Heart disease is one of the leading causes of death worldwide and one of the medical conditions most known to be influenced by diet and lifestyle. What does nutrition science have to say about heart health? What dietary approaches can help prevent heart disease?
This month’s article will discuss the Mediterranean diet in heart disease prevention and illustrate how the principles can theoretically be applied to many cultural cuisines.
Mediterranean Diet
It is no secret that the Mediterranean diet is the most evidence-based dietary pattern for chronic disease prevention and management. But its effectiveness towards heart health is perhaps the most researched.
Ancel Keys was an American physiologist and lead author of The Seven Countries Study – the first major study to investigate diet, lifestyle, and other risk factors for cardiovascular disease. The study launched in 1958, was published in 1980, and has since been cited thousands of times in academia, serving as the basis for many follow-up studies.
Time and time again, we see evidence for this dietary pattern in heart disease prevention. It is not a diet per se but rather a dietary pattern that emphasizes whole foods over processed and refined foods. For example, vegetables and fruit, whole grains, legumes, fish, and olive oil as the principal fat used in cooking.
A similar dietary pattern called DASH (Dietary Approaches at Stopping Hypertension) is also recommended by the Canadian Heart and Stroke Foundation for managing blood pressure. We will discuss this in future articles, but for now, one can liken DASH to the Mediterranean dietary pattern with an added emphasis on reducing sodium (i.e., salt).
Why is the Mediterranean diet ideal for heart health?
Plant forward, full of fibre, abundant in heart-healthy fats, moderate/low in saturated fat, and with a focus on whole foods vs. processed – the Mediterranean diet has a lot going for it. Some of the cardioprotective effects of the food representative of a Mediterranean eating pattern include:
- Reduced blood pressure
- Improved vascular function
- Reduced oxidative stress
- Improved blood lipids
- Weight reduction
Each of these features combined leads to improved heart health and reduced morbidity and mortality from cardiovascular disease. Let’s look at some of the nutrient features.
Antioxidants
There are thousands of molecules that can act as antioxidants, including micronutrients such as Vitamin C, E, and A. Other plant-based nutrients, called “phytonutrients,” can also act as antioxidants. One such class of phytonutrients with antioxidant properties is polyphenols, which can be further subclassified. Flavonoids account for over 60% of polyphenols and are readily observed as the colour in many of our fruits and vegetables. Other polyphenols (Ex. Phenolic acids and polyphenolic amides) can be found in whole grains like oats and many seeds, as well as spices like chili peppers and curcumin.
Another Mediterranean dietary component is red wine (in moderation), to which the polyphenol resveratrol is thought to confer a health benefit.
Antioxidants are certainly an integral part of heart health, and it is well accepted that obtaining a diverse amount of these nutrients through food sources is the ideal strategy. When shopping through the produce aisle, think colour and variety!
Heart Healthy Fats
The Mediterranean diet places more emphasis on unsaturated fats than saturated fats. It emphasizes monounsaturated fats found in olive oil, avocado, nuts, and seeds. It also emphasizes omega-3 unsaturated fats found in fatty fish such as salmon, mackerel, and trout. Omega-3s can also be found in plant-based foods like hemp hearts, flax seeds, and walnuts. Plant-based omega-3 is called ALA (Alpha Linolenic Acid) and is the most common form. However, it is a precursor to the more beneficial forms of omega-3, called EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These have potent anti-inflammatory and heart health benefits, among others.
Our bodies can mediate the conversion of ALA to EPA and DHA, but it is not efficient. Fish is recommended 2-3 times per week because fatty fish are more efficient at this biochemical process through their algal-based diets rich in ALA.
If not eating fish regularly, I recommend daily supplementation. Just as there is no recommended amount of olive oil in a day, there is no daily recommended amount of EPA and DHA fats. In research, controversy still exists on an optimal dose and the ratio of EPA and DHA.
A reasonable dose should be considered together in collaboration with your healthcare provider, but a combined 600-1250mg of EPA and DHA combined is a reasonable amount to look for in a supplement for the average person.
Fibre from Varied Sources
Fibre has long been known to confer health benefits, and scientific research is identifying more and more examples of its impact on chronic disease prevention and management, including heart health. But nearly half of Canadians do not meet their fibre requirements.
Another hallmark of the Mediterranean diet is the emphasis on plant-based foods rich in fibre. Most Canadians also do not eat the recommended amount of vegetables and fruits, and even fewer regularly include legumes in their diet.
Legumes (i.e., Lentils, peas, chickpeas, beans, and soybeans) are fibre powerhouses, but often people do not know how to include them. One could simply add a handful to soups, salads, or wraps. Or try a plant-based meal. For example, many ethnic cuisines, such as black beans in many Latin American dishes, lentils in Indian Dahl, or chickpeas and lentils in Mediterranean dishes.
We also find fibre in vegetables, fruits, nuts, seeds, and grains. It is important to include a variety of different plant-based foods to optimize fibre intake due to the numerous health benefits conferred by different types of fibre.
What’s In A Name?
Cultural foods in a Mediterranean Diet context.
Just because the health advantages of a Mediterranean diet were discovered in the Mediterranean does not mean it cannot be applied to other cultural cuisines. If we remove the name Mediterranean diet, we could theoretically call it a plant-forward, pescatarian leaning diet, low in processed foods and refined sugar.
In fact, so-called Blue Zones (i.e., distinct regions in the world with the longest living, disability-free people) share similar eating patterns and nutrient composition in their culturally dissimilar foods and dishes.
It’s no surprise that two of the Blue Zones are found in Mediterranean regions (Ex. Ikaria, Greece; Sardinia, Italy). However, Okinawa (Japan) and Nicoya (Costa Rica) are also coastal regions that, despite different food ingredients, share a similar eating pattern with respect to nutrients of important characteristics of the Mediterranean diet.
Perhaps some nuances to the Mediterranean diet may be the regular use of olive oil and moderate red wine. But similarities include the plant-forward, pescatarian leaning approach with lots of fresh local ingredients and minimal use of processed or heavily refined foods.
Various Dietary Strategies To Align With Mediterranean And DASH Pattern
Pick one or two to try this week!
- Increase fibre in diet from varied plant-based food sources
- Try plant-based dishes from different cultural cuisines
- Add legumes to soups, salads, or wraps
- Focus on colour in the produce aisle
- Focus more unsaturated fats than saturated fats
- Incorporate olive oil, nuts, seeds, and avocados
- Include fatty fish more often while moderating red meat
- Reduce sodium in the diet
- Limit processed and refined foods
- Use herbs and spices liberally
- Enjoy meals mindfully
To book an appointment
It’s simple! If you feel you would benefit from a nutrition refresher, would like some accountability, or to set some new nutrition goals together – please reach out to book with either Daniel Neuman, or Britney Lentz. Britney is our new dietitian and is here Monday, Tuesday and Wednesday. We look forward to seeing you!
Dan Neuman
Registered Dietitian MSc