- Your heart is what you eat. Diet is a significant modifiable risk factor for cardiovascular disease (CVD). Although age, sex, and genetics are important nonmodifiable risk factors, most new cases of heart attacks today can be predicted by the presence and level of 9 risk (or cardioprotective) factors that can easily be assessed and modified.2 Eight of these 9 risk factors are influenced by diet, and most act by promoting atherogenesis, which is the most important background condition for CVD.
- In addition to providing caloric needs, several foods have cardio protective effects. Although controversial, a polymeal has been suggested to be an effective, non-pharmacological, safe, cheap, and tasty alternative to reduce CVD risk.3 The suggested ingredients of such polymeal includes wine, fish, dark chocolate, fruits, vegetables, garlic, and almonds. Combining the ingredients of the polymeal may reduce CVD events by 76%.3 However, the benefit of garlic is highly questionable while wine and dark chocolate are not necessary for eating a healthy diet. The overwhelming benefit of fruits, vegetables, fish, and nuts are discussed elsewhere.
- The rising epidemic of CVD in low and middle income countries (LMIC) is primarily due to the effects of changing diets and nutrition. An unhealthy diet is high in saturated fats, salt, and refined carbohydrates but also low in fruits and vegetables. Diets are sweeter and have a higher calorie intake than ever before.
- The proportion of total energy from fat appears largely unrelated to risk of cardiovascular disease, cancer, diabetes and obesity (in the absence of caloric excess).-
- A diet high in saturated fats and trans fats leads to abnormal levels of lipids in the blood, the major risk factor for CVD.1 Saturated fats are found in animal products as well as tropical oils. Saturated fats should be replaced with polyunsaturated, and monounsaturated fats, which are beneficial for heart health.4 Olive and canola oils and nuts are sources of monounsaturated fats.4 Soybean and sunflower oils are sources of polyunsaturated fat.4
- Saturated fat intake should not exceed 7% of total energy especially for high-risk groups, like people with diabetes. Total fat intake should be between 25-35% of total calories consumed to prevent and control obesity to allow adequate supply of vitamins and minerals.4
- Trans fats are oils that have been hydrogenated to turn them into semi-hard fats; they adversely alter the fat levels in the blood.4 Every effort should be made to avoid consumption of this fat.
- The essential fatty acids omega-3 and omega-6 are found in oily fish, nuts and seeds and actually protect the heart.4 The human body cannot make omega-3 and omega-6 acids so they must be consumed.4
- A diet high in salt increases the risk of developing high blood pressure, an important risk factor for CVD. A universal reduction of 3g of salt a day would lead to a 50% reduction in the number of people needing treatment for high blood pressure. This would also lead to a 22% drop in the number of deaths resulting from strokes and a 16% fall in the number of deaths from coronary artery disease (CAD). The American Heart Association now recommends a sodium intake of 1.5g, or less than 4g of salt per day (See Salt Restriction).5
- Low fruit and vegetable intake accounts for about 20% of CVD worldwide. Adults should consume at least 500g of fresh fruit and vegetables a day or 5 to 7 portions a day. A half-cup is generally considered as a portion. However, consuming 10-13 portions of fruits and vegetables in the DASH diets have been shown to have greater CVD benefits. 6-8
- The Dietary Approaches to Stop Hypertension (DASH) diet is widely promoted in the US for the prevention and treatment of high blood pressure. It is high in fruits, vegetables, low-fat dairy, and wholegrain foods but low in saturated fat and refined sugar.7 This diet has been shown to be beneficial in the prevention and management of CVD risk in youth and adults with and without diabetes.6-8
- Eating nuts regularly is associated with decreased risk of CAD. Nuts are high in unsaturated fatty acids, low in saturated fats and improve the fat levels in the blood. Nuts are an energy dense food source and must be eaten as part of a balanced diet.4
- Whole grains are rich in dietary fiber that has a positive effect of blood fat levels, lowering the risk of CAD.4
- Soft drinks, high in empty calories, are consumed with increasing frequency worldwide and are a major driver of escalating epidemics of obesity and diabetes.
- Carbohydrates vary in their effects to raise blood sugar especially in people with diabetes. Glycemic index and glycemic load are terms used to explain the qualitative and quantitative differences in carbohydrates.
- There is a reduced risk of death from CVD in places where fish consumption is high. Eat 1 to 2 servings of fish a week as part of a heart protective diet (see Fish).4
Q. Does dietary supplements really help people?
A. Contrary to common belief, several commonly used dietary vitamin and mineral supplements may be associated with increased risk of death according to a study of 38,772 women followed for 19 years. The most commonly used supplements were calcium, multivitamins, vitamin C, and vitamin E B6, folic acid, iron, magnesium, copper, zinc, and most of them were used in combination. Several commonly used dietary vitamin and mineral supplements may be associated with increased total mortality (8-15%) except for calcium which was associated with decreased risk (9%).9
1. De Caterina R, Zampolli A, Del Turco S, Madonna R, Massaro M. Nutritional mechanisms that influence cardiovascular disease. Am J Clin Nutr. Feb 2006;83(2):421S-426S.
2. Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. Sep 11 2004;364(9438):937-952.
3. Franco OH, Bonneux L, de Laet C, Peeters A, Steyerberg EW, Mackenbach JP. The Polymeal: a more natural, safer, and probably tastier (than the Polypill) strategy to reduce cardiovascular disease by more than 75%. Bmj. Dec 18 2004;329(7480):1447-1450.
4. Joint WHO/FAO Expert Consultation. WHO Technical Report Series 916: Diet, Nutrition and the Prevention of Chronic Diseases
Geneva: World Health Organization 2003.
5. Lloyd-Jones D. M., Hong Y, Labarthe D, et al. Defining and setting national goals for cardiovascular health promotion and disease reduction: the American Heart Association’s strategic Impact Goal through 2020 and beyond. Circulation. Feb 2 2010;121(4):586-613.
6. Liese AD, Bortsov A, Gunther AL, et al. Association of DASH diet with cardiovascular risk factors in youth with diabetes mellitus: the SEARCH for Diabetes in Youth study. Circulation. Apr 5 2011;123(13):1410-1417.
7. Liese AD, Nichols M, Sun X, D’Agostino RB, Jr., Haffner SM. Adherence to the DASH Diet is inversely associated with incidence of type 2 diabetes: the insulin resistance atherosclerosis study. Diabetes Care. Aug 2009;32(8):1434-1436.
8. Karanja N, Erlinger TP, Pao-Hwa L, Miller ER, 3rd, Bray GA. The DASH diet for high blood pressure: from clinical trial to dinner table. Cleve Clin J Med. Sep 2004;71(9):745-753.
9. Mursu J, Robien K, Harnack LJ, Park K, Jacobs DR, Jr. Dietary Supplements and Mortality Rate in Older Women: The Iowa Women’s Health Study. Arch Intern Med. Oct 10 2011;171(18):1625-1633.