Walnut vs Peanut - Health impact and Nutrition Comparison
In this article we are going to discuss the differences between peanuts and walnuts. Both of these are well-known, important crops grown worldwide. These nuts are some of the most loved snacks and today, we will dig a little deeper and find out if they are healthy, what their similarities, as well as their differences are.
Peanut (Arachis hypogaea) or “groundnut”, as it is known in some parts of the world, is the edible seed of a legume plant. Botanically speaking, peanuts are not considered to be true nuts, but are used as such in the kitchen due to similar nutritional properties. Although a legume; it is generally included amongst the oilseeds due to its high oil content.
The walnut also known as Juglans regia, is an appreciated nut that belongs to the Juglandaceae family. The fruit includes four main parts: the kernel, the skin, the shell, and the green husk. It is widely cultivated due to its edible kernel.
The nutritional values below are presented for raw peanuts of all types and English walnuts.
Macronutrients and Calories
Walnuts and peanuts are both highly dense in nutrients. Peanuts consist of 6.5% water, while walnuts contain only 4% water.
One hundred grams of walnuts contain 654 calories, while peanuts have fewer calories in total, containing 567 in a 100g serving. So both of these nut types are very high in calories.
Protein and Fats
Peanuts have higher protein content whereas walnuts are richer in fats.
Both walnuts and peanuts have high levels of all essential amino acids. Peanuts are richer in tryptophan, histidine, and threonine. Walnuts have a smaller amount of lysine compared with peanuts.
Walnuts are richer in healthy fats, containing large amounts of polyunsaturated fatty acids. Replacement of saturated fatty acids with polyunsaturated fatty acids has been associated with reduced cardiovascular disease risk (1).
On the other hand, peanuts contain larger amounts of monounsaturated fatty acids. Either of them has the same low amount of saturated fatty acids.
Both types do not contain cholesterol.
Walnuts and peanuts contain nearly the same amount of carbohydrates. Yet, peanuts are richer in dietary fiber.
The main component of the carbohydrates found in walnuts, other than fiber, is sucrose. Walnuts contain a very small amount of fructose and glucose.
Although walnuts are more diverse in vitamins, peanuts provide a larger percentage of daily values of several vitamins which are vitamins B1, B3, B9, and vitamin E.
Walnuts, on the other hand, are richer in vitamin B2 and vitamin B6. Peanuts have a complete lack of vitamin C, vitamin A, and vitamin K, which can be found in walnuts.
Both of these nuts are equal in vitamin B2.
In this category, it is almost a tie. Both of the nuts are equal in calcium, magnesium, zinc, and phosphorus. Although walnuts contain less sodium than peanuts.
Peanuts contain a higher level of iron and potassium, while walnuts are richer in copper.
Peanut has a low glycemic index and glycemic load. On a 100 –point scale, the glycemic index of peanuts is 14, and the glycemic load of peanuts is one (2).
Having said that, both walnut’s glycemic index and glycemic load are zero (2).
The pH value of walnuts is more acidic, tantamount to 5.42, whereas the acidity of peanuts, depending on their type, is close to neutral. Raw peanuts’ pH value is 6.87 and roasted peanuts’ pH value equals to 6.31 (3).
The acidic effect of foods can also be quantified by calculating the potential renal acid load (PRAL) of the diet, which is based on dietary intakes of protein and mineral ions (4).
In this case, the PRAL value of walnuts is 5.6, which is considered to be acid-forming. The PRAL value of peanuts is 6.2, making them slightly more acid-forming than walnuts.
Weight Loss and Diets
Walnuts and peanuts are very high in calories. However, the amount of protein, healthy fats, and dietary fiber in their consistency makes them applicable for a healthy diet.
Nevertheless, between these two nuts, peanuts are the better choice for low calories and low fats diets, whilst walnuts are more suitable for a low-carb and a low glycemic index diet.
Contrary to expectations, clinical trials, epidemiological studies, and systematic reviews of different studies have shown that walnut consumption in the diet does not contribute to weight gain or hinder weight loss goals as compared to a control diet (5).
