Whole Grains for Heart Health: Benefits and Tips

What exactly is a whole grain?

A whole grain retains the bran, germ and endosperm in the expected proportions of the original kernel, even when cracked, ground or rolled; refining usually removes the bran and germ, reducing fiber and other components^1,2,3. Oats, brown rice, whole wheat, rye, barley, whole-grain corn, sorghum, quinoa, amaranth, buckwheat and popcorn can all qualify. Under Brazilian regulations, quinoa and amaranth are pseudocereals included in the whole-grain category^1,3. Beans, lentils, peas and chickpeas are legumes rather than whole-grain cereals, although they remain fiber-rich, heart-supportive foods². Wheat, rye and barley contain gluten, and oats may be cross-contaminated during cultivation or processing. People with celiac disease, wheat allergy or another gluten-related condition need to avoid contraindicated grains and, when appropriate, choose certified gluten-free products with individualized guidance.

How can you tell whether a packaged food is truly whole grain?

In Brazil, the word “integral” or “whole grain” should be checked against the percentage stated on the package. Under RDC 712/2022, a cereal-based product may use this designation only if at least 30% of its ingredients are whole grain, whole-grain ingredients exceed refined ones, and the percentage is disclosed on the label¹. A legally classified whole-grain product may therefore still contain refined flour and other ingredients. Compare the declared whole-grain percentage, check where the whole grain or whole-grain flour appears in the ingredient list, and review fiber, sodium, added sugars and saturated fat^1,2,3. Dark color is not proof of whole-grain content because it may come from malt, molasses or other ingredients³.

What heart benefits are supported by evidence?

Whole-grain intake is associated with lower cardiovascular risk, but its benefit must be understood as part of the overall diet. In a meta-analysis of cohort studies, a 90 g-per-day increase was associated with a 19% lower risk of coronary heart disease, a 12% lower risk of stroke, a 22% lower risk of cardiovascular disease and a 17% lower risk of death from any cause⁴. These observational associations do not prove that adding a specific amount of one food will prevent a heart attack or stroke; for stroke, the confidence interval included the possibility of no statistically significant effect⁴. A systematic review of randomized trials comparing whole and refined grains found modest and variable effects on cardiovascular risk factors, with certainty differing by outcome and no basis for promising an individual clinical benefit⁵. The likely benefits come from several modest effects combined with replacing refined flour, sugary products or foods high in saturated fat^6,2,7,5.

Does oatmeal offer a particular cholesterol benefit?

Oats contain beta-glucan, a soluble fiber linked to cholesterol reduction, but oatmeal is not a cholesterol-lowering drug. In a systematic review, interventions based predominantly on oats produced modest average reductions in LDL and total cholesterol compared with control groups, but the overall quality of the evidence was considered low⁸. The interventions and products varied and had methodological limitations. Results should therefore not be assumed to apply with the same magnitude to brown rice, wheat, quinoa or every other whole grain⁸. Whole grains can complement care, but they do not replace prescribed treatment for high cholesterol, hypertension, diabetes or weight management^5,8.

How much should you eat, and how can you increase it safely?

There is no single whole-grain amount that is right for everyone. The European Society of Cardiology describes 30–45 g of fiber per day, preferably including whole grains, as a feature of a healthy diet⁷. As practical cardiovascular prevention guidance, the Brazilian guideline recommends that at least half of the grains consumed be whole grain⁹. Brazilian guidelines also prioritize fiber-rich carbohydrates for dyslipidemia and include whole grains in the DASH eating pattern for blood pressure management^10,6. Because trials assessed different quantities, products and intervention periods, their results do not establish a universal target; dry weight, cooked food and serving counts are not interchangeable measures⁵. Practical serving examples include one slice of whole-grain bread, half a cup of cooked brown rice, oatmeal or whole-grain pasta, or three cups of popcorn prepared without excess salt or fat³.

Which practical swaps can support heart health?

