It is a potentially deadly health condition that affects tens of millions of American adults.
High cholesterol causes fatty deposits to build up in the arteries, restricting blood flow. Left untreated, it can raise the risk of a heart attack, stroke and even dementia.
And the problem appears to be growing.
According to the Centers for Disease Control and Prevention, the proportion of American adults with high cholesterol rose from 29 percent in 2019 to 33 percent in 2023, the most recent year on record.
To bring their cholesterol under control, millions of Americans are prescribed statins, daily medications that lower levels of ‘bad’ low-density lipoprotein (LDL) cholesterol and reduce the risk of heart attack and stroke.
For many, the pills are lifesaving. But the drugs are sometimes associated with side effects, with certain patients reporting muscle pain, digestive problems and headaches.
And for others, statins alone are not enough. Many patients taking the medications still fail to get their cholesterol down to recommended safe levels.
Now experts have told the Daily Mail that many could benefit from a plant-based eating plan that studies suggest can dramatically lower cholesterol, in some cases producing reductions approaching those seen with statins.
Known as the Portfolio diet, the eating plan was developed by researchers at the University of Toronto in the early 2000s and centers on four types of foods known to help lower cholesterol: soluble fiber, unsaturated fats, nuts and plant proteins such as beans and lentils.
Changes to your diet can combat high cholesterol, which affects tens of millions of American adults
Each has previously been shown to help lower cholesterol on its own.
But Dr David Jenkins, the diet’s creator and a professor of nutritional sciences at the University of Toronto, says that combined, these foods can work much like a financial portfolio, using several different approaches to maximize the overall return.
And the numbers appear to bear this out.
In one landmark study, published in the Journal of the American Medical Association, people who followed the Portfolio diet saw levels of LDL fall nearly 29 percent in just one month.
That was almost identical to the 31 percent reduction seen among participants taking a daily 20mg dose of the statin lovastatin.
For years, however, there was less evidence about whether following the diet over the long term translated into a lower risk of heart disease.
More recent research suggests it does.
A Harvard study that tracked the diets of nearly 210,000 US health professionals for up to 30 years found those who followed the Portfolio diet most closely had a 14 percent lower risk of cardiovascular disease than those who followed it the least closely.
‘More and more people have raised cholesterol. But not all of them require a heavy cholesterol reduction, as many of the newer, stronger statins provide,’ Jenkins said.
‘For most people, in fact, a smaller cholesterol reduction, like that provided by the diet, will do. And it benefits anyone trying to eat more healthily, not just those looking to reduce their cholesterol.’
So what is the Portfolio diet and why could it have such a dramatic effect on cholesterol levels?
First, it is important to understand what cholesterol is.
Cholesterol is a waxy, fat-like substance that the body needs to function. But having too much of certain types in the blood can be dangerous.
Two of the best known are LDL and HDL (high-density lipoprotein), known as ‘good’ cholesterol.
Too much LDL can lead to fatty deposits called plaques building up in the walls of arteries, narrowing them and raising the risk of a heart attack and stroke.
HDL, meanwhile, helps transport cholesterol from the bloodstream back to the liver, where it can be removed from the body.
It has long been known that diet can affect cholesterol levels. Foods high in saturated fat, such as fatty meats, butter and full-fat dairy products, can raise LDL.
For lunch, try a salad with chickpeas, leafy greens, avocado and sunflower seeds, drizzled with olive oil or, if on the go, a wholegrain wrap with hummus, chickpeas, roasted vegetables and salad
Genetics can also play a major role, while obesity, smoking, physical inactivity and certain health conditions can increase the risk of unhealthy cholesterol levels.
But for many people, changing what they eat can make a meaningful difference.
Cutting back on red meat and replacing it with foods lower in saturated fat, for example, can reduce LDL cholesterol. The renowned Mediterranean diet, which emphasizes fruits, vegetables, whole grains, nuts, fish and olive oil, has also been repeatedly linked to improved cholesterol levels and better heart health.
But some experts now say that none of these dietary changes can rival the cholesterol reduction provided by the Portfolio diet.
Its benefits lie in its combined approach, according to Dell Stanford, senior dietitian at the British Heart Foundation.
‘A lot of different foods can lower bad cholesterol, whether that’s oats, beans or certain vegetables. But these tend to only lower it individually by a relatively small amount,’ she said.