Considerable pieces of evidence show that incorporating peanut and peanut butter into the diet does not lead to weight gain or higher body weight (6).
In the research related to weight loss, diets incorporated with peanuts, peanut butter, and peanut oil, have shown to provide an improved long-term weight maintenance (6).
Since the protein in peanuts and walnuts is plant based, it carries with it additional components that have positive health benefits like fiber and unique bioactive components, unlike animal protein.
Research has identified numerous compounds in peanuts and in their skins that may have added health benefits beyond basic nutrition (6).
Peanuts have been touted as a functional food with numerous functional components like Coenzyme Q10 which protects the heart during the period of lack of oxygen, for example high altitudes and clogged arteries (6).
Peanut products, such as raw, butter, and oil, are more beneficial to heart health when compared to low-fat diets (6).
The high monounsaturated fat peanut diet has been studied to lower total body cholesterol by 11% and “bad” low density lipoprotein by 14%, while “good” high density lipoprotein was maintained with a reduction in triglycerides (6).
There is strong evidence supporting an association between monounsaturated fat, as well as overall nut intake, and a reduction in the risk of coronary heart disease (6).
Walnuts have been shown to decrease low density lipoprotein cholesterol and diastolic blood pressure, two major risk factors for cardiovascular disease (7).
The effect of walnuts on multiple cardiovascular disease targets, over relatively short periods of time supports recommendations for their inclusion in a heart-healthy diet (7).
Walnuts contain several components that have antioxidant and anti-inflammatory effects.
Animal and human studies suggest that supplementation with walnuts in the diet may improve cognition and reduce the risk and/or progression of mild cognitive impairment and Alzheimer's disease (8).
The American Diabetes Association ranks peanuts and other nuts as diabetes superfoods. Peanuts make the list because they contain magnesium, fiber and heart-healthy oils and do not overly affect your blood glucose (6).
Walnut consumers showed lower risk for diabetes compared with non-nut consumers based on self-report, as well as fasting blood glucose levels (9).
One study showed that increased walnut intake significantly reduces the prevalence of diabetes. The gender by walnut interaction suggests that the effect may be more potent among women than men (9).
Unsaturated fats, certain vitamins and minerals, and the bioactive components have shown to have cancer-preventive effects, which are all packaged into a peanut kernel (6).
In particular, the phytosterols in peanuts that have been studied in regards to cancer, have been reported to reduce prostate tumor growth by over 40% and cut the occurrences of cancer spreading to other parts of the body by almost 50% (6).
Researchers have identified biochemicals found in walnuts that have cancer-prevention properties. Walnuts are an example of foods that contain many components that have individually been found to be beneficial against cancer. Walnuts are an exceptional plant-based source of 18-carbon α-linolenic acid (11).
Downsides & Risks
Tree nut allergy is common and often severe (10).
The exact cause of the allergy is unknown.
The cotyledons, which are parts of the embryo of the seeds, are probably the major source of allergen for most individuals, as the skins and hearts are often removed during processing.
Symptoms can include vomiting, diarrhea, urticaria, angioedema, which includes swelling of the lips, face, throat and skin, as well as asthma and anaphylactic shock (6).
In summary, walnuts are higher in calories and fats, whereas peanuts are richer in fiber and provide a larger percentage of daily values of several vitamins, such as vitamins B1, B3, B9, and vitamin E.
Both of the nuts are equal in calcium, magnesium, zinc, and phosphorus. Although walnuts contain less sodium than peanuts, they are richer in copper. On the other hand peanuts contain a higher level of iron and potassium.
Vitamin and Mineral Summary Scores
Comparison summary table
|Lower in Sugar|
|Lower in Sodium|
|Lower in Saturated Fat|
|Lower in glycemic index|
|Lower in price|
|Rich in minerals|
|Lower in Cholesterol||Equal|
|Rich in vitamins||Equal|
Which food is preferable for your diet?
|Low Calories diet|
|Low Fats diet|
|Low Carbs diet|
|Low glycemic index diet|
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All nutrients comparison - raw data values