Open Letter to Editor, JACC

Open Letter To the Editor-in-Chief, Journal of the American College of Cardiology

October 27, 2017

 

Dear Dr. Fuster,

In your recent update to the Expert Consensus Decision Pathway, (1) no specific mention was made of a safe and efficacious non-statin therapy, the plant-based diet.

Vegetarian and vegan diets can be very efficacious in reducing serum cholesterol and, importantly, LDL. Studies have shown that those following a plant-based diet have significantly lower total cholesterol and LDL levels. (2)

One study showed that a low-fat vegetarian diet was as effective at lowering cholesterol levels as the Standard Heart Association diet combined with Lovostatin. (3)  Studies of vegetarians also suggest that plant-based diets reduce the overall risk of coronary disease events by an estimated 40%. (4)

A prospective randomized trial of children and their adult parents found that a plant-based, or vegan, diet reduced total cholesterol, LDL cholesterol and hs-CRP levels by more than the American Heart Association diet. (5)  This study is especially important given the recent increase in the incidence of hypercholesterolemia in children, and the fact that atherosclerosis seems to start early in life.

Epidemiological research also points to the lower total cholesterol and LDL cholesterol levels in those already following plant-based diet. One study showed that vegans had on average a total cholesterol of only 142 mg/dl and an LDL cholesterol of only 69 mg/dl. (6) Other studies have also shown a much lower than average level of total cholesterol and LDL. (7, 8)

The physician will already be aware of the role of saturated fats in hypercholestrolemia. More controversial lately has been the role of dietary cholesterol. When the baseline of cholesterol intake is zero or low, a significant rise in serum cholesterol results from increases in dietary cholesterol. This effect become less pronounced as the baseline dietary cholesterol intake increases, (9) which helps explain why there has been conflicting results from research.

Another important effect of dietary cholesterol is that it increases the amount of LDL relative to HDL resulting in a more atherogenic ratio. (10)

A newer area of research has focused on the role of the gut microbiota in the pathogenesis of atherosclerosis. It has been found that vegetarians and vegans have bacterial flora that produce less trimethylamine-N-oxide (TMAO), thought to be atherogenic, than the flora of meat eaters. (11)

One study found that microbial metabolism of dietary l-carnitine, a trimethylamine found in red meat, produces TMAO, which has been shown to promote atherosclerosis. (12, 13) Through a separate mechanism, the choline found in egg yolks promotes the production of TMAO in a dose-response manner. (14)

A prime goal of lowering LDL cholesterol is to prevent and treat coronary artery disease. As early as 1960 researchers investigated using a very low-fat vegan or nearly vegan diet to treat CAD of varying severity, and achieved very positive results. (15)

More recently in 1990, a prospective, randomized, controlled trial showed that a vegetarian, nearly vegan, diet resulted in a modest regression in coronary artery stenosis in most patients, greatly reduced angina symptoms, and on average a 40% reduction in serum LDL. (16, 17) Follow up after 5 years showed continued reduction in stenosis. (17)

A smaller study showed that patients, treated with a low-fat vegan diet and followed for 5 years, maintained a modest reduction in coronary artery stenosis. (18) A larger study showed similar results over a period of almost 4 years. (19)

Research has been accumulating on the value of nuts in the prevention and treatment of a variety of diseases, including cardiovascular disease, indicating that the low-fat regimen now more commonly employed may be enhanced by moderate amounts of tree nuts. (20)

The plant-based diet is a valuable treatment for hypercholesterolemia that integrates well with pharmacotherapy. Doctors should titrate current medications and dosages as patients show improvement on plant-based nutritional medicine. They should reassess clinically relevant factors and lab values frequently after beginning treatment until patient stabilizes. (21)

The statin drugs and the new PCSK9 inhibitors are valuable medications and will remain important in pharmacotherapy. However, other treatments are also safe and efficacious. For some patients, treatment with a plant-based diet alone is sufficient. For other patients, treatment may need to be integrated with either a statin drug or a non statin PCSK9 inhibitor. In these cases, a plant-based diet may reduce the dosage the patient needs, saving the patient and insurer considerable expense.

Most patients are willing to give a vegetarian diet a try once they receive information on its health benefits. The acceptability of a low-fat vegan diet is often high. (22)  Even in rural Appalachia, a vegetarian diet found acceptance by patients when prescribed by their physicians. (23) In one study, cardiac patients had 89% compliance with a plant-based diet over 4 years. (19)

The healthfulness and safety of a plant-based diet has also been confirmed by the Academy of Nutrition and Dietetics, which confirmed its therapeutic value:

“It is the position of the Academy of Nutrition and Dietetics that appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases. These diets are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes… high intakes of vegetables, fruits, whole grains, legumes, soy products, nuts, and seeds (all rich in fiber and phytochemicals) are characteristics of vegetarian and vegan diets that produce lower total and low-density lipoprotein cholesterol levels…Interventional studies point to the safety and efficacy and, indeed, the superiority of plant-based diets over pharmacotherapy for the treatment of hypercholesterolemia and atherosclerosis in many cases…”

The prevention and treatment of hypercholesterolemia with a plant-based diet has been shown to be both safe and efficacious. It has no contraindications, adverse effects, costs nothing, integrates easily with other treatments and reduces the risk of common comorbidities such as type 2 diabetes. The plant-based diet deserves to be explicitly included in the Decision Pathway.

