Diet therapy is a means of using diets prescribed by a dietician to enhance health. Several diseases are treated or managed to some extent by therapeutic diets. Managing or treating certain conditions involves including foods that enhance certain health conditions. On the other hand, one should avoid foods, which deteriorate health conditions. Some health issues may need temporary diet therapy. On the other hand, diet therapy may become a permanent form of intervention required to ensure healthy lifestyles. Diet therapies have become specialized and require the inputs of professionals such as physicians or dieticians. It is imperative to note that diet therapies may be altered depending on the health changes observed.
A gluten-free diet, for instance, maybe necessary for one to stay healthy because such persons must avoid diets rich in gluten to protect their intestines. In addition, individuals with obesity may require ketogenic diets or avoid high-sugar foods to manage their conditions, specifically blood sugar levels. Intakes of certain nutrients such as salts and saturated fats may be restricted to manage blood pressure and cholesterol respectively. It is not simple to adapt to new restrictive diets and therefore individuals are advised to work with their physicians or dieticians to ensure that they make gradual changes and adhere to diet therapies. According to nutrition specialists, ‘recommended balanced diets’ should contain the right “macronutrient composition, micronutrients, and dietary quality to ensure adequate nutrition, energy balance for health and weight maintenance and prevention of non-communicable diseases (NCDs) in healthy populations” (Naude et al., 2014). This study focuses on diet therapies and cardiovascular diseases.
Various factors drive cardiovascular disease, including stroke. According to Roth et al. (2015), the global cases of cardiovascular and circulatory conditions have increased. The authors have attributed the increase to “the combined effect of population growth, the aging of populations, and epidemiologic changes in cardiovascular disease” (Roth et al., 2015). They further note that drivers of cardiovascular disease should be separated to understand regional and national interventions for cardiovascular disease. Disentangling these drivers also leads to improved comprehension of roles and relative of various demographic and epidemiologic trends to understand current policies. Finally, disentangling also assists in evaluating the relevance of aging and growth in people and progresses achieved towards the reduction of premature deaths associated with cardiovascular disease. Among all these factors, diets have critical roles in cardiovascular disease.
Diets rich in sodium are known risk factors for cardiovascular disease (Packham et al., 2015). Hyperkalemia (serum potassium level, >5.0 mmol per liter) associated with renal diseases is a notable electrolyte condition that is also responsible for serious cardiac dysrhythmias and increased mortality (Packham et al., 2015). It has been observed that individuals with renal dysfunction and others with diabetes are highly susceptible to hyperkalemia. It has been noted that some specific therapies for controlling the renin-angiotensin–aldosterone system (RAAS) are linked to hyperkalemia in patients with kidney conditions or heart failure, although such therapies are vital for “proteinuric chronic kidney disease, diabetic nephropathy, and systolic heart failure” (Packham et al., 2015). In addition, studies have also established that the application of available polymer resins such as sodium polystyrene sulfonate leads to unfavorable side effects with unknown effectiveness (Packham et al., 2015). On this note, it is clear that such therapies to control hyperkalemia are responsible for certain chronic diseases such as cardiovascular disease and other acute conditions. Hence, Packham et al. (2015) concluded that new additional agents are required to manage hyperkalemia safely in patients with chronic and acute conditions.
Obesity is also a risk factor for several conditions, including cardiovascular disease, type-2 diabetes, and metabolic syndrome. In this regard, some interventions have focused on diet therapies to manage obesity, particularly in individuals with cardiovascular disease. A study by Hu and Bazzano (2014) indicates that obesity remains a critical public health issue and by 2005, there were nearly 937 million cases of overweight and 396 million cases of obese people globall,y and these numbers were projected to increase. Hence, obesity needs a careful approach and effective management. On this note, diet therapies have been adopted to control obesity and perhaps cardiovascular disease and other chronic conditions.
