Research finds almond snacking may reduce adjusted relative risk of cardiovascular disease by about 30%.
Modesto, CA (26 May 2020) – For decades, researchers have investigated how eating almonds promotes heart health and now, there’s a novel discovery related to almond benefits. In a newly-published study1, snacking on almonds improved endothelial function, which is a key indicator of vascular health. In addition, consuming almonds instead of a usual snack also lowered “bad” LDL-cholesterol, which is consistent with previous research. The study was funded by the Almond Board of California.
The study was a 6-week randomized control, parallel-arm trial, where participants (with above average cardiovascular disease risk) consumed almonds or a calorie-matched control snack providing 20% of each participants’ estimated daily energy needs. The research team then compared cardiometabolic health markers between the two groups. They found that the almond group, compared to the control group, had increased endothelium-dependent vasodilation by a 4% unit increase (measured through flow mediated dilation or FMD), which is a strong predictor of the initiation and progression of the disease atherosclerosis. Improved FMD means that arteries can dilate more easily in response to increased blood flow, which is a strong indicator of cardiovascular health.
LDL-cholesterol levels decreased in the almond group relative to the control group. There was no difference between the two groups in liver fat and several other measures (triglycerides, HDL-cholesterol, glucose, insulin and others).
“This study shows that eating almonds in place of the typical snacks that many of us consume (such as crisps, biscuits and pastries) is beneficial for our heart health by reducing levels of bad LDL-cholesterol and improving the health of our arteries. Based on existing data on risk of cardiovascular disease, we predict that replacing typical snacks with almonds in the long term would result in a 30% reduction in the adjusted relative risk of a cardiovascular event,” said Dr. Wendy Hall, PhD, co-principal investigator and Reader in Nutritional Sciences at King’s College London. Adjusted relative risk is the probability of an event happening to a person compared to another person who does not take a step in disease prevention, such as making a diet change.
Besides the new FMD finding in the almond group, the study took an innovative approach to the comparison food used in this study. The researchers developed a control food that was carefully matched in terms of fat and sugar (14% of energy from saturated fat and 23% of energy from sugar) to reflect a typical UK snack (excluding fruit) derived from the UK National Diet and Nutrition Survey (NDNS). This neutral comparator snack helped determine that the almonds, and nothing else, were responsible for the beneficial changes in health markers.
Study at a Glance:
The Study
- This randomized, controlled parallel dietary intervention study investigated the effects of almond consumption on cardiometabolic risk factors in adults with above average risk of CVD. The study looked at the impact of almonds vs. a control food designed to provide the same number of calories and carbohydrate/fat/protein composition to match average snack intakes in an adult UK population.
- Adults 30-70 years old (n=51 in almond group, n=56 in control group) consumed 20% of their calorie requirements as whole roasted almonds or a control food for 6 weeks. Cardiometabolic risk factors were measured, including endothelial function (flow-mediated dilation), liver fat, blood lipids including cholesterol levels and triglycerides, glucose, insulin, insulin resistance, hormones related to obesity and blood sugar regulation (leptin, adiponectin, resistin), and other known CVD risk factors.
- Prior to beginning the study, a 3-week trial was conducted to ensure that the control food had a neutral effect on lipids, blood pressure and body weight/composition.
Results
- The results show that replacing typical snacks with almonds can improve endothelial function, cardiac autonomic function and reduce LDL-cholesterol levels.
- Almonds, compared with control, increased endothelium-dependent vasodilation (mean difference 4.1 % units of measurement, 95% CI 2.2, 5.9).
- Plasma LDL-cholesterol concentrations decreased in the almond group relative to control (mean difference -0.25 mmol/L, 95% CI -0.45, -0.04).
- The long-phase heart rate variability parameter, very low-frequency power, was increased during night-time following the almond treatment compared to control (mean difference 337 ms2, 95% CI 12, 661), indicating greater parasympathetic regulation.
- Based on previously reported pooled data from cohort studies, the changes observed over 6 weeks in this disease-free population as a result of replacing usual snacks with almonds, if sustained in the long-term, would be predicted to reduce the adjusted relative risk of having a cardiovascular event of 32% in populations without pre-existing cardiovascular disease relative to a similar population that did not replace their snacks with almonds.
- There were no differences in liver fat between groups. Also, there were no group differences in triglycerides, HDL-cholesterol, glucose, insulin, insulin resistance, leptin, adiponectin, resistin, liver function enzymes, fetuin-A, body composition, pancreatic fat, intramyocellular lipids, fecal short chain fatty acids, blood pressure or 24-hour heart rate variability. The non-HDL cholesterol decreased in almond group and the HDL-cholesterol was maintained.
Study Limitations:
Limitations of the study were the fact that there were some differences between groups in cardiometabolic disease risk factors at baseline. The imbalance in recruitment by sex could mean that the results may not be as applicable to men since they made up only 30% of the randomized study population. Also, the participants were free-living, and although almond compliance was confirmed, it is possible there is potential for some inaccuracies in their reported food intake.
Conclusion:
The degree of improvement in endothelial function and LDL-cholesterol levels suggests that replacing typical snacks with almonds (as 20% of total calories, equivalent to about 2.5 servings or 70 grams) has the potential to reduce adjusted relative CVD risk by 32%. Replacing typical snacks with almonds can have positive impact on daily nutrient intake and potentially play a role in improving cardiovascular health.
This new study supports years of almond heart health research including a systematic review and meta-analysis2 in providing more evidence to include almonds in heart healthy eating plans. Almonds provide fiber (12.5 / 3.5 g per 100g / 28g serving) and 15 essential nutrients including (per 100g / 28g serving): magnesium (270 / 76 mg), potassium (733 / 205 mg), and vitamin E (25.6 / 7.2 mg).
1 VitaDikariyanto, Leanne Smith, Lucy Francis, May Robertson, Eslem Kusaslan, Molly O'Callaghan-Latham, Camille Palanche, Maria D'Annibale, Dimitra Christodoulou, Nicolas Basty, Brandon Whitcher, Haris Shuaib, Geoffrey Charles-Edwards, Philip J Chowienczyk, Peter R Ellis, Sarah E E Berry, Wendy L Hall, Snacking on whole almonds for 6 weeks improves endothelial function and lowers LDL cholesterol but does not affect liver fat and other cardiometabolic risk factors in healthy adults: the ATTIS study, a randomized controlled trial, The American Journal of Clinical Nutrition, nqaa100, https://doi.org/10.1093/ajcn/nqaa100.
2 Musa-Veloso K, Paulionis L, Poon T, Lee HL. The effects of almond consumption on fasting blood lipid levels: a systematic review and meta-analysis of randomised controlled trials. Journal of Nutritional Science 2016; 5(e34):1-15.
