The Latest Research on Walnuts + Heart Health
Heart disease has been the leading cause of death in Americans1, and caring for your heart is always important. Diet is a controllable risk factor for heart disease, and walnuts and other foods that provide good fats are smart choices.
Walnuts have long been recognized as a heart-healthy food*, with decades of scientific research showing how eating walnuts affects various factors related to heart health such as cholesterol, blood pressure, inflammation and blood vessel function. Scientists are learning new information that is changing what we know about heart health. Here are a few research studies that have recently been published related to walnuts and heart health.
- A study2 published in Circulation (2021) explored the effects of a walnut-enriched diet on overall cholesterol in elderly individuals, researchers found an association between regular daily walnut consumption and sustained lower levels of cholesterol including a 15 percent lower risk of cardiovascular disease.
- A study3 from the Harvard T.H. Chan School of Public Health and published in Nutrients (2021) looked at the link between higher walnut consumption – both in terms of the amount and frequency – and longer life expectancy. The study found that eating five or more servings (one serving = one ounce) per week was associated with a 14% lower risk of death (from any cause), 25% lower risk of dying from cardiovascular diseases, and a gain in about 1.3 years of life expectancy, compared to those who didn’t consume walnuts. The study suggests that even a few handfuls of walnuts per week may help promote longevity.
- A study4 published in the Journal of the American College of Cardiology (2020) looked at regular consumption of foods rich in marine or plant-based omega-3s and risk of death among individuals who have suffered a heart attack. Fun fact! Walnuts are the only nut that is an excellent source of plant-based omega-3 ALA, providing 2.5 grams per one ounce.
- Another recent study5 published in the Journal of the American College of Cardiology (2020) explored regular consumption of walnuts and anti-inflammatory effects. Chronic inflammation, caused by factors such as poor diet, obesity, stress and high blood pressure, is damaging and a factor associated with heart disease risk.
- A study6 published in BMJ Open Heart (2020) analyzed the impact of traditional Mediterranean diet, green Mediterranean diet, and healthy US diet on LDL cholesterol, weight and insulin resistance. Both Mediterranean diets contained 28 g/day walnuts, and the green Mediterranean diet also contained 3-4 cups/day of green tea and 100 g frozen cubes of Wolffia globosa duckweed (Mankai). Walnuts are a key ingredient in both a green Mediterranean diet and the traditional Mediterranean diet, which put fruits, vegetables, grains, olive oil, nuts and seeds at the center of the plate.
- A long-term study7 published in Nutrition, Metabolism and Cardiovascular Diseases (2021) investigated the link between cardiovascular risk factors and young adults who consumed walnuts versus those who did not. Specifically, the study looked at factors including blood pressure, waist circumference and abdominal obesity.
- A study8 published in Journal of Nutrition (2020) used a novel, machine-learning model to identify 19 markers in the body that were associated with walnut consumption. A “walnut signature,” if you will. The body forms specific metabolites based on what food is consumed. This “walnut signature” was associated with a lower risk of type 2 diabetes and risk of cardiovascular disease in an older Mediterranean population at high cardiovascular risk.
Keeping these findings in mind, there are many ways to support heart health – starting with something as simple as choices at the grocery store.
Tips for Heart-Smart Shopping
- Read Nutrition Facts labels, even for foods you think may be good for you. When there’s more than one choice, compare labels. Look for food items with the American Heart Association Heart-Check mark on them. More than 1,000 products carry the Heart-Check mark!
- Focus on good fats. Replace saturated fats (found in animal-based foods like butter, cream and meat) with the good fats, monounsaturated and polyunsaturated (found in walnuts, fish and avocados). Try avocado instead of mayo on sandwiches, and snack on walnuts instead of chips or pretzels.
- Choose foods with less sodium, and prepare foods with little or no salt. Check out these heart-smart recipes!