The growing interest in the low-carbohydrate diet (ketogenic diet) to manage obesity and facilitate weight loss is important for this study. According to Hu and Bazzano (2014), despite thisrealizationn, some experts have failed to recommend low-carbohydrate diets to control cardiovascular disease. A perception exists that such diets could lead to adverse outcomes on cardiovascular disease risk factors specifically because of the assumption that the level of saturated fats will increase in low-carbohydrate diets relative to weight loss diets (Hu & Bazzano, 2014). It is noted that certain professional organisations, including the American Dietetic Association have warned the public against the use of a low-carbohydrate diet. Recent studies, however, have shown that low-carbohydrate diets have a dual effect of reducing body weight and enhancing cardiovascular risk factors (Hu & Bazzano, 2014). Consumption of diets with low carbohydrate contents leads to low total energy intake, which is a significant risk factor for obesity. A major source of concern has been whether effects of a low-carbohydrate diet on cardiovascular disease emanate from the decreased consumption of carbohydrates or total energy intake (Hu & Bazzano, 2014). On this note, a study by Hu and Bazzano (2014) demonstrated that “low-carbohydrate diets not only decrease body weight but also improve cardiovascular risk factors” (p. 337). Based on this new evidence, it is necessary to encourage the consumption of healthy low-carbohydrate diet as an effective, alternative diet therapy for managing conditions of cardiovascular and obesity risk factors. Some studies have confirmed that ketogenic diets have shown effectiveness in obesity, cardiovascular risk factors and hyperlipidemia management in short-term to medium-term interventions (Paoli, 2014). At the same time, physicians have also raised some concerns about the use of ketogenic diets to manage chronic diseases and obesity. Many challenges about the use of ketogenic diets could be related to a lack of sufficient evidence because the study is relatively new, particularly the physiological processes involved.
The media have also promoted certain weigh loss diets such as Atkins diet. These diets have however focused on restricting carbohydrate intakes, protein rich diets, and total and saturate fat consumption (Naude et al., 2014). Contrary to their intended goals, many experts have asserted that such diets are more important for weight loss relative to improving cardiovascular health, balanced diets for weight management and managing or curing diabetes (Naude et al., 2014). As these diets strive for extremely low carbohydrate contents, they focus on restricting consumption of most fruits, vegetables, legumes, whole grains and other types of foods rich in carbohydrates. Hence, it becomes apparent that these forms of diets could have detrimental effects over a long period. Generally, low carbohydrate diets require people to substitute carbohydrate rich foods with high protein and fat foods. However, since there are various forms and guidelines for these diets, definitions for ‘low’, implementation strategies, guidelines and health outcome claims for these substitutes differ significantly. Naude et al. (2014) identified two forms of very low carbohydrate diets. The first category of very low carbohydrate diet consists of high fat variant (high fat and protein contents). The second category is referred to as high protein variant, which has high protein content with recommended amount of fat contents and therefore not extreme in terms of carbohydrate restriction. These diets remain controversial as means of managing cardiovascular disease and weight management. In fact, researchers have focused on determining their benefits and harmful outcomes relative to healthy balanced diets (Naude et al., 2014). The researchers concluded that there was perhaps little or no variation in weight loss and improvement in cardiovascular risk factors after two years of follow up when obese adults without or without diabetes were subjected to low carbohydrate diets and isoenergetic balanced weight loss diets (Naude et al., 2014).
