A landmark study has proven what we’ve all long suspected: For better or worse, cancer and diet are connected.
The new study, published in May 2019, revealed that over 80,000 new cancer cases in 2015 were solely attributed to eating a poor (or innutritious) diet. The researchers stated that these cases were among U.S. adults ages 20 and older. 
But the findings may not be what you are expecting. The researchers evaluated seven dietary factors in the study to reveal the link between cancer and diet. They included low consumption of whole grains, dairy products, vegetables, and fruits as well as a high consumption of red meats, processed meats, and sugar-loaded beverages.
The greatest association between cancer and diet? Low whole-grain consumption! This was followed by low dairy consumption and then high processed meat intake. Next were low vegetable and fruit consumption, high red meat intake, and, finally, high consumption of sugar-sweetened drinks.
But this doesn’t mean that simply filling your diet with whole grains and dairy products will reduce your risk of cancer. In fact, due to its highly inflammatory properties and other startling ingredients, I advise my friends, family, and patients to avoid cow’s dairy altogether. (Stay tuned; I’ll be discussing the dangers of dairy more in the coming months.)
Why? Well, the study simply focused on how the consumption of macronutrients (carbs, fats, and protein) are linked to cancer versus investigating the role of micronutrients. Micronutrients are the vitamins and minerals found in your foods.
Consider this: The amount of micronutrients in your food determines their nutritional value. And since the study was based on the link between a poor, innutritious diet and cancer, we must turn our focus from the macronutrient connection to the micronutrient connection.
I feel confident that if the researchers had focused on the micronutrients, they would have determined that it’s likely the lack of fiber in those who consumed diets low in whole grains and the lack of vitamin D, magnesium, and other essential micronutrients found in some dairy products that were causing the issue. And there are so many amazing, delicious, and more nutritious options out there.
So what should you do to help prevent or reduce your risk of cancer? Take a look below for specific foods and nutrients that have been shown to fight cancer.
According to a major review of over 200 studies focusing on nutrition and cancer, here’s a list of some of the foods and nutrients shown to potentially decrease a person’s risk of cancer by 40 percent to 70 percent!  (Note that these foods should be consumed as part of a well-balanced, whole foods-based diet for optimum benefits.)
While omega-6 fatty acids have been found to be cancer-promoting fats, omega 3s have shown promise in animal studies to possibly contain protective properties against cancer.  When it comes to food sources of omega 3s, certain wild-caught fish, such as salmon, and vegetarian sources such as chia seeds, walnuts, and edamame will deliver power-packed punches of this fatty acid.
This superfood is abundant in fiber, omega-3s, and protein. In animal studies, flax seeds have been shown to reduce metastasis, reduce the number of tumors by almost 50 percent, and even reduce tumor growth rate of breast cancer cells. [4, 5, 6]
Additionally, in a pilot study, 25 men with prostate cancer (who were scheduled for prostatectomy surgery) ate a low-fat diet supplemented with 30 grams of ground flaxseed each day. About a month later, researchers noted significant changes in the men’s serum cholesterol, total testosterone, and the free androgen index, indicating that supplementing with or consuming flaxseed may be beneficial for men battling prostate cancer. 
These studies show that flax seeds should be incorporated for those concerned with cancer and diet.
Notice that the study mentioned a diet low in whole grains was directly tied to an increased likelihood of developing certain cancers but it didn’t say why. While whole grains give our bodies an abundance of fiber, it also contains much of the pesticides you need to avoid to remain healthy. Moreover, whole grains contain gluten—and gluten intolerance is becoming a more prevalent issue every day.
As a result, I suggest that instead of concentrating on consuming whole grains, focus on eating fiber-filled foods that will provide numerous other health benefits as well. These include buckwheat, amaranth, quinoa, wild rice, gluten-free oatmeal, and more. Studies have shown these ancient and health-promoting grains can even help fight or manage certain diseases and health concerns, such as diabetes, hypertension, and heart disease. Some animal studies have even suggested it may show promise in treating Alzheimer’s disease, though more research is needed to confirm these findings. 
Numerous studies have shown that high vegetable consumption has a protective effect against cancer. Interestingly, raw vegetables were the most protective, with the following listed as having consistent or highly protective effects: carrots, green vegetables, tomatoes, garlic, onion, leeks, and scallions. [9, 10, 11]
Specifically, cruciferous vegetables (such as broccoli, cauliflower, Brussels sprouts, and more) have been a popular source of study for cancer and diet. One case-control study found that subjects with the highest intake of cruciferous vegetables had only half the risk of developing breast cancer of the group with the lowest intake.  Additionally, numerous studies have shown that five or more servings a week are directly linked to a 33–72 percent decreased likelihood of developing different types of cancer, including non-Hodgkin’s lymphoma, bladder cancer, prostate cancer, and even lung cancer. [13, 14, 15, 16]
When eaten along with health-promoting, nutritious vegetables, fruits have also been found to potentially help fight and prevent cancer. Vitamin C has been a notable nutrient when it comes to fighting cancer and has even been used in some cancer treatments (in higher doses well beyond what’s possible to consume in your daily diet).  Citrus fruits and berries are both great sources of vitamin C that you can include in your daily diet.
Additionally, red and purple grapes contain resveratrol, which has been shown to help prevent cancer in the breast, liver, stomach, and lymphatic system.  Note that the most resveratrol is found in the skin of the grapes.