Beneficial Changes in Total Cholesterol, LDL-C, Biomarkers of Intestinal Inflammation, and Vitamin E status in Adults with Metabolic Syndrome Consuming Almonds as Snack Foods: A Randomized Controlled Clinical Trial
This study investigated the impact of daily almond consumption on adults with metabolic syndrome. Researchers focused on the effects of almonds as a snack on various health indicators, specifically noting beneficial changes in total and LDL cholesterol levels, along with improvements in certain markers of intestinal inflammation.
College of Health researcher(s)
College unit(s)
Highlights
- A daily snack of almonds benefited people with metabolic syndrome
- Almond snacking improved gut inflammation biomarkers
- Almond snacking increased α-tocopherol, soluble fiber, copper, magnesium intakes
- Almond snacking improved plasma α-tocopherol/cholesterol ratio
- Almond snacking improved low density lipoprotein & total cholesterol concentrations
Abstract
Chronic inflammation and gut barrier breakdown contribute to the progression of metabolic syndrome, and affect the development of cardiometabolic diseases, especially in persons consuming low quality diets with limited bioactive compounds. Almonds are a rich source of bioactive compounds with antioxidant and anti-inflammatory properties. We hypothesize almond consumption can help disrupt metabolic syndrome progression by improving gut and cardiometabolic health, decreasing inflammation and oxidative stress. To test this hypothesis, adults with metabolic syndrome were randomized to consume either almonds (2 oz, whole, dry roasted, n=38) or crackers (control, equal caloric content, n=39), as a daily snack for 12 weeks, and samples were collected (0, 4, and 12 weeks). Compared with participants consuming crackers, almond consumption resulted in lower plasma total and LDL-cholesterol concentrations, a modest improvement in waist circumference (week 4), and improved dietary intakes of α-tocopherol, soluble fiber, copper, biotin, magnesium, polyunsaturated fatty acids, and monounsaturated fatty acids. Almond consumption raised plasma α-tocopherol concentrations (relative to cholesterol concentrations) and increased excretion of a vitamin E biomarker (α-CEHC). Almond consumption improved biomarkers of gut barrier function and intestinal inflammation (fecal calprotectin, myeloperoxidase) in participants with elevated inflammation at baseline. Total body weight, caloric intake, and markers of carbohydrate metabolism (glucose, insulin), systemic inflammation (plasma IL-6, CRP, LBP, CD14), and oxidative damage (malondialdehyde) were not altered by almond consumption. In conclusion, daily almond snacking improves nutrient intake and decreases gut inflammation in participants with metabolic syndrome. These beneficial dietary and inflammatory changes may contribute to the improvements in cardiovascular health observed.
Almond Study FAQ
What was the purpose of this study?
The study aimed to investigate the effects of daily almond consumption as a snack on adults with metabolic syndrome. Specifically, the researchers hypothesized that almonds could help disrupt the progression of metabolic syndrome by improving gut and cardiometabolic health, and decreasing inflammation and oxidative stress. They assessed changes in cardiometabolic indicators, vitamin E status, intestinal inflammation, systemic inflammation, oxidative stress, mineral status, polyphenol concentrations, glycemic control, and anthropometric measures over 12 weeks.
How was the study conducted?
Adults diagnosed with metabolic syndrome were randomly assigned to one of two groups for 12 weeks: an almond group (n=38) who consumed 2 ounces of whole, dry roasted almonds daily, or a control group (n=39) who consumed crackers with the same caloric content. Participants were instructed to maintain their usual eating patterns but to reduce other food intake to match the snack's calorie content. Dietary intake was recorded, and blood, urine, and stool samples were collected at the beginning, 4 weeks, and 12 weeks into the study to assess various health markers. The laboratory staff analyzing the samples were blinded to the treatment groups.
What were the main findings regarding cholesterol levels?
Almond consumption for 12 weeks significantly decreased plasma total cholesterol and low-density lipoprotein cholesterol (LDL-C) concentrations compared to the cracker control group. A notable number of participants in the almond group experienced a substantial decrease in both total cholesterol and LDL-C. However, almond consumption did not significantly alter high-density lipoprotein cholesterol (HDL-C) or triglyceride concentrations.
Did almond snacking affect body weight or waist circumference?
While almond consumption did not lead to a change in overall body weight, it was associated with a modest but statistically significant decrease in waist circumference after 4 weeks. This decrease in waist circumference showed a trend towards significance at 12 weeks compared to the cracker group.
How did almond consumption impact nutrient intake and vitamin E status?
Participants in the almond group showed significant increases in dietary intake of several beneficial nutrients compared to both their baseline and the cracker group. These included increases in soluble fiber, copper, biotin, magnesium, polyunsaturated fatty acids (primarily omega-6), and monounsaturated fatty acids. Furthermore, almond consumption significantly increased dietary α-tocopherol (a form of vitamin E) intake and resulted in higher plasma α-tocopherol concentrations and improved plasma α-tocopherol/cholesterol ratios, indicating improved vitamin E status.
Were there any observed changes in markers of inflammation?
Almond consumption improved biomarkers of gut barrier function and intestinal inflammation, specifically fecal calprotectin and myeloperoxidase, particularly in participants who had elevated levels of these markers at the start of the study. However, the study did not observe significant changes in markers of systemic inflammation (such as plasma IL-6, CRP, LBP, CD14) or oxidative damage (malondialdehyde).
Did almond consumption affect blood sugar levels?
No significant changes were observed in markers of carbohydrate metabolism, including fasting glucose, insulin, or Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), in either the almond or cracker groups.
What were the key takeaways regarding the health benefits of daily almond snacking for individuals with metabolic syndrome?
Daily almond snacking, at a quantity of 2 ounces, demonstrated several benefits for adults with metabolic syndrome. It improved diet quality by increasing the intake of important nutrients like fiber, healthy fats, magnesium, and vitamin E. This led to beneficial changes in total cholesterol and LDL-C levels and improved vitamin E status. Additionally, for individuals with elevated intestinal inflammation, almond consumption helped improve markers of gut barrier function and inflammation. The study suggests that incorporating almonds as a daily snack can be a feasible and effective dietary strategy to address some of the key issues associated with metabolic syndrome.