I like to think of fats in our diet being like the oil in a car. We need them for the smooth running of our cells particularly our brain cells. In the last few decades there has been a very negative message on fat in the diet due to over-consumption of saturated and trans fats but now we are hearing much more about the importance of healthy essential fats. Knowing what those healthy ones are can be confusing. I hope the following facts on fats will help to clarify which fats to eat plenty of and those to eat in moderation or avoid.
Fats are essential for the body and have many functions:
- Important energy source
- Essential for the absorption of fat soluble vitamins A,D, E & K
- Protect vital organs
- Keeps the body insulated
- Essential for cell membranes structure and fluidity
- Hormone production
- Brain function and the nervous system
The different types of fats in the diet are saturated, unsaturated (predominately Essential Fatty Acids – Omega 3, 6 and 9) and trans fats. Some fats are better than others. Saturated, hydrogenated and trans fats may cause high LDL cholesterol (the bad one) and arterial plaques, a major risk for heart disease.
These are usually solid or waxy at room temperature and are generally derived from meat products (whole milk, butter, cream, cheese, lard, shortening and dairy products that contain whole milk). These fats should be eaten in moderation.
Coconut and palm oil are vegetarian sources of saturated fat and contain no cholesterol, making them a healthy choice. Coconut oil is thought to be very beneficial health wise and is an excellent choice for cooking as its chemical structure is very stable when heated.
These come from adding hydrogen to vegetable oil through a process called hydrogenation and is a method often used in the food industry. Trans-fats may be found in meat products, vegetable shortening, some margarine, some processed foods, biscuits, cakes, fried foods such as doughnuts and French fries. Trans-fats are found in trace amounts in natural fats but at a level the body can cope with. However with unnaturally high levels, the body struggles to metabolize them which can lead to damaging effects on our cells.
These remain liquid at room temperature and can be categorized into polyunsaturated, monounsaturated and essential fatty acids – the omega fats.
The Good Fats – Omega 3
Oily fish contains an abundant supply of omega 3. This is an essential fat, meaning we cannot make it ourselves and so we have to obtain it from our diet. It would appear that many of us are deficient in omega 3 and food sources are limited. Foods that contain omega 3 are fish such as salmon, mackerel, anchovies, sardines, herring, fresh tuna, trout, pilchards, with other sources being linseeds (flaxseeds), walnuts and pumpkin seeds. However in general our body finds it much easier to beneficially utilize the omega 3 from oily fish than from nuts and seeds.
Tinned tuna does not count as an oily fish as the canning process reduces the fats!
Omega 6 is another essential fat but we don’t tend to be as deficient in omega 6 because it is easier to obtain from our diet. Good sources of omega 6 are peanuts (try to eat these unsalted!), most nuts, particularly walnuts, almonds and Brazils, seeds such as sunflower, sesame and hemp and soyabeans.
This is not to say that omega 6 is not important but we need to ensure we consume a balance of omega 3 to omega 6. In a typical Western diet the intake of omega 6 to omega 3 has been so much higher, in part due to our excessive consumption of seed oils, that it has been estimated that the ratio omega 6 to omega 3 could be as high as 15:1. Excessive omega 6 intake can block the uptake of omega 3. It can also lead to a high level of pro-inflammatory compounds being formed in the body which are not desirable.
Olive oil as opposed to the more highly refined sunflower oil and corn oil is a monounsaturated oil and contains another form of healthy fat, that of omega 9. This, like omega 3, has an anti-inflammatory effect on the body, making it a desirable choice!
What are the’ Good Fats Good For!’
They are important for keeping our cells healthy as these fats sit in our cell membranes keeping them flexible. This increases their ability to stay hydrated, hold on to nutrients and electrolytes and to communicate with each other. Healthy brain function is reliant on these fats, particularly the growing brains of children. A deficiency in children and adults can lead to problems with concentration, behavior and mood.
They are also vital for hormone production, nerve transmission, blood clotting, organ function, healthy eyes and can lower cholesterol. They also have an anti-inflammatory effect. Chronic inflammation in the body is a cause of many diseases such as cancer, diabetes and heart disease.
A summary of fat facts and some helpful tips:
- Fats are important for brain health – our brains are 60% fat!
- Eat saturated fats in moderation.
- Avoid bought cakes, biscuits and pastries which may contain trans-fats.
- Eat 2-3 portions of oily fish per week. Tinned sardines on wholemeal toast are a great quick and easy meal or snack.
- Eat a small handful of nuts and seeds a day for a regular intake of healthy fats.
- Use monounsaturated oils such as olive oil or rapeseed oil for cooking. It contains more saturates which makes it less damaged by heat.
- Oils in dark glass bottles are less likely to get damaged by light. Keep your oils in a dark, cool cupboard, not next to your oven or on a window sill.
- Keep packets of nuts in the fridge as this prevents the healthy oils in them from becoming rancid too quickly. Never eat stale nuts as rancid oils are not good for us.