Cancer
Bladder Cancer
Bladder cancer accounts for about 3% of all cancers in the U.S. In 2023, an estimated 82,000 adults were diagnosed with bladder cancer, and more than 16,000 died from the disease. The average lifetime risk of developing bladder cancer is 1 in 28 for men and 1 in 91 for women.
Research shows a strong association between red meat consumption and bladder cancer risk. An analysis found that an additional 100 grams of red meat per day––equivalent to a quarter pound––is associated with a 51% increased risk of bladder cancer. The same analysis found that an additional 50 grams of processed red meat per day––equivalent to one-tenth of a pound––is associated with a 20% increased risk of bladder cancer.
Red meat increases the risk of bladder cancer through the creation of heterocyclic amines and polycyclic aromatic hydrocarbons, carcinogenic chemicals generated during high-temperature cooking.
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Breast Cancer
Breast cancer is the most common cancer among women in the United States, posing a significant health burden with an estimated 297,700 new cases and more than 43,100 deaths projected in 2023. The number of women diagnosed continues to grow annually, with diet playing a major role.
There is significant evidence linking red meat consumption and an increased risk of breast cancer. The Women's Health Initiative Observational Study found that women who ate the most red meat had a 23% increased risk of invasive breast cancer compared with women who ate the least. Recent studies have found that the risk for breast cancer from red meat consumption is substantial in both pre- and postmenopausal women. Evidence shows even adolescents are at increased risk.
Eating red meat promotes breast cancer risk in various ways. Red meat:
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contains growth promoters, which stimulate cancer cell growth and proliferation;
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reduces circulating melatonin, a hormone that protects against breast cancer;
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contains heme iron, which contributes to tumor growth and interferes with drug treatment;
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contains heme iron, which increases the risk of breast cancer recurrence;
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contains arachidonic acid, which induces cancer cell migration and invasion;
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contains the breast cancer promoter Bisphenol A, which gets to red meat from food packaging and containers; and,
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sometimes contains bovine leukemia virus (BLV), which has been linked to breast cancer.
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Colorectal Cancer
Colorectal cancer is the third most common cancer in the United States. In 2023, an estimated 153,000 adults in the United States were diagnosed with this disease, including more than 106,000 new cases of colon cancer and 46,000 new cases of rectal cancer. The lifetime risk of developing colorectal cancer is about 1 in 23 for men and 1 in 26 for women.
There is strong evidence linking a diet high in red meat and processed red meats to an increased risk of colorectal cancer. High consumers of red meat and processed red meat are at 20-30% greater risk for developing colorectal cancer.
A study initiated by Kana Wu, M.D., Ph.D., of the Department of Nutrition at the Harvard T.H. Chan School of Public Health, identified a specific pattern of damaged DNA in those with diets high in red meat and processed red meat. This pattern, known as a mutational signature, is caused by specific compounds produced in the body after the consumption of red meat.
Red meat preservatives, such as nitrates and nitrites, and the heme iron naturally occurring in the meat, can lead to the endogenous formation of these DNA-damaging compounds. In addition, studies have found that chemicals formed when red meat is cooked at high temperatures––such as heterocyclic amines and polycyclic aromatic hydrocarbons––also cause the accumulation of mutations that promote colorectal cancer.
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Esophageal Cancer​
Esophageal cancer represents about 1% of all cancers diagnosed in the U.S. It is estimated that in 2023 more than 21,000 adults were diagnosed with this disease, and more than 16,100 will die from it. Esophageal cancer is more common in men, with a lifetime risk of 1 in 125, compared to 1 in 417 in women. Several studies have found that high consumption of red meat and processed red meat is associated with an increased risk of esophageal cancer.
Studies show that high red meat intake is associated with a 38% higher risk of esophageal cancer compared to low intake. The link was strongest with processed red meats like bacon, sausage, and deli meats.
Cooking meat at high temperatures––such as when broiling, frying, and grilling––produces heterocyclic amines that are carcinogenic and can damage esophageal cells, leading to increased cancer risk.
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Gastric Cancer
Gastric (stomach) cancer accounts for approximately 1.5% of all new cancer diagnoses in the U.S. annually. In 2023, there were an estimated 26,500 new cases. Evidence shows that the consumption of red and processed meat is significantly associated with an increased risk of gastric cancer.
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Studies show that high intake of red meat and processed red meat is associated with a 45% increased risk of gastric cancer. High consumption of ground beef, for example, is associated with a 28% increased risk of gastric cancer. An analysis of studies participating in the ‘Stomach cancer Pooling (StoP) Project’ found that an intake of 150 grams per day of both red meat and processed red meat––equivalent to a third of a pound––significantly increased the risk of gastric cancer by 85%.
