Do spreads enriched with plant sterols really help reduce cholesterol?by Jennifer Bowden
ANSWER: Foods and dietary supplements enriched with plant sterols are not new: they’ve been around since Elvis Presley was shimmying across the stage in the 1950s. Since then, the cholesterol-lowering powers of plant sterols have been well researched – hence the manufacturers’ claims.
We now know that consuming 1.5-2.4g of plant sterols each day can reduce blood levels of LDL (bad) cholesterol by up to 10%. Elevated total and LDL cholesterol levels are considered major risk factors for cardiovascular disease.
In the gut, plant sterols compete with cholesterol for absorption, so when regularly consumed, they gradually lower circulating cholesterol levels over several weeks.
The richest natural source of plant sterols are vegetable oils, followed by nuts and seeds, then grain products, fruits and vegetables; however, the quantities found are relatively small. For example, a recent Chinese study found vegetable oils had the highest phytosterol content (150-1230mg per 100g). So, to benefit from a daily dose of 2g of sterols, you’d need to consume at least half a cup and as much as four cups of plant oil each day.
But it is relatively simple to consume 2g of sterols in plant-oil-based spreads that are enriched with the odourless, tasteless compounds. In the case of ProActiv, 25g (1 tablespoon) contains 2g of sterols.
Studies have found that you will get no further cholesterol-lowering benefit from consuming more than 2-3g of sterols a day, nor will ongoing use further lower cholesterol levels below the initial 10% reduction.
However, good diet and lifestyle may reduce LDL cholesterol levels by a further 5% – a total of 15% from the original starting point.
A daily 30g serving of nuts is a great place to start in boosting your heart health. Nuts are a rich source of protein, fibre, heart-healthy fats, vitamin E, magnesium, potassium, plant sterols and many other important nutrients. A large study in Spain of otherwise healthy adults at high risk of cardiovascular disease, Predimed, found that a Mediterranean diet supplemented with either extra-virgin olive oil or mixed nuts reduced the risk of cardiovascular events by 30% compared with a low-fat diet.
Eating healthier fats, such as oily fish, avocado, seeds and vegetable oils and spreads, rather than animal fats, boosts heart health, as does eating less trans fat, which is found in some bakery and pastry products, along with potato chips, breakfast bars and takeaway foods.
A diet rich in wholefoods – fresh fruit, vegetables, nuts, seeds, lean meats, chicken, seafood and wholegrains – and with fewer ultra-processed foods will reduce the intake of trans fats. What’s more, fruit and vegetables are also useful sources of plant sterols, cholesterol-lowering soluble fibre, vitamins and many other nutrients.
Oats and barley are also effective in improving heart health, because both are rich in a soluble fibre called beta-glucan, which binds cholesterol in the gut and prevents it from being absorbed. Studies have found that eating about 3g of beta-glucan a day may reduce total and LDL cholesterol levels by about 5% and 7% respectively. Depending on the type of oats (whole, rolled or oatmeal), ½-2∕3 of a cup would provide the recommended 3g of beta-glucan fibre.
So, enjoy the health benefits of a spread enriched with plant sterols, along with the bounty of health-promoting nutrients and fibre found in a wholefood-rich diet.
This article was first published in the April 14, 2018 issue of the New Zealand Listener.
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