Clinical Trial With Broccoli Sprout Extract to Patients With Type 2 Diabetes

Overview

Type 2 diabetes (T2D) results from a combination of insufficient insulin secretion from pancreatic islets and insulin resistance of target cells. The investigators have extensive pre-clinical data suggesting that BSE through its high content of the isothiocyanate sulforaphane improves hepatic insulin sensitivity. BSE as a dietary supplement could therefore benefit both patients with T2D and individuals at risk for the disease. BSE-containing sulforaphane is suggested to activate Nuclear factor-like 2 (NRF2). The investigators aim to study the clinical effect of using BSE as a dietary supplement on glucose tolerance and insulin sensitivity.

Sulforaphane binds to Keap1 in the cytosol, leading to nuclear translocation of this transcription factor. In the nucleus NRF2 induces the expression of a large number of anti-oxidative genes. Sulforaphane is contained at high concentration in broccoli sprout extracts (BSE). Human studies have been conducted using broccoli sprout products without complication. It is being tested for the treatment or prevention of cancer and inflammatory diseases in \~30 clinical trials without any serious adverse events reported. The low toxicity makes BSE ideal as a dietary supplement for preventing and treating T2D. The investigators aim to study the clinical effect of sulforaphane on glucose tolerance in T2D patients. Sulforaphane will be given as BSE. BSE is a freeze-dried powder of an aqueous extract of broccoli sprouts that provides a consistent and stable source of sulforaphane. The investigators will use a parallel arm study design with patients receiving BSE or placebo. The randomization will be double-blind. The study will be done at one centre. Patients with BMI between 25-40 kg/m2 will be included. Another inclusion criterion is HbA1c 6-10%. Patients will be treated for 12 weeks to enable us to observe effects on HbA1c (HbA1c turn-over is 3 months). Patients will come to a screening visit and if they give informed consent and are included they attend a second visit 2-3 weeks later. The patients will undergo an oral glucose tolerance test (OGTT) before and after the 12-week treatment period. The reason for using OGTT rather than e.g. insulin clamps as the readout is that it is a harmless standard procedure that gives an integrated view of glucose tolerance.