods attractive and affordable sources of protein for people of all ages (Table_2)
• In the UK's Balance of Good Health "plate" model for healthy eating, peanuts and peanut butter are part of the same food group as meat, poultry and fish protein.
• 2 tablespoons (30g) of peanut butter or 1 oz peanuts (30 g) can be substituted for 1 oz lean meat, poultry or fish Ref: Menu Planning in the National School Lunch Program, USDA, September 2000
• Like the other vegetable protein sources beans, peas and lentils to which they are related, peanuts and peanut butter are cholesterol-free.
  

Peanuts and Peanut Butter Servings Contribute to Daily Protein Requirements
A serving of peanuts is 30g (the size of a small handful) and a serving of peanut butter is two tablespoons (about the size of a golf ball), weighing 30g. Because each serving of roasted peanuts is almost one-quarter protein (24.5%), daily servings can make meaningful contributions to protein Estimated Average Requirements (EAR) for people of all ages (see box).

  











- Ref: UK Nutrient Databank 2001

Peanut protein and heart health¹

Levels of the amino acid arginine are higher in peanuts than in any other common nut or legume in the British diet. In addition to the beneficial effects of unsaturated fats which peanuts and peanut butter contain, this amino acid may contribute to heart health because arginine is the basis for the body's production of nitric oxide (NO), which relaxes smooth muscle cells in the walls of blood vessels (vasodilation). NO also has a role in inhibiting blood platelets from sticking together to form clots (adhesion and aggregation)



Table 1: Amino acid content of peanuts and peanut butter (mg/100g)

* = essential amino acid