Eating almonds daily could be a beneficial exercise recovery food, according to a new study published in medical journal Frontiers in Nutrition.
The randomized controlled trial showed that female and male participants who ate 57 grams of almonds daily for one month had more of the beneficial fat called 12,13-dihydroxy-9Z-octadecenoic acid (12,13-DiHOME) in their blood immediately after a session of intense exercise than control participants. This molecule, a so-called oxidized fat, is synthesized from linoleic acid by brown fat tissue, and has a beneficial effect on metabolic health and energy regulation.
“Here we show that volunteers who consumed 57 grams of almonds daily for one month before a single ‘weekend warrior’ exercise bout had more beneficial 12,13-DiHOME in their blood immediately after exercising than control volunteers,” corresponding author Dr David C Nieman, a professor and director of the Appalachian State University Human Performance Laboratory at the North Carolina Research Campus, said in a statement.
“They also reported feeling less fatigue and tension, better leg-back strength, and decreased muscle damage after exercise than control volunteers,” Nieman added.
Almonds are good for exercise recovery
The study involved 38 men and 26 women between the ages of 30 and 65, who didn’t engage in regular weight training. Approximately half were randomized to the almond diet group, and the other half to the control group, who ate a calorie-matched cereal bar daily.
The researchers took blood and urine samples from the participants before and after the four-week period of dietary supplementation. Performance measures included a 30-second Wingate anaerobic test, a 50-meter shuttle run test, and vertical jump, bench press, and leg-back strength exercises. Additional blood and urine samples were taken immediately after this 90-minute session of “eccentric exercise” and daily for four days afterwards.
After each blood draw, the participants filled out the Profile of Mood States (POMS) questionnaire to quantify their mental state, and rated the pain and stiffness they felt after strenuous exercise on a 10-interval scale.
The researchers said that, as expected, the 90-minute exercise led to an increase in the volunteers’ self-reported feeling of muscle damage and muscle soreness, as well as an increased POMS score, indicating self-reported decreased vigor and increased fatigue, anxiety, and depression.
The exercise also resulted in transient elevated levels of pro-inflammatory proteins in the blood that are consistent with minor muscle damage. However, these changes in protein levels were equal in the almond and cereal bar groups.
Importantly, immediately after exercise, the concentration of the beneficial 12,13-DiHOME was 69 percent higher in blood plasma of participants in the almond group than in participants in the control group. This molecule is known to increase the transport of fatty acid and its uptake by skeletal muscle, with the overall effect of stimulating metabolic recovery after exercise.
The reverse pattern was found for another oxylipin, the mildly toxic 9,10-Dihydroxy-12-octadecenoic acid (9,10-diHOME), which was 40 percent higher immediately after exercise in the blood of the control group than in the almond group. Unlike 12,13-DiHOME, 9,10-diHOME has been shown to have negative effects on overall health and the body’s recovery from exercise.
Nieman and colleagues concluded that daily consumption of almonds leads to a change in metabolism, down-regulating inflammation, and oxidative stress from exercise and enabling the body to recover faster.
“We conclude that almonds provide a unique and complex nutrient and polyphenol mixture that may support metabolic recovery from stressful levels of exercise,” Nieman said. “Almonds have high amounts of protein, healthy types of fats, vitamin E, minerals, and fiber. And the brown skin of almonds contains polyphenols that end up in the large intestine and help control inflammation and oxidative stress.”
Potatoes for building muscles
This study adds to a growing body of evidence that plant-based foods might be beneficial for exercise recovery. A study published last year in the scientific journal Medicine & Science found that potato protein can be as effective as animal-derived milk in building muscle.
“Ingestion of 30 grams of potato protein concentrate increases muscle protein synthesis rates at rest and during recovery from exercise in healthy, young males,” the study concluded. “Muscle protein synthesis rates following the ingestion of 30 grams of potato protein do not differ from rates observed after ingesting an equivalent amount of milk protein.”