Nutritional Values of Peanuts

Peanuts

Peanut, also known as groundnut (Arachis hypogaea) is a crop of global importance. It is widely grown in the tropics and subtropics, being important to both smallholder and large commercial producers. It is classified as both a grain legume, and, because of its high oil content, an oil crop. World annual production is about 46 million tonnes per year.

As a legume, peanut belongs to the botanical family Fabaceae (also known as Leguminosae, and commonly known as the bean or pea family). Like most other legumes, peanuts harbor symbiotic nitrogen-fixing bacteria in root nodules. This capacity to fix nitrogen means peanuts require less nitrogen-containing fertilizer and improve soil fertility, making them valuable in crop rotations.

Peanuts are similar in taste and nutritional profile to tree nuts such as walnuts and almonds, and are often served in similar ways in Western cuisines. The botanical definition of a “nut” is a fruit whose ovary wall becomes very hard at maturity. Using this criterion, the peanut is not a nut, but rather a legume. However, for culinary purposes and in common English language usage, peanuts are usually referred to as nuts.
 
Peanuts originated in South America where they have existed for thousands of years. They played an important role in the diet of the Aztecs and other Native Indians in South America and Mexico.

The Spanish and Portuguese explorers who found peanuts growing in the New World brought them on their voyages to Africa. They flourished in many African countries and were incorporated into local traditional food cultures. Since they were revered as a sacred food, they were placed aboard African boats traveling to North America during the beginning of the slave trade, which is how they were first introduced into this region.

In the 19th century, peanuts experienced a great gain in popularity in the U.S. thanks to the efforts of two specific people. The first was George Washington Carver, who not only suggested that farmers plant peanuts to replace their cotton fields that were destroyed by the boll weevil following the Civil War, but also invented more than 300 uses for this legume. At the end of the 19th century, a physician practicing in St. Louis, Missouri, created a ground up paste made from peanuts and prescribed this nutritious high protein, low carbohydrate food to his patients. While he may not have actually “invented” peanut butter since peanut paste had probably used by many cultures for centuries, his new discovery quickly caught on and became, and still remains, a very popular food.

Today, the leading commercial producers of peanuts are India, China, Nigeria, Indonesia and the United States.
Let’s take a quick look at the nutritional values of peanuts while munching that favorite snack.

Substitute for meat
For those looking for excellent and cheap alternatives to meats, peanut is one of them. Like other legumes and dried beans, peanuts contain protein of lower biological value than meats but when eaten with cereals, the total protein value approaches that of meat and thus, costs less.

About 1 cup raw peanuts may be substituted for a serving of meat or fish. For vegetarians, dried beans, legumes and nuts are the primary protein source of their diet.

Vitamin-B to boost energy
Dried beans and legumes such as peanuts are rich in vitamin-B namely thiamin, riboflavin and niacin which help release energy from nutrients. Thiamin supports normal appetite and nerve function. Riboflavin supports skin health, cracks and redness at the corners of mouth, inflammation of the tongue and dermatitis. Niacin also supports the skin, nervous and digestive systems.

Cholesterol-lowering property
Peanut is rich in dietary fiber, a food component that has been associated with the prevention of several chronic diseases such as cardiovascular diseases, colon cancer, and control of diabetes. According to a recent study, among the legumes consumed, peanut showed a marked decrease in the total cholesterol levels of the subjects. Dietary fiber lowers the blood cholesterol levels by binding the bile acids in the intestines.
It is then excreted from the body via the feces, preventing the re-absorption of bile acids in the liver to become cholesterol again, thus lowers cholesterol levels.

Likewise, peanut’s fat content contributes to more energy and thus, is one of the foods added in supplementary foods for children to give a high-calorie, high-protein dish like banana-peanut mix and in disaster foods such as the food bar.

Peanuts Rival Fruit as a Source of Antioxidants
Not only do peanuts contain oleic acid, the healthful fat found in olive oil, but new research shows these tasty legumes are also as rich in antioxidants as many fruits. While unable to boast an antioxidant content that can compare with the fruits highest in antioxidants, such as pomegranate, roasted peanuts do rival the antioxidant content of blackberries and strawberries, and are far richer in antioxidants than apples, carrots or beets.

Research conducted by a team of University of Florida scientists,  shows that peanuts contain high concentrations of antioxidant polyphenols, primarily a compound called p-coumaric acid, and that roasting can increase peanuts’ p-coumaric acid levels, boosting their overall antioxidant content by as much as 22%.

Peanuts Protective, but Pickled Foods Increase Risk of Colon Cancer
A number of studies have shown that nutrients found in peanuts, including folic acid, phytosterols, phytic acid (inositol hexaphosphate) and resveratrol, may have anti-cancer effects. A rich source all these nutrients—including the phytosterol beta-sisterol, which has demonstrated anti-cancer actions—peanuts have long been considered a likely candidate as a colon cancer-preventive food.

Colorectal cancer is the second most fatal malignancy in developed countries and the third most frequent cancer worldwide. In Taiwan, not only has incidence of colon cancer increased, but the likelihood of dying from the disease rose 74% from 1993 to 2002.

Taiwanese researchers decided to examine peanuts’ anti-colon cancer potential and conducted a 10-year study involving 12,026 men and 11,917 women to see if eating peanuts might affect risk of colon cancer.(Yeh CC, You SL, et al., World J Gastroenterol)
Researchers tracked study participants’ weekly food intake, collecting data on frequently consumed foods and folk dishes such as sweet potato, bean products, peanut products, pickled foods, and foods that contained nitrates or were smoked.

Risk of colon cancer was found to be highly correlated with both peanuts, which greatly lessened risk, and pickled foods, which greatly increased risk, particularly in women.

Eating peanuts just 2 or more times each week was associated with a 58% lowered risk of colon cancer in women and a 27% lowered risk in men.

Help Prevent Gallstones
Twenty years of dietary data collected on over 80,000 women from the Nurses’ Health Study shows that women who eat least 1 ounce of nuts, peanuts or peanut butter each week have a 25% lower risk of developing gallstones. Since 1 ounce is only 28.6 nuts or about 2 tablespoons of nut butter, preventing gallbladder disease may be as easy as packing one peanut butter and jelly sandwich (be sure to use whole wheat bread for its fiber, vitamins and minerals) for lunch each week, having a handful of peanuts as an afternoon pick me up, or tossing some peanuts on your oatmeal or salad.

Eating Nuts Lowers Risk of Weight Gain
Although nuts are known to provide a variety of cardio-protective benefits, many avoid them for fear of weight gain. A prospective study published in the journal Obesity shows such fears are groundless. In fact, people who eat nuts at least twice a week are much less likely to gain weight than those who almost never eat nuts.

The 28-month study involving 8,865 adult men and women in Spain, found that participants who ate nuts at least two times per week were 31% less likely to gain weight than were participants who never or almost never ate nuts.

And, among the study participants who gained weight, those who never or almost never ate nuts gained more (an average of 424 g more) than those who ate nuts at least twice weekly.
 
Study authors concluded, “Frequent nut consumption was associated with a reduced risk of weight gain (5 kg or more). These results support the recommendation of nut consumption as an important component of a cardio-protective diet and also allay fears of possible weight gain.”