What the trial measured, and what it did not
James describes a 90-day study. The published paper, in Nutrition and Diabetes in 2021, reports a 12-week trial. It was a randomised, double-blind, placebo-controlled study at a government medical college in Andhra Pradesh. It enrolled 40 people with type 2 diabetes, with 20 in each group.
Participants took 15 grams of flour at breakfast and 15 grams at dinner, in place of part of their usual rice or wheat. The other group took placebo flour. The paper reports that HbA1c, a measure of average blood sugar over about three months, fell by -2.73 mmol/mol (-0.25%) in the jackfruit group. It rose by 0.22 mmol/mol (0.02%) in the placebo group, with p = 0.006. Fasting and after-meal glucose also fell more in the jackfruit group.
The authors name the limits themselves: a small sample, a short study and a single centre. They also disclose that James Joseph is a co-author, the inventor and CEO of the company that makes the flour, and that the company funded the study. Read the trial with that in mind.
James also says a glycemic study at the University of Sydney found the flour has a 40% lower glycemic load than two rotis or a cup of rice. We have not checked that study for this article. This is not medical advice.