Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder affecting millions globally, with India projected to have a significant number of cases by 2030. Medical nutrition therapy (MNT) plays a crucial role in managing T2DM, often synergistically with pharmacological interventions. Jackfruit (Artocarpus heterophyllus), widely cultivated in tropical regions, is rich in dietary fiber, carbohydrates, vitamins, and minerals. While ripe jackfruit's high sugar content raises concerns for diabetics, the unripe, green jackfruit has shown promise in preclinical studies due to its phytochemical compounds like carotenoids, proanthocyanidin, flavonoids, and others. These compounds exhibit antidiabetic and antioxidant effects, potentially through mechanisms such as inhibiting lipid peroxide formation. Previous observational studies in Kerala, India, suggested reduced antidiabetic medication needs during jackfruit season. However, a rigorous randomized controlled trial was lacking to assess green jackfruit flour's efficacy in achieving optimal glycemic control in T2DM patients. This study aimed to fill this gap by evaluating the efficacy of Jackfruit365™ green jackfruit flour as an MNT in patients with T2DM.

Numerous in vitro and in vivo studies have explored jackfruit's antidiabetic potential. These studies, using various jackfruit parts (seeds, leaves), demonstrated significant antihyperglycemic activity in diabetic animal models, often linked to increased insulin secretion or release from bound forms. The mechanisms involved may include flavonoid action and antioxidant properties inhibiting lipid peroxidation. A previous single-blinded clinical study using jackfruit leaf decoction showed a significant reduction in FPG and PPG in T2DM patients. However, the present study is the first to investigate the efficacy of green jackfruit flour in a double-blind, placebo-controlled trial, utilizing a more practical and culturally relevant approach to dietary integration.

This randomized, double-blind, placebo-controlled study (CTRI/2019/05/019417) was conducted between May 2019 and February 2020 at Rajiv Gandhi Institute of Medical Sciences, Srikakulam, India. 42 patients were enrolled, with two excluded due to ineligibility, leaving 40 patients (20 per group). Patients (aged 18-60 years, diagnosed with T2DM for >1 year, on oral hypoglycemic agents, and with HbA1c < 8%) were randomized (1:1) to receive either 30 g/day of Jackfruit365™ green jackfruit flour (Group A) or placebo flour (Group B). The flour replaced an equal volume of rice or wheat flour in breakfast and dinner meals. The primary endpoint was the mean change in HbA1c from baseline to week 12. Secondary endpoints included changes in FPG, PPG, body weight, and lipid profile. A subset of patients underwent continuous glucose monitoring (CGM) for 14 days. Data analysis used independent t-tests, with p<0.05 considered statistically significant. Green jackfruit flour (108 kcal, 20g net carbs, 5g fiber) was compared to placebo flour (146 kcal, 30g net carbs, 2.54g fiber).

At week 12, Group A (jackfruit flour) showed a significantly greater reduction in HbA1c (-2.73 mmol/mol, -0.25%) compared to Group B (0.22 mmol/mol, 0.02%), p=0.006. Group A also demonstrated significantly greater reductions in FPG (-1.63 mmol/L, p=0.043) and PPG (-2.03 mmol/L, p=0.001) than Group B. Continuous glucose monitoring data (although with limitations due to patient dropout) numerically showed lower glucose levels in the jackfruit flour group. No significant changes were observed in body weight or lipid profiles between the groups.

The findings strongly support the efficacy of green jackfruit flour as an effective MNT for T2DM. The significant reductions in HbA1c, FPG, and PPG in Group A, compared to the slight increase in HbA1c in Group B, clearly indicate the positive impact of jackfruit flour on glycemic control. This aligns with the established benefits of MNT, particularly high-fiber, low-calorie diets in improving glycemic targets. The jackfruit flour's lower calorie and carbohydrate content, combined with its higher fiber content compared to the placebo flour, likely contributed to these improvements. Notably, the reduction in HbA1c occurred without significant weight loss, which is particularly relevant in the South Asian population, where diabetes frequently affects non-obese individuals. The results are consistent with preclinical findings demonstrating the antidiabetic properties of jackfruit, potentially mediated by flavonoids and antioxidants. While the CGM data provides supportive evidence, the limited sample size necessitates cautious interpretation.

This double-blind, placebo-controlled study demonstrates the efficacy of incorporating Jackfruit365™ green jackfruit flour (30 g/day) into daily meals as an MNT for T2DM patients. The significant improvements in HbA1c, FPG, and PPG levels highlight its potential as a viable dietary intervention for glycemic control. The ease of integration into various dishes makes it a practical and culturally acceptable addition to existing dietary patterns. Future research should include larger, multicenter trials with longer durations and higher HbA1c inclusion criteria to further validate these findings and explore the underlying mechanisms of action.

The study had several limitations. The relatively small sample size and shorter duration might limit the generalizability of the results. The lower HbA1c exclusion criterion could have biased the sample toward patients with better baseline glycemic control. The single-center design restricts the generalizability to other populations. Lastly, the CGM data analysis had a significant dropout rate, impacting the reliability of the findings from this secondary outcome measure.