Disease Prevention with Peanuts

People have enjoyed the delicious crunch of peanuts throughout history, but their nutritional value wasn’t recognized until recently. In the United States, it wasn’t until the 20th century that peanut butter, made up of 90% ground peanuts, became known as a good protein source.

Now, extensive research shows that peanuts, peanut butter, and peanut oil all help to prevent chronic diseases, including heart disease, diabetes, and cancer. Peanuts, peanut butter, and peanut oil have potent lipid lowering effects and may act to reduce inflammation, one of the underlying mechanisms contributing to chronic disease.1 Studies continue to show that the peanut’s unique nutrient profile and bioactive components play a beneficial role in many areas of health and disease prevention.

Jiang R, Jacobs DR Jr, Mayer-Davis E, et al. Nut and seed consumption and inflammatory markers in the multi-ethnic study of atherosclerosis. Am J Epidemiol. 2006;163(3):222–231. doi:10.1093/aje/kwj033.


Mortality

One of the most impactful measures in research is mortality, also known as death rate. When certain behaviors or practices are positively or negatively linked to mortality, it signifies that they should or should not be continued. For example, smoking is associated with death from certain cancers, which is why doctors recommend kicking the habit.

Dietary factors have also been shown to have effects on mortality. In fact, in several population groups (Caucasians, African Americans, and the elderly), studies show that when people eat more nuts, including peanuts, their risk of mortality from all causes decreases. (Fraser, 1997). And this benefit is especially pronounced for those who consume peanuts almost every day: when people eat a small serving of peanuts more than five times per week, the risk of mortality is reduced by more than 40%, when compared to those who eat peanuts less frequently.

Several studies have shown that eating nuts, peanuts, and peanut butter impact heart disease in particular. A study of Seventh-Day Adventists in 1992 found that eating more nuts and peanuts significantly decreased the risk of death from ischemic heart disease (Fraser, 1992). And the 1996 Iowa Women’s Health Study showed that increasing consumption of nuts, peanuts, and peanut butter reduced the risk of death due to coronary heart disease (Kushi, 1996).

Who would have thought that while enjoying the flavor of peanuts and peanut butter, we could also be promoting our longevity?


Heart Disease

Almost two decades ago, research pointed to the fact that frequently eating peanuts lowers the risk of heart disease. The effects are evident for people of all ages and genders, and even for individuals with various conditions, such as diabetes.1–3 Additional population studies have shown that peanuts may be one of the most commonly consumed cardio-protective whole foods. Heart disease risk is lowered with increased frequency of peanut consumption in the following studies:

  • Adventist Health Study1
  • Iowa Women’s Health Study4
  • Nurses’ Health Study2
  • Physicians’ Health Study5

About a handful of peanuts eaten five or more times a week can cut the risk of heart disease in half. 5 Even eating peanuts just twice a week can reduce your risk of death from heart disease by 24%.6 That means adding a small serving of peanuts to your diet can have preventative effects similar to that of certain prescription drugs!

Peanuts, peanut butter, and peanut oil are filled with heart-healthy monounsaturated and polyunsaturated fats. These fats lower total and “bad” LDL cholesterol as well as triglyceride levels, while keeping “good” HDL cholesterol high. A controlled study of people eating diets high in either peanut oil, peanuts and peanut butter, or olive oil, all of which are high in monounsaturated fat (MUFA), showed that levels of total cholesterol, bad LDL cholesterol, and triglycerides were lowered, while good HDL cholesterol levels remained high.7 In this study, a low-fat (STEP II) diet was also compared, although a diet high in peanuts lowered cholesterol, triglyceride levels increased. Similar effects were observed in a 2013 study: participants who ate peanuts, even peanuts with different flavorings, had lower levels of total cholesterol and triglycerides.8

Peanuts have low amounts of saturated fat, which is found in many animal products, and have no trans fat at all. A study by the U.S. Department of Agriculture found that levels of trans fat are non-detectable in all types of peanut butter—even the creamy kind.9

After much scientific evidence regarding the positive health benefits of peanuts and nuts, the U.S. Food and Drug Administration released a report in 2003 that states, “Scientific evidence suggests but does not prove that eating 1.5 ounces of most nuts, such as peanuts, as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease.”10

Studies also show that including peanuts in your diet as a source of protein lowers blood pressure, which can decrease heart disease risk. Peanuts have a unique mix of functional components, vitamins, and minerals that help the body prevent heart disease. Eating peanuts and peanut butter isn’t just delicious—it makes your heart happy, too!

