‘Dietary guidelines are likely wrong’: Saturated fat does not increase cardiovascular disease risk, argue researchers
Dietary guidelines around the globe largely suggest reducing, or eliminating, saturated fatty acids from consumer diets.
In the UK, for example, it is recommended men eat no more than 30g of saturated fat a day, and women, no more than 20g. The reason cited is that eating too much saturated fat can raise ‘bad’ LDL cholesterol levels, which can increase the risk of heart disease and stroke.
The World Health Organization’s (WHO) 2020 dietary guidelines on saturated acids, too, recommends reducing total intake of saturated fat – to less than 10% of total energy intake. One way of cutting fat intake, the WHO suggests, is by replacing butter, lard and ghee with oils rich in polyunsaturated fats.
Not all working in nutrition are convinced. During a recent webinar hosted by think tank Competere, researchers agreed there is a link between saturated fatty acid consumption and increased blood cholesterol, but stressed there is ‘no evidence’ that eating food containing saturated fat increases risk of coronary heart disease, stroke, or cancer.
Is butter back?
Saturated fats, which are found in butter, meat, and coconut oil, are usually hard at room temperature. This is because the fatty acid chains all have single bonds.
Unsaturated fats, whether they be poly- or monounsaturated, have at least one double bond between carbon molecules, and are usually liquid at room temperature. Examples of unsaturated fats include oils from vegetables, nuts and seeds.
Half-way through the last century, consumption of saturated fatty acids was associated with an increase in cholesterol, and therefore an increased risk of coronary heart disease. But over the last 20 years, science has revisited old data and mined new data to bring emerging evidence to light.
In a systematic analysis investigating health effects of dietary risks in 195 countries between 1990 and 2017, published in The Lancet in 2019, for example, the highest dietary risk factor for cardiovascular diseases was found to be a diet high in sodium, explained Francesco Visioli, professor of human nutrition at Italy’s University of Padova. Further down the list was a diet high in trans fats, and even further down, a diet high in red meat.
“Saturated fat is not even mentioned,” stressed Prof Visioli.
A systematic review and meta-analysis of butter consumption and risk of cardiovascular disease, diabetes, and total mortality, published in Plos One in 2016, found that butter consumption neither promoted nor prevented these health issues.
Another meta-analysis, investigating links between saturated fats and cardiovascular disease (Clinical Nutrition, 2010) again found saturated fats to be neutral in its promotion and prevention of CVD.
“There is no direct, real evidence that eating saturated fat is harmful towards cardiovascular disease,” said Prof Visioli. “Yes, it raises blood cholesterol, yes it’s better to replace saturated fat with polyunsaturated fat, but if you eat foods that are high in saturated fat, there is no evidence to date that this behaviour will increase your risk.”
‘Let’s not focus solely on saturated fat’
Could it be that research to date has focused too heavily on specific macro- or micronutrients?
Previous research has suggested that saturated fat is more harmful in the US than in Europe. It’s unlikely that Americans respond differently to saturated fat than their EU counterparts – and much more likely that it’s the way the two populations consume saturated fat which is at play.
In the US, the majority of saturated fat is consumed in meat. In Europe, and more specifically the Netherlands, saturated fat is mostly consumed in dairy.
“We do not eat saturated fat or poly- or monounsaturated fat, or vitamin C or vitamin D. We eat food,” said Prof Visioli. “So if you just focus on saturated fat, are you missing the [point]?
“You should look at meat, you should look at dairy products, or you should look at products with palm oil or other kinds of fat [in them]. We should really start to think of the whole food rather than a single ingredient.”
In saying that, the professor told delegates he was not condoning a diet high in saturated fat: “Don’t eat too much fat, in general, because it’s high calorie.”
But he does advocate for dietary guidelines to be revisited. “We’ve been told by the WHO and many other organisations to reduce saturated fat…but maybe we should revisit this approach. Because the recommendations of the WHO do not take into account the latest evidence.”
Palm oil is 50% saturated fat, is it unhealthy?
Meta-analyses have also been conducted to investigate the health impact of palm oil consumption.
Palm oil – the most consumed vegetable oil in the world – is made up of 50% saturated fatty acids, and as such, has suffered from a poor reputation from a health perspective.
“The connotation with palm oil has always been that because of its saturated fatty acid content and high levels, it must behave like all other saturated fat, and therefore it will constitute a risk for heart disease in a given population,” explained consultant Dr Kalyana Sundram, who is a former CEO of the Malaysian Palm Oil Council (MPOC).
Dr Sundram’s own meta-analysis of 32 human dietary intervention trials investigating the effect of palm oil-enriched treatments on blood cholesterol compared to monounsaturated fat-enriched diets revealed that the effects were ‘neither positive nor negative’, he explained: “Palm oil was behaving more like a neutral fatty acid.”
These findings, combined with new evidence concerning the health impact of saturated fatty acids, draw attention to ‘low’ or ‘no saturated fat’ front-of-pack claims. If saturated fat is not as bad for our health as once thought, why are brands touting these messages?
Dr Sundram puts it down to companies’ bottom lines, and urged consumers to ask more questions.
“Food companies know that consumers will follow, to some extent, [national dietary] recommendations, and every time they make a claim that they have reduced saturated fat content in a product, they’re going to get a buzz word that it is healthier food.
“But the question has always been: in replacing saturated fat, what have you [replaced it with?]”
Dr Sundram continued: “You really have to ask questions about whether food companies are ethically teaching better nutrition to the consumer. Eighty percent of the time, they’re not. They’re looking after the profits.”
