Brazil nuts improve lipids, oxidative stress and blood vessel function in obese adolescents

Summary: Brazil nuts protect against vascular disease in overweight female adolescents.Recent research published in the journal Nutrition & Metabolism offers evidence that Brazil nuts, besides being more effective at raising serum selenium levels than selenium taken as a supplement, improve the lipid profile and protect against blood vessel damage. The authors state:

"Obesity is a chronic disease associated to an inflammatory process resulting in oxidative stress that leads to morpho-functional microvascular damage that could be improved by some dietary interventions. In this study, the intake of Brazil nuts (Bertholletia excelsa), composed of bioactive substances like selenium, α- e γ- tocopherol, folate and polyunsaturated fatty acids, have been investigated on antioxidant capacity, lipid and metabolic profiles and nutritive skin microcirculation in obese adolescents."

Their study subjects comprising obese female adolescents were randomized to a group that consumed 15-25 g/day of Brazil nuts in capsules for 16 weeks and a placebo group. Anthropometry, metabolic-lipid profiles, oxidative stress, capillary diameters, functional capillary density, red blood cell velocity (RBCV) were measured at baseline (T0) and after the Brazil nut intervention (T1). What did the data show?

"At T1, BNG [the Brazil nut group] had increased selenium levels, RBCV and RBCVmax and reduced total (TC) and LDL-cholesterol. Compared to PG [placebo group], Brazil nuts intake reduced TC, triglycerides and LDL-ox and increased RBCV."

In other words, compared to the placebo group, the Brazil nut cohort had better blood vessel function, lower total and LDL cholesterol and, importantly, reduced oxidized cholesterol (LDL-ox, the truly 'bad' cholesterol). Naturally, they also had higher selenium levels. The authors conclude:

"Brazil nuts intake improved the lipid profile and microvascular function in obese adolescents, possibly due to its high level of unsaturated fatty acids and bioactive substances.