Fact Check: Can walnuts prevent heart attack?
Claim: In a reel posted on Instagram it is claimed that walnuts prevent heart attacks. As per the user welln_ess360, walnuts are packed with heart-healthy nutrients like omega-3, fatty acids, fiber and antioxidants. It is further claimed that walnuts also lower cholesterol, reduce inflammation and improve the function of blood vessels. Instagram User claims that eating walnuts prevents heart attacks. The video can be seen here.
Fact Check: This claim is MISLEADING.While walnuts contain nutrients that support cardiovascular health and can reduce risk factors associated with heart disease, they should not be seen as a direct preventive measure against heart attacks
Understanding Heart Attack
As per National Heart, Lung and Blood Institute, US “A heart attack, also known as a myocardial infarction, happens when the flow of blood that brings oxygen to a part of your heart muscle suddenly becomes blocked and the heart can’t get enough oxygen. If blood flow is not restored quickly, the heart muscle will begin to die.” (1)
Risk Factors Associated with Heart Attacks
Heart attack risk is influenced by several lifestyle and health factors. An unhealthy diet high in saturated fats or sodium, lack of regular physical activity, and smoking are significant contributors. Medical conditions like high cholesterol, high blood pressure (including during pregnancy), high blood sugar or diabetes, high triglycerides, and obesity also increase the risk. When three or more of these conditions occur together, it is called metabolic syndrome, which significantly raises the risk of a heart attack. Uncontrollable factors include age (with increased risk for men over 45 and women over 55 or after menopause), family history of early heart disease, and infections from bacteria and viruses. (1)
Understanding Walnuts
Walnuts are abundant in heart-healthy fats such as omega-3 and omega-6, and they are packed with antioxidants. Additionally, walnuts provide a rich source of protein, vitamins (including Vitamin E, Vitamin B6, and folic acid), minerals (such as copper, phosphorus, and manganese), and dietary fiber. They contain sterols that positively impact human metabolism and hinder cholesterol absorption, thereby reducing blood cholesterol levels. (2)
Can Walnuts Prevent Heart Attacks?
Several scientific studies have investigated the relationship between walnut consumption and heart health.
In a study published by Penny M. Kris-Etherton in The Journal Of Nutrition, it was observed that the short-term impact of walnuts on various cardiovascular disease markers validates their recommendation for a heart-healthy diet. (3)
An article published in The American Journal of Clinical Nutrition by Deirdre K Banel et. al. found that incorporating walnuts into the diet improved blood lipid profile without adversely affecting body weight or blood pressure. (4)
While scientific studies suggest that consuming walnuts positively impacts cardiovascular health, such as lowering cholesterol and providing anti-inflammatory benefits, no scientific evidence supports the claim that walnuts prevent heart attacks. Further, there is no evidence that walnuts can improve the function of blood vessels.
Walnuts consumption is not listed by any medical guidelines as a preventive measure for heart attack
What do experts say?
The Health Dialogues Fact Check Team spoke with Dr. Prem Aggarwal, Cardiologist and Chairman of Sanjeevan Hospital, "Walnuts are indeed beneficial for heart health as they help lower cholesterol and have anti-inflammatory properties, which are essential for managing cardiovascular disease. However, it's important to clarify that there is no scientific evidence or medical consensus to the claim that walnut consumption can directly prevent heart attacks. While they assist in managing certain risk factors, they do not directly improve blood vessel function or prevent heart attacks. So, while incorporating walnuts into your diet is certainly advantageous, they shouldn't be viewed as a definitive solution for preventing heart attacks."
Dr. Manav Aggarwal, Interventional Cardiologist, Sanjeevan Hospital, New Delhi further added, "While walnuts are a nutritious food and have many health benefits, claiming that they can outright prevent heart attacks appears to be an overstatement. Including walnuts in a balanced diet can contribute to heart health by providing healthy fats, antioxidants, and other nutrients, but walnuts alone can't prevent heart attacks. They should be part of an overall healthy lifestyle that includes regular exercise and avoiding harmful habits like smoking."
Medical Dialogues Final Take
Walnuts positively impact cardiovascular health by lowering cholesterol levels, possessing anti-inflammatory properties, and providing nutritional benefits. While scientific evidence supports that walnuts can aid with certain cardiovascular disease risk factors, there is no proof that they improve blood vessel function. Additionally, no scientific evidence or medical consensus clearly specifies that that walnuts can prevent heart attacks.
Hence the claim that walnuts can prevent heart attack is an overstatement and MISLEADING.
References
- https://www.nhlbi.nih.gov/health/heart-attack
- https://www.phytojournal.com/archives/2018/vol7issue2/PartR/7-2-169-977.pdf
- Kris-Etherton PM. Walnuts decrease risk of cardiovascular disease: a summary of efficacy and biologic mechanisms. J Nutr. 2014 Apr;144(4 Suppl):547S-554S. doi: 10.3945/jn.113.182907. Epub 2014 Feb 5. PMID: 24500935.
- Guasch-Ferré M, Li J, Hu FB, Salas-Salvadó J, Tobias DK. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: an updated meta-analysis and systematic review of controlled trials. Am J Clin Nutr. 2018 Jul 1;108(1):174-187. doi: 10.1093/ajcn/nqy091. PMID: 29931130; PMCID: PMC6862936.