‘The idea behind the Portfolio diet is that combining as many of these individual foods together will result in a large reduction in cholesterol. And studies have shown this, with the bigger reduction occurring for patients who adhere to the diet the most strictly.’
The first food group it focuses on, Jenkins said, is fiber – more specifically, a type known as viscous fiber.
Fiber, a form of carbohydrate, is already known to have a host of health benefits. Studies suggest it can help with weight control, regulate blood sugar and reduce the risk of colorectal cancer.
But experts say viscous fiber, found in foods such as oats, barley, beans, lentils, eggplant, sweet potatoes, apples and citrus fruits, as well as flax and chia seeds, has particular benefits for cholesterol.
This is because it forms a gel-like substance in the digestive tract that traps bile acids, which are made from cholesterol, preventing them from being reabsorbed and instead carrying them out of the body in stool.
To replace the lost bile acids, the liver pulls more cholesterol from the blood, helping to drive down LDL levels.
The second key component of the diet is plant protein.
‘Plant proteins like tofu or tempeh, as well as nuts, seeds and legumes, seem to work by reducing the amount of cholesterol made in the liver,’ Jenkins said.
Plant sources of protein also tend to contain less saturated fat than many animal sources, making them a heart-healthy alternative to foods such as fatty or processed meats.
Unsaturated fats are another important part of the Portfolio diet. Replacing saturated fats, such as butter, with unsaturated alternatives can help reduce LDL cholesterol.
Experts say tofu can work well as part of the Portfolio diet
Good options include extra virgin olive oil, as well as canola, soybean and sunflower oils, said Jenkins.
The heart benefits of this approach have been demonstrated in major studies. A landmark Spanish trial found that people who followed a Mediterranean-style diet supplemented with either extra virgin olive oil or nuts had a significantly lower risk of major cardiovascular events than those advised to follow a low-fat diet.
Finally, the Portfolio diet includes plant sterols, natural compounds found in small amounts in foods such as nuts, seeds, fruits and vegetables.
Because they have a similar structure to cholesterol, plant sterols compete with it for absorption in the digestive system, meaning less cholesterol gets into the bloodstream.
However, it can be difficult to get the amounts used in cholesterol-lowering diets from ordinary foods alone, so sterols are also added to certain fortified foods and supplements.
‘Combined, these all work to increase the amount of bad cholesterol excreted by the body as well as reducing its reabsorption back into the body,’ Jenkins said.
‘That’s why the diet is able to have a similar effect to a statin.’
And the diet’s potential benefits may extend beyond cholesterol.
Research has suggested that following the Portfolio diet is also associated with a lower risk of type 2 diabetes, itself a major risk factor for heart disease.
Some people may also find it helpful for weight loss, said nutritionist Rhiannon Lambert.
She has noticed an uptick in client interest in the Portfolio diet in recent years at her London clinic, Rhitrition.
‘The diet isn’t designed as a weight-loss plan, but some people might lose weight if they naturally reduce their total calorie intake or increase their intake of high-fiber foods that promote fullness,’ she said.
‘Foods such as oats, beans, vegetables and fruit can help with satisfaction after meals, which may support appetite regulation.’
A sample day of eating, she suggests, could begin with oatmeal made with soy milk and topped with berries and a small handful of nuts.
For lunch, try a salad with chickpeas, leafy greens, avocado and sunflower seeds, drizzled with olive oil. If you’re on the go, a whole-grain wrap with hummus, chickpeas, roasted vegetables and salad is another option.
Dinner could be a simple stir-fry with tofu and vegetables such as broccoli, served with rice. For dessert, try a sterol-fortified yogurt with berries and nuts.
But the diet’s key benefit, Lambert added, lies in its flexibility.
‘Because the diet’s key components are food groups, rather than specific foods, there is no single right way to follow it.
‘It can be tailored to an individual’s preferences, cultural background, health needs and lifestyle,’ she said.
While meat is technically not part of the Portfolio diet, experts say followers do not necessarily have to give up animal protein entirely. Small amounts of lean protein, such as chicken, as well as fish, can still be included.
But experts stress that people who have been prescribed statins should not stop taking them in favor of the diet.
‘People already living with cardiovascular disease will need to get their cholesterol levels down much further than the general public, and to get there they will almost certainly require statins,’ said the British Heart Foundation’s Stanford.
‘But if you’re a relatively healthy person trying to keep your cholesterol level down, then this diet is a great way to do that.’