1. Fraser GE, Shavlik DJ. Risk factors for all-cause and coronary heart disease mortality in the oldest-old. The Adventist Health Study. Arch Intern Med.1997;157(19):2249–2258.

2. Hu FB, Stampfer MJ, Manson JE, et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. 1998;317(7169):1341–1345.

3. Li TY, Brennan AM, Wedick NM, Mantzoros C, Rifai N, Hu FB. Regular consumption of nuts is associated with a lower risk of cardiovascular disease in women with type 2 diabetes. J Nutr.2009;139(7):1333–1338.

4. Kushi LH, Folsom AR, Prineas RJ, Mink PJ, Wu Y, Bostick RM. Dietary antioxidant vitamins and death from coronary heart disease in postmenopausal women. N Engl J Med.1996;334(18):1156–1162.

5. Albert CM, Gaziano JM, Willett WC, Manson JE. Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health Study. Arch Intern Med.2002;162(12):1382–1387.

6. Bao Y, Han J, Hu FB, et al. Association of nut consumption with total and cause-specific mortality. N Engl J Med.2013;369(21):2001–2011.

7. Kris-Etherton PM, Pearson TA, Wan Y, et al. High-monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations. Am J Clin Nutr.1999;70(6):1009–1015.

8. Jones JB, Provost M, Keaver L, Breen C, Ludy M-J, Mattes RD. A randomized trial on the effects of flavorings on the health benefits of daily peanut consumption. Am J Clin Nutr.

8. Sanders TH. Non-detectable levels of trans-fatty acids in peanut butter. J Agric Food Chem.2001;49(5):2349–2351.

9. U.S. Food and Drug Administration. Labeling & Nutrition – Summary of Qualified Health Claims Subject to Enforcement Discretion. Available at: http://www.fda.gov/food/ingredientspackaginglabeling/labelingnutrition/ucm072926.htm.


Artery Health

Peanut protein and bioactives help keep arteries healthy

An exciting study from Penn State University demonstrates a new way in which peanuts are heart healthy. This study is the first to show that combining peanut protein, bioactives, vitamins and minerals can help keep your arteries flexible.1

Key Findings:

  • First study to show that peanut protein and bioactives help keep arteries flexible
  • Peanuts prevent arteries from stiffening after a high-fat meal
  • After high-fat meals, peanuts reduce the rise in triglyceride levels by 32%


Peanuts Help Keep Arteries Flexible

The human body has up to 100,000 miles of arteries, veins and capillaries.2 These blood vessels carry oxygen and nutrients throughout the body and must remain flexible in order to work properly.

After a high-fat meal, levels of fat in the blood tend to rise rapidly, causing blood vessels to become stiff. Over time, this stiffening causes the heart to work harder, increasing the risk of heart attack and stroke.

In this study, participants who ate peanuts as part of a high-fat shake reduced the rise in blood triglycerides by 32% compared to a control shake. The control and peanut shakes were carefully designed to have the same fatty acid profile; therefore researchers attribute this response to peanut protein and bioactives.

Remarkably, peanuts also caused the participants’ arteries to remain open and flexible, despite the shake deriving a whopping 50% of its calories from fat.

Peanut Protein and Bioactives

Peanut protein, along with bioactives, vitamins and minerals, likely play a major role in preventing this stiffening response. Peanuts contain more protein than any other nut and more arginine than almost all other foods. This is important because arginine is used to make nitric oxide, a vasodilator that helps keep blood vessels open and elastic.

This study is unique because it is the first to show that peanut protein and bioactives work together to keep arteries flexible after a high-fat meal.

Decades of research show that the healthy mono- and polyunsaturated fats in peanuts lower blood cholesterol and significantly reduce the risk of heart disease.3 Peanuts received a Food and Drug Administration (FDA) Qualified Health Claim for Heart Health in 2003, and peanuts are also included on the list of foods certified by the American Heart Association’s Heart-Check program.

1. 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.

2. The Franklin Institute. The Heart: Engine of Life. Accessed 03-30-17 at: https://www.fi.edu/heart/blood-vessels.

3. Aune D, Keum N, Giovannucci EL, et al. Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies. BMC Med 2016;14(207).


Diabetes

Plant Protein Reduces Risk of Type 2 Diabetes

A major new study out of Harvard School of Public Health published in American Journal of Epidemiology shows consuming peanuts and peanut butter reduces type 2 diabetes risk.

