When it comes to fat, it comes in a few different forms: unsaturated, saturated, trans, and cholesterol. I’m going to focus on saturated here, but in short: unsaturated fats are good for you (think olive oil, walnuts, salmon), trans fats are bad for you (think twinkies) and cholesterol in food doesn’t have much of an impact on blood cholesterol, so it’s not really something to watch out for on a nutrition fact label. In terms of saturated fat, it’s a little more complicated.
We’ve been told for a long time that saturated fat is bad for you. There’s saturated fat in tons of processed foods like sausages, bacon, cakes and pastries. But, there’s also saturated fat in things like eggs and milk, which we say are good for you. So, what’s the deal? Is all saturated fat bad?
First off, what are saturated fats? They’re fats that are solid at room temperature, and have fatty acid chains that are saturated in hydrogens, meaning, there's no double bonds in their chemical structure.
Sources of saturated fats include:
beef
lamb
pork
poultry, especially with skin
beef fat
lard and cream
butter
cheese
ice cream
coconut
palm oil
palm kernel oil
some baked and fried foods
The reason saturated fats have such a bad rep is because they increase LDL cholesterol (bad cholesterol) in the blood, which, with a high enough consumption, can lead to heart disease. Basically, the LDL cholesterol can be deposited on the walls of our arteries and form what we call atherosclerotic plaque. As it progresses, our arteries get narrower and that plaque can block blood flow, which can lead to a heart attack or stroke (1).
The previous statement about LDL cholesterol is pretty much undisputable. Too much LDL cholesterol can cause heart disease (2). Plus, a high saturated fat intake definitely increases LDL (3), and reducing consumption can decrease LDL and cardiovascular risk (by up to 17%) (4)! But… there’s an exception to this saturated fat rule.
Dairy intake, from things like milk, yogurt, cream and (wait for it…) cheese (!) have not been shown to increase LDL cholesterol, nor cause an increase in cardiovascular risk – they may even be beneficial (5, 6). So, you don’t have to choose the low-fat cheeses, milks and yogurts! I personally love 10% fat yogurt. The population of France, who has the highest per-capita dairy fat consumption of any industrial nation (7) actually has less than a third of the heart disease death rates than the US and a longer average life expectancy than the US (8). Of course, there are many other factors to this, like a more positive attitude towards eating, more attention spent on the sensory qualities of food, eating for a significantly longer period of time, etc (9). But, the high fat dairy consumption versus the heart disease rates are interesting too.
The reason dairy seems to be fine when it comes to LDL cholesterol may be due to the effects of the structure of dairy nutrients that prevent the saturated fat from being digested and absorbed properly by our gut. Now, this isn’t the case for butter – it seems like it does still increase LDL and thus cardiovascular risk (1).
Eggs also contain saturated fat, and have been a hot nutrition topic for a while. The cholesterol in eggs, however, is usually the nutrient that people like to talk about. Even though this post isn’t about dietary cholesterol, the cholesterol in food has a very minimal impact on blood cholesterol (LDL cholesterol included, of course) (1). In terms of their saturated fat content, it’s minimal, and thus eggs don’t increase LDL cholesterol – just like dairy. Indeed, studies have shown that eating them 5+ days per week doesn’t have a negative impact on cardiovascular risk (10,11). And, people who eat eggs are more likely to meet the recommendations for nutrients like choline, vitamin A and vitamin B12 (1). Plus, eggs have been shown to be beneficial for heart health (7).
Now, we know that most dairy - and eggs – can’t increase cardiovascular risk. But does that mean that cheese gives the same health benefits as, say, salmon or walnuts (both excellent sources of omega 3s/unsaturated fats)? Unfortunately, no. There’s a ton of research that shows that replacing saturated fat with unsaturated fat reduces LDL cholesterol and lowers the risk of heart disease and related deaths (3). Unsaturated fats like omega 3s are also supportive to a healthy immune system, suppress inflammation and may protect against some cancers (12). Some great sources of unsaturated fat are:
· Fatty fish (herring, mackerel, salmon, sardines, tuna)
· Nuts (walnuts, almonds, cashews, hazelnuts, macadamia nuts, peanuts, pecans, pistachios)
· Sesame seeds, flaxseeds, chia seeds
· Oils (canola, olive, flaxseed, peanut, sesame)
· Olives
· Avocados
· Peanut butter
· Marine algae
· Yeast
To replace saturated fats with unsaturated fats, sauté foods in olive or canola oil instead of butter, snack on mixed nuts instead of potato chips, garnish salads with sesame seeds instead of bacon, eat salmon instead of steak, or try an avocado-based chocolate mousse instead of the regular thing.
That being said, any food with saturated fat can be part of a healthy, balanced diet. I love the saying, “the poison is in the dose.” Also, a lot of foods that contain saturated fat also contain unsaturated fat. So, although we do have to be conscious of foods that are high in saturated fat, we also have to
1) Look at the ratio of saturated to unsaturated fat
2) Realize that not all saturated fats are equal! Having cheese every day is fine!
In summary, try not to go crazy with saturated fats, especially the ones that increase LDL cholesterol. And, try to implement unsaturated fats into your diet as much as possible. Your salad was looking a little boring without the walnuts, anyway!
Works cited
1. Wolrich, J. Food Isn’t Medicine. Vermillion London, 2021.
2. Borén, J. et al. Low-density lipoproteins cause atherosclerotic cardiovascular disease: pathophysiological, genetic, and therapeutic insights: a consensus statement from the European Atherosclerosis Society Consensus Panel. European Heart Journal 41 (2020) 2313–2330.
3. Mach, F. et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. European Heart Journal 41 (2020) 111–188.
4. Hooper, L. et al. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database of Systematic Reviews (2020).
5. Thorning, TK. et al. Whole dairy matrix or single nutrients in assessment of health effects: current evidence and knowledge gaps. The American Journal of Clinical Nutrition 105 (2017) 1033–1045.
6. Drouin-Chartier, JP. et al. Systematic review of the association between dairy product consumption and risk of cardiovascular-related clinical outcomes. Advances in Nutrition 7 (2016) 1026–1040.
7. Guyenet, S. Butter, margarine and heart disease. Whole Health Source, 2008.
8. OECD. OECD Factbook 2010: Economic, Environmental and Social Statistics. OECD Publishing, 2010.
9. Tribole, E. & Resch, E. Intuitive Eating, 4th edition. St Martin’s Press, 2020.
10. Melough, MM. et al. Association of eggs with dietary nutrient adequacy and cardiovascular risk factors in US adults. Public Health Nutrition 22 (2019) 2033–2042.
11. Magriplis, E. et al. Frequency and Quantity of Egg Intake Is Not Associated with Dyslipidemia: The Hellenic National Nutrition and Health Survey (HNNHS). Nutrients 11 (2019) 1105.
12. Rolfes, S. & Whitney, E. Understanding nutrition. Cengage Learning Inc, 2022.