The Mediterranean and DASH Diets: A Genetic Perspective on Heart-Healthy Eating

The Mediterranean and DASH Diets: A Genetic Perspective on Heart-Healthy Eating

In the realm of nutritional science, the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets have emerged as leading dietary patterns for promoting cardiovascular health and overall well-being. Both diets emphasise the consumption of whole foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats. For those interested in the interplay between genetics and nutrition, understanding these diets' implications is essential. This article explores the benefits and drawbacks of the Mediterranean and DASH diets, firmly grounded in scientific evidence.

What are the Mediterranean and DASH Diets?

Mediterranean Diet: Originating from the traditional eating habits of countries bordering the Mediterranean Sea, this diet emphasises plant-based foods (legumes, pulses, nuts/seeds, vegetables and fruits), healthy fats (particularly extra virgin olive oil), moderate consumption of fish and poultry, and limited intake of red meat and sweets. It restricts consumption of processed, packaged and refined foods.

DASH Diet: Developed to combat high blood pressure, the DASH diet focuses on fruits, vegetables, whole grains, lean proteins, and low-fat dairy products. It limits foods high in saturated fat, cholesterol, and sodium. The diet is rich in nutrients like potassium, calcium, and magnesium, which help lower blood pressure.

Pros of the Mediterranean and DASH Diets

  1. Cardiovascular Health Benefits

Reduced Risk of Heart Disease: Numerous studies have shown that both diets significantly reduce the risk of cardiovascular diseases. A landmark study, the PREDIMED trial, demonstrated that adherence to the Mediterranean diet supplemented with extra-virgin olive oil or nuts led to a substantial reduction in major cardiovascular events among high-risk individuals1. Similarly, the DASH diet has been proven to lower blood pressure levels, a key risk factor for heart disease2.

  1. Improved Blood Pressure

Lowering Hypertension: The DASH diet was specifically designed to reduce blood pressure. Clinical trials have consistently shown that the DASH diet lowers systolic and diastolic blood pressure in individuals with hypertension and prehypertension3. The Mediterranean diet also contributes to lower blood pressure due to its emphasis on fruits, vegetables, and healthy fats4.

  1. Enhanced Metabolic Health

Better Glycaemic Control: Both diets have been associated with improved insulin sensitivity and glycaemic control. A recent study found that the Mediterranean diet led to a greater reduction in HbA1c levels compared to a low-fat diet in individuals with type 2 diabetes5. Similarly, in healthy individuals, the Med Diet is inversely associated with risk of type 2 diabetes6. The DASH diet's emphasis on whole grains and fibre-rich foods also aids in stabilising blood sugar levels7.

  1. Gut Health

Supporting Gut Health: Adherence to the Mediterranean and DASH diets has been associated with improved gut microbiota diversity and composition. Research indicates that the high intake of fibre, polyphenols, and healthy fats in these dietary patterns promotes the growth of beneficial gut bacteria, which play a crucial role in maintaining gut health and overall systemic health. These diets contribute to reduced gut inflammation and improved gut barrier function, enhancing digestive health, lowering the risk of gastrointestinal disorders, and helping to prevent gut-mediated chronic diseases.

  1. Weight Management

Promoting Healthy Weight: Adherence to the Mediterranean and DASH diets has been linked to lower body mass index (BMI) and waist circumference. A systematic review indicated that these dietary patterns are effective in preventing overweight and obesity8.

  1. Nutrient-Rich and Sustainable

Balanced Nutrient Intake: Both diets provide a wide array of essential nutrients, vitamins, and minerals. The emphasis on whole foods ensures adequate intake of fibre, antioxidants, and phytonutrients, contributing to overall health and disease prevention9.

  1. Cognitive Benefits

Reduced Risk of Cognitive Decline: Studies have suggested that the Mediterranean diet may protect against cognitive decline and neurodegenerative diseases. Recent research has indicated that adherence to the Mediterranean diet is associated with a reduced risk of Alzheimer's disease10.

  1. Mental Health Benefits

Improvement in Depression and Anxiety Symptoms: The SMILES trial investigated the impact of a 12-week dietary intervention on adults with major depression. Participants who followed a Mediterranean-style diet showed significantly greater improvements in depressive symptoms compared to those receiving social support alone11. Similarly, the TANDIM trial published in 2023 concluded that 62% of the Mediterranean Diet group reported improvement in depressive symptoms, along with significantly reduced anxiety and perceived stress12.

