Dairy Products and Calcium Protect Against Colorectal Cancer: Nature and JAMA Studies (2025)
Summary
- A study involving 542,778 women found that consuming 300 milligrams of calcium daily (equivalent to one cup of milk) reduced colorectal cancer risk by 17%, while 200 grams of dairy milk daily lowered risk by 14%.
- Calcium protects against colorectal cancer by binding to bile acids and free fats in the intestine. It also strengthens the gut barrier and reduces gene mutations linked to cancer development
- Dairy milk contains additional protective compounds like conjugated linoleic acid, butyric acid and sphingomyelin, which have shown anti-cancer properties in animal studies
- Processed meats were also found to increase colorectal cancer risk by 8% per 30-gram daily consumption, primarily due to preservatives and harmful compounds produced during high-temperature cooking
- For optimal nutritional benefits, opt for raw, grass fed dairy instead of conventional pasteurized milk varieties, as it retains more beneficial fats, nutrients and natural enzymes
Study Shows Calcium Protects Against Colorectal Cancer (Nature)
Consuming the amount of calcium found in a glass of milk could reduce the risk of colorectal cancer, according to a new study involving women.
That was regardless of whether the calcium came from dairy or non-dairy sources. Foods such as figs, leafy greens, and tofu are among the non-dairy sources of calcium.
In the study published in Nature Communications (Jan 2025), the authors said this suggests calcium itself, rather than milk, was the main factor responsible for cutting the risk.
Using dietary and health data provided by more than 542,000 women with an average age of 59 over for around 16 years, researchers from Oxford University studied whether 97 foods affected colorectal cancer risk. They found that consuming an extra 300mg of calcium a day was associated with a 17% lower colorectal risk from the baseline. In the US, the lifetime risk of developing the disease is approximately 4.4% for men and 4.1% for women.
Americans should consume around 1,000mg of calcium a day, according to the Office for Dietary Supplements.
That was regardless of whether the calcium came from dairy or non-dairy sources. Foods such as figs, leafy greens, and tofu are among the non-dairy sources of calcium.
In the study published in Nature Communications (Jan 2025), the authors said this suggests calcium itself, rather than milk, was the main factor responsible for cutting the risk.
Using dietary and health data provided by more than 542,000 women with an average age of 59 over for around 16 years, researchers from Oxford University studied whether 97 foods affected colorectal cancer risk. They found that consuming an extra 300mg of calcium a day was associated with a 17% lower colorectal risk from the baseline. In the US, the lifetime risk of developing the disease is approximately 4.4% for men and 4.1% for women.
Calcium is commonly known as a mineral the body needs to build and maintain strong bones. But calcium may have a protective effect against colorectal cancer because it binds to bile acids and free fatty acids in the colon, which helps reduce their cancer-causing potential, the study said.
Colorectal cancer is the third-leading cause of cancer-related death in US men and the forth-leading cause in US women, according to The American Cancer Society. The rate of people being diagnosed with the condition has fallen since the mid-1980s, but in people under 55, rates have been increasing by 1% to 2% a year since the mid-1990s.
The link between colorectal cancer risk and diet is well-established, and experts recommending people cut down on ultra-processed foods and red meat, and instead eat plenty of fruits, vegetables, and whole grains. But the new findings could help provide even more targeted dietary guidance.
The study was observational, meaning the researchers didn't intervene in any way, and more research is needed to confirm a link between calcium intake and cancer risk.
"It is difficult to separate the effects of individual nutrients from an effect of milk per se," Tom Sanders, professor emeritus of nutrition and dietetics at King's College London, said.
The study was observational, meaning the researchers didn't intervene in any way, and more research is needed to confirm a link between calcium intake and cancer risk.
"It is difficult to separate the effects of individual nutrients from an effect of milk per se," Tom Sanders, professor emeritus of nutrition and dietetics at King's College London, said.
"We already know that around half of all bowel cancers could be prevented by having a healthier lifestyle, and this new research supports this, with a particular focus on dairy," Lisa Wilde, director of research and external affairs at the charity Bowel Cancer UK, said. If you don't drink dairy milk, there are other ways you can get calcium and still reduce your bowel cancer risk, she added.
