When someone is first diagnosed with angina or any other cardiovascular problem, one tries to find ways to make one’s lifestyle healthier. For example, it is common for a new patient of high blood pressure to have ‘fatty foods’ drastically reduced, if not completely eliminated from his or her diet. While this, and many other dietary modifications are well-intended and instituted with the intent of improving one’s cardiac health, they are not always scientifically sound, and may not achieve their purpose. For example, diets rich in unsaturated fats have been found to be more helpful in lowering blood cholesterol, as opposed to low-fat diets. 

Those who try to educate themselves about a healthy cardiovascular diet often end up confused by contradicting advice about what to eat and what not to eat. The truth is, there are few absolutes. 

Which dietary nutrients are best for the heart? 

There is growing evidence that, with a few exceptions, individual nutrients have limited effects on chronic cardiovascular diseases. Instead, it is whole foods and multi-component dietary interventions that have an impact on cardiac health.

These dietary interventions take advantage of the beneficial effects of each of their multiple nutrient components and combine them to achieve greater effects as compared with single nutrient supplementation. Thus, nutrients work together to improve (or worsen) the health of your heart.

What does a good diet include? 

Your daily energy intake must be limited to achieve or maintain a Body Mass Index within normal limits. Skipping meals to achieve this is not a good idea; those who consume seven helpings of cereal for breakfast every week were found to have a lowered risk of heart failure as compared to those who didn’t have any at all.

Eating whole, unprocessed grains reduces total cholesterol levels. All types of vegetables, green leafy vegetables, soy protein and nuts lower the risk of heart failure, as do fruits like apples, pears and berries. 

30-40 grams of fibre per day from whole grain products, fruits and vegetables is advised, as are 2-3 servings (200 grams per day) each of fruits and vegetables.

Saturated fats should be reduced to less than 10% of one’s total energy intake, by replacing them with Polyunsaturated Fatty Acids (PUFA).

What does a good diet cut back on?

Meat and poultry have both been associated with an increased risk of coronary heart disease. Fish has no such effect. However, the form in which fish is consumed is significant; fried fish has been linked to lower cardiac output and a higher chance of heart failure. 

Those who consume high amounts of sweet beverages every day are at greater risk as compared to those who don’t. Trans fats should be cut down to less than 1% of one’s energy intake. 

Restricting salt intake is conclusively linked to lower blood pressure; total daily consumption should be limited to less than 2.4 grams.

What is the DASH diet? 

One diet plan that has been proven to be effective against cardiovascular diseases is the Dietary Approach to Stop Hypertension (DASH). 

This diet is: 

• High in vegetables, fruits, low-fat fermented dairy products, whole grains, poultry, fish, and nuts;
• Low in sweets, sugar-sweetened beverages, and red meats;
• Low in saturated fat, total fat, and cholesterol;
• Rich in potassium, magnesium, and calcium;
• Rich in protein and fiber.

How does the DASH diet help maintain cardiovascular health? 

Several studies have found that consistently consuming and adhering to a DASH diet:

• Promotes weight loss
• Lowers blood pressure, over and above any reduction achieved by certain medicines. 
• Improves the pumping action of the heart. 
• Increases exercise capacity. 
• Lowers the blood levels of substances which indicate underlying heart disease. 
• Lowers risk of coronary artery disease and stroke. 
• Decreases the chances of heart failure. 
• Reduces the risk of mortality even in those already facing heart failure. 

Bottom line: a balanced diet which allows most foods in moderation

One must remember that the protective value of different kinds of food is relative. For example, if consumed in place of red/processed meats, fish may be helpful, but not if used as a replacement for vegetables or whole grains. One must also keep in mind that while plant-based diets are advisable, certain essential nutrients like dietary cholesterol are present mostly only in animal products. 

Some foods have a varying effect on cardiac health; consuming lots of high-fat dairy products may be harmful, but low-fat dairy products may actually have beneficial effects on blood pressure. And certain items that are considered unnecessary or better avoided may actually help; recent research has found that moderate coffee drinking does no harm, and may even have a protective effect on coronary artery disease.

While all of the above may sound confusing, it is all underpinned by a common principle: diets should be based on nutrient requirements, and one’s daily meals should conform to one’s diet. Last, but not the least, this diet should take into account each individual’s cultural and personal tastes and the dietary restrictions required by any coexisting diseases other than cardiovascular disease.

References: 

1: Institute of Medicine (US) Committee on Nutrition Services for Medicare Beneficiaries. The Role of Nutrition in Maintaining Health in the Nation’s Elderly: Evaluating Coverage of Nutrition Services for the Medicare Population. Washington (DC): National Academies Press (US); 2000. 5, Cardiovascular Disease.

2: Ravera A, Carubelli V, Sciatti E, et al. Nutrition and Cardiovascular Disease: Finding the Perfect Recipe for Cardiovascular Health. Nutrients. 2016;8(6):363

3: Kerley CP. A Review of Plant-based Diets to Prevent and Treat Heart Failure. Card Fail Rev. 2018;4(1):54‐61

4: Eilat-Adar S, Sinai T, Yosefy C, Henkin Y. Nutritional recommendations for cardiovascular disease prevention. Nutrients. 2013;5(9):3646‐3683.

5: Bowen KJ, Sullivan VK, Kris-Etherton PM, Petersen KS. Nutrition and Cardiovascular Disease-an Update. Curr Atheroscler Rep. 2018;20(2):8