Starting with one whole-grain swap each day can be a practical way to make gradual changes. Try mixing brown and white rice while gradually increasing the brown rice, adding oats to fruit or yogurt, rotating barley, quinoa, corn and other grains, choosing bread and pasta by their whole-grain percentage, or making popcorn with little salt and fat^2,7,3. The American Heart Association recommends choosing products made mainly with whole grains instead of refined grains within an eating pattern low in ultra-processed foods, added sugars and salt^2,3. Keep fruit, vegetables, beans and other legumes in the diet because fiber goals should not depend on grains alone^2,7,3. During Brazil’s September Heart Month and around World Heart Day on September 29, this is a practical change to consider—without expecting one food to eliminate cardiovascular risk.

When should you seek individualized advice?

Whole-grain choices and amounts should be personalized, particularly for people with coronary artery disease, high cholesterol, hypertension, diabetes, digestive concerns, gluten-related conditions or specific weight goals. A clinical assessment should consider test results, medications, daily routines, cultural preferences and the overall diet before establishing fiber targets or substitutions. Intake can be increased gradually, and improving carbohydrate quality is not a reason to stop prescribed treatment. Numbered references: 1. Précoma DB, Oliveira GMM, Simão AF, et al.; Brazilian Society of Cardiology. Atualização da Diretriz de Prevenção Cardiovascular da Sociedade Brasileira de Cardiologia — 2019. Arquivos Brasileiros de Cardiologia. 2019;113(4):787-891. DOI: https://doi.org/10.5935/abc.20190204. 2. Faludi AA, Izar MCO, Saraiva JFK, et al.; Brazilian Society of Cardiology. Atualização da Diretriz Brasileira de Dislipidemias e Prevenção da Aterosclerose — 2017. Arquivos Brasileiros de Cardiologia. 2017;109(2 Suppl. 1):1-76. DOI: https://doi.org/10.5935/abc.20170121. 3. Barroso WKS, Rodrigues CIS, Bortolotto LA, et al.; Brazilian Society of Cardiology. Diretrizes Brasileiras de Hipertensão Arterial — 2020. Arquivos Brasileiros de Cardiologia. 2021;116(3):516-658. DOI: https://doi.org/10.36660/abc.20201238. 4. Brazilian Health Regulatory Agency. Resolução da Diretoria Colegiada — RDC No. 712, July 1, 2022: requirements for the composition and labeling of cereal-containing foods classified and identified as whole grain and for highlighting whole-grain ingredients. Diário Oficial da União. 2022. Official URL: https://bvsms.saude.gov.br/bvs/saudelegis/anvisa/2022/rdc0712_01_07_2022.html. Accessed March 8, 2025. 5. Lichtenstein AH, Appel LJ, Vadiveloo M, et al.; American Heart Association. 2021 Dietary Guidance to Improve Cardiovascular Health: A Scientific Statement From the American Heart Association. Circulation. 2021;144(23):e472-e487. DOI: https://doi.org/10.1161/CIR.0000000000001031. 6. Visseren FLJ, Mach F, Smulders YM, et al.; ESC Scientific Document Group. 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice. European Heart Journal. 2021;42(34):3227-3337. DOI: https://doi.org/10.1093/eurheartj/ehab484. 7. Aune D, Keum N, Giovannucci E, Fadnes LT, Boffetta P, Greenwood DC, Tonstad S, Vatten LJ, Riboli E, Norat T. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2016;353:i2716. DOI: https://doi.org/10.1136/bmj.i2716. 8. Marshall S, Petocz P, Duve E, Abbott K, Cassettari T, Blumfield M, Fayet-Moore F. The effect of replacing refined grains with whole grains on cardiovascular risk factors: a systematic review and meta-analysis of randomized controlled trials with GRADE clinical recommendation. Journal of the Academy of Nutrition and Dietetics. 2020;120(11):1859-1883.e31. DOI: https://doi.org/10.1016/j.jand.2020.06.021. 9. Kelly SA, Hartley L, Loveman E, Colquitt JL, Jones HM, Al-Khudairy L, et al. Whole grain cereals for the primary or secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews. 2017;8(8):CD005051. DOI: https://doi.org/10.1002/14651858.CD005051.pub3. 10. American Heart Association. Whole Grains, Refined Grains, and Dietary Fiber. American Heart Association. 2024. Official URL: https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/whole-grains-refined-grains-and-dietary-fiber. Accessed March 8, 2025. This content is for information and education only and does not replace an individual medical consultation.