A number of previous studies suggest a therapeutic effect of tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts) on metabolic dysfunctions.  Cyril Kendall, from the University of Toronto (Canada), and colleagues completed two meta-analyses looking at the effects of tree nuts on triglycerides and fasting blood glucose as relevant to Metabolic Syndrome; and the effects of tree nuts on HbA1c and fasting blood glucose levels as they relate to type- diabetes.   In the analysis focusing on Metabolic Syndrome, the researchers selected 47 randomized control trials involving a total of 2,200 participants, to find that consuming 2 ounces of tree nuts a day decreased triglycerides by 0.06 mmol/L and reduced fasting blood glucose by 0.08 mmol/L, over an average follow-up of eight weeks.  Separetely, the team’s meta-analysis of 12 randomized clinical trials on glycemic control in type-2 diabetes involved 450 participants compared the effects of diets emphasizing tree nuts to isocaloric diets without tree nuts on HbA1c (a marker of longer term blood sugar control), fasting blood glucose, fasting insulin and insulin resistance (HOMA-1R). The results showed that diets emphasizing about 2 ounces of tree nuts per day significantly lowered HbA1c as well as  fasting glucose.  The study authors write that: “Pooled analyses show that tree nuts improve glycemic control in individuals with type 2 diabetes, supporting their inclusion in a healthy diet,” and separately that: “Pooled analyses show a [Metabolic Syndrome] benefit of tree nuts through modest decreases in triglycerides and fasting blood glucose with no adverse effects on other criteria across nut types.”

Source: http://www.worldhealth.net/news/macadamias-benefit-metabolic-disorders/