Peanut Research

The evidence for the role of peanuts and peanut butter as a key food in a healthy diet is mounting. It is clear that incorporating frequent consumption of peanuts, peanut butter and other nuts into our everyday healthy eating habits can have big payoffs in terms of disease risk reduction. Inexpensive, tasty, versatile and nutritious, peanuts are truly one of nature’s original functional foods. 

For information on some of the most frequently asked questions about peanuts, browse through the following topics:

What is considered to be one serving of peanuts or peanut butter?

A serving of peanuts is considered to be ¼ cup (60 mL) and a serving of peanut butter is 2 tbsp (30 mL).

What nutrients are there in a serving of peanuts or peanut butter?

A serving of dry roasted, unsalted peanuts contains 9 grams of protein, has no sodium or cholesterol, and is:

  • a source of fibre, potassium, zinc, vitamin B6, riboflavin, phosphorus, folate, selenium, thiamin and pantothenic acid
  • a good source of vitamin E, copper and magnesium
  • an excellent source of niacin and manganese

A serving of natural peanut butter contains 7.5 grams of protein, has no sodium or cholesterol, and is:

  • a source of fibre, magnesium, zinc, phosphorus, thiamin, folate and pantothenic acid
  • a good source of copper and vitamin E
  • an excellent source of manganese and niacin

 How do peanuts compare nutritionally to nuts?

All nuts and peanuts contain similar nutrients and have a high proportion of heart-healthy monounsaturated and polyunsaturated fats. Per ¼-cup (60-mL) serving: walnuts have the highest omega-3 fat content; almonds have the highest vitamin E and calcium content; and peanuts have the highest protein, folate and niacin content.1 Also, peanuts contain more arginine than many other foods, which can help to open up blood vessels and allow blood to flow better.2,3

Why are peanuts and peanut products good food choices for people who have diabetes?

One key factor for diabetes prevention is healthy eating habits, coupled with weight control and physical activity.

Recent research from Loma Linda University found that adults with type 2 diabetes who consumed 1-1.5 servings (about 45 g) of peanuts and/or peanut butter as part of their daily American Diabetes Association (ADA) meal plan had better overall diets with cardioprotective properties compared to those who didn’t consume peanuts/peanut butter.4

Peanuts and other legumes can be important sources of fibre, and have a low glycemic index of 15, which is helpful in managing type 2 diabetes.5 In addition, nuts and peanuts have high proportions of unsaturated fat (monounsaturated and polyunsaturated), and offer magnesium and fibre, which all have a beneficial effect on reducing diabetes risk.

Are peanuts gluten-free?

Natural peanuts are gluten-free, but some peanut products, such as peanut butter or dry roasted nuts may contain traces of wheat. If you follow a gluten-free diet, read labels carefully to ensure you’re purchasing only natural peanut products with no wheat-based additives.

How much protein is in a serving of peanuts or peanut butter?

A ¼-cup (60-mL) serving of dry roasted peanuts contains 9 grams of protein and a 2-tbsp (30-mL) serving of natural peanut butter contains 7.5 grams of protein. Nuts and peanuts (which are in fact legumes) are plant-based proteins and fit in the protein foods category as part of a healthy diet in Canada’s food guide.

How can peanuts help with weight management?

To help manage obesity or just to maintain a healthy weight, healthy eating habits, physical activity and sufficient sleep are essential. Peanuts can help, too. Peanuts are chock full of protein, fibre and essential vitamins and minerals. They are cholesterol-free and contain mono- and polyunsaturated fats – the good fats that are part of a healthy diet. They help you feel fuller longer than carbohydrate-based foods – making them perfect for snacking.

Should I be concerned about the fat content of peanuts and peanut butter?

Eighty-five per cent of the fat in peanuts is the ‘good’ unsaturated fat (about 52% monounsaturated and 33% polyunsaturated). Unsaturated fats are important in heart health as they help to lower blood cholesterol levels. A serving of the vast majority of peanut butters available in Canada is trans-fat-free. Peanuts and peanut butter are naturally cholesterol-free.

Should I be concerned about the amount of sodium in peanuts?

A common misconception is that peanuts and peanut butter are high in sodium. However, a ¼-cup (60-mL) serving of unsalted, dry roasted peanuts, as well as a 2-tbsp (30-mL) serving of natural peanut butter, each contain only 2 mg of sodium, and are considered sodium-free.

Peanut butter also contains much less sodium than people may think – most contains less than 140 mg of sodium per serving and is considered “low in sodium” by the Canadian Food Inspection Agency’s Industry Labeling Tool.

