Written by Diana Licalzi, MS, RD, CDCES

Vegetables and Type 2 Diabetes

Vegetables provide fiber, antioxidants, and other nutrients that can help manage inflammation, support weight loss, and boost overall health. They are also delicious and filling while remaining relatively low in calories. But today, we will focus on one group of vegetables in particular, as evidence has shown that they may provide even more diabetes-related health benefits than some other vegetable groups: cruciferous vegetables. 

So, what makes a vegetable cruciferous? They typically have four-petaled flowers that look like a crucifix or a cross.  Examples of vegetables that are the members of the cruciferous family are:

• Arugula (also called rocket)
• Bok choy
• Broccoli
• Brussels sprouts
• Cabbage
• Cauliflower
• Chard
• Radish
• Kale
• Turnip and 
• Watercress

This group of vegetables has long been known for its impressive health benefits, from its cancer-protective properties to its nutrients that may support heart and brain health. Cruciferous vegetables are also packed with essential nutrients like vitamins A, C, K, folate, fiber, and potassium, all of which your body needs to function well.

But you probably want to know why cruciferous vegetables are the top vegetables for helping with blood sugar management.

Why Cruciferous Vegetables Help Treat Type 2 Diabetes

1. Fiber

Broccoli, in particular, is a great source of fiber. Just 1 cup of broccoli provides about 5 of the recommended 25 to 35 grams of fiber you should have per day! 

2. Glucosinolates

Cruciferous vegetables also contain glucosinolates, a compound that gives many of them their bitter flavor. Glucosinolates are sulfur-containing compounds that, when consumed, get broken down into different metabolites such as isothiocyanate, which can also go on to do amazing things for the body like help protect your cells from free radical damage, fight inflammation, decrease blood pressure, improve insulin sensitivity and much more as depicted by the detailed image below So, consuming cruciferous veggies can help protect our cells from disease-causing damage, which could lead to diseases and disorders like cancer or T2D! 

3. Sulforaphane 

By eating our beloved cruciferous veggies, you can also get sulforaphane, a compound derived from plants that might help reduce the risk of cancer, heart disease, and diabetes! A meta-analysis including 11 prospective studies (754,729 participants, 58,297 incident type 2 diabetes cases) found a 13% lower risk of type 2 diabetes with high cruciferous vegetable intake (Chen et al., 2018). 

Sulforaphane in cruciferous vegetables is stored in an inactive form called glucoraphanin. The enzyme myrosinase converts glucoraphanin to sulforaphane's active form. This activation is triggered by chopping or chewing but can also be produced in the gut by certain bacteria.

One way sulforaphane might help with diabetes management is through its potent anti-inflammatory properties, helping to mitigate inflammation in the body. Since chronic inflammation plays a significant role in the development of insulin resistance and type 2 diabetes, consuming plants containing sulforaphane may indirectly improve insulin sensitivity and lower the risk of diabetes.

Furthermore, sulforaphane acts as a powerful antioxidant, which means that it can protect cells from damage. This can ultimately help preserve the function of insulin-producing beta cells in the pancreas, which get damaged with insulin resistance, thereby reducing the risk of diabetes.

Also, interestingly, when broccoli consumption was combined with exercise, participants experienced a reduction in hyperglycemia significantly greater than those who just ate broccoli than those who just exercised.[2] The exercises included in this study were moderate warm-ups (5 to 10 min), resistance or strength exercises (20 min), and 20 min of aerobic exercise at a moderate intensity. The study also found that those who ate 10 grams of broccoli a day for 12 weeks experienced reduced fibrinogen levels, which can lead to clot formation and platelet aggregation, which are common cardiovascular complications associated with diabetes. 

4. Affordability

The next reason we love cruciferous veggies is because of their affordability. For instance, you can buy a single broccoli crown for about a dollar fifty per pound and frozen broccoli for even cheaper at Walmart. If you buy it fresh, it lasts about three to five days in the fridge. Buying broccoli and other cruciferous veggies gives you a lot of nutrient bang for your buck. You can also purchase them at the beginning of the week and use them throughout. Also, don’t shy away from frozen options too. Once picked, it’s flash-frozen, preserving all of the veggie’s vitamins and minerals.

5. Hydration

Eating broccoli and other cruciferous veggies is another way for people with elevated blood sugars to stay hydrated. According to the Centers for Disease Control and Prevention, being dehydrated concentrates your blood sugar, causing a rise in blood glucose levels. Since broccoli is 90% water, regular consumption can help keep you hydrated and keep your blood sugar levels in check. 

6. Versatility

What’s great about broccoli, as well as its other cruciferous family members, is that you can cook it in so many ways—enjoy the florets raw, steamed, or sautéed, and add them to soups, stews, salads, casseroles, stir-frys, pasta, and more. 

Choosing Veggies for Type 2 Diabetes 

Although we love broccoli and its health benefits, this doesn't mean it is the only veggie you should be eating. Our philosophy is the more, the merrier! Plus, bonus points for incorporating as many colors as possible. When selecting your veggies, here are some things to remember: 

• Choose fresh, frozen, and canned vegetables and vegetable juices without added sodium, fat, or sugar.
• If using canned or frozen vegetables, look for ones that say no salt was added to the label.
• As a general rule, frozen or canned vegetables in sauces are higher in both fat and sodium.
• If using canned vegetables with sodium, drain them and rinse them with water to reduce the amount of sodium left on them.

If you are trying to keep your insulin sensitivity in check, eat at least three to five servings of vegetables daily. This is a minimum, and more is better! A serving of vegetables is:

• ½ cup of cooked vegetables 
• 1 cup of raw vegetables

The bottom line is that cruciferous vegetables are excellent to include as part of a balanced and nutritious meal pattern that can help with blood sugar management. These vegetables will also help keep you feeling fuller longer and give you steady energy. So, next time you are at the grocery store, don't forget to add some broccoli or your cruciferous veggies of choice to your cart!

References 

1. https://www.sciencedirect.com/science/article/pii/S2667031323000271
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8471572