A randomized controlled trial published in ‘Frontiers in Nutrition’ shows that daily consumption of almonds produces a change in metabolismreducing inflammation and oxidative stress from exercise and allowing the body to recover more quickly after physical activity.
Specifically, it produces an increase in the amount of the exercise recovery molecule. This molecule, called oxylipin (oxidized fat), is synthesized from linoleic acid by brown adipose tissue, and has a beneficial effect on metabolic health and energy regulation.
Corresponding author David C Nieman, Professor and Director of Appalachian State University’s Human Performance Laboratory, North Carolina Research Campus, noted that “Volunteers who consumed 57 grams of almonds per day for a month before a single ‘weekend warrior’ exercise session had more of the beneficial fat acid 12,13-dihydroxy-9Z-octadecenoic acid (12,13-DiHOME) in the blood immediately after activity than control volunteers.” They also reported less fatigue and tension, greater leg strength, and less muscle damage after of exercise than control volunteers.
Four weeks of dietary supplementation with almonds
The clinical trial involved 38 men and 26 women between the ages of 30 and 65, who did not engage in regular weight training. Approximately half were randomly assigned to the almond diet group, and the other half to the control group, which ate a daily cereal bar with the same calories. The researchers took blood and urine samples 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 the next four days.
After each blood draw, the participants filled out the ‘Profile of Mood States’ (POMS) questionnaire. to quantify his mental state and assessed his delayed-onset muscle pain – that is, the pain and stiffness they feel after unusual or strenuous exercise – on a 10-interval scale.
As expected, the 90-minute exercise caused an increase in the sensation of muscle damage and muscle pain according to the volunteers themselvesas well as an increase in the POMS score, which indicated a decrease in vigor according to the volunteers themselves and an increase in fatigue, anxiety and depression.
Exercise also caused a transient increase in proinflammatory cytokine levels. as IL-6, IL-8, IL-10, and MCP-1 in the blood, consistent with minor muscle damage. However, these changes in cytokines were the same in the almond and cereal bar groups.
Differences in two concentrations of dihome
It is important to note that immediately after exercise, the concentration of the beneficial 12,13-DiHOME was 69 percent higher in the blood plasma of participants in the almond group than in control group participants. 12,13-DiHOME is known to increase fatty acid transport and uptake by skeletal muscle, with the overall effect of promoting post-exercise metabolic recovery.
The reverse pattern was found for another oxylipin, the slightly toxic 9,10-dihydroxy-12-octadecenoic acid (9,10-diHOME). which was 40 percent higher immediately after exercise in the control group’s blood than in the almond group. Unlike 12,13-DiHOME, 9,10-diHOME has been shown to have negative effects on general health and the body’s recovery from exercise.
Almond skin polyphenols may be the key
“We conclude that almonds provide a unique and complex blend of nutrients and polyphenols that can favor metabolic recovery after stressful levels of exercise. Almonds contain large amounts of protein, types of healthy 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,” says Nieman.
