India has more people living with diabetes than almost anywhere on earth, so this is a subject Indian kitchens have a direct stake in. It is also a subject where wellness writing tends to lose its footing entirely. So: numbers, with their error bars.
What the pooled evidence says
Two recent meta-analyses have looked at this properly. In 2024, Karim and colleagues pooled fifteen randomised trials covering 869 people with diabetes or prediabetes, in Diabetology & Metabolic Syndrome. Saffron supplementation was associated with a fall in fasting blood glucose of about 8.75 mg/dL and in HbA1c of about 0.34 percentage points, along with a drop in triglycerides.
In 2025, Zhang and colleagues pooled twenty-five trials and 1,486 participants with metabolic syndrome and related conditions, in Phytotherapy Research. They found a similar direction and a similar size: fasting glucose down about 6.67 mg/dL, HbA1c down about 0.25 percentage points.
A smaller Iranian trial from 2019 in overweight prediabetic adults used just 15 mg a day for eight weeks and saw fasting glucose fall by around 8 mg/dL and HbA1c by 0.15 points against placebo, with antioxidant activity rising. Notably, it changed nothing about their weight or their cholesterol.
Reading those numbers honestly
An HbA1c reduction of a quarter to a third of a percentage point is a real, measurable change. It is also a fraction of what metformin does, and a fraction of what a serious change in diet and walking does. Both meta-analyses say plainly that more and better trials are needed, and neither found saffron improved insulin resistance itself.
So the fair statement is: across a reasonable number of trials, saffron shifts glucose markers slightly in the right direction. Nobody should adjust a diabetes medication because of it, and nobody should regard a pinch of kesar as managing anything. If you take medication for blood sugar, tell your doctor about any supplement — the point is that the effect is real enough to be worth mentioning, not large enough to rely on.
The bit we find genuinely interesting
The trials that measured antioxidant markers tend to find them improving alongside the glucose numbers. That fits everything else known about crocin and crocetin, and it is probably the same underlying mechanism showing up in the eye studies, the brain studies and here. One spice, one class of compounds, a lot of different measuring instruments pointed at it.
The research behind this
- Karim M et al. Effects of saffron (Crocus sativus L.) supplementation on cardiometabolic indices in diabetic and prediabetic overweight patients: a systematic review and meta-analysis of RCTs. Diabetology & Metabolic Syndrome, 2024.
- Zhang X et al. Effects of saffron supplementation on glycolipid metabolism and blood pressure in patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials. Phytotherapy Research, 2025.
- Karimi-Nazari E et al. Effect of saffron (Crocus sativus L.) on lipid profile, glycemic indices and antioxidant status among overweight/obese prediabetic individuals: a double-blinded, randomized controlled trial. Clinical Nutrition ESPEN, 2019.
- Zamani M et al. The effects of saffron supplementation on cardiovascular risk factors in adults: a systematic review and dose-response meta-analysis. Frontiers in Nutrition, 2022.
This article summarises published research. It is not medical advice, and saffron is a food, not a treatment for diabetes. Never change prescribed medication without speaking to your doctor.
