One of the joys of lockdown in our remote Dorset village is the cheese delivery from Neals Yard Dairy – a cornucopia of the most flavoursome British and Irish farmhouse cheeses. Guilty treat? After all, doesn’t the abundance of saturated fat in cheese increase so-called ‘bad’ LDL cholesterol, clogging your arteries and raising your risk of heart disease? In a word, no.
A ‘State-of-the-Art Review’ of all the evidence, published this summer in the Journal of the American College of Cardiology (JACC), concludes that ‘Whole-fat dairy, unprocessed [red] meat, eggs and dark chocolate are…. not associated with increased risk of CVD (cardiovascular disease)’. (It’s worth noting here, that the authors advise only ‘modest amounts’ of red meat.)
Although saturated fatty acids (SFAs) increase LDL cholesterol in most individuals, the Review adds, they don’t raise the levels of the dangerous, small, dense LDL particles but ‘larger LDL [particles] which are much less strongly related to CVD risk’. What’s more, these foods contain lots of other valuable nutrients that we shouldn’t miss out on.
Saturated fat – as opposed to mono- and poly-unsaturated fats – has been demonised since the mid 1950s when it became the alleged cause of President Dwight D Eisenhower’s fatal heart attack. Latterly, it’s said that allegation was down to the economic and political undesirability of blaming his consumption of sugar and tobacco, both key domestic crops, rather than any evidence. As a result, for over 40 years the dietary advice in the US and this country has dictated that we reduce our risk of cholesterol-raising foods to avoid heart disease. So health-conscious mortals opted for margarine, low or no fat yogurt, egg white omelettes, fish or poultry and perish the thought of finishing a meal with a tantalising cheese board and a few squares of chocolate made with 70% cocoa.
The State-of-the-Art Review reflects a recent revolution in dietary thinking. Since the beginning of this century, ‘a number of trials comparing high and low-fat diets have shown that high fat is better for health’, according to science journalist and nutrition campaigner Nina Teicholz. Not only does a high fat diet appear to have a positive effect in and of itself (more about this further down) but eating a low fat diet is very likely to increase our consumption of sugar and refined carbohydrates. ‘I think [those] have more of an impact on CVD, type 2 diabetes, cancer and obesity than saturated fat,’ says nutritionist and author Dr Marilyn Glenville.
However, this is a battlefield with wars being waged over several issues. Although the authors of the JACC Review hoped their work would inform the 2020 Dietary Guidelines for Americans, the five-person Subcommittee responsible for the latest edict was unmoved. The evidence linking saturated fats to heart disease was judged to be “strong”, both for adults and children, they said.
Opposition forces say that only looking at levels of LDL cholesterol is unreliable. You need to examine ‘hard’ outcome data like heart attacks and death. The JACC Review looked at a wide range of randomised controlled clinical trials on over 50,000 people where saturated fats were replaced by unsaturated fats; the studies concluded that saturated fats have no effect on death from heart disease and all other causes. (This is not to say that unsaturated fats are undesirable; the evidence for the benefits of a Mediterranean diet is high, says Dr Glenville.)
Despite widespread medical opinion, having a high level of LDL cholesterol may not be related to death from heart disease. The evidence for a link is weak and one big study showed that, in fact, the higher people’s LDL, the longer their chance of survival. The large-scale US Framingham study, which monitored three generations, revealed little difference in cholesterol levels between the majority of those who did and did not develop heart disease. Further research found that of more than 130,000 patients hospitalised with a heart attack, 75% had normal total cholesterol and LDL levels.
More important may be metabolic syndrome, which is linked to high consumption of sugar and other carbs. Metabolic syndrome is diagnosed when a patient has three or more of these conditions:
- Low levels of high-density lipoprotein (HDL), so-called ‘good’ cholesterol.
- High triglyceride levels (the third fat measured in total cholesterol, along with HDL and LDL).
- Type 2 diabetes or a pre-diabetic state known as impaired glucose tolerance.
- Raised blood pressure (higher than 140/90mmHg).
- Increased waist measurement (more than 90cm for men and 84cm for women).
Whether or not you want to eat all these SFA-rich foods – red meat is contentious for several reasons, including animal welfare and the environment as well as health – there are benefits in choosing full fat versions of, for instance, live natural yogurt, which provides beneficial gut bacteria without added sugar. Like yogurt, cheese contains a range of valuable nutrients, including probiotics, and is consistently found to be associated with lower CVD risk. Whole-fat dairy foods may also be protective against type 2-diabetes.
Eggs are nutrient powerhouses, providing all the omega-3 essential fatty acids our bodies need and can’t make themselves, as Dr Glenville points out.
Dark chocolate with more than 70% cocoa contains ingredients called flavanols, which can reduce blood pressure and other risk factors for dementia and diabetes, according to Margaret Rayman, Professor of Nutritional Medicine at the University of Surrey. The amount of sugar in 70% and 80% dark chocolate is very low but some versions have even less.
NB: There may be individuals with medical conditions that make it unwise for them to eat in this way.