- Stock up on shelf-stable, nutrient-dense foods. In the event that you are staying inside for an extended period of time, keep your household nourished with nutrient-dense foods. One ounce of walnuts offers important nutrients for optimum health including 4g of protein, 2g of fiber and is a good source of magnesium (45mg).
- Did you know? The best way to store walnuts is in an airtight container in the refrigerator. If you don’t plan to use them for a month or longer, store them in the freezer.
- Prioritize fruits and veggies. Look for fresh, frozen or canned produce that’s in season or on sale to save money.
For additional ways to care for your heart, visit the following resources:
3 Ways to Eat Heart-Healthy with Walnuts this Week
3 Simple Ways to Show Your Heart Some Love this Month
Heart-Healthy Walnut Recipes
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It is important to note this article provides a snapshot of the research related to this area of study. These findings do not show cause and effect, and additional research is needed to determine how these results apply to broader populations.
* California walnuts are certified by the American Heart Association. Heart-Check certification does not apply to recipes, research or information unless expressly stated. Supportive but not conclusive research shows that eating 1.5 ounces of walnuts per day, as part of a low saturated fat and low cholesterol diet and not resulting in increased caloric intake, may reduce the risk of coronary heart disease. One ounce of walnuts offers 18g of total fat, 2.5g of monounsaturated fat, 13g of polyunsaturated fat including 2.5g of alpha-linolenic acid – the plant-based omega-3.
Sources:
1Centers for Disease Control and Prevention. Underlying Cause of Death, 1999–2018. CDC WONDER Online Database. Atlanta, GA: Centers for Disease Control and Prevention; 2018. Accessed October 26, 2020.
2Rajaram S, Cofan M, Sala-Vila A, Haddad E, Serra M, Bitok E, Roth I, Freitas-Simoes TM, Kaur A, Valls-Pedret C, Domenech M, Oda K, Corella D, Sabate J, Ros E. Effects of walnut consumption for 2 years on blood lipids and lipoprotein subclasses among healthy elders: Findings from the Walnuts and Healthy Aging (WAHA) randomized controlled trial. Circulation. 2021;144:00–00. DOI: 10.1161/CIRCULATIONAHA.121.054051.
3Liu X, Guasch-Ferré M, Tobias DK, Li Y. Association of Walnut Consumption with Total and Cause-Specific Mortality and Life Expectancy in U.S. Adults. Nutrients. 2021; 13(8):2699. https://doi.org/10.3390/nu13082699
4Lázaro I, Rueda F, Cediel G, et al. Circulating Omega-3 Fatty Acids and Incident Adverse Events in Patients With Acute Myocardial Infarction. J Am Coll Cardiol. 2020 Oct, 76 (18) 2089–2097. doi:10.1016/j.jacc.2020.08.073
5Cofán M, Rajaram S, Sala-Vila A, et al. Effects of 2-Year Walnut-Supplemented Diet on Inflammatory Biomarkers. J Am Coll Cardiol. 2020 Nov, 76 (19) 2282–2284.
6Tsaban G, Yaskolka Meir A, Rinott E, et al. The effect of green Mediterranean diet on cardiometabolic risk; a randomised controlled trial Heart Published Online First: 23 November 2020. doi: 10.1136/heartjnl-2020-317802
7Steffen LM, Yi SY, Duprez D, Zhou X, Shikany JM, Jacobs Jr DR, Walnut Consumption and Cardiac Phenotypes: the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Nutrition, Metabolism and Cardiovascular Diseases. 2021; 31(1): 95-101 https://doi.org/10.1016/j.numecd.2020.09.001.
8Guasch-Ferré M, Hernández-Alonso P, Drouin-Chartier JP, et al. Walnut Consumption, Plasma Metabolomics, and Risk of Type 2 Diabetes and Cardiovascular Disease [published online ahead of print, 2020 Dec 31]. J Nutr. 2020;nxaa374. doi:10.1093/jn/nxaa374