January 19, 2019
Taking Stock of the Portfolio Diet

Taking Stock of the Portfolio Diet

by Wellness Letter  

If you have high cholesterol, one thing you can do is change your diet to see if that lowers your numbers enough so that you don’t need to take medication. And one dietary approach that’s received scientific support over the past 15 years involves not just limiting foods that raise blood cholesterol (notably animal products high in saturated fat), but also adding foods that lower it.

Developed by researchers at the University of Toronto, the Portfolio Diet puts several cholesterol-lowering plant foods and food components together in one meal plan, in the context of a low-saturated-fat diet.

The serving amounts listed below are based on a 2,000-calorie daily diet:

  • Plant protein: 50 grams a day, from soy foods such as tofu, soy milk, and soy meat analogues, plus legumes like beans and lentils.
  • Nuts: 45 grams a day (about a handful) of all kinds, including peanuts—or nut butters (about 3 tablespoons).
  • Viscous soluble fiber: 20 grams a day, from oats, barley, eggplant, okra, apples, berries, oranges, and psyllium.
  • Plant sterols: 2 grams a day, from fortified foods such as spreads, juices, and yogurt, or from supplements. (Sterols also occur naturally in foods such as wheat bran, peanuts, almonds, and vegetable oils but in amounts too small to meet the diet’s recommendation.)

Each component has been shown to lower cholesterol by 5 to 10 percent, but the idea is that the effects add up.

Does the Portfolio Diet work?

Yes—and then some—according to a 2018 meta-analysis and systematic review of seven clinical trials published in Progress in Cardiovascular Diseases, which included a total of 439 people with high cholesterol. It found that following the Portfolio Diet for four to 24 weeks, in conjunction with a low-saturated-fat diet, reduced LDL (“bad”) cholesterol by 27 percent compared to baseline—and compared to just 10 percent in people following low-saturated-fat “control” diets. That’s about as much as the starting dose of a lower-strength statin. Not too surprisingly, the greater the adherence to the diet, the better the results.

Improvements were also seen in other cardiometabolic risk factors including triglycerides, blood pressure (slight), and C-reactive protein (a marker for inflammation, which is implicated not only in heart disease but also in cancer and other chronic illnesses). Overall, the researchers concluded that the diet reduced the estimated 10-year risk of heart disease by 13 percent. Several major health organizations—the Canadian Cardiovascular Society, Diabetes Canada, the European Atherosclerosis Society, and Heart UK—recognize the benefits of the diet.

Portfolio pointers

  • If your cholesterol is very high, the diet alone may not be enough to bring it into a healthy range. You should also exercise and lose excess weight. If that’s still not enough, you may be a candidate for statin therapy.
  • The diet can be challenging. You must like soy foods, beans, and mucilaginous foods like eggplant and okra, for instance. But even if you don’t follow it 100 percent, you can still benefit. Simply substitute some portfolio foods for foods you normally eat every day, such as a soy burger in place of a hamburger, nuts instead of chips, and peanut butter or a sterol-enriched spread instead of butter.
  • You don’t need to eliminate all animal foods to get results. Though the earliest studies used a strict vegetarian diet, more recent ones have included low-fat dairy and lean meat. (Researchers are also further testing an “enhanced” version of the diet that includes healthy monounsaturated fats and exercise.)
  • While the diet lowers LDL cholesterol and other risk factors, it’s not yet known if it reduces heart attacks and deaths, as statins do. And it doesn’t produce the same effects as some stronger statins. But if you’re on a statin, it may allow you to take a lower dose (with your doctor’s okay) or to reduce your total and LDL cholesterol levels even further on the same statin dose.

Bottom line: No single food is the answer to a cholesterol problem. But if you combine certain healthful ones, the results add up. If you try the Portfolio Diet, it may be worthwhile to also invest in dietary counseling with a registered dietitian. In one study, participants who had just two sessions over six months did just as well as those who had more intensive counseling.

For an infographic on the diet, go to The Portfolio Diet: An evidence-based eating plan for lower cholesterol.

This article first appeared in the UC Berkeley Wellness Letter.

Also see Cholesterol Guidelines: What's New?