Are peanuts considered heart-healthy?

Around the world, studies have confirmed that regularly eating nuts and peanuts can help reduce the risk of coronary heart disease (CHD). Information from the Practice-based Evidence in Nutrition (PEN, February 12, 2014) database notes that: Data from clinical trials provides generally consistent evidence to suggest that consuming about 50 to 100 g (1.5 to 3.5 servings) of nuts or peanuts five times or more per week as part of a diet containing 35% energy as fat (high in mono- and/or polyunsaturated fatty acids) decreases total and LDL cholesterol in normo- and hyperlipidemic individuals. Effects appear to be dose-related, particularly among individuals with higher baseline LDL cholesterol levels and those who are not obese.

Canada’s McMaster University, site of the largest meta-analysis ever undertaken of the role of diet in heart disease, singled out nuts and vegetables for their strong association with reduced rates of coronary heart disease.6 Researchers at McMaster reported that consumption of 30 g of nuts per day (a small handful), combined with a Mediterranean dietary pattern (fruits, vegetables, whole grains, legumes) led to a 13% reduction of symptoms over one year in a study of 1,224 participants (men, aged 55 to 80 years, and women, aged 60 to 80 years) at high risk of heart disease.7

Furthermore, a Shanghai study of 75,000 middle-aged women aged 34 to 59 years pointed to the link between nut consumption and “a lower risk of coronary heart disease.”8 Another 2009 study that reviewed four large studies totaling over 160,000 men and women showed that eating about 1 ounce of peanuts daily can cut the risk of heart disease in half. This same study found that eating a small handful of peanuts 1 to 2 times per week decreases the risk by over 25%.9

The 2019 Canada’s food guide recommends consuming plant-based protein foods more often. Nuts, such as peanuts, are associated with decreased LDL-cholesterol.10

Do peanuts grow in Canada?

The Canadian climate isn’t very conducive to growing peanuts, which require sandy soil and warm weather. Peanuts are grown in a few isolated areas in Canada, but demand greatly exceeds supply. As a result, U.S. export statistics for 2019 show shipments of all peanuts and peanut products to Canada at 127,465 metric tonnes.

Are food allergies life-long?

Children commonly outgrow food allergies. However, allergies to peanuts, nuts, fish and shellfish are usually life-long. 

If someone is allergic to peanuts, will they be allergic to other tree nuts, and vice versa?

Peanut is a part of the legume family and not tree nut; however, while peanuts and tree nuts are different, in some cases people with a tree nut allergy also react to peanuts. Consult your allergist before eating peanuts or any tree nuts that are not a regular part of your diet.11

Are there reasons why a peanut allergy is so severe?

Peanuts are a complex plant food, with more than 30 different proteins. Research is underway to identify exactly which proteins trigger an allergic reaction, and why the reaction can vary in severity among allergy sufferers. Peanut allergy appears to be progressive – subsequent reactions tend to be more severe. Health Canada has identified ten primary food allergens: eggs, milk, soy, tree nuts, peanuts, seafood (fish, crustaceans and shellfish), sesame, sulphites, mustard and wheat.

Are peanut allergies increasing?

Research indicates that all food allergies are increasing. Some hypothesize that the lack of early childhood exposure to potential allergens, such as infectious agents and parasites, has increased susceptibility to allergic diseases. It’s difficult to determine if the increased reports of food allergies in general and peanut allergy in particular are due to actual increases in incidence or a result of increased awareness among consumers and health professionals.

Can smelling a peanut cause a severe reaction?

No, simply smelling the aroma of peanuts is not the same as breathing in protein particles which would cause an allergic reaction. The chemicals which are detected as the odour of peanuts are aromatic molecules called pyrazines and are incapable of causing allergic reactions.

How many peanuts must be ingested to cause a reaction?

Recent evidence indicates that even trace amounts of peanuts can be enough to cause a major reaction in those very few individuals who are severely allergic.

Can anything be done to manage peanut allergy and prevent a reaction?

The only certain way to prevent a reaction is avoidance – there is no treatment to prevent peanut allergy. However, with proper management, awareness and education, most reactions to food allergens can be avoided.

Individuals with a food allergy should diligently read all food labels and ask questions about foods prepared away from the home (such as at school or a restaurant). In the day care or school setting, parents of a child with a food allergy should inform teachers and school staff, so they are prepared to recognize and treat severe allergic reactions immediately and seek first aid.

