Fortifying the plant-based diet for heart health

Naji M. Hamdan, M.D.
Cardiologist, Providence Heart and Vascular Institute
Terese Scollard, MBA, RD, LD
Regional clinical nutrition manager, Providence Health & Services

Published June 2012

There has been extensive publicity recently about plant-based diets. In an interview on CNN, former President Bill Clinton talked about his conversion to a plant-based diet to improve his heart health. Popular books, such as “The China Study” and “Skinny Bitch,” and the documentary “Food, Inc.” have increased awareness and curiosity about the subject.

Today, an estimated 7.3 million Americans now follow some sort of plant-based diet. These diets come in many forms, ranging from vegan (no meat, eggs or dairy products) to lacto-vegetarian (dairy products are allowed) to what we consider just vegetarian (eggs and dairy are allowed).

Advocates say that plant-based diets can prevent or reverse heart disease, diabetes, cancer and obesity. Researchers, however, don’t yet know if the heart benefits are derived from the diet or some other factor related to a healthy lifestyle.

Medical research on the cardiovascular benefits of a plant-based diet is limited, but we do know that people following a plant-based diet are at lower risk for hypertension and ischemic heart disease. A study published in 2011 found that participants who ate a plant-based diet low in saturated fats and rich in vegetables, fruits, grains, nuts and soy proteins reduced their LDL cholesterol more than those who merely cut back on fat.

Although we’re familiar with nutritional benefits of a balanced diet, including one that contains meat, it’s less clear what makes for an optimal plant-based diet. Physicians treating vegans, lacto-vegetarians and ovo-lacto vegetarians should consider the following:

  • The key nutrients at risk in a strict plant-based diet are vitamin B-12, calcium, iron, zinc, vitamin D, riboflavin, iodine and long-chain omega-3 fatty acids. This is especially true for older adults, who may have difficulty absorbing vitamin B-12 due to atrophic gastritis, or whose cutaneous vitamin D production has decreased due to aging.

  • Not all vegetarian food substitutes are fortified with proper nutrients, so patients should read food labels and choose fortified products over non-fortified.

  • Long-term vegans who are low in vitamin B-12 may be unaware of this because their diets are rich in folacin, which can mask the symptoms of a vitamin B-12 deficiency. Vegan diets should include B-12 supplements or B-12-fortified foods.

  • Protein needs may be higher than the recommended dietary allowance if the person is consuming hard-to-digest protein sources, such as legumes.

  • Finally, make sure that the patient’s plant-based diet isn’t hiding an eating disorder. Becoming a vegan or a vegetarian can be a socially acceptable excuse to limit food intake.

Nutritional counseling from a registered dietitian at Providence can benefit patients, particularly those who have diabetes, hyperlipidemia or renal disease, or who are older or pregnant.

For patients who are questioning whether to switch to a plant-based diet, it’s important to stress that a diet containing the traditional four food groups – even moderate portions of meat, fish and poultry – can improve long-term heart health more than an overly restrictive diet.