Peanuts Help Control Blood Sugar
The glycemic index (GI) is a point scale used to compare how high your blood sugar and insulin levels spike after eating the same amount of carbohydrates from different foods. Foods that are digested more slowly release sugar gradually into the bloodstream, so they have a lower GI and are healthier. The GI content of foods is measured on a 100-point scale, with 100 representing the highest GI foods. Peanuts have a GI of 14, making them a low GI food.
Another way to measure blood sugar after eating is by assessing the “glycemic load” (GL). This scale also measures blood sugar spikes, but uses the typical serving size of each food item instead of a standard carbohydrate amount, making it an even better tool to show how different foods can affect blood sugar.
Foods with a higher GI and GL can cause blood sugar and insulin to spike soon after eating, and after a meal, blood sugar can then drop even lower than before. This crash in blood sugar can make a person feel tired and hungry for more food, and this rollercoaster cycle of highs and lows can contribute to the development of pre-diabetes and diabetes. In addition, low-GI diets can significantly improve long-term glucose control in people with diabetes, similar to the amounts achieved with medication.
Peanuts and peanut butter are both low GI and GL foods, as they contain healthy oils, protein, and fiber that have a positive effect on blood sugar control. Research has shown that peanuts can help control blood sugar in both healthy individuals and those with type 2 diabetes. Peanuts and peanut butter have even been shown to help lessen the spike in blood sugar when paired with high-carbohydrate or high-GL foods.
A 2013 study by Reis and colleagues showed that, when eaten in the morning, peanuts and peanut butter positively impact blood sugar control throughout the day for women at high risk for type 2 diabetes. Not only did consuming 1.5 ounces of peanuts or peanut butter at breakfast help to decrease blood sugar spikes early in the day, but effects were also seen hours later when participants showed more even blood sugar control following a high-carbohydrate lunch in the absence of peanuts or peanut butter.
Their findings were later supported by a 2018 study from the University of the Incarnate Word, which investigated the effect of peanut butter consumption with a high glycemic index breakfast on blood sugar. Investigators found that when peanut butter was added to the high glycemic index meal, the spike in blood glucose was significantly lower than without peanut butter. They explained that this effect may be due in part to its high protein and healthy fat content.
Plus, eating peanuts/tree nuts can help with long-term blood sugar control. One study published in Diabetologia showed that eating mixed nuts (including peanuts) in place of high-carbohydrate foods improved long-term blood sugar control and lowered cholesterol in men and women with type 2 diabetes.
Peanuts vs. Almonds
If you think pricier almonds are healthier than peanuts, it’s time to think again. In a study comparing the effects of peanut or almond consumption on the health of diabetic patients, both were found to be equally beneficial.
Two groups of participants, a Peanut group and Almond group, were fed low-carb diets over 12 weeks. Each were instructed to consume approximately 2 servings of peanuts or almonds every day.
After 12 weeks authors found that both groups showed improvement in hemoglobin A1c levels (a marker of long-term glucose control) and glucose levels. In fact, peanuts improved both fasting glucose levels and 2-hr postprandial glucose levels (glucose levels tested 2 hours after a meal).
The authors noted that while nuts are routinely recommended for diabetics to help with glucose control, the higher costs of tree nuts can make them more difficult to acquire for some. Peanuts are a low-cost option that can help to keep diabetics healthy if consumed daily as part of a balanced diet.
Peanuts are a Good Source of Magnesium
Magnesium has been shown to play a role in reducing the risk of diabetes due to its positive relationship with how insulin is released and absorbed in the body. Peanuts contain 12% of the daily value for magnesium, making them a “good source” of the nutrient, according to the Food and Drug Administration (FDA). In one study, individuals who ate peanuts every day for three weeks not only had a higher intake of magnesium, but blood magnesium also improved to above recommended levels.
Clinical studies have shown that when individuals don’t consume enough magnesium, their risk of type 2 diabetes increases.
Magnesium also plays a role in metabolic syndrome, inflammation, and insulin resistance in people of all ages. Studies show an association between magnesium deficiency and insulin resistance in children as well as inflammation and metabolic syndrome in middle-aged and older adults.
Plant Protein Reduces Risk of Type 2 Diabetes
A major study from the Harvard School of Public Health shows that consuming peanuts and peanut butter reduces type 2 diabetes risk (Malik et al., Dietary Protein Intake and Risk of Type 2 Diabetes in US Men and Women, Am J Epidemiol, 2016).
Powerful Plant Protein
Harvard researchers assessed more than 20 years of data following more than 200,000 people in the United States. Their research centered on the relationship between plant and animal protein consumption and type 2 diabetes risk. Investigators found:
- Study participants who ate high levels of plant protein reduced their risk of type 2 diabetes by 9%.
- In contrast, those participants with diets higher in animal protein increased their risk of type 2 diabetes by 13% (see graph below)
- In the study, “whole grains and peanuts and peanut butter were the most commonly consumed major food sources of vegetable protein” (p. 9-10)
Healthy Substitutions Lead to Major Health Benefits in the Future
Substitution of 5% of energy from plant protein (legumes, peanuts, peanut butter, other nuts and whole grains) was made for an equal amount of total carbohydrate, refined carbohydrate, or animal protein. These substitutions resulted in a 19-23% reduced risk of diabetes:
Plant Protein Substitution For:
22% lower risk of diabetes
Refined grains and sugar
19% lower risk
23% lower risk
Substituting peanuts and peanut butter for animal protein, refined grains or potatoes resulted in 7-21% reduced risk of type 2 diabetes.
Substituting peanuts and peanut butter for processed meat resulted in the largest diabetes risk reduction (21%).
Peanuts and Peanut Butter are Healthy Food Choices for Type 2 Diabetes
Guidelines for preventing diabetes include maintaining an appropriate body weight, being physically active, and making healthy food choices.
Peanuts contain not only plant protein (in fact, they are higher in protein than other nuts), but they also contain fiber and polyunsaturated fatty acids. Protein, fiber and fat are crucial foods for maintaining satiety (feeling full) and supporting normal blood sugar levels—these are critical factors in maintaining your weight and preventing diabetes.
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Lesley N. Lilly, Cynthia J. Heiss, Sofia F. Maragoudakis, Kelli L. Braden & Scott E. Smith (2018) The Effect of Added Peanut Butter on the Glycemic Response to a High–Glycemic Index Meal: A Pilot Study, Journal of the American College of Nutrition, DOI: 10.1080/07315724.2018.1519404
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