 

Cons of the Mediterranean and DASH Diets

  1. Accessibility and Cost

Potentially Higher Costs: The emphasis on fresh produce, whole grains, and lean proteins such as fish can be more expensive than processed or fast foods, potentially making these diets less accessible to individuals with limited financial resources.

  1. Dietary Compliance

Adherence Challenges: Changing dietary habits can be challenging. Individuals accustomed to high-fat, high-sodium, or high-sugar diets may find it difficult to adjust to the Mediterranean or DASH dietary patterns. However, personalised guidance from a health professional can help to shift these eating patterns.

  1. Individual Nutritional Needs

One Size Does Not Fit All: While generally healthful, these diets may not meet the specific nutritional needs of all individuals, such as those with certain food allergies, intolerances, or metabolic conditions. However, a qualified health professional can assist in tailoring a modified version of this diet to suit individual requirements.

Genetic Considerations: How Your Genes May Influence Diet Efficacy

  1. Lipid Metabolism Genes (e.g., APOA1, APOE)

Cholesterol Levels: Genetic variations can affect lipid metabolism and response to dietary fats. For instance, individuals with certain APOE genotypes may experience different changes in lipid profiles when following diets rich in monounsaturated fats, like the Mediterranean diet13.

  1. Blood Pressure Regulation Genes (e.g., ACE, AGT)

Hypertension Risk: Genes involved in the renin-angiotensin system, such as ACE and AGT, influence blood pressure regulation. The DASH diet's effectiveness in lowering blood pressure may vary depending on these genetic factors14.

  1. Glucose Metabolism Genes (e.g., TCF7L2)

Diabetes Risk: Variants in genes like TCF7L2 are associated with type 2 diabetes risk. The Mediterranean diet's benefits on glycaemic control may be more pronounced in individuals with certain genetic predispositions15.

  1. Taste Receptor Genes (e.g., TAS2R38)

Dietary Preferences: Genetic variations can influence taste perception and food preferences, potentially affecting adherence to diets rich in bitter foods such as certain vegetables16. This can be improved over time with repeated exposure, however.

Further Evidence-Based Insights: What the Research Says

Long-Term Health Outcomes

  • Reduced Mortality Rates: A meta-analysis published recently found that adherence to the Mediterranean diet is associated with a reduction in overall mortality, cardiovascular mortality, and incidence of cancer and Parkinson's and Alzheimer's diseases17.
  • DASH Diet Effectiveness: The DASH diet has been endorsed by health organisations like the American Heart Association for its proven benefits in lowering blood pressure and improving cardiovascular health18.

Gut Health

  • Microbiome Diversity: Both diets promote a healthy gut microbiome due to high fibre intake from fruits, vegetables, and whole grains. A diverse microbiome is linked to numerous health benefits, including improved immune function and reduced inflammation19.

Anti-Inflammatory Effects

  • Reduced Inflammation Markers: Studies have shown that the Mediterranean diet lowers levels of inflammatory markers like C-reactive protein (CRP), contributing to its protective effects against chronic diseases20,21.

Balancing Genetics and Diet: Personalised Nutrition for Optimal Health

Personalised Dietary Recommendations: Understanding your genetic profile can help tailor the Mediterranean or DASH diet to maximise benefits. For example, individuals with certain lipid metabolism genes may need to adjust their intake of fats accordingly.

Monitoring Health Markers: Keeping track of blood pressure, lipid profiles, and blood glucose levels can help assess how well the diet is working for you and make necessary adjustments.

Consultation with Healthcare Providers: Dietitians or nutritionists can provide personalised advice, taking into account genetic factors, health goals, and dietary preferences.

Conclusion: Are the Mediterranean and DASH Diets Right for You?

The Mediterranean and DASH diets offer substantial health benefits, including improved cardiovascular health and gut health, better glycaemic control, enhanced metabolic function, reduced inflammation and risk of cancer and neurodegenerative diseases.

While generally suitable for most people, individual responses can vary. Integrating genetic insights with nutritional guidance allows for a personalised approach, optimising the diets' effectiveness and aligning them with your unique health needs.

By considering your genetic predispositions and working with healthcare professionals, you can make informed decisions about adopting the Mediterranean or DASH diet as part of a sustainable and health-promoting lifestyle.

Disclaimer: This article is intended for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before making significant changes to your diet or lifestyle.

