Cardiovascular disease

Background

Cardiovascular disease (CVD) is one of Australia and Aotearoa New Zealand’s largest health problems. According to the Australian Bureau of Statistics, the prevalence of CVD is one in twenty across the entire population or 1.2 million people in 2017-18.[1] In the older population of seventy-five years and above the prevalence is now one in four. Currently, one in four deaths in Australia is caused by CVD each year. For men it is the number one cause of death while for women it is number two, just after dementia.[2] Aotearoa New Zealand follows a similar pattern, the leading cause of death is heart, stroke and blood vessel disease.[3]

CVD has a disproportionate impact on our Indigenous populations; total cardiovascular disease mortality rate among Māori was more than twice as high as that among non-Māori.[4] In Australia, Indigenous adults had a higher rate of CVD than non-Indigenous adults (27% and 21%, respectively).[5]

Consideration must be given to the fact that these numbers don’t show the burden of this disease (Figure 1) on the individual and their loved ones.

CVD Burden of Disease
Figure 1. Cardiovascular Disease and the Burden of Disease. Source: American Heart Association

Pathological processes

The atherosclerotic process includes injury to arterial endothelium, fatty streaks due to macrophage ingestion of oxidized low-density lipoprotein (LDL) cholesterol at the damaged site, platelet aggregation, and fibrosis. These events contribute to plaque formation in the intimal layer of medium and large sized arteries. Progressive arterial narrowing causes ischemia (supply-demand mismatch), which occurs initially with exertion but may eventually occur at rest. Atherosclerosis commonly begins in early childhood [6] (perhaps even during fetal development in some cases [7] and is increased by maternal hypercholesterolemia [8]) and slowly progresses throughout life. Rapid progression may occur by the third decade of life.

Nutritional considerations

Dietary factors are central to the CVD pathogenesis, and diet changes are integral to its prevention, treatment and potential reversal.

Reversal of heart disease
Dietary interventions have been found to be highly protective of heart health, offering significant protection against heart disease.[9] In 1990 Dr Dean Ornish published his landmark randomised controlled study showing the reversal of heart disease with lifestyle interventions including a low fat healthy plant-based diet, moderate exercise, stress reduction and social support. Forty-eight men and women with moderate to severe coronary artery disease were randomised into either the intensive lifestyle changes group or to usual care. Among the intervention group there was a 40% reduction in LDL-cholesterol in the first year without cholesterol lowering drugs. After one year the mean percentage of coronary artery diameter stenosis significantly improved in the intervention group and worsened in the control group (p=0.02); after 5 years of follow up the difference had increased further (p=0.001) (Figure 2).[10,11]

Percentage diameter stenosis
Figure 2. Mean percentage diameter stenosis in treatment and control groups at baseline, 1 year, and 5 years. Source: Ornish D, et al. JAMA. 1998
Effect of single high fat meal
Figure 3. Effect of a single high-fat meal on endothelial function in healthy subjects. Source: Vogel RA, et al. Am J Cardiol. 1997

These findings were supported by a large longitudinal case-series of 198 consecutive CVD patients who voluntarily asked for dietary treatment, which was a low-fat whole food plant-based diet only with no other lifestyle changes as an adjunct to usual cardiovascular care. The mean follow-up was 3.7 years with an 83% adherence; of this group only one patient experienced a major cardiac event (0.6%) suggesting recurrence of the disease. Of the non-adherent participants (21), 62% experienced an adverse event.[12]

A healthy plant-based diet and endothelial function
Flow-mediated brachial artery vasoactivity is an indicator for endothelial health. Endothelial function is significantly impaired 2, 3 and 4 hours after ingestion of a high fat meal (p<0.05) (Figure 3).[13]

Primary goals of dietary interventions

The following information is kindly reproduced with the permission of Dr Neal Barnard, Physicians Committee For Responsible Medicine.[15] Dr Barnard is an International Advisor for Doctors For Nutrition.

Controlling blood lipid concentrations
Saturated fats, trans fats, and cholesterol in the diet increase concentrations of blood lipids, particularly LDL cholesterol, while soluble fiber tends to reduce them. Controlling blood lipoprotein concentrations with a combination of diet, exercise, and medication, if necessary, is a cornerstone of treatment for most coronary heart disease (CHD) patients. The Lifestyle Heart Trial conducted by Dr. Ornish resulted in a 37% reduction in LDL cholesterol with a vegetarian diet that focused on fruits, vegetables, soy, and no vegetable oils. Non-fat milk and yogurt were allowed, and total fat intake was less than 10% of the total calories.[16] These results are significantly more dramatic than the 5% LDL reduction from the AHA diet.[17] This diet does advocate for an increase in vegetables, fruit, and whole grains; however, the diet allows small amounts of cholesterol and saturated fat from animal products, which most likely moderates the cholesterol-lowering effects.

