The body of evidence about nuts and health continues to grow. These local and international research papers, recently published, corroborate decades of research about the importance of a regular handful of nuts in a healthy diet.

A calorie-restricted diet enriched with tree nuts and peanuts reduces the expression of CX3CR1 in peripheral blood mononuclear cells in patients with coronary artery disease. (2021).
This study looked at the effects of a low-calorie diet, with and without nuts, on gut bacterial abundance, metabolic markers, and gene expression in peripheral blood mononuclear cells (PBMCs) in stable coronary artery disease patients with overweight or obesity. Study participants were randomly allocated to a nut-free calorie-restricted diet as 25% of energy deficit (CRD) or a CRD enriched with 39–60g/day of mixed nuts (CRDEN) for 8 weeks. Compared with the CRD group, the CRDEN group had a significant reduction in expression of fractalkine receptor (CX3CR1) – a ‘chemokine’ or small protein, linked with inflammation. The researchers say their findings offer further evidence for the benefits of a diet containing nuts on factors associated with inflammation.

The impact of nutrition on the development and progression of peripheral artery disease: A systematic review. (2021).
This systematic review collated the outcomes of 82 studies, published over 45 years, which looked at the impact of nutritional intake on peripheral artery disease (PAD). The nutrients were structured in fruits, vegetables and antioxidants, fats and oils, dietary fibre, meat, proteins, vitamins and trace elements, and diets and lifestyle. It found the Mediterranean diet, nuts, and polyunsaturated fat were associated with a lower incidence of PAD. On the flip side, saturated fat, cholesterol, and processed meat were linked with higher rates of cardiovascular events in people with PAD.

Lack of association between nuts and legumes consumption and metabolic syndrome in young Iranian nurses. (2021).
This study explored the association between nuts and legumes and components of metabolic syndrome in 420 female Iranian nurses. Consumption of nuts and legumes was not associated with waist circumference, diastolic blood pressure, serum triglycerides, HDL-cholesterol, and fasting blood sugar. The researchers concluded that study participants in the highest category of nuts and legume consumption did not have higher odds for metabolic syndrome or its components.

Adherence to a plant-based diet and consumption of specific plant foods – Associations with 3-year weight-loss maintenance and cardiometabolic risk factors: A secondary analysis of the PREVIEW intervention study. (2021).
This 3-year study examined associations of an overall plant-based diet (PBD) and specific plant foods with weight-loss maintenance and cardiometabolic risk factors in 710 people (aged 26–70 years) at high risk of type 2 diabetes. Adherence to a PBD diet was linked with improved weight management, but not cardiometabolic risk factors. Whereas consumption of nuts, fruits, and vegetables was inversely associated with weight regain and cardiometabolic risk factors, suggesting that specific components in a PBD are important as well. Specific to nuts, intake was inversely linked with regain of weight and fat mass, and increments in total cholesterol and LDL-cholesterol.

Plant-based, antioxidant-rich snacks elevate plasma antioxidant ability and alter gut bacterial composition in older adults. (2021).
In this study, 42 healthy and sub-healthy older adults (>65 years) in two senior living facilities were given plant-based, antioxidant-rich smoothies and sesame seed snacks for 4 months. The smoothie contained 1 exchange of vegetables (2 kinds), 1 exchange of fruits (2 kinds), and 1 exchange of nuts – foods consumed in limited quantities among older adults due to changes in their chewing and swallowing functions. After 4 months, antioxidant ability increased and gut microbiota composition was altered, suggesting that texture-modified, plant-based snacks are useful nutrition support to benefit healthy aging.

The effect of walnut consumption on cardio-metabolic profiles of individuals with abnormal glucose homeostasis: A systematic review and meta-analysis of clinical trials. (2021).
This review looked at randomised controlled trials, of people with abnormal glucose homeostasis (that is, impaired glucose tolerance or pre-diabetes). Twelve studies were included in the systematic review and eight in the meta-analysis. It found that walnut consumption may increase flow-mediated dilation and lower LDL-cholesterol levels in people with abnormal glucose homeostasis. It did not affect other cardio-metabolic measures (including triglyceride, total- and HDL-cholesterol levels, or fasting blood glucose and HbA1C levels) or anthropometric measures, including weight.

Association between plant-based dietary patterns and risk of cardiovascular disease: A systematic review and meta-analysis of prospective cohort studies. (2021).
This systematic review and a meta-analysis collated the outcomes of 10 studies, involving 698,707 participants. It found higher overall plant-based diet index (PDI) and healthful PDI scores were linked with a reduced CVD risk. The highest adherence to plant-based diets was associated with a 16% lower risk of CVD and a 12% lower risk of CHD, compared with the lowest. The review suggests that diets lower in animal foods and unhealthy plant foods, and higher in healthy plant foods (whole grains, fruits, vegetables, nuts and legumes) are beneficial for CVD prevention.

Effects of plant-based diets on weight status in type 2 diabetes: A systematic review and meta-analysis of randomised controlled trials. (2021).
Australian-based researchers collated the outcomes of seven randomised controlled trials on the impact of plant-based diets (PBDs), compared with regular meat-eating diet (RMDs), on body weight, BMI and waist circumference, for ≥6 weeks, in adults with type 2 diabetes. PBDs significantly lowered body weight, BMI and WC, compared to RMDs. PBDs alone significantly reduced body weight (by 5.1%), BMI (by 5.4%) and WC (by 4.3%). And a significant reduction in body weight and BMI was also seen in PBD trials that didn’t limit energy intake, suggesting that PBDs are effective in reducing body weight and BMI irrespective of energy restrictions. The findings provide evidence for a role for PBDs in managing central adiposity in people with type 2 diabetes.