Respectfully,

Amanda Strombom, President, and Stewart Rose, Vice President,

Vegetarians of Washington

 

References

 

1.

Lloyd-Jones D, Morris P, Ballantyne C, et.al. 2017 Focused Update of the 2016 ACC Expert Consensus Decision Pathway on the Role of Non-Statin Therapies for LDL-Cholesterol Lowering in the Management of Atherosclerotic Cardiovascular Disease Risk. Journal of the American College of Cardiology. Oct 2017;70(14):1785-1822.

2.

Li D, Sinclair A, Mann N, et.al. The association of diet and thrombotic risk factors in healthy male vegetarians and meat-eaters. European Journal of Clinical Nutrition. Aug 1999;53(8):612-9.

3.

Jenkins D, Kendall C, Marchie A, et.al. Direct comparison of a dietary portfolio of cholesterol-lowering foods with a statin in hypercholesterolemic participants. American Journal of Clinical Nutrition. Feb 2005;81(2):380-7.

4.

Kwok C, Umar S, Myint P, et.al. Vegetarian diet, Seventh Day Adventists and risk of cardiovascular mortality: a systematic review and meta-analysis. International Journal of Cardiology. Oct 2014;176(3):680-6.

5.

Macknin M, Kong T, Weier A, et.al. Plant-Based, No-Added-Fat or American Heart Association Diets: Impact on Cardiovascular Risk in Obese Children with Hypercholesterolemia and Their Parents. Journal of Pediatrics. Apr 2015;166(4):953-9.

6.

De Biase S, Fernandes S, Gianini R, Duarte J. Vegetarian diet and cholesterol and triglycerides levels. Arquivos Brasileiros de Cardiologia. Jan 2007;88(1):35-9.

7.

Thorogood M, Carter R, Benfield L, et.al. Plasma and lipoprotein cholesterol concentrations in people with different diets in Britain. British Medical Journal (Clin Res Ed). Aug 1987;295(6594):351–353.

8.

Haddad E, Berk LKJ, et.al. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. American Journal of Clinical Nutrition. Sep 1999;70(3 Suppl):586S-593S.

9.

Hopkins P. Effects of dietary cholesterol on serum cholesterol: a meta-analysis and review. American Journal of Clinical Nutrition. Jun 1992;55(6):1060-70.

10.

Weggemans R, Zock P, Katan M. Dietary cholesterol from eggs increases the ratio of total cholesterol to high-density lipoprotein cholesterol in humans: a meta-analysis. American Journal of Clinical Nutrition. May 2001;73(5):885-91.

11.

Glick-Bauer M, Yeh MC. The Health Advantage of a Vegan Diet: Exploring the Gut Microbiota Connection. Nutrients. Oct 2014;6(11):4822-38.

12.

Ussher J, Lopaschuk G, Arduini A. Gut microbiota metabolism of l-carnitine and cardiovascular risk. Atherosclerosis. Dec 2013;231(2):456-61.

13.

Koeth R, Wang Z, Levison B, et.al. Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis. Nature Medicine. May 2013;19(5):576-585.

14.

Miller C, Corbin K, da Costa K, et.al. Effect of egg ingestion on trimethylamine-N-oxide production in humans: a randomized, controlled, dose-response study. American Journal of Clinical Nutrition. Sep 2014;100(3):778–786.

15.

Morrison LM. Diet in Coronary Atherosclerosis. JAMA. Jun 1960;173(8):884-888.

16.

Ornish D, Brown S, Scherwitz L, et.al. Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial. Lancet. Jul 1990;336(8708):129-33.

17.

Ornish D, Scherwitz L, Billings J, et.al. Intensive Lifestyle Changes for Reversal of Coronary Heart Disease. JAMA. 1998;280(23):2001-7.

18.

Esselstyn CJ, Ellis S, Medendorp S, Crowe T. A strategy to arrest and reverse coronary artery disease: a 5-year longitudinal study of a single physician’s practice. Journal of Family Practice. Dec 1995;41(6):560-8.

19.

Esselstyn CJ, Gendy G, Doyle J, et.al. A way to reverse CAD? Journal of Family Practice. Jul 2014;63(7):356-364b.

20.

Aune D, Keum N, Giovannucci E, et.al. Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies. BMC Medicine. Dec 2016;14(1):207.

21.

Tuso P. Nutritional Update for Physicians: Plant-Based Diets. The Permanente Journal. Spring 2013;17(2):61-66.

22.

Lea E, Crawford D, Worsley A. Public views of the benefits and barriers to the consumption of a plant-based diet. European Journal of Clinical Nutrition. Jul 2006;60(7):828-37.

23.

Drozek D, Diehl H, Nakazawa M, et.al. Short-term effectiveness of a lifestyle intervention program for reducing selected chronic disease risk factors in individuals living in rural appalachia: a pilot cohort study. Advances in Preventive Medicine. 2014;2014:798184.