Reducing blood pressure
Hypertension is a major risk factor for CVD. The same dietary and lifestyle changes that reduce total and LDL cholesterol can also significantly reduce blood pressure and lower the risk of a cardiac event.

Controlling blood sugar levels
CVD is a leading cause of death for people with diabetes. Dietary interventions can increase insulin sensitivity for individuals with type 2 diabetes and improve blood glucose control for individuals with type 1 or type 2 diabetes.

Improving antioxidant status and endothelial function
Dietary antioxidants, folate, magnesium, and other substances in foods may reduce the burden of oxidized LDL and improve endothelial function through increased availability of nitric oxide.

Reducing inflammation
The role of inflammatory processes in atherosclerosis is increasingly apparent. Loss of excess body fat reduces CRP, an indicator of inflammation.[18]

The following dietary steps help patients in achieving these goals:

Avoiding animal-derived food products
Dairy products, meat, and eggs are the primary sources of saturated fat and cholesterol. Following diets low in saturated fat and cholesterol can help reduce progression of atherosclerosis.[19]

Low-fat, plant-based (vegetarian and vegan) regimens are significantly effective in reducing LDL cholesterol by approximately 15-30%.[20],[21],[22] Such regimens have also been shown to reduce body weight and blood pressure, and to be useful in programs for reversing atherosclerosis.

Low-fat plant-based diets are also highly acceptable to patients, provided they are prescribed along with basic diet instruction and support.[23] Combining daily aerobic exercise with a healthful diet adds to its benefit, particularly with regard to weight and blood glucose control.[24]

Avoiding hydrogenated and partially hydrogenated oils
These products contain trans fats that increase LDL cholesterol and can reduce HDL cholesterol.[25],[26],[27] Trans fatty acids also have pro-inflammatory effects similar to those of saturated fat and adversely affect vascular reactivity, reducing arterial flow-mediated dilation (a direct measure of vascular endothelial function).[28]

Increasing fibre-containing whole plant foods
Soluble fibre, as is found in oats, barley, and beans, is particularly cardioprotective. Fruits and vegetables are also sources of soluble dietary fibre and pectin, and are associated with reduced atherosclerotic progression.[29] Most Australians do not consume adequate fibre, but large studies have shown that individuals following plant-based diets typically have fibre intakes that meet or exceed recommendations.[30],[31]

Consuming soy and legumes
In addition to reducing blood lipids, soy has cardioprotective effects, such as lowering oxidized LDL and blood pressure. Other legumes have also lowered total and LDL cholesterol in randomized controlled trials.[34]

Clinical trials have combined these dietary lipid-lowering strategies. A vegetarian diet emphasizing specific cholesterol-lowering foods appears to be particularly effective, lowering LDL cholesterol concentration by 33%+4%, P< .001 in 2 weeks, an effect similar to that of statin drugs. In addition to excluding animal products, subjects consumed at least 600 g (equivalent to 4 cups) of green leafy vegetables (cabbage, bok choy, chard, spinach, Brussels sprouts, leeks, broccoli, and cauliflower), 500 grams (2 1/2 cups) peas, sweet yellow corn, and eggplant, and 60-120 grams of peanuts, almonds, cashews, or avocado (1/2-3/4 cup) per day. The vegetables were steamed or boiled. The diet included soy milk and fruit, and the bulk of starch came from peas and corn. Reductions in cholesterol appeared to correlate with soluble fibre and vegetable protein intake. Diet analysis reported the subjects consumed 72g of vegetable protein and 64g of fibre (18g soluble, 45g insoluble) per day.[35]

Increasing fruits and vegetables
Fruits and vegetables can help reduce atherosclerosis and lower risk for CVD, particularly if the diet is low in saturated fat.[36] The benefits of these foods go beyond the absence of cholesterol, very little saturated fat, and abundant fibre; among their active components are vitamin C, antioxidant flavonoids, and folic acid.[37],[38],[39]

Several studies have shown that higher dietary intakes of carotenoid-containing fruits and vegetables are associated with a decreased risk of coronary artery disease.[40] Others have found an inverse relationship between lower blood levels of carotenoids and higher risk for cardiovascular events.[41]

In addition to the above considerations, evidence suggests that other dietary factors may be helpful, as described below:

In epidemiological studies, whole grain consumption is associated with a lower risk of heart disease, as is frequent consumption of nuts.[42],[43] In addition to providing the lipid-lowering benefit of dietary fibre, these foods provide magnesium and vitamin E, both of which are inversely related to CVD occurrence or mortality.[44],[45] Nuts are high in fat and calories, however, and may influence body weight.