References

  1. Estruch, R., Ros, E., Salas-Salvadó, J., et al. (2018). Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. New England Journal of Medicine, 378(25). doi: 10.1056/nejmoa1800389.
  2. Siervo, M., Lara, J., Chowdhury, S., et al. (2015). Effects of the Dietary Approach to Stop Hypertension (DASH) diet on cardiovascular risk factors: a systematic review and meta-analysis. British Journal of Nutrition, 113(1), 1–15.
  3. Sacks, F. M., Svetkey, L. P., Vollmer, W. M., et al. (2001). Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. New England Journal of Medicine, 344(1), 3–10.
  4. Chiva-Blanch, G., Badimon, L., & Estruch, R. (2014). Latest evidence of the effects of the Mediterranean diet in prevention of cardiovascular disease. Current Atherosclerosis Reports, 16(10), 446.
  5. Esposito, K., Maiorino, M. I., Ciotola, M., et al. (2009). Effects of a Mediterranean-style diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetes: a randomized trial. Annals of Internal Medicine, 151(5), 306–314.
  6. Zeraattalab-Motlagh S, Jayedi A, Shab-Bidar S. Mediterranean dietary pattern and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of prospective cohort studies. Eur J Nutr. 2022;61(4):1735-1748. doi:10.1007/s00394-021-02761-3
  7. Soltani, S., Shirani, F., Chitsazi, M. J., & Salehi-Abargouei, A. (2016). The effects of Dietary Approaches to Stop Hypertension (DASH) diet on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. Obesity Reviews, 17(5), 442–454.
  8. Kastorini, C. M., Milionis, H. J., Esposito, K., et al. (2011). The effect of Mediterranean diet on metabolic syndrome and its components: a meta-analysis of 50 studies and 534,906 individuals. Journal of the American College of Cardiology, 57(11), 1299–1313.
  9. Trichopoulou, A., & Vasilopoulou, E. (2000). Mediterranean diet and longevity. British Journal of Nutrition, 84(S2), S205–S209.
  10. Scarmeas, N., Stern, Y., Tang, M. X., et al. (2006). Mediterranean diet and risk for Alzheimer's disease. Annals of Neurology, 59(6), 912–921.
  11. Jacka FN, O'Neil A, Opie R, et al. A randomised controlled trial of dietary improvement for adults with major depression (the 'SMILES' trial) [published correction appears in BMC Med. 2018 Dec 28;16(1):236. doi: 10.1186/s12916-018-1220-6]. BMC Med. 2017;15(1):23. Published 2017 Jan 30. doi:10.1186/s12916-017-0791-y

 

  1. Staudacher HM, Mahoney S, Canale K, et al. Clinical trial: A Mediterranean diet is feasible and improves gastrointestinal and psychological symptoms in irritable bowel syndrome. Aliment Pharmacol Ther. 2024;59(4):492-503. doi:10.1111/apt.17791
  2. Ferguson, J. F., Phillips, C. M., & McMonagle, J. (2010). Gene–nutrient interactions in the metabolic syndrome. Journal of Nutrigenetics and Nutrigenomics, 3(4–6), 147–160.
  3. Svetkey, L. P., Chen, Y., King, A. C., et al. (2011). Genetic variants in the renin-angiotensin-aldosterone system and blood pressure responses to the DASH diet. Journal of Human Hypertension, 25(12), 1–8.
  4. Corella, D., Coltell, O., Sorlí, J. V., et al. (2016). Polymorphisms associated with increased risk for type 2 diabetes are modified by lifestyle factors in the prevention of diabetes with Mediterranean diet PREDIMED trial. Nutrition, Metabolism and Cardiovascular Diseases, 26(6), 528–536.
  5. Chamoun, E., Carroll, N. A., Duizer, L. M., et al. (2018). The relationship between single nucleotide polymorphisms in taste receptors, eating behaviors, and health: A systematic review. Physiology & Behavior, 192, 208–219.
  6. Sofi, F., Abbate, R., Gensini, G. F., & Casini, A. (2010). Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis. American Journal of Clinical Nutrition, 92(5), 1189–1196.
  7. American Heart Association. (2014). DASH Eating Plan.
  8. De Filippis, F., Pellegrini, N., Vannini, L., et al. (2016). High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome. Gut, 65(11), 1812–1821.
  9. Tsigalou, C., Konstantinidis, T., Paraschaki, A., et al. (2020). Mediterranean Diet as a Tool to Combat Inflammation and Chronic Diseases. An Overview. Biomedicines, 8(7), 201. https://doi.org/10.3390/biomedicines8070201
  10. Norde MM, Collese TS, Giovannucci E, Rogero MM. A posteriori dietary patterns and their association with systemic low-grade inflammation in adults: a systematic review and meta-analysis. Nutr Rev. 2021;79(3):331-350. doi:10.1093/nutrit/nuaa010

 

 

Back to blog