Walnuts are a dense nutrition source. They are comprised of more than fifty percent fat, most of which is unsaturated fat. Due to the high fat content, walnuts are also packed with calories, but the kind that are good for you. About fifteen percent of each walnut is protein, so walnuts are also good for your muscles, especially when combined with other incomplete or complete proteins.
Even better, walnuts have a substantial amount of fiber, rivaling raspberries by volume and mass. Walnuts also contain more of the neurotransmitter serotonin than any other food by a huge margin.
The researchers of the study were interested in a few key phytochemicals found in walnuts. First was ellagitannin, a large molecule common in many plants. Ellagitannin is a kind of tannin, which is the substance that can give wine its astringent feel. The second phytochemicals the researchers focused on were tocopherols. Together with tocotrienols, tocopherols are the antioxidant chemicals that make up vitamin E.
Due to the level of antioxidants found in walnuts, the researchers wondered if walnut consumption would help reduce oxidative stress. Although walnuts may be high in nutrients that can combat the effects of exercise-related stress, that doesn’t necessarily mean those nutrients enter your bloodstream for use by the body.
The researchers took sixteen people and randomly fed them walnuts or a meal containing similar amounts of fat, protein, and carbohydrates. The meal did not contain any of the above phytochemicals found in walnuts. The walnuts amounted to a little under a cup worth of shelled walnuts, or ninety grams.
After the meal the participants had blood drawn and tested at regular intervals starting immediately afterward and continuing for 24 hours. The researchers were looking for elevated levels of the antioxidants in question, reduced oxidative stress, or both.
Antioxidant levels did increase, but a-tocopherol, the kind you normally find in supplements, was not elevated. The major increase was in y-tocopherol, which is more common in a typical American diet. That said, walnut consumption did decrease oxidative stress when compared to a meal that had the same macronutrient and calorie profile.
In addition to being cool information about walnuts, this study also points to a greater issue. Simply taking in calories from non-nutritious meals is a bad idea. This is sometimes called “micronutrient hunger” or something similar. Essentially, you may feel satiated, you may have taken in enough calories throughout the day, and you may even have consumed enough protein, carbs, and fats, but if your food sources were deficient in healthy micronutrients, then you have a hidden kind of nutrient starvation.
So the bottom line is clear. Walnuts are a good part of a healthy diet. In general, try to eat whole and highly nutritious foods, and you will feel, look, and perform better.
1. Ella Haddad, et. al., “Effect of a walnut meal on postprandial oxidative stress and antioxidants in healthy individuals,” Nutrition Journal 2014, 13:4.
Photo courtesy of Shutterstock.