Rye, lignans and links to cancer, heart disease and diabetes
What it found
In people, eating wholegrain cereals like rye was linked to fewer heart attacks, strokes and cases of diabetes.
Evidence that rye protects against cancer is not strong enough to draw firm conclusions.
What they found
Studies in people
Heart attacks and stroke
Large studies following people over time found that eating more wholegrain cereals was linked to fewer heart attacks. In about 22 000 Finnish men followed for 6 years, those eating the most cereal fibre had less than half the risk of dying from a heart attack compared with those eating the least. A similar link was seen for stroke in women after menopause.
Breast cancer
Studies comparing women with and without breast cancer gave mixed results. Some found that low levels of a rye compound called enterolactone in the blood were linked to higher breast cancer risk. But one study following people forward in time found both very low and very high levels were linked to increased risk.
Stomach and oesophagus cancer
Many studies comparing people with and without stomach cancer suggest that fibre-rich foods like wholegrain cereals may lower the risk. This protective link was strongest for cancers where the stomach meets the oesophagus. Whole grains might help by binding to harmful nitrogen compounds in the gut.
Animal and lab studies
Prostate cancer in animals
In experiments on rats and mice, eating a lot of rye bran slowed the early growth of hormone-sensitive prostate cancer and increased tumour cell death. Adding fat to the rye diet cancelled out these benefits. The effect was temporary and did not work on fast-growing tumours.
Studies in people and animals
Diabetes risk
Two large studies following women over time found that eating more cereal fibre was linked to a lower chance of developing diabetes. In patients who already needed insulin, eating bread high in rye bran improved their daily blood sugar or let them use less insulin. Rye bran also lowered blood sugar in diabetic rats and mice.
How rye compounds are absorbed
Rye contains plant compounds called lignans. Gut bacteria turn these into mammalian compounds like enterolactone, which then enters the blood. People missing part of their intestine cannot complete this conversion. Eating a high-fat diet lowers the amount of enterolactone made, as shown in both people and mice.
What the authors conclude
- They say there is strong evidence that eating wholegrain products like rye lowers the risk of heart attacks, and probably diabetes and stroke too.
- They conclude that current studies in people do not prove rye or its plant compounds protect against cancer, though some findings point that way.
- They call for long feeding trials in people to find out exactly what rye does to tumours and other disease markers.
How it was done
Rates of breast and prostate cancer differ widely between countries, and moving to a Western lifestyle raises the risk. The authors wanted to see if plant compounds in rye might explain some of these differences.
The authors gathered results from studies following large groups of people over time, studies comparing sick and healthy people, and experiments in animals. They looked at how rye, its fibre and its plant compounds related to cancer, heart disease and diabetes.
What it can’t tell you
- These are mostly observational studies in people, so they can show a link between eating rye and lower disease risk but cannot prove rye caused the benefit.
- Animal experiments showing slower tumour growth cannot prove the same thing happens in people eating rye.
- The studies measured different things over different time periods, making it hard to know exactly how much rye someone would need to eat.
Who paid
- Authors work at
- University of Umeå, Sweden
The paper
- Title
- Rye, lignans and human health
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Hallmans G, Zhang JX, Lundin E, et al (2003). Rye, lignans and human health. The Proceedings of the Nutrition Society. doi:10.1079/pns2002229Free full textPubMed 12749346DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error