Vegan diets are linked with less cancer overall, and dairy and eggs are linked with some cancers

Vegan diets are linked with less cancer overall

A 2026 review found vegan diets linked with about 23% less cancer overall, from three studies the authors called limited. The World Health Organization’s cancer agency classifies processed meat as a cause of cancer, and dairy and eggs are linked with prostate, ovarian and breast cancer.

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Processed meat causes colorectal cancer, and red meat probably does

The World Health Organization’s cancer agency classifies processed meat as a cause of colorectal cancer and red meat as a probable cause. The risk climbs with every daily serving, and there’s no amount of processed meat where it stops rising.

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Adventist vegetarians had 12% less cancer overall and 45% less stomach cancer

The Adventist Health Study-2 followed 79,468 people to 2015. Vegetarians had 12% less cancer overall (suggestive, but not quite conclusive), 45% less stomach cancer, 25% less lymphoma, and about 20% less colorectal cancer, and vegans had about 25% less breast and prostate cancer.

The same 2026 review, on PubMed: vegans had about 23% less cancer overall

This is the PubMed record of the 2026 European Journal of Epidemiology review, not a second study. Vegans, counted separately from other vegetarians, had about 23% less cancer overall than non-vegetarians, from three studies. The authors called the vegan evidence limited. Colorectal cancer was not lower.

Plant-based diets were linked with less colorectal cancer

A 2025 meta-analysis of 10 prospective studies found plant-based diets linked with about 9% less colorectal cancer, and diets built on healthy plant foods with about 10% less. The paper did not find that vegans had the lowest risk.

Vegetarians had a lower risk of five cancers, and vegans did not

In the British Journal of Cancer, vegetarians had a lower risk of pancreatic, breast, prostate, and kidney cancer, and of myeloma, and a higher risk of one cancer of the esophagus. Vegans were not shown to have a lower risk of those cancers. They had a higher risk of colorectal cancer, from 93 cases, and that link weakened once the first four years were left out.

Vegans, counted separately, had about 23% less cancer overall

A 2026 review found vegetarian diets linked with less cancer overall and with less cancer of several types. Vegans, counted separately, had about 23% less cancer overall than non-vegetarians, from three studies, and the authors called that evidence limited. Vegan diets were not linked with less colorectal cancer.

In a small breast cancer study, 5 of 10 controls had died, and 2 of 20 on the vegan diet

Of the 30 women still followed, 5 of 10 in the control group had died and 2 of 20 in the vegan group had, about five years after the last visit. The control group’s death rate was about five times as high. With a sample this small, it’s a signal, not a settled result.

Full text of the vegan diet cancer survival study (PDF)

The PDF has the full text of the same survival analysis.

Eating more red and processed meat raises colorectal cancer risk

This meta-analysis found that eating more red and processed meat increases the risk of colorectal cancer.

IARC, the WHO’s cancer agency, says processed meat causes cancer and red meat probably does

After reviewing more than 800 studies, a working group of 22 experts at the WHO’s cancer agency put processed meat in Group 1, carcinogenic to humans, based on sufficient evidence for colorectal cancer. They put red meat in Group 2A, probably carcinogenic.

Colorectal cancer risk rose 18% for every 50 g of processed meat a day

Pooling ten prospective cohorts, researchers found that colorectal cancer risk rose 18% for every 50 g of processed meat a day and 17% for every 100 g of red meat a day. The risk climbed roughly in a straight line up to about 140 g a day.

Vegans had 16% less cancer than meat eaters in the Adventist study

Among 69,120 Adventists, vegans had 16% less cancer overall than non-vegetarians and 34% less of the cancers specific to women. Vegetarians as a whole had 8% less cancer overall and 24% less cancer of the gastrointestinal tract.

British vegetarians had 12% less cancer, but no less colorectal cancer

Pooling two UK cohorts of 61,647 people with 4,998 cancers, researchers found that vegetarians (including 2,246 vegans) had 12% less cancer overall, 63% less stomach cancer, and 77% less multiple myeloma. Colorectal cancer was the exception and was no lower in vegetarians.

Men with prostate cancer who ate the most plant foods had 47% less progression

Among 2,062 men with prostate cancer, those who ate the most plant foods after diagnosis had 47% less disease progression. Among men with a Gleason score of 7 or higher, those with the highest healthy plant-based diet scores had 55% less.

A vegan lifestyle program lowered PSA in men with early prostate cancer

This trial randomized 93 men with early prostate cancer who had turned down conventional treatment. On a vegan diet with exercise and stress management, their PSA fell 4%, while it rose 6% in the usual-care group. No one in the lifestyle group needed treatment that year, compared with six men in the control group.

Two years in, 27% of men on usual care had cancer treatment, versus 5% on the lifestyle program

After two years of the same prostate cancer trial, 27% of the usual-care group had gone on to surgery, radiation, or androgen deprivation therapy, compared with 5% of the lifestyle group. There were no deaths in either group.

Plant-based diets came with 18% less digestive cancer across 3,059,009 people

In this meta-analysis of 3,059,009 people, the pooled cohort studies linked plant-based eating with an 18% lower risk of digestive-system cancers, and the case-control studies with a 30% lower risk. The clearest links were for pancreatic and colorectal cancer.

Replacing animal foods with plant foods came with less cancer and fewer deaths

Across 17 substitution studies, replacing animal foods or animal protein with plant foods came with lower colorectal and breast cancer risk in six of them and no difference in four. It also came with fewer deaths from cancer and from all causes.

People who ate the most heme iron from meat had 18% more colon cancer

Across prospective cohorts with 566,607 people and 4,734 cases, colon cancer risk was 18% higher at the highest heme-iron intakes than at the lowest. Heme is the iron-carrying pigment that makes red meat red.

High milk intake came with 10% more cancer deaths in women

Across 34 cohorts with 3,171,186 people and 88,545 deaths, high milk intake came with 10% higher cancer mortality in women, and 17% higher for whole milk. Deaths from liver cancer were 13% higher, from ovarian cancer 32%, and from prostate cancer 23%. In women, fermented milk was linked with lower cancer mortality.

Each 400 g of dairy a day came with 7% more prostate cancer

In a meta-analysis of 32 studies, every 400 g of dairy a day came with a 7% higher risk of prostate cancer, and milk and calcium from dairy showed the same link. Calcium from supplements or non-dairy foods didn’t, which suggests the problem is the dairy rather than the calcium.

Whole milk was linked with more ovarian cancer in 29 studies

In a meta-analysis of 29 studies, drinking whole milk came with a higher risk of ovarian cancer. In the same analysis, though, low-fat milk, dietary calcium, and vitamin D were linked with lower risk.

Eggs were linked with slightly more breast cancer in 13 studies

In a meta-analysis of 13 studies, eating eggs came with about 4% higher breast cancer risk overall, and about 10% higher for two to five eggs a week. The effect is small, but breast cancer is one of the most common cancers.

Eating lots of eggs was linked with 21% more ovarian cancer

Across 12 studies with 629,453 people and 3,728 cases, high egg intake came with a 21% higher risk of ovarian cancer. The link was statistically significant in the case-control studies but fell just short in the cohort studies.