A note on fish, fish oil, and omega-3 supplements
Although some studies have suggested that omega-3 polyunsaturated fatty acids in fish reduce the incidence of heart disease, the overall evidence does not support the addition of fish or omega-3 supplements to an otherwise plant-focused diet to reduce cardiovascular disease risk.[46],[47],[48],[49],[50],[51]


Medical supervision of diet change is essential

Shifting to a low fat plant-based diet can lead to rapid reductions in medication needs; people who are on medications for high blood pressure especially should seek medical supervision.


Further resources

PCRM logo

Physician’s Committee for Responsible Medicine: Heart Disease overview, news and resources.

FAQs

Both Dr Ornish and Dr Esselstyn’s patients required a whole food plant-based eating pattern that was very low in fat. This is believed to be because fat, even from plant-based sources, can increase cholesterol levels and impair the function of the endothelial cells that line our blood vessels. Both doctors recommend people with established heart disease avoid high-fat plant-foods, especially oils, but also coconut, avocado, and nuts and seeds and products incorporating these ingredients.

For this reason it is essential that anyone with established heart disease or strong risk factors refer to either Dr Ornish or Dr Esselstyn’s books:

and/or consult a credentialed plant-based doctor, dietitian, or nutritionist to ensure the appropriate prescription.

Although Dr Ornish and Dr Esselstyn’s research has focussed on coronary artery disease, the vast majority of strokes are caused by a similar mechanism and can be thought of as ‘brain attacks’, involving disruption of the supply of blood from the arteries that supply the brain. For this reason it is certain that risk of stroke will be similarly reduced. High blood pressure is also a major risk factor for both types of stroke and is very effectively treated by the Ornish and Esselstyn regimens.

Once again the mechanism of peripheral vascular disease, and even erectile dysfunction is the same, involving narrowing and/or occlusion of the arteries that supply the relevant part of the body. Patients who have undertaken Dr Ornish and Dr Esselstyn’s regimens report rapid improvements and resolution in symptoms of both of these conditions also.