During digestion, the heme iron in red meat is broken down into N-nitroso compounds, which promote gastric cancer by damaging the stomach’s cell lining. The nitrates and nitrites used to preserve red meat also lead to formation of carcinogenic N-nitroso compounds.
Cooking red meat at high temperatures produces heterocyclic amines and polycyclic aromatic hydrocarbons, which increase cancer risk.
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Liver Cancer
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Liver cancer accounts for about 2.1% of all new cancers in the U.S. In 2023, an estimated 41,000 adults were diagnosed with this disease, and more than 29,000 will died from it. The incidence of liver cancer, which is more common in men than women, has more than tripled since 1980.
There is strong evidence linking red meat consumption and liver cancer. The high-fat content of red meat seems to be a major cause. Fat intake plays a role in insulin resistance, which can lead to liver disease and cancer. The NIH–AARP Diet and Health study found that red meat and saturated fat intakes were associated with a 2.6 times higher risk of chronic liver disease (CLD) and a 1.7 times higher risk of hepatocellular carcinoma (HCC).
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Furthermore, cooking red meat at high temperatures causes the formation of known carcinogens, including heme iron, N-nitroso compounds, and heterocyclic amine. These are known to cause liver tumors.
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Lung Cancer
Lung cancer is the leading cause of cancer death in the U.S. In 2023, an estimated 238,300 individuals were diagnosed with this disease, and more than 127,000 deaths from lung cancer were expected. The disease is most common in older individuals, with the average age of diagnosis being 70. There is evidence showing that consuming red meat, particularly in high amounts, increases the risk of lung cancer.
Studies show that for every additional 120 grams and 50 grams of red meat consumed per day, the risk of lung cancer increases by 35% and 20%, respectively. The NIH–AARP Diet and Health Study found that getting people to reduce their red meat and processed red meat intake could prevent 1 in 10 cases of lung cancers.
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Processed red meats like bacon, ham, and sausages have preservatives that can form carcinogenic compounds
when digested. Cooking red meat at high temperatures, such as when grilling or barbecuing, also produces carcinogenic compounds called heterocyclic amines and polycyclic aromatic hydrocarbons.
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A study published by the American Association for Cancer Research showed that the risk of lung cancer is exceptionally high in those with both high red meat intake and other lung cancer risk factors, such as smoking cigarettes and heavy alcohol consumption.
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Pancreatic Cancer
Pancreatic cancer accounts for about 3% of all cancers in the U.S. and 7% of all cancer deaths. In 2023, an estimated 64,000 adults were diagnosed with this disease, and more than 50,000 died from it. The average lifetime risk of pancreatic cancer is about 1 in 64. There is strong evidence linking pancreatic cancer with a high intake of red meat and processed red meat.
Studies have found that a 100 grams per day increase in red meat consumption—equivalent to a quarter pound—was associated with a statistically significant 11% increase in pancreatic cancer risk. In comparison, a 50 grams per day increase in processed red meat consumption was associated with an 8% increased risk. The evidence suggests that there may be a gender-specific association between red meat and processed red meat consumption and pancreatic cancer risk, with men potentially at a higher risk than women.
Potential mechanisms by which red meat and processed red meats could influence pancreatic cancer risk include carcinogenic compounds formed during high-temperature cooking and preservatives used in processed red meats.
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Prostate Cancer
Prostate cancer is the most common cancer and the second leading cause of cancer death among men in the United States. In 2023, an estimated 288,300 men in the United States were diagnosed with this disease, and more than 34,000 deaths from prostate cancer were expected. The pancreatic cancer incidence rate has increased by 3% per year overall since 2014; for advanced-stage prostate cancer, the increase has been by 5%.
Research has closely linked the high consumption of red meat and processed red meat to prostate cancer risk.
A study found that people who consumed high amounts of ground beef were 2.3 times more likely to develop aggressive prostate cancer than those who consumed less. Another study found a 50% increase in the risk of advanced prostate from the weekly consumption of each of the following:
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three or more servings of red meat;
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one and a half or more servings of processed red meat;
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one or more servings of grilled red meat; and,
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one or more servings of well-done red meat.
The preparation method plays a significant role. Several studies have linked a high intake of well-done grilled or barbecued red meat and processed red meat to an increased risk of advanced or aggressive prostate cancer. When red meat is cooked at high temperatures over an open flame, it produces heterocyclic amines and polycyclic aromatic hydrocarbons. These chemicals cause several types of cancer, including prostate cancer.