Ever heard of the portfolio diet? It may lower risk for heart disease and stroke

A lesser-known dietary pattern called the portfolio diet may lower the risk for heart disease and stroke, new research shows.

The portfolio diet is designed to lower "bad" LDL cholesterol, a leading risk factor for cardiovascular disease. It includes a select "portfolio" of plant-based proteins such as soy and other legumes; foods with viscous fiber such as oats, barley, berries, apples and citrus fruit; nuts and seeds; phytosterols that reduce cholesterol absorption through fortified foods or supplements; and avocado and healthy plant-based oils high in monounsaturated fat.

"Through this research, we found that the portfolio diet score was consistently associated with a lower risk of both heart disease and stroke, highlighting an opportunity for people to lower their heart disease risk through consuming more of these foods recommended in the diet," the study's lead author, Dr. Andrea Glenn, said. Glenn is a registered dietitian and postdoctoral fellow at the Harvard T.H. Chan School of Public Health in Boston and the University of Toronto.

Previous research has shown the portfolio diet can lower LDL cholesterol as much as an early-generation statin. But little was known about how following the diet over a prolonged period of time might affect cardiovascular disease risk.

To find out, researchers looked at the diet data of 166,270 women and 43,970 men enrolled in long-term health studies who did not have cardiovascular disease when they enrolled in the mid-1980s and early 1990s. They answered food questionnaires every four years.

Researchers used the portfolio diet score to rank the participants' consumption of plant proteins, nuts and seeds, viscous fiber, phytosterols and plant sources of monounsaturated fatty acids. After up to 30 years of follow-up, those with the highest portfolio diet score had a 14% lower risk of coronary heart disease and stroke compared to those with the lowest score. The findings were published Wednesday in the American Heart Association journal Circulation.

"We're always looking at ways to reduce the risk of heart disease, and one effective way to do that is to lower blood cholesterol levels, particularly LDL cholesterol," said Dr. Kristina Petersen, an associate professor of nutritional sciences at Penn State in University Park, Pennsylvania.

Petersen, who was not involved in the research, is well-versed in how diets can affect heart health. She co-authored an AHA scientific statement published in April that scored 10 popular diets for their heart-health benefits. The Dietary Approaches to Stop Hypertension – or DASH – diet was the only eating pattern to get a perfect score, with the Mediterranean and pescetarian diets rounding out the top three. The portfolio diet was excluded from the assessment "because it's not particularly common," she said.

The portfolio diet may not be as well known as the DASH and Mediterranean diets, but there are significant overlaps, Glenn said. They all emphasize eating whole grains, fruits, vegetables, plant protein, nuts and plant oils. But the portfolio diet, she said, is more "plant forward" and discourages animal proteins more than other dietary patterns.

For those who want to follow a vegan or vegetarian diet that offers heart-health benefits, Petersen believes the portfolio diet is a good choice.

Given the low public awareness of the portfolio diet, Glenn said she hopes the new findings help boost its profile.

"It's not an all-or-nothing approach. You can take your own diet and make a few small changes and see cardiovascular benefits," she said. "You also do not have to follow it as a strict vegan or vegetarian diet to see benefits, but the more of the foods (from the portfolio diet) that you eat, the greater your heart disease risk protection, as we saw in the current study. We need to get the word out."