New meta-analysis supports almonds’ role in heart health
Systematic review shows improved blood lipid levels with almond consumption and is entitled: ‘The effects of almond consumption on fasting blood lipid levels: a systematic review and meta-analysis of randomised controlled trials’ Kathy Musa-Veloso, Lina Paulionis, Theresa Poon and Han Youl Lee.
A new systematic review and meta-analysis published in the Journal of Nutritional Science found that eating almonds results in significant reductions in total cholesterol, “bad” LDL-cholesterol and triglycerides, while having no significant impact on “good” HDL cholesterol levels, adding to the weight of evidence that supports the consumption of almonds as part of a healthy diet to help maintain healthy blood lipid levels and reduce the risk of heart disease.
Additional findings from sub-group analyses showed that blood lipid levels were most substantially improved in the studies in which the dose of almonds was at least 45 g/day (~1.5 oz/day) and in which the studied populations had elevated blood lipid levels at baseline. The study, conducted by Dr. Kathy Musa-Veloso and colleagues, was funded by the Almond Board of California and independently evaluated in a peer-reviewed journal.
The analysis included 18 published randomized controlled trials and a total of 837 participants. When data from all of the studies were pooled, the reduction in total cholesterol was 0.153 mmol/L (5.92 mg/dL). When the meta-analysis was restricted to those studies where the amount of almonds consumed was at least 45 g/day (~1.5 oz/day), the reduction in total cholesterol was 0.212 mmol/L (8.20 mg/dL). These data suggest that the effects of almonds on total cholesterol are dose-dependent, with a larger almond intake resulting in a greater reduction in total cholesterol. When the meta-analysis was based on studies in which the subjects had elevated total cholesterol levels (at baseline), the reduction in total cholesterol was 0.271 mmol/L (10.48 mg/dL), suggesting that the effects of almonds on total cholesterol levels are most impactful in these individuals.
A similar pattern was observed for LDL-cholesterol. Specifically, when data from all of the studies were pooled, the reduction was 0.124 mmol/L (4.80 mg/dL). The LDL-cholesterol reductions were 0.132 mmol/L (5.10 mg/dL) and 0.158 mmol/L (6.11 mg/dL) when the meta-analysis was restricted to those studies in which at least 45 g (~1.5 oz) of almonds were consumed per day and in which the subjects had elevated LDL-cholesterol levels at baseline, respectively.
The researchers noted that although the mechanism for cholesterol reduction is not fully understood, the composition of almonds – which includes a favorable fatty acid profile (high in mono- and polyunsaturated fats and low in saturated fats), nutrient composition (containing 6 grams of plant protein and 4 grams of dietary fiber per ounce (28 grams), plus other key constituents like flavonoids and sterols) – may all play a role in their favorable effects on blood lipids.
Moreover, the researchers noted in their review that there were significant reductions in body weight with the almond interventions relative to the control in three of the studies analyzed. The authors drew attention to the study by Berryman et al.,2 in particular, which was a rigorously controlled diet study in which all of the foods were provided during both the almond and control intervention periods. Participants experienced significant improvements in body weight, waist circumference and body composition (including abdominal fat mass) with 6 weeks of an almond diet vs. a control diet. The authors of the meta-analysis noted that these observations of improvements in body weight and composition are consistent with the finding by Novotny et al. (2012) that not all of the energy in almonds is actually metabolizable3. It is important to recognize that maintaining a healthy weight, along with consuming a healthy diet, are lifestyle factors that can help promote heart health.
The health benefits of almonds have been well-established in heart-healthy eating plans including the Mediterranean Diet, and reflected in current science-based dietary guidance to consume nuts regularly as part of a healthy dietary pattern.
“These results strengthen decades of research about how the regular consumption of almonds can favorably impact blood lipid levels and have a positive effect on heart health,” commented Dr. Kathy Musa-Veloso, lead author of the systematic review and meta-analysis. “The consumption of almonds as part of a healthy diet should be encouraged in order to improve blood lipid levels and reduce the risk of heart disease.” Dr. Musa-Veloso is Director of Health Claims and Clinical Trials at Intertek Scientific & Regulatory Consultancy.
A one-ounce (28 grams) serving of almonds provides 160 calories, with 6 grams of plant-based protein, 4 grams of filling dietary fiber, 13 grams of “good” unsaturated fats and essential vitamins and minerals including vitamin E (50% DV), magnesium (20% DV) and potassium (6% DV).
‘The effects of almond consumption on fasting blood lipid levels: a systematic review and meta-analysis of randomised controlled trials’ Kathy Musa-Veloso, Lina Paulionis, Theresa Poon and Han Youl Lee is Open Access and is available to download in full.
Study at a Glance:
The systematic review was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eighteen (18) randomized controlled human intervention trials were identified that met all of the inclusion criteria and none of the exclusion criteria described below. The Almond Board of California provided funding for this scientific, systematic review. The analysis and interpretation of the data were conducted by the study authors, independently of the Almond Board of California.