Diet therapies for cardiovascular disease have also extended to highlight the relationship with the chronic kidney disease (CKD) and its related morbidity. Such conditions are public health problems associated with end stage renal disease. They require effective renal therapies. On this note, it has been observed that cardiovascular disease is a major contributing factor for premature deaths among individuals with CKD, particularly in cases of dialysis-dependent and renal transplant patients (Currie & Delles, 2014). The presence of end stage renal disease is a strong indicator of adverse health outcomes. In most cases, a small percentage of patients with chronic kidney disease may progress to the end stage renal disease, which often requires renal replacement therapy. In such conditions, available evidence has shown that proteinuria (urinary protein excretion) has critical role in all-cause deaths and cardiovascular effects in chronic kidney disease patients and other general patients. While proteinuria has been identified as major risk factor for cardiovascular disease, little evidence exists to show its onset and progression (Currie & Delles, 2014). More often, some studies have shown the link between proteinuria and other significant cardiovascular risk factors as cross-sectional and therefore conclusive results cannot be provided (Currie & Delles, 2014). Nevertheless, interests have been demonstrated by using dietary therapies to manage cardiovascular risk factors in patients with proteinuria. Specifically, interventions concentrate on reducing the levels of proteinuria and changes in other related risk factors such as obesity, diabetes, smoking, blood pressure and lipid saturation (Currie & Delles, 2014). Results had shown that diet changes in patients with renal disease also required controls of blood pressure. While diet therapy is recommended to control the condition as well as related cardiovascular disease, concerns have been raised because of the delicate management between good healthy diets and reduction of protein to control proteinuria in patients. While a good protein diet may be restricted to 1.0 g/kg/day in the later stages of a renal disease, in some instances, diet therapies may be indigestible and adherence among patients may vary. Further, sodium intake is restricted to slow down the progress of cardiovascular risks in patients with chronic kidney disease. Currently, there are no clear dietary guidelines on sodium consumption for individuals with proteinuria, but available findings have demonstrated that dietary sodium therapy can improve the outcome of “renin-angiotensin-aldosterone system (RAAS) agents in limiting urinary protein excretion” (Currie & Delles, 2014). On this note, it is necessary to provide a dietetic therapy for individuals with cardiovascular disease, chronic kidney disease and proteinuria, as well as to develop guidelines to facilitate diet changes in patients.
Heart failure is also a contributing factor for cardiac output. Dietary sodium therapy is perhaps the most effective way to enhance self-care behaviours and generally encouraged for patients with heart failure (Colin-Ramirez et al., 2015). In this regard, all heart failure guidelines have recommended dietary restriction of sodium intakes. High sodium rich diets are normally related to fluid retention in the body. Heart failure affects cardiac activities, increased systemic venous pressure or block blood away from the kidney. All these outcomes may negatively affect renal functions and as a result, trigger nervous system and the RAAS, and then develop a constant cycle of sodium and water retention irrespective of fluid already presence in the body.
Diet therapies also include a Mediterranean diet to control cardiovascular disease (Yang, Farioli, Korre, & Kales, 2014). The Mediterranean diet consists of the same feeding habits conventionally adhered to by natives along the Mediterranean Sea. The diet usually is associated with high intake of “fruits, olive oil, cereals, vegetables, nuts, non-refined breads, legumes and potatoes” (Yang et al., 2014). In addition, the diet encourages modest consumption of fish and poultry; low consumption of dairy products, meat, processed meat, red meat and sweets; and restricted consumption of wine with food (Yang et al., 2014). According to Yang et al. (2014), many studies have evaluated Mediterranean diet adherence using a scoring rubric and they have found contrary links with cardiovascular disease morbidity and mortality. However, such studies had focused on older adults or individuals with existing health problems among Mediterranean people. While little was known about the efficacy of a Mediterranean diet on young working individuals outside non-Mediterranean regions, a study by Yang et al. (2014) showed that young and active adults who greatly observed the diet requirements experienced reduced cases of metabolic syndrome and other chronic conditions. The authors concluded that Mediterranean diet was effective for the subjects and therefore further studies were required to justify the use of the diet among young, working populations (Yang et al., 2014).
In fact, studies on Mediterranean subjects, adults or others with existing health conditions have indicated that individuals who greatly adhered to the diet had lower risk for developing cardiovascular morbidity or mortality (Yang et al., 2014). In addition, diets included changes to lifestyles, which were associated with reduced cases of cardiovascular disease risk. The Mediterranean diet has, over the time, been linked to improved “health status, low cases of all-cause mortality and protective/ameliorative effects on chronic diseases” (Yang et al., 2014). Mediterranean diet was therefore found to be beneficial to individuals with cardiovascular risks factors such as “hypertension, obesity, diabetes and other metabolic conditions in addition to risks of cardiovascular related morbidity and mortality” (Yang et al., 2014).
