Black beans, whole wheat and blood vessel stiffness after a meal
What it found
In nine middle-aged people with stiff arteries, eating whole wheat at breakfast reduced a measure of artery stiffness two hours later, while black beans did not.
White rice raised blood pressure; beans and wheat did not.
What they found
Studies in people
Artery stiffness
Two hours after eating whole wheat, a measure of artery stiffness called AIx75 fell from 26.1% to 16.2%. Black beans and white rice did not change it.
Blood pressure
White rice raised the top blood pressure number by 6.2 mmHg in the arm and 5.7 mmHg in the aorta. Neither wheat nor beans raised these numbers.
Bean diastolic pressure
Black beans raised the bottom blood pressure number in the arm by 2.9 mmHg, but this was not seen in the aorta.
Heart function
All three foods lowered heart rate. Wheat and beans lengthened the time the heart takes to pump out blood, which the authors say suggests better heart function.
Pulse pressure
Pulse pressure in the arm rose by 6.7 mmHg with wheat and 5.4 mmHg with white rice. In the aorta it rose by 4.5 mmHg with white rice only.
Other findings
Eating time
People took longer to eat wheat (8.0 minutes) and beans (7.3 minutes) than white rice (4.9 minutes).
What the authors conclude
“Eating whole wheat or beans acutely improved overall vascular and heart health when compared to white rice.”
Also in their conclusions
- They conclude that eating whole wheat or beans acutely improved overall vascular and heart health when compared to white rice.
- They say the effects of wheat and beans were distinct, with whole wheat having a major positive effect on blood vessel stiffness.
- They suggest that regular inclusion of both whole wheat and beans in the diet would be beneficial for improving cardiovascular health in persons exhibiting signs of arterial dysfunction.
How it was done
The authors wanted to see whether beans or whole grains could quickly help blood vessels relax in people who already have stiff arteries, since most of the day is spent in the fed state and how vessels respond to food may matter over time.
Nine adults aged 50 to 64 with arterial stiffness ate ¾ cup of cooked black beans, ¾ cup of cooked whole wheat kernels, or ¾ cup of cooked white rice on three separate mornings, at least six days apart. Blood vessel and heart measurements were taken before and two hours after the first bite.
What it can’t tell you
- This was a small pilot study with only nine people, so the results may not apply to everyone.
- The study only looked at one meal and two hours after eating, so it cannot show what happens with long-term eating habits.
- Blood glucose and other metabolic measures were not taken, so the reasons behind the effects are not known.
Who paid
- Funding
- Funded by Canadian Pacific Kansas City; St. Boniface Hospital Foundation (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.
- Authors work at
- Canadian Centre for Agri-Food Research in Health and Medicine, Canada; University of Manitoba, Canada
The paper
- Title
- Distinct Effects of Wheat and Black Bean Consumption on Postprandial Vascular Responses in People with Arterial Stiffness: A Pilot Randomized Cross-Over Study
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Zahradka P, Perera D, Charney J, Taylor CG (2025). Distinct Effects of Wheat and Black Bean Consumption on Postprandial Vascular Responses in People with Arterial Stiffness: A Pilot Randomized Cross-Over Study. Nutrients. doi:10.3390/nu17071159Free full textPubMed 40218917DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error