Several risk factors for cancer fall outside of our control — from age to gender to genetics — yet diet is one aspect of our lives we can control to reduce cancer risk. Following a healthy diet is one of the most effective ways to boost overall health and reduce the risk of developing cancer, says Andrew Woodward, MS, RD, CSO, an oncology nutritionist at Loma Linda University Cancer Center. For February's Cancer Prevention Awareness Month, Woodward imparts top nutrition tips for those seeking to lower their risk of developing cancer.
Woodward says adopting a flexible Mediterranean diet is one of the healthiest ways to eat, and it also reduces cancer risk and supports heart health. The Mediterranean diet is not the latest “diet” trend for weight reduction, he says, but rather a model for healthy eating that has been followed for thousands of years. It emphasizes nutritious foods that provide essential vitamins, minerals, and other naturally occurring compounds that promote good health, such as phytochemicals in fruits and vegetables. In addition, Mediterranean diet foods tend to be high in fiber and contain healthy fats while limiting sodium, added sugars, and saturated fat.
Healthy fats such as olives and olive oil, avocados, nuts, and seeds play a significant role in the Mediterranean diet, while less healthy fats from red meats, dairy, and processed foods such as baked goods take a backseat. This diet's primary sources of protein include seafood, legumes (beans, peas, lentils), nuts, and seeds.
The Mediterranean diet is prevalent in several Blue Zones — areas where people live longer than average. People can modify the basic Mediterranean diet, using it as a template while making adjustments to meet contemporary and individual needs, Woodward says. For example, the diet can lean more toward low-carb or accommodate vegetarian and vegan food choices.
Visualizing the breakdown of a Mediterranean diet-style meal can help. Woodward recommends starting with a nine-inch plate for portion control. Fill half of the plate with vegetables, a quarter with protein, like fish or beans, and the last quarter with minimally processed starches or carbohydrates such as brown rice, whole-grain pasta, or whole-grain bread. Additionally, Woodward says a defining feature of the Mediterranean diet is cooking with olive oil.
Extra virgin olive oil is made with the first press of the olives. Woodward says it is packed with polyphenols — compounds that exert anticancer effects through cancer cell destruction or removal by modifying signaling pathways, inhibiting cell cycle events, and other mechanisms. Oleuropein, another compound in the oil, spurs antioxidant activity and may stimulate the immune system, which is essential for cancer prevention. Finally, the oleocanthal component in olive oil also seems to provide anti-inflammatory benefits. The American Institute for Cancer Research identifies inflammation as one of the key "enabling characteristics" of cells acquiring hallmarks of cancer.
While olive oil contains all these benefits, taking extra spoonfuls of it separately only adds unnecessary calories, Woodward says; a better use of olive oil is to use it as a condiment in food preparation. Instead of using other oils, such as vegetable oil, popular in the U.S., Woodward urges opting for olive oil. He says quality olive oils come not only from Italy but also areas like California, Spain, and Portugal. He adds that recent findings show that polyphenols help keep olive oil stable for cooking across a wide temperature range. He suggests that you may want to use canola, avocado or sesame oils for different flavor profiles.
Vegetables represent the largest proportion of food groups that make up the Mediterranean diet. Woodward says vegetables are rich in phytochemicals — potent compounds that help fight cancer and reduce the risk of its development. For example, cruciferous vegetables like broccoli, brussels sprouts, cabbage, cauliflower, and kale contain phytochemicals known as glucosinolates. Upon preparation and consumption, the glucosinolates in cruciferous vegetables break down into biologically active compounds with anticancer effects, such as sulforaphane, which deactivates carcinogens.
Woodward encourages curating the plate with colorfully mixed vegetables, from dark leafy greens like kale, to reds like tomatoes, and oranges in carrots. Eating whole, colorful fruits as snacks between meals can also offer more phytochemicals, he says. For example, a phytochemical called anthocyanin that lends fruits like grapes and berries a dark purplish-red hue also serves as a potent anti-inflammatory substance.
“For many Americans, a predictable misunderstanding on the Mediterranean diet is that the portions of carbs like bread and pasta are large and dominant,” Woodward says. “In reality, the dominant foods of this diet are actually olive oil and plant-based foods.”
He adds that many people pair a Mediterranean diet with regular exercise to lose weight. This endeavor is crucial in lowering cancer risk since being overweight is the second top risk factor for the development of many cancers.
“It’s not about how much you lose, it's about how much you keep off,” Woodward says. “Some other diets are not sustainable in that sense, whereas the Mediterranean diet is sustainable. The Mediterranean diet blends together all of these cancer-fighting facets.”