Peanuts contain various bioactive plant compounds and antioxidants.
In fact, peanuts are as rich in antioxidants as many fruits (14).
Most of the antioxidants are located in the skin of peanuts (15), which is rarely eaten and then only with raw peanuts.
Here we will focus on those plant compounds found in peanut kernels, which are eaten more often.
A few noteworthy plant compounds found in peanut kernels include:
- p-Coumaric acid: A polyphenol that is one of the main antioxidants in peanuts (14, 16).
- Resveratrol: A powerful antioxidant that may reduce the risk of cancer and cardiovascular disease (17). Resveratrol is most notably found in red wine.
- Isoflavones: A class of antioxidant polyphenols, the most common of which is genistein. Categorized as phytoestrogens, isoflavones are associated with a variety of health effects, both good and bad (18).
- Phytic Acid: Found in plant seeds (including nuts), phytic acid may impair the absorption of iron and zinc from peanuts and other foods eaten at the same time (19).
- Phytosterols: Peanut oil contains considerable amounts of phytosterols, the most common of which is beta-sitosterol (16). Phytosterols impair the absorption of cholesterol from the digestive tract (20).
BOTTOM LINE:Peanuts contain various plant compounds. These include antioxidants, such as coumaric acid and resveratrol, as well as antinutrients like phytic acid.
Obesity is on the increase in the US (21).
Peanuts have been widely studied with regard to weight maintenance.
Despite being high in fat and calories, peanuts do not appear to contribute to weight gain.
These studies are all observational, which means that they cannot prove causation. In fact, it is well possible that the consumption of peanuts may be a marker of other healthful behaviors, which contribute to reduced weight gain.
However, one small study in healthy women showed that when peanuts were given as a substitute for other sources of fat in a low-fat diet, the women lost 3 kg over a 6-month period, despite being told to maintain their initial weight (26).
Another study found that when 89 g (500 kcal) of peanuts were added to the daily diet of healthy adults for 8 weeks, they did not gain as much weight as expected (27).
Various factors make peanuts a weight loss friendly food:
- Peanuts may reduce food intake by promoting satiety to a greater extent than other common snacks, such as rice cakes (27, 28).
- Because of how satiating peanuts are, people appear to compensate for increased peanut consumption by eating less of other foods (27).
- When whole peanuts are not chewed well enough, a portion of them may pass through the digestive system without being absorbed (27, 29).
- The high content of protein and monounsaturated fat in peanuts may increase energy expenditure (29, 30).
- Peanuts are a source of insoluble dietary fiber, which is linked with reduced risk of weight gain (31, 32).
BOTTOM LINE:Peanuts are very filling, and can be considered an effective component of a weight loss diet.
In addition to being a weight loss friendly food, eating peanuts has been linked with several other health benefits.
Heart disease is one of the leading causes of death worldwide.
BOTTOM LINE:As a source of many heart-healthy nutrients, peanuts may help prevent heart disease.
Gallstones affect approximately 10-25% of adults in the US (38).
Most gallstones are largely composed of cholesterol. Therefore, the cholesterol-lowering effect of peanuts has been suggested to be a possible explanation (40).
Further studies are needed to confirm these findings.
BOTTOM LINE:Peanut consumption may cut the risk of gallstones.