A New Study Finds that Eating Nuts Like Almonds Can Help Reduce Weight and Symptoms of Metabolic Syndrome

Research, conducted in Spain, shows that the Mediterranean diet and increased nut consumption are associated with reductions in body weight, BMI, waist circumference, triglyceride concentrations, and blood pressure.

Milan - Metabolic syndrome (MetS) is a serious problem, which in Italy is estimated to affect about a quarter of the population¹. Also known as insulin resistance syndrome, it identifies a group of metabolic complications of obesity including excess abdominal fat, elevated triglycerides, low HDL cholesterol, blood pressure, and elevated blood sugar, all of which are associated with diseases including type 2 diabetes, cardiovascular disease, and hepatic steatosis.

As part of the recent PREDIMED-Plus study, waist circumference, HDL cholesterol levels, triglyceride levels, fasting blood glucose, blood pressure, and excess body weight were assessed to determine whether - over the course of a follow-up year - up - changes in the consumption of nuts were associated with changes in symptoms of the metabolic syndrome.

Reading the data, it emerged that the extent of MetS symptoms and excess weight were inversely proportional to nut consumption.

These findings suggest that increased consumption of nuts, including almonds, may prove to be an effective dietary strategy for weight management and positively impacting metabolic syndrome factors.

This new result² is part of the PREDIMED-Plus study, a clinical study conducted in Spain on 6,874 participants, multicentre, parallel-group, single-blind, lasting 6 years, designed to evaluate the long-term effects on cardiovascular events and mortality of an intensive weight loss program, based on a Mediterranean diet with reduced energy/caloric content, the promotion of physical activity and behavioral support. The intervention group is compared with the control group following an unrestricted Mediterranean diet.

Years of cardiovascular health research - including a systematic review and meta-analysis³ - supports the inclusion of almonds in heart-healthy eating plans.

Almonds are suitable for the Mediterranean diet, which emphasizes the consumption of plant foods, including nuts, and is recommended by health authorities, including the WHO. In the landmark PREDIMED study, cardiovascular disease in those following the Med Diet was lowered by approximately 30% compared to those in the control diet.

Almond’s nutritional profile, which includes plant protein (6g / 30g), fiber (4g / 30g), good fats, and important vitamins and minerals such as vitamin E (7.7mg / 30g), magnesium (81 mg / 30 g) and potassium (220 mg / 30 g), makes them an excellent alternative for an energetic and healthy snack.

Almonds also contain linoleic acid, a fatty acid that contributes to the maintenance of normal cholesterol levels, which are important for heart health¹.

Study at a glance:

• The aim of this study was to determine if changes in nut consumption over a 1-year follow-up are associated with changes in Metabolic syndrome (MetS) symptoms in middle-aged and older Spanish adults with high cardiovascular disease risk.  MetS refers to a cluster of metabolic complications of obesity including abdominal obesity (determined by increased waist circumference), elevated triglycerides, reduced HDL-cholesterol, elevated blood pressure, and elevated blood glucose.
• This present study includes those participants who completed a food questionnaire at the start of the study and at the 1-year follow-up time.  People with extremely high or low energy intakes were excluded, which resulted in data analyzed for 5,800 participants (3,005 men and 2,795 women, ages 55-75 years old).  The participants were overweight or obese (BMI ≥ 27 and <40) and had MetS. 
• The nut consumption (including almonds) was validated by a food questionnaire conducted by dietitians and adherence to the Med Diet was confirmed.  From baseline to the 1-year mark, MetS symptoms were assessed including waist circumference, HDL-cholesterol levels, triglyceride levels, fasting blood glucose, blood pressure (both systolic and diastolic), and excess body weight (both BMI and body weight). 
• The researchers then grouped the participants into three groups (tertiles) by determining increases in nut consumption during this time period.  After 1 year, average nut consumption amounts for tertile 1, tertile 2, and tertile 3 were as follows (P < 0.001):
  • Tertile 1:              18.4 ± 14.4 g/day of nuts
  • Tertile 2:              24.6 ± 11.2 g/day of nuts
  • Tertile 3:              44.7 ± 18.9 g/day of nuts

Results:

• Significant increases in extra virgin olive oil consumption and adherence to the Med Diet were observed across the 3 tertiles from tertile 1 to tertile 3.
• After the 1-year follow-up, the groups with the largest nut consumption (tertiles 2 and 3) had consistent calorie intake compared to baseline, which suggests increased nut consumption did not have a significant impact on overall calorie intake.
• When the three groups were compared to one another, the group that ate the most nuts (tertile 3) also increased consumption of extra virgin olive oil EVOO and improved adherence to the Mediterranean the most.
• When assessing at MetS features and weight change, with each tertile of increasing nut intake, waist circumference, blood triglyceride concentrations, systolic blood pressure, and BMI decreased significantly (P<0.05).
• For women, HDL-cholesterol levels increased with each tertile of increasing nut intake (P= 0.044).
• When comparing the group that ate the most nuts (tertile 3) to the group that ate the least nuts (tertile 1), participants in tertile 3 had greater decreases in waist circumference (men only), total body weight, and BMI (P<0.05).
• There were no significant changes between each group in fasting blood glucose and diastolic blood pressure.
• The researchers note that these findings, except for the increase in HDL-cholesterol, are consistent with previous studies.

Limitations of this study should be noted, and include:

• The study population were older adults who were obese/overweight, presented with MetS, and had a higher CVD risk so the results may not be applicable to other populations. 
• The food questionnaire may cause overestimations of certain food groups, and the study design of recruiting attendance at the educational sessions may have limited inclusion of lower-income participants.
• More study is needed to assess long-term results.

¹ ISS - https://www.epicentro.iss.it/diabete/epidemiologia

² Julibert A, Bibiloni M, Gallardo-Alfaro L, et al. Metabolic Syndrome Features and Excess Weight Were Inversely Associated with Nut Consumption after 1-Year Follow-Up in the PREDIMED-Plus Study, The Journal of Nutrition, nxaa289, https://doi.org/10.1093/jn/nxaa289

³ 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. 

⁴The beneficial effect is achieved with a daily intake of 10 g of linoleic acid.  Almonds provide 12 g of linoleic acid per 100 g.