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: Result
Total carbohydrate 22% lower risk of diabetes
Refined grains and sugar 19% lower risk
Animal protein 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.

This study provides evidence that peanuts and peanut butter are healthy food choices and, when substituted for meats and refined carbohydrates in the diet, can lower the risk of type 2 diabetes.


Blood Sugar

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 blood stream, 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 (Jenkins, 1981).

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 (Salmeron, 1997).

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 (Jenkins, 1981). In addition, low-GI diets can significantly improve long-term glucose control in people with diabetes, similar to the amounts achieved with medication (Ajala, 2013).

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 (Kirkmeyer, 2000 and Jenkins, 2011). 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 (Johnston, 2005).

Plus, snacking on peanuts can help maintain blood sugar in between meals. One study showed that snacking on peanuts in place of high-carbohydrate foods improved blood sugar control and lowered cholesterol in men and women with type 2 diabetes (Kirkmeyer, 2000 and Jenkins, 2011).

A recent study 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 (Mattes, 2012).

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 (Mooren, 2011). 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 (Alpher, 2003).

When individuals don’t consume enough magnesium, their risk of type 2 diabetes increases (Lopez-Ridaura, 2003; Larsson, 2007).

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 (Huerta, 2005) as well as inflammation and metabolic syndrome in middle age and older adults (Song, 2005).


Inflammation

Inflammation in the body is a mechanism thought to be at the center of the majority of chronic diseases. Certain inflammatory factors in our blood, like C-reactive protein (CRP), have been identified as predictors of cardiovascular disease. Fortunately, the foods you choose to eat can have an impact on inflammation. Population studies and smaller human studies have led to the understanding that some dietary factors may play a role in reducing inflammation (Nettleton, 2006). Certain fats, antioxidants, dietary fiber, arginine, and magnesium are components that have been shown to help regulate inflammation (Salas-Salvado, 2007). Foods with low glycemic loads have shown to decrease inflammation as well (Neuhouser ML). Fortunately, peanuts are chock-full of these anti-inflammatory ingredients.

A relationship has also been observed between frequent peanut consumption and reduced inflammatory factors (Jiang, 2006). This may be why peanuts are associated with a reduced risk of cardiovascular disease and diabetes.

Magnesium

Since many Americans don’t consume levels of magnesium that match the Recommended Dietary Allowance (RDA), a small number of peanuts daily is a great way to boost intake. A study at Purdue University showed that eating peanuts every day increases blood magnesium too (Alpher, 2003)!

For those who don’t get enough magnesium, one study showed that levels of inflammation-causing CRP was more likely to be elevated. Another study looking at more than 11,000 women from the Women’s Health Study showed that low magnesium intake was associated with an increased risk of inflammation (Song, 2005).


Other Diseases

So now we know peanuts can help improve cholesterol levels and reduce the risk of heart disease (the leading cause of death in the United States). But peanut consumption can improve your health in many other ways, too!

Blood Pressure

One-third of Americans have high blood pressure, and many may not even know they have it. High blood pressure increases your risk of heart disease and stroke, and scientists have learned that the dietary choices we make can have an impact on blood pressure (Appel, 1997). The Dietary Approaches to Stop Hypertension (DASH) eating plan was developed as a dietary pattern that combines nutrients that are thought to be effective at reducing blood pressure. And studies show it works—people sticking to the diet substantially lower their blood pressure.

When following the DASH diet, Nuts, including peanuts and peanut butter, plus seeds and beans, are eaten four to five times per week. Peanuts and peanut butter contain magnesium, potassium, fiber, arginine, and many bioactive components, each of which could be contributing to lowering blood pressure.

The OMNIHeart (Optimal Macronutrient Intake Trial for Heart Health) study took the DASH diet a step further (Appel, 2005). It followed the same diet principles, but tested optimal diet patterns by replacing saturated fat with three different macronutrients:

  1. Healthy carbohydrates
  2. Healthy unsaturated fats
  3. Protein (half from plant sources)

Peanuts and peanut butter were used in all thse diets, but they contributed most to the diet higher in plant protein (about 4 ounces per week). Because all the diets were healthy, they reduced the risk of heart disease and blood pressure; however, the protein diet and the unsaturated fat diet reduced this risk even further. Peanuts contributed healthy plant protein and healthy unsaturated fats to these diets in addition to micronutrients and bioactives. When part of a healthy diet, peanuts, peanut butter, and peanut oil, which is high in unsaturated fats, can help you keep this silent condition in check!