In consultation with their physicians, individuals who experience severe allergic reactions should always carry appropriate medication such as a self-injectable form of epinephrine (adrenaline) and should also consider wearing an identity bracelet or medallion to alert others if they have a problem.

How is a severe allergic reaction to peanuts treated?

Epinephrine, when prescribed by a physician, should be administered immediately to the individual suffering from a severe reaction to food. Emergency medical services must then be obtained for further treatment.

It is important to note that an injection of epinephrine does not cure the allergic reaction – it only alleviates the immediate reaction to allow the extra time necessary to seek emergency medical services.

Should peanut oil be avoided?

The process of refining oil removes the protein which would trigger an allergic reaction. Peanut oil (sometimes labelled as arachis oil) is commonly used as a component in vegetable oil, as a carrier in processed foods or as an emulsifier/lubricant in cosmetics. The oil is highly refined, and should pose no problem for those with allergies. However, oils which are cold pressed to retain their flavour or oil that has been used to cook peanuts do contain protein and therefore should be avoided.

Can a food be made less allergenic by cooking it?

No. A food allergy is an immune system response to a protein in a food. The protein remains in the food during heating, therefore, you cannot make a food less allergenic by cooking it.

Where can I learn more about peanut allergies?

Food Allergy Canada's website has a wide variety of resources and tools available, to provide additional, in-depth information about food allergies, including peanut allergies.

When should peanuts be introduced to infants and children?

In January 2019, the Canadian Paediatric Society (CPS) released updated recommendations on the specific timing of early introduction of allergenic foods for high-risk infants.12 The following guidance for practice is based on evidence supporting the early introduction of common allergenic foods to high risk infants:

  • Infants considered to be at high risk for allergenic disease have either a personal history of atopy (e.g. eczema) or a first-degree relative with atopy such as a parent or sibling.
  • For high-risk infants, and based on their developmental readiness for food, consider introducing peanut at around 6 months of age, but not before an infant is 4 months of age.
  • For infants at no or low risk for food allergy, introducing complementary foods at about 6 months is recommended.
  • Breastfeeding should be promoted for up to 2 years and beyond.
  • Allergenic foods should be introduced one at a time to gauge reaction, without unnecessary delay between each new food.
  • If an infant appears to be tolerating peanut, advise parents to offer if a few times a week to maintain tolerance. If an adverse reaction is observed, advise parents to consult with a primary care provider about next steps.
  • The texture or size of any complementary food should be age-appropriate to prevent choking.

The most striking evidence for early introduction of peanut was the Learning Early About Peanut (LEAP) prospective allergy study in the U.K. – the first randomized controlled trial to show that early peanut introduction could help prevent peanut allergy in high risk infants. In the study, 640 high-risk infants between the ages of 4 to
11 months were randomly assigned to either consume peanut protein at least 3 times per week, or avoid peanuts until they were 5 years old. Findings showed an overall relative risk reduction in peanut allergy of up to 80% with early peanut introduction.13

How should peanuts be introduced to young infants?

Canadian allergists suggest a few options for feeding peanut-containing foods to young infants. The simplest method is to combine 2 tsp (10 mL) of smooth peanut butter with 2-3 tsp (10-15 mL) of hot water, then allow to cool. This mixture can be offered alone, or added to 2-3 tbsp (30-45 mL) of infant cereal, pureed fruit or vegetables, or other soft food such as tofu or yogurt. This will provide 2 g of peanut protein in each serving. Once prepared, a small amount of this mixture can be offered to the infant on the tip of a spoon. After 10 minutes, if no symptoms develop, the remainder of the peanut-containing food can be given, at the infant’s usual pace of eating.14

It is not recommended to place the food on the skin first, as the food may cause irritation that could be misinterpreted as an allergic reaction. Skin contact with a food is not a way to determine if it will be tolerated when it is eaten. Whole peanuts are a choking hazard and should not be offered to children under four years of age.14

How much and how often should peanuts be fed to an infant?

Once peanut protein is introduced into the diet and tolerated, it should be consumed on a regular basis in order to maintain a tolerance. The total amount consumed per week should be a total of 6-7 g of peanut protein over three or more feedings, which would satisfy the recommendation made by the National Institute of Allergy and Infectious Diseases (NIAID) guidelines for early peanut introduction. Lesser amounts may be adequate, as long as there is regular exposure (e.g. several times a week).14

 Where can I learn more about peanut allergies and early introduction?

Food Allergy Canada is an excellent resource for more information early introduction research and guidelines.

