Around 9.6 million patients around the world died from cancer in 2018, making it one of the leading causes of death. 
While there are different reasons for developing cancer, studies suggest there is a connection between cancer and diet. Certain lifestyle changes, such as following some healthy diet plans, may reduce the risks of cancers. [2, 3]
There are several studies that point to certain dietary habits that can increase or decrease the risk of cancer.
This article explains the link between cancer and diet, which foods and habits can cause cancer, and which foods you should eat to reduce the risk.
Cancer and Diet: What May Increase The Risk
While it’s difficult to say which food will cause cancer, research says high consumption of certain foods may increase the risk of this life-threatening disease.
1. Refined Carbs and Sugar
Processed foods have low fiber and nutrients, but high sugar content that may increase the cancer risk. 
A study conducted on 47,000 adults was published in the International Journal of Cancer. It shows those who ate refined diet were more prone to die in colon cancer compared to those who consumed food with low refined carbs. 
Some studies show that a high level of insulin and blood glucose level can increase the risk of cancer by stimulating the cell division, and supporting the growth and spread of cancer cells. [9, 10, 11]
It’s because blood glucose and insulin can cause inflammation in your body. The inflammation can contribute to the growth of cancer cells that are difficult to eliminate. 
A 2013 research concludes that you may have a high risk of developing colorectal cancer if you have diabetes. 
2. Foods That are Overcooked
If you’re a fan of grilled and deep-fried foods, we have bad news for you.
Research has shown that cooking methods such as grilling, frying, barbequing, and broiling can produce harmful components like advanced glycation end-products (AGEs) and heterocyclic amines (HA). 
Certain foods, such as red meat, cheese, fried eggs, butter, margarine, etc. are most likely to produce these harmful compounds when exposed to high temperature.
3. Processed Meat
Processed meats are considered as a carcinogen — a substance that causes cancer. 
Processed meat is made by salting, smoking, or curing to preserve the flavor. Ham, hot dogs, deli meats, and salami are some of the processed meats.
A research published in 2016 has found that consuming processed meat is associated with a higher risk of colorectal cancer. 
In fact, people who eat a large amount of processed meat have shown a 20-50% higher risk of developing colorectal cancer than those who don’t. 
You’re highly likely to develop colorectal cancer if you eat 50 grams of processed meat every day. 
4. Dairy Products
A 2012 study conducted on 4000 men with prostate cancer found that excessive drinking of whole milk can increase the risk of cancer progression and death. 
However, more research is needed to establish this fact.
Like your food, your weight also plays a big role in developing cancer. 
A research published in the Journal of Obesity concludes that being overweight can increase your risk of 13 different types of cancer, including colon, kidney, esophagus, and even breast cancer after menopause. 
In fact, obesity is responsible for 14% and 20% of all cancer-related deaths in men and women, respectively in the U.S. 
Cancer and Diet: Foods That Fight Cancer
While some foods can cause cancer, there are some other types of foods that can reduce the risk of it.
Although there’s no food that can prevent cancer, certain foods can fight the disease by blocking the blood vessels that feed cancer cells. 
How these foods can fight cancer also depends on how they are cultivated.
Some of the cancer-fighting foods include:
Fruits are loaded with nutrients, such as vitamins, minerals, and antioxidants that can fight certain types of cancer.
According to a study published in 2008, consuming three servings of citrus fruit per week may decrease the risk of stomach cancer by 28%. 
Some cruciferous vegetables like cabbage, broccoli, and cauliflower contain antioxidants and phytochemicals that can fight certain cancers.
Research shows these vegetables has sulforaphane, a component that reduced the tumor size in lab mice by more than 50%. 
Spices like cinnamon and turmeric have shown to contain potent cancer-fighting properties in several studies.
A 2011 research shows curcumin, a substance in turmeric could reduce potentially cancerous lesions in the colon by 40%. 
Another study published in the journal BMC Cancer concludes that the anti-cancer properties of cinnamon may prevent cancer from spreading. 
In a 2008 clinical trial, men who took 30 grams of ground flaxseeds daily experienced slower prostate cancer growth than the control group. 
The cancer-fighting abilities of flaxseeds have also been proved in studies conducted on women with breast cancer. 
A scientific review published in The British Journal of Nutrition reports that consuming nuts on a regular basis could reduce the risk of cancer-related deaths. 
6. Legumes and Beans
Fiber-rich foods such as beans and legumes have been shown to protect you from certain cancers, particularly colorectal cancer. 
A 2009 research conducted on 3,500 people concludes that eating more legumes could reduce the risk of cancer by up to 50%. 
7. Other Foods
- Garlic has powerful anti-cancer properties that may protect your body from certain types of cancer, such as prostate and stomach cancer. [56, 57, 58, 59]
- Several studies have shown that consuming olive oil may reduce the risk of cancer. [60, 61]
- Evidence shows that consuming fish can reduce the risk of cancer by 12%. 
- Although high consumption of the dairy product is related to certain cancer, studies show that moderate consumption of high-quality dairy products like fermented milk or fresh milk from a grass-fed cow can protect you from cancer. [63, 64]
Diet Plan to Reduce The Risk of Cancer
Several popular diet plans such as keto diet, plant-based diet, etc. have shown protective effects against certain cancers.
As high blood sugar and insulin are considered as one of the main causes of cancer, following a low-carb diet may reduce the risk of it.
While there is no food that can completely prevent cancer, some foods can reduce the risks of dying from cancer.
A diet plan where you need to eat fresh fruits, vegetables, fiber-rich beans, and legumes, as well as high-quality dairy products, may eventually protect you from certain cancers.
On the other hand, processed foods, red meat, alcohol, as well as refined carbs can increase the risk of cancer, meaning that you need to avoid these foods.
Whether you have cancer or not, following a healthy and balanced diet can help improve the quality of your life.