Research shows that eating broccoli three to five times per week can lower the risk of breast, prostate and colon cancers. A new study from the University of Illinois finds that including broccoli in the diet may also protect against liver cancer.

"The normal story about broccoli and health is that it can protect against a number of different cancers. But nobody had looked at liver cancer," says Elizabeth Jeffery, a U of I emeritus professor of nutrition. "We decided that liver cancer needed to be studied particularly because of the obesity epidemic in the U.S. It is already in the literature that obesity enhances the risk for liver cancer, and this is particularly true for men. They have almost a 5-fold greater risk for liver cancer if they are obese."

The majority of the U.S. population eats a diet high in saturated fats and added sugars, said Jeffery. However, both of these are stored in the liver and can be converted to body fat. Consuming a high-fat, high-sugar diet and having excess body fat is linked with the development of non-alcoholic fatty liver disease, which can lead to diseases such as cirrhosis and liver cancer.

"We called this a Westernized-style diet in the study because we wanted to model how so many of us are eating today," Jeffery said.

Previous research suggests that broccoli, a brassica vegetable containing bioactive compounds, may impede the accumulation of fat in the liver and protect against non-alcoholic fatty liver disease in mice. Jeffery and her team wanted to find out the impact of feeding broccoli to mice with a known liver cancer-causing carcinogen. The researchers studied four groups of mice; some of which were on a control diet or the Westernized diet, and some were given or not given broccoli.

"We wanted to look at this liver carcinogen in mice that were either obese or not obese," Jeffery explains. "We did not do it using a genetic strain of obese mice, but mice that became obese the way that people do, by eating a high-fat, high-sugar diet."

Although the researchers were predominantly interested in broccoli's impact on the formation and progression of cancerous tumors in the liver, Jeffery said they also wanted to observe the health of the liver and how the liver was metabolizing lipids because of the high-fat diet.

The study found that in mice on the Westernized diet both the number of cancer nodules and the size of the cancer nodules increased in the liver. But when broccoli was added to the diet, the number of nodules decreased.

"That was what we really set out to show," Jeffery says. "But on top of that we were looking at the liver health. There are actually two ways of getting fatty liver; one, by eating a high-fat, high-sugar diet and the other by drinking too much alcohol. In this case, it is called non-alcoholic fatty liver, because we didn't use the alcohol. And it is something that is becoming prevalent among Americans. This disease means you are no longer controlling the amount of fat that is accumulating in your liver."

"We found that the Westernized diet did increase fatty liver, but we saw that the broccoli protected against it. Broccoli stopped too much uptake of fat into the liver by decreasing the uptake and increasing the output of lipid from the liver," she said.

The researchers found that adding broccoli to the diet of the mice did not make them "thin," or affect their body weight, but it did bring the liver under control, ultimately making them healthier. "This is one of the things that makes this very exciting for us," she says.

"I think it's very difficult, particularly given the choices in fast food restaurants, for everybody to eat a lower-fat diet. But more and more now you can get broccoli almost everywhere you go. Most restaurants will offer broccoli, and it's really a good idea to have it with your meal," Jeffery adds.

Jeffery's previous research shows that eating broccoli freshly chopped or lightly steamed is the best way to get to the vegetables' cancer-fighting compound, sulforaphane. Although the researchers only used broccoli in the study, Jeffery said that other brassica vegetables, such as cauliflower or Brussel sprouts, may have the same effect.

Q and A

Q: I just read how much fiber is recommended. How can I get enough without taking supplements?

A: It's not always easy to do, but you can start with focusing on fiber-rich, low-calorie plant foods like vegetables, fruits and whole grains. Make a goal to include these at every meal and the fiber begins to add up. Aim to eat five servings (2 1/2-3 cups) of vegetables and fruits plus three servings of whole grains and you'll be on your way to the recommended amount of fiber — close to 21 grams. Depending on overall calorie needs, most adults should be aiming for 25 to 35 grams of fiber per day. You get closer to that target with each added step to boost fiber. Include protein and fiber-packed pulses (dried beans and peas) and a few nuts and seeds, and you can add 8-10 grams fiber daily. Work your way up to 7 to 10 servings of vegetables and fruits daily, and gradually replace refined grains with whole grains. You can also choose a cereal with 5 or more grams of dietary fiber per serving for breakfast or as a snack. Add dried beans (like kidney beans, garbanzo beans, and lentils) to salads or soups and make a habit of snacking on a handful of nuts instead of low-fiber chips or crackers. Add fiber supplements if necessary to reach the level your doctor recommends, but then try gradually increasing high fiber foods and decreasing fiber supplements. By adding high fiber foods you also get many valuable nutrients and health-protective phytochemicals that a fiber supplement can't provide. Moreover, research now shows that different types of fiber provide different health-related benefits. By getting fiber from a variety of plant foods, you'll get a full complement of fiber types. — American Institute for Cancer Research.

RECIPE

It's definitely time to clean off the grill. This recipe for Lemon & Herb Chicken Kebabs, from Eating Well magazine, is a perfect way to get the season started.

Lemon & Herb Chicken Kebabs

1 cup low-fat plain yogurt

Zest of 1 lemon

1 tablespoon lemon juice

1 1/2 tablespoons chopped fresh oregano and/or marjoram

2 cloves garlic, minced

2 tablespoons extra-virgin olive oil, divided

3/4 teaspoon salt, divided

1/2 teaspoon ground pepper, divided

1 pound boneless, skinless chicken thighs, trimmed, cut into 1-inch pieces

1 large bell pepper, cut into 1-inch pieces

1 medium red onion, cut into 1-inch pieces

Combine yogurt, lemon zest, lemon juice, oregano, garlic, 1 tablespoon oil, 1/2 teaspoon salt and 1/4 teaspoon pepper in a medium bowl. Transfer 1/2 cup of the mixture to a small bowl and refrigerate until ready to use. Add chicken to the remaining yogurt mixture and stir to coat. Let marinate at room temperature for 20 minutes or refrigerate up to 1 day.

Preheat grill to high. Toss bell pepper and onion in a large bowl with the remaining 1 tablespoon oil and 1/4 teaspoon each salt and pepper. Thread the marinated chicken, bell pepper and onion pieces alternately onto eight 8-10 inch skewers. Discard marinade. Reduce grill heat to medium. Oil the grill rack. Grill the skewers, turning once, until the chicken is cooked through and the vegetables are tender-crisp, 6 to 8 minutes per side. Serve with the reserved yogurt sauce for dipping. Serves 4 (serving size: 2 kebabs and 2 tablespoons sauce each).

Per serving: 291 calories, 25 g protein, 10 g carbohydrates, 16 g fat, 79 mg cholesterol, 2 g fiber, 545 mg sodium.

Charlyn Fargo is a registered dietitian at Hy-Vee in Springfield, Ill., and the media representative for the Illinois Academy of Nutrition and Dietetics. For comments or questions, contact her at charfarg@aol.com or follow her on Twitter @Nutrition Rd. To find out more about Charlyn Fargo and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: Steven Depolo