Are organic peanuts available?

Yes, organic peanuts, peanut butter and other peanut products are available.

What are aflatoxins?

Aflatoxins are naturally occurring substances produced by soil-based moulds. Farmers, food manufacturers and the government work together to monitor, regulate and minimize the presence of this mould-based substance in the food supply.

When plants are subjected to severe drought and heat stress, the natural protective mechanisms in the plant breaks down and allows the growth of the moulds that can produce aflatoxins.

How are aflatoxins detected?

Farmers, food manufacturers and government work together to create a web of checks and balances that monitor, regulate and minimize this mould-based substance in the food supply. In the case of peanuts:

  • Farmers work to manage soil-based mould in the field
  • Shellers clean, sort, segregate and test the peanuts after harvest
  • USDA inspects peanuts and issues aflatoxin certifications to shellers
  • Processors and manufacturers sort the peanuts again and often times reclean them; they also blanch the peanuts, which further reduces the possible presence of aflatoxin 

Are peanuts genetically modified?

No, USA-grown peanuts are not genetically modified.

Will my child develop a peanut allergy if I eat peanuts and peanut butter while pregnant and/or breastfeeding?

There is a large volume of research available which supports that there is no correlation between peanut consumption during pregnancy or while breastfeeding with the development of peanut allergy. In 2013, the Canadian Paediatric Society (CPS) updated its advice to consumers to not restrict maternal diet during pregnancy or lactation, as there is no evidence that avoiding peanut or other potential allergens during these times helps to prevent allergy. This position statement from the CPS aligns with the current thinking in allergy prevention in the United States, Europe and Australia.

A study in 2003 that looked at the factors associated with the development of peanut allergy in childhood also found no link between breastfeeding and peanut allergy, and there was no difference in peanut intake during lactation between mothers with and without children with peanut allergy.15

 

Download this PDF with answers to all of the FAQs.

Peanut FAQs


References:

  1. Canadian Nutrient File, 2015.
  2. Palmer, R.M., Ashton, D.S., Moncada, S. Vascular endothelial cells synthesize nitric oxide from L-arginine. Nature 1998; 333:664-6.
  3. Huynh, N.N., Chin-Dusting, J. Amino Acids, Arginase and Nitric Oxide in Vascular Health. Clinical and Experimental Pharmacology and Physiology 2006; 33(1-2):1-8.
  4. Wien, et al., A randomized controlled trial to evaluate the effect of incorporating peanuts into an American Diabetes Association meal plan on the nutrient profile of the total diet and cardiometabolic parameters of adults with type 2 diabetes. Nutr J. 2014; 13:10. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3902416
  5. Jenkins, D., et al. Starchy Foods and Glycemic Index. Diabetes Care 1988; 11:2-149.
  6. Mente, A., et al. A Systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Archives of Internal Medicine 2009; 169(7):659-669.
  7. Salas-Salvado, J., et al. Effect of a Mediterranean diet supplemented with nuts on metabolic syndrome status: one year results of the PREDIMED randomized trial. Archives of Internal Medicine 2008; 168(22):2449-2458.
  8. Jiang, R., et al. Nut and peanut butter consumption and risk of type 2 diabetes in women. Journal of the American Medical Association 2002; 288(20):2554-2560.
  9. Sabate, J., et al. Nuts and health outcomes: new epidemiologic evidence. American Journal of Clinical Nutrition 2009; 89 (suppl):1S-6S.
  10. Canada’s Dietary Guidelines for Health Professionals and Policy Makers, Health Canada, 2019.
  11. Health Canada. Tree Nuts: One of the ten priority food allergens. 2012. http://www.hc-sc.gc.ca/fn-an/alt_formats/pdf/pubs/securit/tree_nuts-noix-eng.pdf
  12. Canadian Paediatric Society, 2019. Timing of introduction of allergenic solids for infants at high risk. https://www.cps.ca/en/documents/position/allergenic-solids
  13. Du Toit, G., et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy. N Engl J Med 2015; 372:803-813.
  14. Canadian Society of Allergy and Clinical Immunology and Food Allergy Canada. Early Infant Feeding Guidelines FAQs. 2017. http://csaci.ca/wp-content/uploads/2017/10/FAQs-for-early-infant-feeding-guidelines.pdf
  15. Lack, G., Fox, D., Northstone, K., Golding, J., Avon Longitudinal Study of Parents and Children Study Team. Factors associated with the development of peanut allergy in childhood. N Engl J Med 2003; 348:977-985.