Diets rich carotenoids have also been suggested to manage cardiovascular disease. Carotenoids consist of a group of natural, fat-soluble elements found primarily in certain plants. Carotenoids have antioxidants biological properties due to their chemical composition and association with biological membranes (Gammone, Riccioni, & D’Orazio, 2015). Some studies have acknowledged the use of antioxidants as affordable ways for both major and secondary interventions for cardiovascular disease. Specifically, it has been demonstrated that the oxidation of “low-density lipoproteins (LDL) in the vessels has a critical influence in the formation of atherosclerotic lesions” (Gammone et al., 2015). LDLs are resistance to oxidation and are enhanced by diets rich in antioxidant foods. Carotenoids, which are constituents of the Mediterranean diet, provide beneficial outcomes to individuals with cardiovascular disease. Other properties of carotenoids that could possible result in reduction of cardiovascular risk are mainly associated with reduced blood pressure, reducing the levels of cytokines responsible for inflammation and their markers and improving insulin sensitivity in muscles, liver and in other parts of the body organs (Gammone et al., 2015).
In conclusion, diet therapy exists to manage various health risks, including cardiovascular disease. Based on nutritionists’ views recommended balanced diet should have the right amount of nutrients to enhance health, sustain the right body weight and prevent non-communicable diseases in healthy individuals. Some diet therapies are effective, but others could be extremely harmful or their side effects or benefits remain unknown. Such dietetic therapy restricts intake of certain foods such as protein, carbohydrate, and nutrients such as sodium. This situation leads to poor consumption of the necessary nutrient constituents and as a result, dieticians have expressed their concerns about certain diet therapies because of their potential side effects. Other conditions such as obesity and hyperkalemia are linked to cardiovascular disease and therefore diet therapies meant for such conditions have effects on cardiovascular disease management.
References
Colin-Ramirez, E., McAlister, F., Zheng, Y., Sharma, S., Armstrong, P. W., & Ezekowitz, J. A. (2015). The long-term effects of dietary sodium restriction on clinical outcomes in patients with heart failure. American Heart Journal, 169(2), 274- 281.e1.
Currie, G., & Delles, C. (2014). Proteinuria and its relation to cardiovascular disease. International Journal of Nephrology and Renovascular Disease, 7, 13–24.
Gammone, M. A., Riccioni, G., & D’Orazio, N. (2015). Carotenoids: potential allies of cardiovascular health? Food Nutrition Research, 59.
Hu, T., & Bazzano, L. A. (2014). The low-carbohydrate diet and cardiovascular risk factors: Evidence from epidemiologic studies. Nutrition Metabolism and Cardiovascular Diseases, 24(4), 337–343.
Naude, C. E., Schoonees, A., Senekal, M., Young, T., Garner, P., & Volmink, J. (2014). Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis. PLoS One, 9(7), e100652.
Packham, D. K., Rasmussen, H. S., Lavin, P. T., El-Shahawy, M. A., Roger, S. D., Block, G.,… Singh, B. (2015). Sodium Zirconium Cyclosilicate in Hyperkalemia. New England Journal of Medicine, 372, 222-231.
Paoli, A. (2014). Ketogenic Diet for Obesity: Friend or Foe? International Journal of Environmental Research and Public Health, 11(2), 2092–2107.
Roth, G. A., Forouzanfar, M. H., Moran, A. E., Barber, R., Nguyen, G., Feigin, V. L., … Murray, C. J.L. (2015). Demographic and Epidemiologic Drivers of Global Cardiovascular Mortality. New England Journal of Medicine, 372, 1333-1341.
Yang, J., Farioli, A., Korre, M., & Kales, S. N. (2014). Modified Mediterranean Diet Score and Cardiovascular Risk in a North American Working Population. PLoS One, 9(2), e87539.