Dietary Fats: The Good, The Bad & The In-Between
Here is a fascinating look at dietary fats from our Nutritionist, Nereda Merrin.
For years, fat was a four-letter word. We were urged to banish it from our diets whenever possible. We switched to low-fat foods. But the shift didn’t make us healthier, probably because we cut back on healthy fats as well as harmful ones and within processed foods the space left by fat was filled by sugar.
What we know to be true now, is that your body needs some fat from food. It’s a major source of energy. It helps you absorb some vitamins and minerals. It is needed to build cell membranes, the vital exterior of each cell, and the sheaths surrounding nerves. It is essential for blood clotting, muscle movement, and inflammation. Additionally fat is also needed for hunger satiation and therefore weight management.
The type of fat you consume matters, so read on to understand the good, the in-between and the bad.
The Good: Monounsaturated and Polyunsaturated fats
Good fats come mainly from vegetables, nuts, seeds, and fish. They differ from saturated fats by having fewer hydrogen atoms bonded to their carbon chains. Healthy fats are liquid at room temperature, not solid. There are two broad categories of beneficial fats: monounsaturated and polyunsaturated fats.
Good sources of monounsaturated fats are olive oil, peanut oil, canola oil, avocados, and most nuts, as well as high-oleic safflower and sunflower oils.
The discovery that monounsaturated fat could be healthful came from the Seven Countries Study during the 1960s. It revealed that people in Greece and other parts of the Mediterranean region enjoyed a low rate of heart disease despite a high-fat diet. The main fat in their diet, though, was not the saturated animal fat common in countries with higher rates of heart disease. It was olive oil, which contains mainly monounsaturated fat. This finding produced a surge of interest in olive oil and the “Mediterranean diet,” a style of eating regarded as a healthful choice today.
Of all the monounsaturated oils, olive oil is the most nourishing for you due to its high antioxidant content and its higher monounsaturated content (73%).
Despite what has been written about olive oil and cooking please note the following;
- It is largely resistant to heat damage due to its mostly monounsaturated fatty acid content
- It has a high smoke point at 190 – 207C which makes it suitable for most cooking methods including pan frying.
When you pour liquid cooking oil into a pan, there’s a good chance you’re using polyunsaturated fat. Corn oil, sunflower oil, and safflower oil are common examples.
Polyunsaturated fats are essential fats. That means they’re required for normal body functions but your body can’t make them. So you must get them from food. Polyunsaturated fats are used to build cell membranes and the covering of nerves. They are needed for blood clotting, muscle movement, and inflammation.
There are two main types of polyunsaturated fats: omega-3 fatty acids and omega-6 fatty acids. Both types offer health benefits.
Eating polyunsaturated fats in place of saturated fats or highly refined carbohydrates reduces harmful LDL cholesterol and improves your cholesterol profile. It also lowers triglycerides.
Good sources of omega-3 fatty acids include fatty fish such as salmon, mackerel, and sardines, flaxseeds, walnuts, canola oil, and unhydrogenated soybean oil.
Omega-3 fatty acids may help prevent and even treat heart disease and stroke. In addition to reducing blood pressure, raising HDL, and lowering triglycerides, polyunsaturated fats may help prevent lethal heart rhythms from arising. Evidence also suggests they may help reduce the need for corticosteroid medications in people with rheumatoid arthritis.
Omega-6 fatty acids have also been linked to protection against heart disease. Foods rich in linoleic acid and other omega-6 fatty acids include vegetable oils such as safflower, soybean, sunflower, walnut, and corn oils.
The In-between; Saturated fats
Common sources of saturated fat include red meat, whole milk and other whole-milk dairy foods, cheese, coconut oil, and many commercially prepared baked goods and other foods.
While saturated fat does offer some health benefits, a diet high in saturated fat bad can drive up total cholesterol, and tip the balance toward more harmful LDL cholesterol, which prompts blockages to form in arteries in the heart and elsewhere in the body. For that reason, most nutrition experts recommend limiting saturated fat to under 10% of calories a day.
The best way to approach saturated fats is to:
- Avoid commercially prepared baked goods and other foods as you are likely to consume a lot of saturated fat without receiving any nutritional benefit outside of the fat consumption
- Enjoy a plant led diet and ensure that red meat, dairy and coconut oil play only a supporting role.
The Bad; Trans Fats
The worst type of dietary fat is the kind known as trans-fats, it is one of the few areas of nutrition that is black and white. Even small amounts of trans fat can harm health: for every 2% of calories from trans-fat consumed daily, the risk of heart disease rises by 23%.
The foods you are likely to ingest significant trans fats from within Australia are commercially produced baked goods, snacks and take-away goods and some margarines. Basically any commercially produced product that needs to either be crispy and/or have a long shelf life is likely to include trans-fat. Food producers don’t have to label the level of trans fat within their products so it is difficult to know how much trans fat you will be consuming when you eat these foods.
The World Health Organisation (WHO) has declared that if your diet is high in trans-fat, your risk of heart disease increases by 21 per cent and your risk of death, from trans-fat consumption, goes up by 28 per cent. This risk is as a result of the inflammation trans fats create. Inflammation is very closely linked to heart disease, stroke, diabetes, and other chronic conditions.
Ultimately for your own health and that of your family you need to work commercially produced baked goods, snacks and a majority of take-away foods out of your diet to limit the significant health risks that trans-fat consumption results in.
I can’t sugar coat this nutritional red zone for you and apply my usual “everything in moderation” is okay within a balanced diet as that is not true of this fat type as a product ingredient.
So, in summary:
- Eat a sensible amount of monounsaturated and polyunsaturated fats while keeping saturated fats as low as possible and from a whole food source.
- Avoid saturated fats and trans fats altogether when they are entering your mouth as part of a commercially produced baked good, snack or take-away food product!
Hope this helps you understand better how to fit healthy fats into your dietary pattern.
Yours in health and vitality,