PETAI, also known as stink bean, is one of those love-it-or-hate-it ingredients in Malaysian cuisine. Its pungent smell can clear a room, yet it remains a favourite in dishes like sambal petai and petai fried rice.
Beyond the culinary debates, there's a persistent claim amongst Malaysians that eating petai can help prevent diabetes or lower blood sugar levels.
Some even swear by it as a traditional remedy for managing the condition. But can this notoriously smelly bean really help diabetics control their blood sugar?
Verdict:
TRUE
Yes, petai has been scientifically shown to have blood sugar-lowering properties that could potentially help with diabetes management, according to multiple peer-reviewed studies. However, it's important to understand what this means and what it doesn't mean.
A systematic review published in Discover Food in 2024 examined 10 scientific studies on petai's anti-diabetic properties. The review found that seven in vivo studies (studies using live animals) and three in vitro studies (laboratory studies) all proved the effectiveness of stink beans as an anti-diabetic agent.
The research showed that various parts of the petai plant, including seeds, pods, empty pods and even the peel, demonstrated blood sugar-lowering effects.
A comprehensive review published in Evidence-Based Complementary and Alternative Medicine, which is available through PMC (PubMed Central), confirmed that petai extracts from empty pods and seeds have high content of polyphenols, phytosterols and flavonoids.
The hypoglycemic effect, meaning the ability to lower blood sugar, is attributed to the presence of three specific compounds: β-sitosterol, stigmasterol and stigmast-4-en-3-one.
Early research published in Food Chemistry in 1994 by Jamaluddin, Mohamed and Lajis found that petai seeds produce their hypoglycemic effect through the synergistic action of β-sitosterol and stigmasterol. This means these plant sterols work together more effectively than either would alone.
A follow-up study published in Food Chemistry in 1995 by the same researchers specifically identified that stigmast-4-en-3-one from petai empty pods also possesses blood sugar-lowering properties.
More recent research published in the IOP Conference Series in 2022 studied the effect of petai seed extract on alloxan-induced diabetic mice. The study demonstrated that petai extract could lower blood glucose levels in mice that were experimentally given diabetes.
Research published in Archives of Physiology and Biochemistry in 2021 examined petai empty pods specifically. The study found that petai empty pod extract is a potent natural anti-diabetic agent for the prevention of pancreatic and liver dysfunction in rats with type 2 diabetes induced by a high-fat diet and streptozotocin.
So how does petai actually work to lower blood sugar?
According to the scientific literature, petai contains compounds that work through multiple mechanisms. The plant sterols in petai appear to have anti-hyperglycemic effects, meaning they prevent blood sugar from rising too high. The flavonoids and polyphenolic compounds demonstrate anti-diabetic activity through their antioxidant properties.
Additionally, petai's high fibre content plays a role. Dietary fibre slows down glucose absorption from the intestines and prevents a rapid rise in blood insulin levels, which is beneficial for diabetics as well as people fighting obesity.
The research also shows that petai doesn't just lower blood sugar. A 2020 study mentioned in the systematic review found that petai peel extract at 300mg per kilogram of body weight matches the effectiveness of simvastatin, one of the most effective drugs for normalising total cholesterol levels.
This is significant because people with diabetes often have abnormal cholesterol levels, and managing both conditions together is crucial for preventing cardiovascular complications.
However, here are the important caveats that every Malaysian needs to understand.
First, all these studies were conducted on animals (primarily rats and mice) or in laboratory settings. While these results are promising and scientifically significant, they don't automatically translate to the same effects in humans eating petai as part of their regular diet.
The doses used in animal studies are often much higher than what a person would consume by eating petai in a meal. The extract forms used in research are also more concentrated than simply eating the beans.
Second, it's crucial to understand that diabetes is a complex condition with different types and causes, and petai's potential benefits are primarily relevant to Type 2 diabetes management rather than prevention or treatment of Type 1 diabetes.
Type 1 diabetes is an autoimmune condition where the body's immune system attacks and destroys the insulin-producing cells in the pancreas. This type is primarily caused by genetic factors and is not preventable through diet. No amount of petai or any other food can prevent or cure Type 1 diabetes, as it requires insulin therapy for management.
Type 2 diabetes, on the other hand, is increasingly understood to be caused by a combination of factors, with chronic stress playing a more significant role than previously recognised. Research has shown that prolonged stress elevates cortisol levels, which can lead to insulin resistance and increased blood sugar levels over time.
Whilst diet does play a part in Type 2 diabetes development, particularly through its contribution to obesity and metabolic syndrome, it's not simply a matter of eating too much sugar. The relationship is more complex, involving how the body processes nutrients, genetic predisposition, physical activity levels, sleep patterns and importantly, stress management.
This means that whilst petai's blood sugar-lowering compounds may help manage Type 2 diabetes symptoms, it cannot address the underlying causes such as chronic stress, genetic factors or lifestyle patterns. A holistic approach that includes stress reduction, regular physical activity, adequate sleep and overall dietary balance is far more important than any single food item.
Third, petai should never be considered a replacement for diabetes medication. The research suggests petai has potential for development as an oral hypoglycemic agent, but it hasn't been developed into an approved medication and shouldn't be used as such.
Fourth, petai does contain moderate levels of purines, which are broken down into uric acid in the body. For people with kidney problems or those prone to gout, excessive consumption of petai could be problematic.
The Evidence-Based Complementary and Alternative Medicine review notes that petai has been used in folk medicine to treat diabetes, hypertension and kidney problems throughout Southeast Asia for generations. The scientific research is essentially confirming what traditional medicine practitioners have long observed.
What does this mean for the average Malaysian who enjoys petai?
The good news is that eating petai as part of a balanced diet appears to have genuine health benefits beyond just being delicious. The compounds in petai that give it anti-diabetic properties are present when you eat it normally, not just in extracted form.
For people already managing Type 2 diabetes, petai can be part of a healthy diet that includes plenty of vegetables, but it shouldn't replace medication or medical advice. Always consult with your doctor about dietary changes when managing diabetes.
For people looking to prevent Type 2 diabetes, eating petai as part of a diet rich in vegetables, fruits, whole grains and lean proteins, combined with regular exercise, stress management and maintaining a healthy weight, is a sensible approach.
So yes, petai does have scientifically proven anti-diabetic properties that may help with Type 2 diabetes management. Just don't expect it to work miracles, and definitely don't stop taking your medication to eat more sambal petai instead.
The science supports what your grandmother might have told you: petai is good for you, smelly though it may be. But remember, managing and preventing diabetes requires a comprehensive approach that goes well beyond any single food.
References:
1. https://link.springer.com/
2. https://pmc.ncbi.nlm.nih.
3. https://onlinelibrary.
4. https://www.atlantis-press.
5. https://iopscience.iop.org/
