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Grilled Citrus Skewers

June 30, 2020
citrus skewers

Summertime is here, which means it’s time to kick back in the yard and break out the grill! With the heat rising, we decided to make this month’s recipe a grilling/marinade mix.

What’s so great about grilling? The key is in the char and the marinade. The resulting tasty and vibrant flavors make a perfect addition to a summer afternoon!

Char is another name for the process of pyrolysis, in which organic compounds are heated without the presence of oxygen. On the grill, your food is undergoing this process as it sits in the heat. The black marks are the charred parts of the food, resulting in a unique, savory flavor that’s tough to duplicate with other cooking methods.

Another key component is crafting a top-tier marinade, to tenderize and add flavor to whatever you put on the grill. Interestingly, the word “marinade” is believed to originate from the Latin word mare, or sea: historically, sea water was used to preserve meat and impart flavor. (While we’ve aimed to keep this recipe simple, we’ve made sure it’s more interesting than salt water.) The marinade mix in this month’s recipe includes acidic compounds (citric acid in the lemon and lactic acid in the yogurt) which break down protein tissue and allow it to hold more moisture, so the meat is more juicy and tender (up to a point – too much acid or marinating for too long may result in a mushy texture). Use coconutmilk yogurt if you’re avoiding dairy.

What about sweetener in your marinade? This is a matter of some debate. Sugar may be a natural tenderizer, but its main role is to boost flavor and help to achieve a nice caramelized crust. Whether you use sugar, honey, maple syrup, or another type of your choosing, the total amount in this recipe is small and will have little effect on the nutritional profile. Keep in mind that sugar may burn at higher temperatures, so use medium heat (400-450o F).

What about cancer risk? Cooking meats at high temperatures forms substances called heterocyclic amines (HCAs) that are probable carcinogens, as shown in laboratory experiments. Also during grilling, the smoke can carry compounds called PAHs up onto the food. Multiple studies in rats implicate HCAs as a cause of prostate cancer, and PCF-funded researcher Dr. Lorelei Mucci has written that well-done red meat and the associated carcinogens may play some role in prostate cancer risk in humans.

Luckily, marinade plays one more key role in your grilling, and that is cutting down on HCAs themselves. Studies have shown that marinating significantly reduced the production of detectable HCAs. Moreover, one study suggests that using honey as the sweetener (vs white or brown sugar) results in the lowest amount of HCAs. Prolonged cooking time may increase HCA formation, so watch your food carefully: cook thoroughly to kill any bacteria, but remove from the grill in time to avoid excess char. Best of all, choose plant-based foods to grill instead: their chemical makeup does not result in formation of HCAs during cooking.

More good news: you can substitute any sturdy, colorful vegetables in your skewers including red bell peppers, eggplant, zucchini, or cherry tomatoes. For healthy protein options you can try the marinade on tempeh or tofu, or even a meaty fish like haddock or mahi mahi. Nothing needs to be wasted in this recipe: if you like tangy tastes, the grilled charred lemon wedges can be eaten in their entirety for a delicious boost of vitamin C. Summer’s bounty brings a variety of vegetables to many parts of the country – if you can choose locally-grown produce at your grocery store or farmers market, you’ll enjoy the taste and health benefits of seasonal foods. Fresher food is firmer for skewering, tastes better (having traveled fewer “food miles”), and may even contain more nutrients closer to harvest. And, as we strongly recommend in our Wellness Guide, choose whatever brightly-colored, nutrient-rich vegetables you can find in the grocery store – that’s definitely better than no vegetables at all.

No grill? No problem! You can use a stovetop cast-iron grill pan or the broiler instead.

Grilled Citrus Skewers

• 8 oz of chicken, beef, or tofu*, cut into approximately 1” cubes
• 2 cups red pepper, zucchini, red onion, and/or mushroom, cut to match
For the Marinade:
• Zest of 1 lemon (reserve the remaining fruit and cut into 8 pieces)
• 1 tbs of lemon juice
• 2 tbs of olive oil
• 1 tsp honey
• 2 cloves of garlic, mashed to a pulp
• 1/2 cup whole milk yogurt or coconut milk
• 2 tsp salt
• ¼ tsp of black pepper
• Optional: 1 tsp paprika and/or cumin

Whisk together marinade ingredients and place in a 1 quart zip lock bag. Add vegetables and shake to coat. Using a fork or slotted spoon, immediately remove vegetables to a plate, reserving marinade in the bag. Add protein to the bag and let marinate, refrigerated, for 30 minutes.

To prepare the skewers – Alternate vegetables and meat, using the cut lemon wedges to cap each end of the skewer. If using wooden vs. metal skewers, be sure to soak the skewers in water first. Note: if serving as an appetizer, thread onto toothpicks, mixing protein and veggies on each serving.

On a medium grill (400-450 degrees) cook skewers, turning 1-2 times, for about 12-15 minutes, or until meat is cooked through.

Yield: 4 skewers

*If using tofu, select extra firm; cube, drain, and dry the tofu on a rack for 1-2 hours BEFORE marinating.