  1. Australian Bureau of Statistics. Heart, stroke and cardiovascular disease. https://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.001~2017-18~Main%20Features~Heart,%20stroke%20and%20vascular%20disease~55 December 12, 2018
  2. Australian Bureau of Statistics. Causes of death Australia. https://www.abs.gov.au/ausstats/abs@.nsf/mf/3303.0. September 25, 2019
  3. Ministry of Health NZ. Mortality 2017 Data Tables (Provisional) https://www.health.govt.nz/publication/mortality-2017-data-tables August 2019
  4. Ministry of Health NZ. Cardiovascular disease. https://www.health.govt.nz/our-work/populations/maori-health/tatau-kahukura-maori-health-statistics/nga-mana-hauora-tutohu-health-status-indicators/cardiovascular-disease. August 2018
  5. Australian Institute of Health and Welfare. Cardiovascular disease, diabetes and chronic kidney disease—Australian facts: Aboriginal and Torres Strait Islander people 2015, 2015
  6. Zieske AW, Malcom GT, Strong JP. Natural history and risk factors of atherosclerosis in children and youth: the PDAY study. Pediatr Pathol Mol Med. 2002;21(2):213-37.  [PMID:11942537]
  7. Skilton MR. Intrauterine risk factors for precocious atherosclerosis. Pediatrics. 2008;121(3):570-4.  [PMID:18310207]
  8. C Napoli, F P D’Armiento, F P Mancini, A Postiglione, J L Witztum, G Palumbo, W Palinski. Fatty streak formation occurs in human fetal aortas and is greatly enhanced by maternal hypercholesterolemia. Intimal accumulation of low density lipoprotein and its oxidation precede monocyte recruitment into early atherosclerotic lesions. J Clin Invest. 1997 Dec 1;100(11):2680-90. doi:10.1172/jci119813.
  9. Hyunju K, Caulfield LE, et al. Plant-Based Diets Are Associated With a Lower Risk of Incident Cardiovascular Disease, Cardiovascular Disease Mortality, and All-Cause Mortality. Journal of the American Heart Association. 2019;8:eO12865. doi:10.1161/JAHA.119.012865.
  10. Ornish D, Brown SE. Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial. Lancet 1990; 129-33. https://doi.org/10.1016/0140-6736(90)91656-u.
  11. Ornish D, et al. Intensive lifestyle changes for Reversal of Coronary Heart Disease  Five-year follow-up of the Lifestyle Heart Trial. JAMA.1998;280(23):2. doi:10.1001/jama.280.23.2001.
  12. Esselstyn Jr CB et al. A way to reverse CAD? The Journal of Family Practice. 2014; vol 63, 7: 356-364. https://pubmed.ncbi.nlm.nih.gov/25198208/.
  13. R A Vogel, M C Corretti, G D Plotnick. Effect of a single high-fat meal on endothelial function in healthy subjects. Am J Cardiol. 1997 Feb 1;79(3):350-4. doi:10.1016/s0002-9149(96)00760-6.
  14. Physicians Committee for Responsible Medicine website. https://p.widencdn.net/ktho8u/Power-Plate-Brochure. Accessed January 24, 2020
  15. Barnard, Neal D., editor. “Coronary Heart Disease .” Nutrition Guide for Clinicians, 3rd ed., Physicians Committee for Responsible Medicine, 2022. nutritionguide.pcrm.org/nutritionguide/view/Nutrition_Guide_for_Clinicians/1342017/all/Coronary_Heart_Disease
  16. Ornish D, Brown SE, Scherwitz LW, et al. Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial. Lancet. 1990;336(8708):129-33.  [PMID:1973470]
  17. Hunninghake DB, Stein EA, Dujovne CA, et al. The efficacy of intensive dietary therapy alone or combined with lovastatin in outpatients with hypercholesterolemia. N Engl J Med. 1993;328(17):1213-9.  [PMID:8464431]
  18. Clifton PM, Keogh JB, Foster PR, Noakes M. Effect of weight loss on inflammatory and endothelial markers and FMD using two low-fat diets. Int J Obes (Lond) . 2005;29:1445-1451.
  19. Bemelmans WJ, Lefrandt JD, Feskens EJ, et al. Change in saturated fat intake is associated with progression of carotid and femoral intima-media thickness, and with levels of soluble intercellular adhesion molecule-1. Atherosclerosis. 2002;163(1):113-20.  [PMID:12048128]
  20. Ornish D, Scherwitz LW, Billings JH, et al. Intensive lifestyle changes for reversal of coronary heart disease. JAMA. 1998;280(23):2001-7.  [PMID:9863851]
  21. Esselstyn CB. Updating a 12-year experience with arrest and reversal therapy for coronary heart disease (an overdue requiem for palliative cardiology). Am J Cardiol. 1999;84(3):339-41, A8.  [PMID:10496449]
  22. Barnard ND, Scialli AR, Bertron P, et al. Effectiveness of a low-fat vegetarian diet in altering serum lipids in healthy premenopausal women. Am J Cardiol. 2000;85(8):969-72.  [PMID:10760336]
  23. Barnard ND, Scialli AR, Turner-McGrievy G, et al. Acceptability of a low-fat vegan diet compares favorably to a step II diet in a randomized, controlled trial. J Cardiopulm Rehabil. 2004;24(4):229-35.  [PMID:15286527]
  24. Roberts CK, Won D, Pruthi S, et al. Effect of a short-term diet and exercise intervention on oxidative stress, inflammation, MMP-9, and monocyte chemotactic activity in men with metabolic syndrome factors. J Appl Physiol (1985) . 2006;100:1657-1665.
