Guest blog by Vicky Ware
There have been headlines about saturated fats in the news lately – many suggesting that saturated fats are not actually bad for us. This is because a new study was published claiming that the dietary advice in the 1980s to lower intake of saturated fat was not based on good evidence 1.
Although the new study has some good points, it wasn’t without flaws and its results don’t mean we can all eat as much saturated fat as we like without an impact on health. Saturated fat comes from many different sources and these have different effects on health. It all comes back to getting the right balance between different types of fat in our diet.
One complication is that ‘saturated fats’ encompass a range of different fats and each of these is packaged in a different type of food – dairy products have a different effect on your body than red meat, for example, but they both contain saturated fat.
The nutrition guidelines in the UK recommend men eat no more than 30 grams of saturated fat a day and women eat no more than 20 grams 2.
The foods that we’re advised to keep to a minimum are fatty cuts of meat (not including fish) and dairy products – butter, cheese, cream, some savoury snacks, chocolate confectionary and cake. The saturated fat in all of these foods is mainly from dairy 2.
The UK nutrition advice is quite conflicting as the ‘eatwell plate’ has a significant section devoted to milk and dairy foods, and a large section for ‘meat, fish, eggs and beans’ as sources of protein 3.
The dietary advice is to cut down on red meat and dairy, but they word this as cutting down on ‘saturated fats’.
Studying how the foods we eat impact our health is really complicated because there are so many factors involved. Looking at populations can give us a pretty good idea of whether eating a certain way is good for us.
In 1960, 45% of the American diet was from fats and oils, around 13% of the population were obese and less than 1% had type 2 diabetes. Now, Americans eat less fat at 33% of their daily intake – however 34% are now obese and 11% have diabetes 4. It seems that dietary fat is not the cause of obesity and type 2 diabetes because when people ate more of it, the population as a whole were slimmer and less likely to get diabetes.
Some populations in the world eat diets very high in fats – even saturated fats from plant and marine sources but have little or no sign of heart disease 5;22. The Mediterranean diet is well known for being healthy and contains lots of fat 6.
It’s not the amount of fat you eat but the balance of different fats in your diet.
When the 1980s advice to lower saturated fat intake came out, as a population we replaced the fats in our diet with sugar.
Unfortunately, it has since been shown that over time a diet high in easily digestible carbohydrates such as sugar is worse for heart health than eating a poor balance of fats 7.
So it’s important to replace bad fats with good fats, not with easily digestible carbohydrates.
One of the reasons eating lots of saturated fat without a balance of other fats is bad for health is because they increase cholesterol in the blood if not eaten in a diet that contains good fats. Cholesterol is crucial to virtually every process in the human body because our cells are made from it. Our bodies can make cholesterol out of other foods we eat.
It is cholesterol in the blood stream (rather than being stored in the liver, or used to make cells) that negatively affects health – and how much is in the blood is affected by the balance of fats we eat much more than how much cholesterol we eat 8.
Fat such as cholesterol can’t dissolve in water, just like oil won’t dissolve in water but rather clumps together in droplets. This means fats can’t dissolve in blood either and need a ‘chaperone’ to transport them. Cholesterol is transported out of the liver and into the blood by low density lipoprotein (LDL) – think of LDL as a one way tram service out of the liver.
Excess cholesterol is transported back to the liver for storage by high density lipoprotein (HDL) – HDL being the tram back home. The tram lines can’t be moved – LDL takes cholesterol out, HDL brings it back.
The foods you eat affect how much LDL and HDL you have in your body. The typical Western diet tends to mean we have enough LDL (getting cholesterol in to our bloodstream) but not enough HDL to bring the cholesterol back.
If there is too much cholesterol in the blood stream, attached to LDL, it can end up burrowing into artery walls where it sets up an inflammatory response and ultimately causes heart disease.
The more HDL in your body, the lower your chance of having arteries clogged with cholesterol 9.
So, it’s not about reducing the amount of fat we eat but eating the right kind of fat.
Foods that increase our HDL are also associated with good heart health, as well as with reducing onset of some kinds of cancer. These are often polyunsaturated and monounsaturated fats but some saturated fats improve the ratio of HDL to LDL in the blood too – although these are usually from plant not animals sources 10;11.
It is because this ratio between HDL and LDL is so important that eating a low fat diet isn’t going to improve your health – you’ll be cutting back on LDL along with the HDL 10. It is also why people who exercise a lot can still have high cholesterol. Exercise does have some impact on blood cholesterol levels, but the biggest impact is the balance of fats in your diet.
Along with increasing HDL, we also want to decrease inflammation in our body. A large factor in many diseases of Western culture – including heart disease as we describe earlier - is chronic inflammation.
Eating fat is essential for a diet that does not promote inflammation – nuts and seeds along with oily fish and fats from olive oil and avocado are all key to a low inflammation, heart healthy diet 12;13;14.
It’s true that butter is better for you than the margarines of the past, which contained high levels of trans fats – also known as hydrogenated fat. These artificially produced fats were worse for health than the saturated fats in butter. Trans fats are not just artificially produced but are naturally present in meat and dairy in small amounts.
A study found that women who ate 4 teaspoons of margarine a day had 50% more risk of heart disease than women who only ate margarine every now and again 15.
Trans fats not only raise LDL (transporting cholesterol into the blood stream) but also increase inflammation 16.
Every time trans fats contribute 2% to your diet, your risk of coronary heart disease goes up by 23% 16. Happily, far fewer foods now contain trans fats and most supermarkets have taken them out of their own brand foods. If a food does contain hydrogenated fat, it must say so in the ingredients.
An eight year trial looking at just under 50,000 women found that those who followed a low fat diet had virtually identical rates of heat attack, stroke and other types of heart disease as those who didn’t. They didn’t lose any weight either 17;18. It was the type of fat, not the amount of fat which affected health 19.
Yet again it comes back to balance – this time getting a balance between the right kinds of fat.
So we can’t just eat as much saturated fat as we like without expecting an impact on our health. However, so long as we’re getting a good balance of fats in our diet eating saturated fats doesn’t seem to be as bad for health as experts once thought.
Vicky has a degree in Biological Sciences with a focus on biochemistry and immunology and is currently studying for a MSc in Drug Discovery and Protein Biotechnology. She is also an endurance athlete.
Want some more detail on saturated fat? Try these previous posts: The Truth Behind Saturated Fat, The Truth About Saturated Fat - An Update and here's another post by Vicky on inflammation, Inflammation and its Effects.
About Lucy Bee Limited
Lucy Bee is concerned with Fair Trade, ethical and sustainable living, recycling and eating close to nature with additive free products for health.
The views and opinions expressed in videos and articles on the Lucy Bee website/s or social networking sites are those of the author/s and do not necessarily reflect those of Lucy Bee Limited.
Be the first to comment.
At Lucy Bee, we’re passionate about a healthy lifestyle and feeling good through the foods we eat. Our website promotes the nourishing ingredients that we love plus tips for natural beauty and fitness.