"Beneficial Effects of a Freeze-Dried Kale Bar on Type 2 Diabetes Patients: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial "
First author: Per Bendix, Year: 2024, Place: Denmark
In this 12-week blinded trial, adults with type 2 diabetes ate bars with freeze-dried kale or placebo. The kale group showed lower HbA1c, reduced insulin resistance, weight loss, and lower calorie intake. Fasting glucose and LDL cholesterol trended better, while body fat mass and glucose tolerance remained unchanged overall.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/39519473/
"Kale improves bowel movements in constipated women and affects some intestinal microbes and metabolites: a pilot study "
First author: Yuichiro Nishimoto, Nov 29, 2023, Japan
This randomized crossover trial compared whole kale powder with a control powder for four weeks each. Kale increased stool frequency and changed gut bacteria, raising helpful groups and lowering less favorable ones. Effects were strongest in people with low stool output at baseline, suggesting kale supports bowel health and microbiome balance.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/38094924/
"A randomized, double-blinded study evaluating effect of Matcha green tea on human fecal microbiota"
First author: S. Morishima , 2023, Kyoto, Japan
This double-blind trial gave healthy adults matcha or placebo drinks for two weeks. The matcha group showed greater gut microbiome diversity and shifts toward beneficial bacteria, including more Coprococcus and less Fusobacterium. These changes suggest matcha may act like a prebiotic, supporting gut barrier function and healthier metabolic profiles.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/36936880/
"Effect of matcha green tea on cognitive functions and sleep quality in older adults with cognitive decline: A randomized controlled study over 12 months "
First author: Kazuhiko Uchida , date: Aug 30, 2024, Clinical centers in Japan
This year-long randomized trial studied older adults with memory concerns. Participants consumed matcha powder or placebo daily. The matcha group improved in recognizing facial emotions, suggesting better social cognition. Overall cognition and daily function stayed similar. Sleep quality showed a mild, non-significant improvement, indicating selective cognitive and emotional benefits.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/39213264/
"The effects of grape seed extract supplementation on cardiovascular risk factors, liver enzymes and hepatic steatosis in patients with non-alcoholic fatty liver disease: a randomized, double-blind, placebo-controlled study "
First author: P. Ghanbari Year: 2024, Place: Iran
This double-blind trial studied adults with fatty liver disease who took grape seed extract or placebo for eight weeks. The supplement group showed better insulin sensitivity, lower cholesterol, triglycerides, blood pressure, and liver enzymes. HDL increased, and liver fat severity improved, suggesting benefits for metabolic health and cardiovascular risk in NAFLD patients.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/38755622/
"Grape seed extract supplementation along with a restricted-calorie diet improves cardiovascular risk factors in obese or overweight adults: a randomized, double-blind, placebo-controlled clinical trial"
First author: R. Yousefi, Dater 2021 , Place: Iran
This double-blind trial assigned overweight adults to grape seed extract or placebo alongside a calorie-restricted diet for twelve weeks. The grape seed group showed higher HDL, lower LDL, and reductions in triglycerides, total cholesterol, and risk indices like VAI and AIP, suggesting added cardiometabolic benefits beyond dieting alone.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/33044768/
"Pomegranate (Punica granatum L.) peel extract ameliorates metabolic syndrome risk factors in patients with non-alcoholic fatty liver disease "
First author: Hanieh Barghchi , Date: 2023, Place: Iran
This double-blind trial studied adults with fatty liver disease following a calorie-restricted diet. Those taking pomegranate peel extract for eight weeks lost more weight and had better cholesterol, triglycerides, blood pressure, and waist size than placebo. Liver fat and HDL improved, while blood sugar dropped modestly, supporting metabolic and liver health.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/37605174/
"Effects of bread fortification with pomegranate peel powder on inflammation biomarkers, oxidative stress, and mood status in patients with type 2 diabetes: a randomized placebo-controlled trial "
First author: Mohammad Zare , Date: 2025, Place Iran
This placebo-controlled trial gave people with type 2 diabetes bread fortified with pomegranate peel powder for eight weeks. The fortified bread lowered inflammation markers and oxidative stress, improving antioxidant status. Participants also reported better mood, with favorable trends in triglycerides and HDL, suggesting benefits for metabolic and inflammatory health.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/40808706/