Stroke

In a 2012 study published in the American Journal of Clinical Nutrition, researchers found that people who consume foods rich in magnesium have fewer strokes. An intake of 100 milligrams of magnesium per day, which can be consumed in just 2 ounces of peanuts, was associated with a 9% decrease in risk of ischemic stroke. Compared to other nuts, those who consume peanuts and peanut butter achieve higher Recommended Daily Allowances (RDA’s) for many hard-to-get nutrients, including magnesium.

Cancer 

Peanuts don’t just have one nutrient that can help in preventing cancer; they have many! Unsaturated fats, certain vitamins and minerals, and many bioactives with cancer-preventing qualities are all packaged into one peanut kernel (Gonzalez, 2006).

There are many different types of cancer that target different parts of the body, but components in peanuts may work individually or together, and in all different ways, to prevent the progression of this complex disease.

Phytosterols

The relationship between phytosterols and cancer have been extensively studied (Woyengo, 2009). Phytosterols are found in peanuts and are known to reduce bad cholesterol. Plus, new evidence shows they may inhibit lung, stomach, ovarian, prostate, colon, and breast cancer. Phytosterols may prevent cancer cells from growing and spreading, and may cut off the blood flow to cancers. One of the main phytosterols in peanuts is called beta-sitosterol.

Researchers at the State University of New York at Buffalo found that phytosterols reduce prostate tumor growth by over 40% and decreased the chances of cancer spreading to other parts of the body by almost 50% (Awad, 2000; 2001).

Resveratrol

Resveratrol is another compound found in peanuts that has anti-cancer properties. Like phytosterols, resveratrol has been shown to cut off the blood supply to growing cancers and to inhibit cancer cell growth (Athar, 2006). With a number of bioactives helping to prevent disease and promote health, peanuts can help pack a punch to fight cancer!

Gallstone Disease

Gallstone disease occurs when your gallbladder doesn’t empty correctly, leaving too much cholesterol or bilirubin in your bile. Opinions vary as to why the prevalence of gallbladder disease has increased, and it is probably due to many reasons. One of the risk factors for gallstone disease is being overweight or obese, which has become more common over the last few decades in the U.S. Another risk factor is having high triglyceride levels or low “good” HDL cholesterol levels.

Little attention has been paid to how diet affects this disease, but what we eat could very well be having an impact. One study that looked at over 80,000 women from the Nurses’ Health Study found that those who ate peanuts and peanut butter five times a week or more reduced their risk of gallbladder disease by as much as 25% (Tsai, 2004).

Peanuts are known to have beneficial effects on cholesterol levels, primarily due to their unsaturated fats. As a complex plant food, however, peanuts contain additional nutrients and bioactive compounds that are also likely to be contributing to this effect. In fact, authors of the study indicate that the reduced risk of gallbladder disease remained even when fat was factored out. Peanuts are certainly acting to help optimize how our bodies work and can improve our health when we eat a small amount daily.

Alzheimer’s Disease

Peanuts have high levels of niacin and are an excellent source of vitamin E, two nutrients that have been shown to protect against Alzheimer’s disease and age-related cognitive decline.

One study showed that, in almost 4,000 people 65 years or older, niacin from food slowed the rate of cognitive decline (Morris, 2003). In another study, 815 people over the age of 65 without Alzheimer’s disease were followed for almost four years. Although the consumption of vitamin E from supplements had no effect on the incidence of Alzheimer’s, vitamin E intake from food was beneficial (Morris, 2002). Those who ate the most peanuts reduced their risk of Alzheimer’s disease by 70%.

A study from the University of Georgia found that vitamin E levels in peanuts are more than 26% higher than what is reported in the U.S. Department of Agriculture Nutrient Database for Standard Reference (Shin, 2009). This means eating an ounce of peanuts provides 3 milligrams of vitamin E. This is 20% of the recommended intake for adults and 50% of the recommended intake for children.

Peanuts also contain resveratrol, another bioactive component recognized as being beneficial in Alzheimer’s disease and other nerve degeneration diseases (Chen, 2005). The many protective components in peanuts are just beginning to be understood. For the time being, we know that consuming a small serving of peanuts daily may help minimize the damaging effects of aging.