  25. Dyerberg J, Christensen JH, Eskesen D, et al. Trans, and n-3 polyunsaturated fatty acids and vascular function-a yin yang situation? Atheroscler Suppl. 2006;7(2):33-5.  [PMID:16713391]
  26. Ascherio A, Willett WC. Health effects of trans fatty acids. Am J Clin Nutr. 1997;66(4 Suppl):1006S-1010S.  [PMID:9322581]
  27. Brouwer IA, Wanders AJ, Katan MB. Effect of animal and industrial trans fatty acids on HDL and LDL cholesterol levels in humans–a quantitative review. PLoS ONE. 2010;5(3):e9434.  [PMID:20209147]
  28. Mozaffarian D. Trans fatty acids – effects on systemic inflammation and endothelial function. Atheroscler Suppl. 2006;7(2):29-32.  [PMID:16713393]
  29. Wu H, Dwyer KM, Fan Z, et al. Dietary fiber and progression of atherosclerosis: the Los Angeles Atherosclerosis Study. Am J Clin Nutr. 2003;78(6):1085-91.  [PMID:14668268]
  30. Clemens R, Kranz S, Mobley AR, et al. Filling America’s fiber intake gap: summary of a roundtable to probe realistic solutions with a focus on grain-based foods. J Nutr. 2012;142(7):1390S-401S.  [PMID:22649260]
  31. Rizzo NS, Jaceldo-Siegl K, Sabate J, et al. Nutrient profiles of vegetarian and nonvegetarian dietary patterns. J Acad Nutr Diet. 2013;113(12):1610-9.  [PMID:23988511]
  32. Zhang X, Shu XO, Gao YT, et al. Soy food consumption is associated with lower risk of coronary heart disease in Chinese women. J Nutr. 2003;133(9):2874-8.  [PMID:12949380]
  33. Jenkins DJ, Kendall CW, Marchie A, et al. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. JAMA. 2003;290(4):502-10.  [PMID:12876093]
  34. Bazzano LA, Thompson AM, Tees MT, et al. Non-soy legume consumption lowers cholesterol levels: a meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2011;21(2):94-103.  [PMID:19939654]
  35. Jenkins DJ, Popovich DG, Kendall CW, et al. Effect of a diet high in vegetables, fruit, and nuts on serum lipids. Metab Clin Exp. 1997;46(5):530-7.  [PMID:9160820]
  36. Tucker KL, Hallfrisch J, Qiao N, et al. The combination of high fruit and vegetable and low saturated fat intakes is more protective against mortality in aging men than is either alone: the Baltimore Longitudinal Study of Aging. J Nutr. 2005;135(3):556-61.  [PMID:15735093]
  37. Joshipura KJ, Hu FB, Manson JE, et al. The effect of fruit and vegetable intake on risk for coronary heart disease. Ann Intern Med. 2001;134(12):1106-14.  [PMID:11412050]
  38. Hirvonen T, Pietinen P, Virtanen M, et al. Intake of flavonols and flavones and risk of coronary heart disease in male smokers. Epidemiology. 2001;12(1):62-7.  [PMID:11138821]
  39. Voutilainen S, Rissanen TH, Virtanen J, et al. Low dietary folate intake is associated with an excess incidence of acute coronary events: The Kuopio Ischemic Heart Disease Risk Factor Study. Circulation. 2001;103(22):2674-80.  [PMID:11390336]
  40. Osganian SK, Stampfer MJ, Rimm E, et al. Dietary carotenoids and risk of coronary artery disease in women. Am J Clin Nutr. 2003;77(6):1390-9.  [PMID:12791615]
  41. Rissanen TH, Voutilainen S, Nyyssönen K, et al. Low serum lycopene concentration is associated with an excess incidence of acute coronary events and stroke: the Kuopio Ischaemic Heart Disease Risk Factor Study. Br J Nutr. 2001;85(6):749-54.  [PMID:11430780]
  42. Mozaffarian D, Kumanyika SK, Lemaitre RN, et al. Cereal, fruit, and vegetable fiber intake and the risk of cardiovascular disease in elderly individuals. JAMA. 2003;289(13):1659-66.  [PMID:12672734]
  43. Ellsworth JL, Kushi LH, Folsom AR. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutr Metab Cardiovasc Dis. 2001;11(6):372-7.  [PMID:12055701]
  44. Al-Delaimy WK, Rimm EB, Willett WC, et al. Magnesium intake and risk of coronary heart disease among men. J Am Coll Nutr. 2004;23(1):63-70.  [PMID:14963055]
  45. Kushi LH, Folsom AR, Prineas RJ, et al. Dietary antioxidant vitamins and death from coronary heart disease in postmenopausal women. N Engl J Med. 1996;334(18):1156-62.  [PMID:8602181]
  46. Nestel P, Clifton P, Colquhoun D, et al. Indications for omega-3 long chain polyunsaturated fatty acid in the prevention and treatment of cardiovascular disease. Heart, Lung and Circ . 2015;24:769-779.
  47. Endo J, Arita M. Cardioprotective mechanism of omega-3 polyunsaturated fatty acids. J Cardiol. 2016;67(1):22-7.  [PMID:26359712]
  48. Mangat I. Do vegetarians have to eat fish for optimal cardiovascular protection? Am J Clin Nutr. 2009;89(5):1597S-1601S.  [PMID:19321560]
  49. Sanders TA. Plant compared with marine n-3 fatty acid effects on cardiovascular risk factors and outcomes: what is the verdict? Am J Clin Nutr. 2014;100 Suppl 1:453S-8S.  [PMID:24898234]
  50. Smith DA. ACP Journal Club. Review: omega-3 polyunsaturated fatty acid supplements do not reduce major cardiovascular events in adults. Ann Intern Med. 2012;157(12):JC6-5.  [PMID:23247954]
  51. Rizos EC, Ntzani EE, Bika E, et al. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. JAMA. 2012;308(10):1024-33.  [PMID:22968891]

Return to menu of health conditions.