Additional Dairy Nutrients That Support Colon and Gut Health
The featured study12 also noted that dairy milk's protective effects against colorectal cancer involves more than just its calcium content. According to the authors:
“If the protective role of dairy milk and the other dairy-related foods is not wholly attributed to its calcium content, other possible mechanisms may relate to conjugated linoleic acid, butyric acid and sphingomyelin which are present in dairy milk and have been shown to inhibit chemically induced colon carcinogenesis in some animal models.”13
Conjugated linoleic acid (CLA), naturally occurring in milk fat, has anti-inflammatory and anticancer properties.14 Chronic inflammation plays a significant role in gut-related issues, including leaky gut, irritable bowel syndrome (IBS) and colorectal cancer. Another study published in Nutrition Reviews15 in February 2025 supports these findings, stating:
“[C]onjugated linoleic acid metabolites produced by certain gut microbiota have demonstrated an anticarcinogenic effect in CRC (colorectal cancer), influencing pathways for inflammation, proliferation and apoptosis.”16
As for butyric acid, this short-chain fatty acid (SCFA) supports your gut health by nourishing colonocytes, reducing inflammation and enhancing the gut’s natural defense mechanisms.17,18 Meanwhile, sphingomyelin, a type of lipid found in milk fat, has been shown in animal studies to suppress early-stage colon cancer development by interfering with the early stages of tumor formation.19
To access these beneficial milk compounds, it’s essential to choose grass fed milk, ideally raw or minimally processed, as it contains higher levels of CLA, butyric acid and other health-promoting nutrients compared to milk from grain-fed cows (more about this below).20,21
Processed Meats Increase Colorectal Cancer Risk
While the study highlighted the protective role of dairy in reducing colorectal cancer risk, it also underscored a significant dietary factor associated with higher risk — processed meats. This aligns with the evaluation of The International Agency for Research on Cancer (IARC), which classified processed meats as Group 1 carcinogens, meaning there is sufficient evidence of their cancer-causing effect in humans.22 According to the researchers:
“We found an 8% higher risk of colorectal cancer per 30 g/day higher red and processed meat consumption; this is equivalent to a 29% higher risk per 100 g/day, which is substantially larger than the 12% higher risk per 100 g/day reported in the 2018 WCRF dose-response meta-analysis.”23
The risk is largely attributed to how these meats are preserved and cooked. Nitrates and nitrites, commonly used as preservatives in processed meats, convert into N-nitroso compounds in the body, which are known to damage DNA and promote cancer development.
High-temperature cooking methods, such as frying or grilling, also produce harmful compounds like heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are both carcinogenic and contribute to mutations in colon cells that lead to cancer over time.24
These findings highlight the need for a more mindful approach to meat consumption. I recommend you opt for fresh, pasture-raised meats over processed varieties while paying attention to your protein intake. Most adults need 15% of their daily caloric intake from proteins, which is approximately 0.6 to 0.8 grams per kilogram of your ideal body weight each day. This refers to the optimal weight for your height, age and gender, rather than your current weight.
Your proteins shouldn’t come exclusively from muscle meats — one-third of it needs to be from collagen-rich sources, such as bone broth and slow-cooked gelatinous cuts like oxtail to ensure a proper ratio of amino acids, which reduces oxidative stress and supports connective tissue, gut health and detoxification.
Extra Calcium May Reduce Colorectal Cancer Risk, NIH Study Finds (JAMA)
Adding more calcium to your diet could reduce colorectal cancer risk, the third leading cause of death in the United States, another research from the National Institutes of Health (NIH) finds.
The benefit of adding more calcium to the diet held true regardless of the calcium source or the tumor’s location within the colon or rectum.
Researchers surveyed 3.5 million members of the AARP between the ages of 50 and 71 residing in six U.S. states and two metropolitan areas between October 1995 and May 1996. “To our knowledge, this was the largest cohort study” examining the relationship between calcium intake and colorectal cancer risk, the researchers wrote.
After exclusions based on factors like pre-existing cancer, poor health, or unreliable data, the final analysis included more than 470,000 people who were cancer-free at the start of the study.
There were two groups of participants: those who ate 400 mg of calcium daily and those who ate about 2,000 mg per day. The second group’s calcium consumption exceeded the NIH’s current recommendation of 1,000 to 1,200 mg per day for people 19 and older.
