18 Foods Research Links to Increased Cancer Risk

Ultra-processed foods contain multiple added ingredients, such as stabilizers, preservatives, artificial colors and flavors, or bulking and gelling agents. Examples include sugary cereals, soft drinks, baking mixes, frozen dinners, packaged bread, and processed spreads.

Studies show that these foods can contribute to a range of health problems — including cancer. One analysis found that a diet high in ultra-processed foods may raise the risk of several types of cancer, including pancreatic, colorectal, and breast cancers.

Fast food is considered ultra-processed and often high in saturated fats, sodium, and added sugars, with minimal nutritional value. It can also contribute to weight gain — and obesity has been linked to an increased risk of several types of cancer.

For example, obesity is associated with a higher risk of endometrial, esophageal, kidney, liver, and colorectal cancers. The more frequently fast food is consumed, the more likely it is to contribute to these risks.

Processed meats are those that have been flavored or preserved by fermentation, curing, salting, smoking, or adding chemicals. Some examples include ham, bacon, sausages, hot dogs, salami, pepperoni, beef jerky, and deli meats. Some research suggests that these foods can increase cancer risk because of the nitrates and nitrites used as preservatives. For example, studies have found that nitrates and nitrites were positively associated with breast and prostate cancer risks and that increased consumption of processed meats may lead to a higher risk of colon cancer. Processed meats have also been associated with increased risks of lung cancer.

When muscle meat, including pork, beef, poultry, and chicken, is cooked at high temperatures, such as in a frying pan or on a grill, it produces chemicals called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). In lab experiments, these chemicals have been found to cause DNA changes that can lead to cancer; however, there have been no large-scale studies that have confirmed a link between HCAs and PAHs from cooked meats with cancer in humans. While HCAs and PAHs have not been directly linked to increased cancer risk in humans, it is reasonable to be aware of the possible dangers and make food choices accordingly.

There is evidence that drinking alcohol can cause several types of cancers and that the more a person drinks regularly over time, the higher their risk of developing these cancers is. Clear patterns have been identified between alcohol consumption and head and neck cancer, esophageal cancer, liver cancer, breast cancer, and colorectal cancer. There is also evidence that the risk of alcohol-related cancers can be affected by genetics, primarily due to genes involved in creating the enzymes that break down alcohol and the end products of alcohol metabolism.

Research into the effects of dairy products on cancer risk is mixed. Some studies have determined that dairy can be connected to an increased risk of some cancers, while others have determined it may have protective qualities. For example, research into the effects of dairy products on breast cancer has yielded mixed results. Some research suggests that dairy's vitamin D and calcium can protect against breast cancer. At the same time, other studies show that the increased intake of saturated fats from dairy products can increase the risk of breast cancer, as can the compounds and pollutants found in milk, including estrogen.

Sugars and refined carbohydrates, like white rice, white bread, and pasta , may increase the risk of certain cancers. Research has found that refined carbohydrates and sugars lead to higher blood sugar levels after eating than complex carbohydrates, take longer to break down, and do not cause the same blood sugar spikes. Higher intake of foods that caused blood sugar spikes were linked to increased risks of colon and bladder cancer, while complex carbohydrates that do not cause these spikes were linked to reduced colon cancer risk.

Research has found that consuming red meat, particularly daily or in large quantities, has a strong association with increased cancer risk. Studies have determined that eating red meat may increase the risk of breast cancer and most gastric cancers; researchers believe that this may be due to the presence of particular hydrocarbons, amines, and heme iron in red meat. Other research has found that red meat consumption may also contribute to endometrial cancer, lung cancer, and liver cancer.

Studies have found that eating salty foods, including salt-cured meats like bacon, salami, and prosciutto, and pickled foods, is also associated with gastric cancers. Researchers believe this association may occur for a number of reasons. High salt concentrations may directly damage the gastric lining and increase the chances of mutations, and many of these foods are also high in nitrates and nitrites. High salt intake can also increase the virulence of a bacteria called H. pylori, a bacteria in the GI system that is one of the main predisposing factors for gastric cancer.

