ISLAMABAD, FEB 25 (ONLINE): Researchers from the University of Gothenburg in Sweden have found that sulforaphane, a compound found in broccoli sprouts, may help lower blood sugar levels in people with prediabetes.
The study found that the compound works better for people with certain metabolism types and a specific gut bacteria.
While this suggests sulforaphane could be used for more personalised treatment, experts stress that a healthy diet and regular exercise are still key to managing prediabetes.
Prediabetes occurs when an individual’s blood sugar levels are elevated beyond the normal range but have not yet reached the threshold for a type 2 diabetes diagnosis.
Now, a new study from the University of Gothenburg in Sweden, published in Nature MicrobiologyTrusted Source, has linked sulforaphane, a chemical compound found in broccoli sprouts, to improved blood sugar levels in individuals with prediabetes.
The research found that the compound had a more pronounced effect on blood sugar regulation in certain individuals.
Previously, researchers found that sulforaphane, a substance in broccoli sprouts, can help with type 2 diabetes. In a 2017 study, patients who took high doses of sulforaphane had much lower blood sugar levels.
How broccoli sprout compound impacts blood sugar levels
This new research involved 89 individuals with elevated fasting blood sugar, a key marker of prediabetes.
Participants were also had either overweight or obesity and were between the ages of 35 and 75.
For 12 weeks, the participants were randomly assigned either sulforaphane or a placebo, with neither the researchers nor the participants knowing who received which treatment. In total, 74 participants successfully completed all stages of the study.
The study found that participants who took the sulforaphane compound experienced a greater average reduction in fasting blood sugar levels compared to those who received the placebo.
The difference between the two groups was significant. An even more pronounced effect was observed when examining specific clinical subgroups.
The greatest improvements were seen in individuals with early signs of mild age-related diabetes, a relatively lower BMI within the study’s context, low insulin resistance, a low prevalence of fatty liver disease, and lower insulin secretion.
Senior researcher Anders Rosengren, PhD, from the University of Gothenburg explained the key findings to Medical News Today. He told us:
“We have found that sulforaphane, a compound that is highly contained in cruciferous vegatables such as broccoli, reduces blood glucose in individuals with prediabetes, i.e. a pre-stage of type 2 diabetes. In early stages of diabetes, the glucose production from the liver is increased. Sulforaphane interferes specifically with increased glucose production and reduces it. By doing that, fasting blood glucose is kept at lower levels, which is beneficial.”
“We also found that a subgroup of people with mild obesity and well-preserved insulin secretion has even larger effect,” Rosengren added. “Moreover, we found that individuals who have high abundance of a specific gut microbe that converts the inactive precursor to active sulforaphane have increased effect.”
“This opens an avenue for precision treatment of prediabetes to those who benefit most,” he explained.
Gut bacteria may boost sulforaphane’s effect on blood sugar
In the third part of the study, researchers also studied gut bacteria. They found a specific type of bacteria that interacts with sulforaphane and seems to make it more effective at lowering blood sugar levels.
On average, people who took sulforaphane had fasting blood sugar levels that were 0.2 millimoles per litre lower than those who took a placebo.
In a specific group of participants — individuals with mild obesity, low insulin resistance and reduced insulin secretion — the difference was of 0.4 millimoles per litre.
The greatest drop, 0.7 millimoles per litre, occurred in people who were part of that group and also had a particular gut bacterium.
Lifestyle changes should continue to be prioritised
“Prediabetes is estimated to affect 5-10% of the adult population,” Rosengren explained. “Most people don’t know about their condition but it can be suspected if you have relatives with type 2 diabetes, eat unhealthily and have limited exercise and high BMI [body mass index].”
“Lifestyle changes is a cornerstone but we also need additional complements. Sulforaphane can be provided as a functional food and thereby open up a new form of treatment for prediabetes. It is difficult to eat pure broccoli to reach the levels used in our study (you would need several kilograms per day) but it can be achieved by broccoli sprout extracts. As a consumer you have to be careful as the content of sulforaphane vary widely in marketed products. We used [a tool called] Diaopt in order to achieve the proper amounts.”
– Anders Rosengren, PhD
Haley Bishoff, RDN, LD, a plant-based registered dietitian and owner of Rutsu Nutrition in Las Vegas, not involved in this research told MNT that “sulforaphane is a powerful plant compound in cruciferous vegetables like broccoli,” and that “it is well known for its anti-inflammatory, antioxidant, and cancer-fighting properties.”
“The [current] research showed potential with broccoli sprout extract and its ability to help lower blood sugar levels. However, the most benefit was seen in people who already had low insulin resistance and healthy gut microbes,” Bishoff explained.
What are the recommendations for patients and the public?
“First and foremost, it’s important to understand that prediabetes is often preventable and reversible,” Bishoff explained.
“Many medical professionals are focused on treatment with medication, versus prevention as a primary approach. People with a healthy gut microbiome also tend to respond better to diabetic medications and see improved blood sugar control, compared to those who do not. This is another great reason to always prioritize a healthy lifestyle.”
– Haley Bishoff, RDN, LD
“An imbalance in healthy gut bacteria can contribute to elevated blood sugar and insulin resistance,” she added. “To maintain a healthy gut, it’s important to reduce eating ultra-processed foods, refined carbohydrates and high saturated fat foods.”
“Eating a diet rich in prebiotic fiber, fermented foods and food in its natural form will help maintain an overall healthier gut microbiome,” Bishoff advised.
Courtney Pelitera, MS, RD, CNSC, a registered dietitian specializing in sports nutrition and wellness nutrition, also not involved in the study, said that “overall, the study shows that the [broccoli sprout extract] did not benefit blood glucose levels as much as originally predicted.”
“However, it did help to reveal that the health of the gut microbiome correlates with effective blood glucose control. Those that had a healthier gut microbiome were more likely to benefit from the [broccoli sprout extract] with a more effective fasting glucose response,” she noted.
“This study could have bigger implications later on when we have more research in identifying exactly who will benefit from broccoli sprout extract as a treatment for prediabetes. “I think in my own practice, I would use this information to encourage patients to focus on having a healthy gut microbiome,” Pelitera explained.
“We can do this by including a wide variety of fruits and vegetables in the diet along with whole grains. This helps to provide both soluble and insoluble fiber and prebiotics, aiding in the improvement of the microbiome. Also, including [fermented] foods, such a yogurt, kombucha, kimchi, pickled foods, and cheeses adds probiotics and probiotics coming from whole foods into the gut microbiome. I would encourage adding these types of foods into the daily diet before supplementing the broccoli sprout extract.”
– Courtney Pelitera, MS, RD, CNSC
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