Comparing people with the highest calcium intake to those with the lowest, the study found a lower risk of colorectal cancer, according to the study results, published in JAMA Network Open (Feb 2025).
This was true for calcium from all sources (8 percent lower risk), food (16 percent lower risk), and supplements (20 percent lower risk). For every extra 300 mg of calcium daily, the risk also decreased. One large glass of milk—about 8 ounces—provides around 300 mg of dietary calcium.
Dairy foods accounted for about 42 percent of total calcium intake, non-dairy foods about 34 percent, and supplements about 24 percent.
Best High Calcium Foods
Here are six foods that are high in calcium, including some that might surprise you.Seeds
Some seeds pack a punch when it comes to calcium content.One tablespoon of sesame seeds, for example, contains 100mg of calcium, while one tablespoon of poppy seeds contains 127mg or around 10% of the daily recommended amount.
They are also high in other nutrients such as fiber and healthy fats.
Whey protein
As well as being high in protein and helping to promote muscle growth, whey protein powder is very high in calcium.A 1.2-ounce scoop of whey protein powder isolate contains about 160 mg or 12% of the daily recommended amount.
Leafy greens
Leafy greens are rich in many nutrients, including calcium.One cup of cooked collard greens has 268 mg of calcium, or about 21% of the amount the average person needs in a day. And kale has around 250 mg of calcium per 100g, which is more than the 110mg in 100g of whole milk.
Spinach and chard contain lots of calcium, but they also contain a group of molecules called oxalates that bind to calcium and make it unavailable to our bodies.
Tofu
Whether it's firm, soft, or silken, tofu is also a good source of calcium. 120g of the plant-based protein steamed or fried contains 200mg of calcium.Edamame beans, which are young soybeans, also contain the mineral.
Canned fish
Canned fish is higher in calcium than fresh fish because it contains bones that have become soft through cooking and can be eaten.Canned sardines and salmon are particularly rich in calcium, with 60g of canned sardines in oil containing 240 mg, while 85 grams of canned salmon with bones contains 19% of the daily recommended amount.
Figs
Dried figs contain more calcium than any other dried fruit. Just two figs have 100 mg or 10% of the calcium we need each day.They are also high in fiber, copper, potassium, manganese, magnesium, and vitamin K.
Sources and References
businessinsider.com/calcium-lower-colorectal-colon-cancer-risk-foods-contain-high-in-2025-1- 1 Best Practice & Research Clinical Gastroenterology. Volume 66, October 2023, 101839
- 2 Centers for Disease Control and Prevention, Reducing Risk for Colorectal Cancer
- 3 MSD Manual, Colorectal Cancer
- 4 Johns Hopkins Medicine, Colon Cancer Symptoms
- 5, 6, 10, 11, 12, 13, 22, 23, 24 Nature Communications Volume 16, Article Number: 375 (2025)
- 7, 8 Health, January 17, 2025
- 9 American Institute of Cancer Research, Colorectal Cancer Report 2017
- 14 Processes 2021, 9(3), 454
- 15, 16 Nutrition Reviews, Volume 83, Issue 2, February 2025, Pages e602–e614
- 17 Science Direct, Butyric Acid
- 18 Nutrients. 2023 May 11;15(10):2275
- 19 Probiotics Antimicrob Proteins. 2022 Feb 2;14(3):407–414
- 20, 26 Foods. 2019 Aug 17;8(8):350
- 21, 27 University of Minnesota Extension, Grass-Fed Cows Produce Healthier Milk
- 25 Food Sci Nutr. 2018 Feb 28;6(3):681-700
- 28 Raw Milk Institute, February 5, 2024
- 29 Polymers September 2021; 13(18): 3164
- 30 FDA, The Dangers of Raw Milk: Unpasteurized Milk Can Pose a Serious Health Risk
- 31 USDA Consumer Food Safety Practices: Raw Milk Consumption and Food Thermometer Use January 2019 (PDF)
- 32 Realmilk.com July 31, 2011
- 33 Cornell University, Disease Outbreaks Associated with Milk Products (PDF)
- 34, 35 Metabolites 2024, 14(7), 355
- 36 Farm to Consumer, Raw Milk Nation – Interactive Map
- 37 Raw-Milk-Facts.com (Archived)
- 38 Raw Farm USA, Find Near You
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