Research has found that eating microwave popcorn increases the level of PFAS in the body. PFAs, or per- and polyfluoroalkyl substances, are manmade chemicals ponce used in food packaging, including the bags that hold microwave popcorn. They have been linked to multiple types of cancer, but the FDA has stated that they are no longer a concern.

Research in humans is relatively limited, but some animal studies have found that certain food dyes can increase cancer risk. For example, one recent study found that Red 40 can cause DNA damage in mice that may lead to cancer, and research on Yellow 5 found that it could damage the DNA of white blood cells which could result in cancer. If you are concerned about the consumption of food dyes, choose natural whole foods or read nutritional labels closely and opt for products that are dye-free.

Trans fats are created when liquid oils are turned into solid fats, called partially hydrogenated oils. Trans fats have been found to have many health risks. They lower good cholesterol and raise bad cholesterol, which can increase the risk of heart disease and stroke. Research has found that trans fats can also contribute to increased cancer risk, including higher risks of prostate and colorectal cancer. Trans fats are banned in the US.

Betel nuts are the fruit of the areca palm tree, a tree native to the Philippines that has now spread through south and southeast Asia. In these cultures, betel nut chewing plays a traditional role in cultural rituals, religious practices, and other social customs, particularly in Bangladesh, Cambodia, Myanmar, Thailand, Laos, the Philippines, and Vietnam. Research has found that betel nuts are related to oral cancer and oral cancer–related deaths, increasing the risk by as much as 50 percent.

While some studies have found that artificial sweeteners may have associations with increased cancer risk, the results of this research have been inconsistent. For example, some studies have found that artificial sweeteners may cause an increased risk of cancer in postmenopausal women in the US but not in healthy European adults. Reviews of some of these studies have determined that they have only resulted in weak evidence for an association between artificial sweeteners and cancer risk. Still, it is crucial to be aware of these study results to make informed decisions for your own health.

Foods labeled as "diet" or "sugar-free" may be low in calories, fat, sugar, and other things that can lower the calorie content, but this may be done at the expense of replacing these things with additives and chemicals that may increase cancer risk, like fat substitutes, fillers, or thickeners. For example, diet soda uses artificial sweeteners instead of sugar, which may increase cancer risk.

GMO (genetically modified organism) foods have been changed using genetic engineering. GMO crops have genes added to them to improve sustainability, pest resistance, growth, and nutritional content. Generally, the same changes can be made in time through selective breeding, but these results can take generations to appear. Since GMOs became more commonplace, there have been growing concerns that they may increase cancer risk because cancer is generally caused by altered DNA; however, research does not substantiate these claims, and the Food and Drug Administration maintains that GMOs are safe for consumption.

Bisphenol A or BPA is a chemical that was once used in the linings of metal cans, bottle caps, and jar lids. Some studies have found that BPA can seep into foods or beverages and that consuming high levels of BPA can lead to cancers of the breast, ovaries, and prostate. According to the FDA, the BPA levels currently found in foods is considered safe. BPA is still used in some products but has been removed from many others over the years. If you are concerned about the effects of BPA, look for products marked "BPA-free" to limit your risk of exposure.

The following food additives and chemicals have been found to be potential cancer risks:

Nitrates and Nitrites: Both of these chemicals are commonly found in processed meat; research shows that nitrates were associated with increased breast cancer risk and nitrites were positively associated with prostate cancer risk.

BHT, BHA, TBHQ: These synthetic antioxidants and preservatives may cause DNA damage that can lead to cancer.

Potassium Bromate: Some research indicates that potassium bromate, found in some breads, can cause free radicals in the body that can lead to cancer.

Azodicarbonamide: Azodicarbonamide, used in bread dough as a bleaching agent and dough strengthened, was shown to cause cancer in female rats at high doses.