Daily Almond Snack Lowers ‘Bad’ Cholesterol and Improves Gut Health in Adults With Metabolic Syndrome, Study Finds

A randomized clinical trial led by Oregon State University found that eating roughly 2 ounces of almonds a day lowered low-density lipoprotein (LDL) cholesterol and total cholesterol and produced several other metabolic benefits in adults with metabolic syndrome.

The 12-week study, published in July in Nutrition Research, followed 77 adults ages 35 to 60 who met criteria for metabolic syndrome, a cluster of conditions that raise the risk of heart disease, type 2 diabetes and stroke and affects roughly one-third of U.S. adults. Participants were assigned to consume either about 320 calories of whole almonds daily — approximately 2 ounces, or 45 nuts — or an equal-calorie serving of crackers as a control snack.

Researchers reported significant reductions in total cholesterol and LDL among those in the almond group. The almond consumers also showed improved vitamin E status, measures of gut health and higher intakes of fiber, magnesium and unsaturated fats. Waist circumference decreased slightly in the almond group, while body weight and measures of blood glucose remained essentially unchanged.

The study authors said markers of intestinal inflammation and gut barrier function improved with almond consumption. "Crackers were chosen as the control snack because they are commonly consumed foods in the U.S. that have similar calories but lack many of the beneficial compounds found in nuts," lead author Laura M. Beaver, Ph.D., said in a statement accompanying the report. Beaver also noted that the 2-ounce serving is "very achievable" and encouraged healthy adults to consider incorporating almonds into regular snacking habits.

The trial adds to evidence that nut consumption can benefit cardiovascular risk factors. A separate meta-analysis published in August in the journal Nutrients by Intertek Health Sciences reviewed dozens of clinical trials and found that eating as little as one ounce of almonds daily reduced LDL cholesterol, total cholesterol and other markers of heart risk without lowering high-density lipoprotein (HDL) cholesterol. That review also reported improvements in the apolipoprotein B to apolipoprotein A1 ratio, a predictor of heart attack risk, with the largest effects seen in people who began with higher cholesterol levels.

Both the Oregon State trial and the Intertek meta-analysis used whole almonds, though preparation varied across studies. The Almond Board of California provided funding for both projects. The authors and outside experts noted that the findings are consistent with decades of research supporting nuts as part of a heart-healthy diet.

The researchers listed several limitations. The trial’s short duration and relatively small sample size limit assessment of long-term outcomes. The participant group was mostly White and relatively healthy aside from metabolic syndrome, which may limit generalizability. The study also may have underestimated effects in individuals with higher baseline inflammation.

Public health experts say many people have metabolic syndrome or prediabetes without recognizing it, which could mean broader potential benefits from simple dietary swaps. The study’s design compared almonds to a commonly consumed snack rather than to no snack, underscoring the impact of substituting nutrient-dense foods for refined alternatives.

The authors cautioned that while other nuts — such as hazelnuts — may yield similar benefits, head-to-head comparisons have not been conducted in this trial. Longer and more diverse trials would be needed to confirm the durability of the effects and to examine whether similar advantages apply across populations with different baseline risk profiles.

Until further study, clinicians and dietitians may consider recommending nuts as a replacement for energy-dense, nutrient-poor snacks for patients at cardiometabolic risk, while remaining mindful of total calorie intake and individual dietary needs.