Researchers in Canada conducted a 10-week pilot study in 20 healthy adults to test the cardiometabolic effects of consuming freeze-dried SB, measuring outcomes such as blood glucose, lipid levels, insulin resistance, blood pressure, inflammation and gut health before and after the intervention.
Saskatoon is a shrub native to western North America. The berries are high in fiber, vitamins, micronutrients and polyphenols—especially anthocyanins. Animal studies show that consuming SB lowers blood sugar, cholesterol, triglycerides, and inflammation, while improving liver health and insulin resistance.
The researchers of the new study suggested that Saskatoon berries could have the potential to help reduce the risk of conditions like type 2 diabetes, metabolic syndrome, hypertension, and liver disease; however human evidence until now remained limited.
“Despite promising preclinical evidence in animal models, the metabolic benefits of SB have not been documented in human subjects,” they wrote. “To address this knowledge gap, we conducted a single-arm pilot study to evaluate the safety, acceptance, and feasibility of freeze-dried whole SB consumption in humans, as well as its potential cardiometabolic effects.”
Health benefits of daily Saskatoon berries after 10 weeks
The researchers recruited 20 healthy adults from the University of Manitoba and instructed them to consume 40 g of freeze-dried Saskatoon berries daily for 10 weeks while maintaining their usual diet and activity levels.
The researchers conducted four study visits, administering glucose tolerance tests and monitoring adherence at weeks 5 and 10. They analyzed blood samples, and extracted DNA from stool samples and sequenced bacterial genes to profile gut microbiota, measuring fecal short-chain fatty acids (SCFAs). Statistical analyses were then performed to examine relationships between microbiota, SCFAs and clinical outcomes.
After 10 weeks, participants showed significant improvements in several health markers like fasting blood glucose, total cholesterol, LDL cholesterol, non-HDL cholesterol, systolic blood pressure and inflammation. However, body weight, most other blood markers, physical activity, and insulin resistance did not change significantly. Intake of fiber, sugar, and vitamin C increased while overall calorie intake also stayed stable.
The researchers noted that lower fasting and post-meal blood glucose was likely due to increased dietary fiber and anthocyanins, which may work together to improve glucose regulation. They also suggested that berry consumption reduced total cholesterol and LDL cholesterol through SB’s high fiber content.
Gut microbiota diversity did not change overall, however the abundance of the bacterial family Prevotellaceae increased, which is associated with higher SCFA levels and better metabolic health. The researchers noted that the microbiome changes may help explain reductions in blood pressure and other health benefits.
“This study provides the first clinical evidence that the consumption of 40 g/day of dried SB for 10 weeks effectively lowered FPG and apoB-rich lipoprotein-cholesterol, inflammatory biomarkers and blood pressure in healthy adults, which was associated with an improvement in gut microbiota composition and SCFA production,” they wrote.
“The results suggest that dried SB is a well-tolerated, functionally active dietary supplement with the potential to reduce multi-cardiometabolic risks mediated by increased dietary fiber, anthocyanins, and the modulation of gut microbiota composition and SCFA production.”
They noted that larger, controlled trials are needed to confirm these findings, determine optimal dosing and test effects in broader populations.
Source: International Journal of Molecular Science; doi: 10.3390/ijms27083644; “Effects of Daily Saskatoon Berry Supplementation on Cardiometabolic Health, Gut Microbiota, and Short-Chain Fatty Acids in Healthy Adults.” Author: Lee, E. et al.
