Soya oil and Brazil nut oil in metabolic syndrome
What it found
In 31 people with metabolic syndrome, 30 days of daily soya oil raised total and LDL cholesterol, while Brazil nut oil lowered a marker of oxidative stress.
Neither oil changed body measurements or blood pressure.
What they found
Studies in people
Cholesterol with soya oil
In the soya oil group, total cholesterol and LDL cholesterol both rose over the 30 days.
Cholesterol with Brazil nut oil
In the Brazil nut oil group, HDL cholesterol fell and triglycerides rose.
Oxidative stress markers
Malondialdehyde, a marker of lipid peroxidation, fell in the Brazil nut oil group. Total antioxidant capacity improved in the soya oil group.
Body measurements and blood pressure
Neither oil changed body mass index, body fat, waist circumference, or blood pressure.
Blood sugar
After 30 days, the Brazil nut oil group had higher glucose levels than the soya oil group, but neither group's glucose changed significantly from its own starting level.
What the authors conclude
“Although the addition of oils without lifestyle interventions did not alter the anthropometric and blood pressure parameters and promoted undesirable results in the lipid profile, daily supplementation of 10 mL of Brazil nut oil for 30 days decreased lipid peroxidation, contributing to oxidative stress reduction.”
Also in their conclusions
- They say that adding these oils without other lifestyle changes did not affect body measurements or blood pressure and led to unwanted changes in blood fats in both groups.
- They conclude that daily supplementation of 10 mL of Brazil nut oil for 30 days decreased lipid peroxidation, helping to reduce oxidative stress.
- They note that the potential benefits of Brazil nut oil for metabolic syndrome are limited without an overall healthy lifestyle.
How it was done
The authors wanted to compare how Brazil nut oil and soya oil affect body measurements, blood pressure, blood fats and oxidative stress in people with metabolic syndrome, since unsaturated fats are often recommended for heart health.
They randomly gave 31 adults with metabolic syndrome either 10 mL of Brazil nut oil or 10 mL of soya oil daily for 30 days. Measurements were taken at the start and after 30 days.
What it can’t tell you
- This was a 30 day trial in 31 people, so it cannot show what would happen over longer periods or in larger groups.
- The study did not look at whether these changes in blood fats or oxidative stress markers affect actual heart disease outcomes.
Who paid
- Funding
- Funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest. The sponsors had no role in the design, execution, interpretation, or writing of the study.
- Authors work at
- Federal University of Para, Brazil; State University of Ceará, Brazil
The paper
- Title
- Comparison of the Effects of Brazil Nut Oil and Soybean Oil on the Cardiometabolic Parameters of Patients with Metabolic Syndrome: A Randomized Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Costa E Silva LM, Pereira de Melo ML, Faro Reis FV, et al (2019). Comparison of the Effects of Brazil Nut Oil and Soybean Oil on the Cardiometabolic Parameters of Patients with Metabolic Syndrome: A Randomized Trial. Nutrients. doi:10.3390/nu12010046Free full textPubMed 31877968DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error