Oat nutrients and the immune system
What it found
Oats supply fiber, minerals, polyphenols and protein that may help support the immune system, but most of the direct evidence for fighting infection comes from lab and animal studies, not people.
What they found
Studies in people
Beta-glucans in people
In a trial with trained male cyclists, taking oat beta-glucans (5.6 g a day) for 18 days did not change resting or exercise-related immune measures, or the number of upper respiratory tract infections in the two weeks after hard exercise. In a study of older people with low fiber intake, oat beta-glucans or arabinoxylans (12 g a day for 6 weeks) did not affect gut permeability or the gut microbiome compared with a placebo.
Insoluble oat fiber
In the OptiFiT trial with 180 adults with impaired glucose tolerance, 15 g a day of purified oat insoluble fiber for two years did not change two inflammation markers compared with a placebo, even though it improved blood sugar handling in those with impaired fasting glucose.
Polyphenolics and infection
In a study of 315 people, higher ferulic acid intake was linked to a 35% lower chance of having raised CRP, a marker of inflammation. In a trial in adults with high blood lipids, ferulic acid (1 g a day for 6 weeks) reduced CRP and TNF-alpha. Avenanthramides reduced exercise-related inflammation in young and older women.
Animal and lab studies
Beta-glucans in animals and cells
In lab tests on cells, oat beta-glucans increased the production of immune signalling molecules. In mice, oat beta-glucans reduced susceptibility to respiratory infection after exercise stress, and an oat beta-glucan extract protected mice against Staphylococcus aureus and E. vermiformis.
Polyphenolics in animals and cells
In mice infected with influenza, ferulic acid improved survival and reduced weight loss. In lab tests, several flavonoids reduced the infectivity and replication of viruses including herpes simplex type 1, polio type 1, parainfluenza type 3 and respiratory syncytial virus.
Other findings
Minerals in oats
Oats are a good source of iron, zinc, copper and selenium, which support the immune system. Iron and zinc from cereals are poorly absorbed because of phytic acid, but soaking oats overnight can lower phytic acid and help absorption. Selenium from oats is highly bioavailable.
What the authors conclude
“Therefore, oats are a good source of numerous nutrients, including fiber (β-glucans), copper, iron, selenium, zinc, glutamine, and polyphenolic bioactives (ferulic acid and avenanthramides) that can help optimize the immune system and response to infections, including cold/flu viruses and other pathogens.”
Also in their conclusions
- They say oats are a good source of fiber (beta-glucans), copper, iron, selenium, zinc, glutamine and polyphenolic bioactives that can help optimize the immune system and response to infections, including cold and flu viruses.
- They note these nutrients support immunity directly by modulating the innate and adaptive immune system and indirectly by changing the gut microbiota and related metabolites.
- They call for more human studies to show whether oat beta-glucans can modulate immunity and inflammation through the gut microbiota.
How it was done
The authors say good nutrition is the foundation of a healthy immune system, and that nutrient shortfalls raise the risk of infections and make them worse. They wanted to look at how the nutrients in oats might help the body's defenses.
They pulled together and described existing research on oat nutrients, including fiber (beta-glucans), copper, iron, selenium, zinc, polyphenolics (ferulic acid and avenanthramides) and the protein building block glutamine. They looked at how these might affect immunity directly, and indirectly through gut bacteria.
What it can’t tell you
- Many of the studies described were done in animals or in lab dishes, so they cannot show what happens in people.
- Some human studies were small or short, and some looked at markers in the blood rather than whether people actually got fewer infections.
- The review cannot show that eating oats prevents or treats any illness.
Who paid
- Conflicts
- Oliver Chen and Eunice Mah are employees of Biofortis Research, Merieux NutriSciences and report no other competing conflicts of interest. ElHadji Dioum, YiFang Chu, Ankita Marwaha are employees of PepsiCo Inc. Shobana Shanmugam, Nagappa Malleshi, Vasudevan Sudha, Rajagopal Gayathri, Ranjit Unnikrishnan, Ranjit Mohan Anjana, Kamala Krishnaswamy, Viswanathan Mohan are from the Madras Diabetes Research Foundation, Chennai, India and report no competing conflicts of interest.
- Authors work at
- Tufts University, USA; Quaker Oats Center of Excellence, USA; Madras Diabetes Research Foundation, India
The paper
- Title
- The Role of Oat Nutrients in the Immune System: A Narrative Review
- 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
- Chen O, Mah E, Dioum E, et al (2021). The Role of Oat Nutrients in the Immune System: A Narrative Review. Nutrients. doi:10.3390/nu13041048Free full textPubMed 33804909DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error