Questions about fat

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Is it more important to consider the amount of fat I am consuming, or to focus on the types of fat that I am having?

For fats we advise that people avoid trans fats (hydrogenated vegetable oils) and refined polyunsaturated vegetable oils, but that the other fats can be consumed in line with their dietary approaches.  In particular we recommend the consumption of omega-3 fats, e.g. from oily fish, and monounsaturated fats, e.g. extra-virgin olive oil, as these have been shown to have some health promoting properties.

My heart surgeon (or other healthcare professional, e.g. GP) told me I cannot have fat but you’re telling me I can? (The response below is typical of the feedback we received from a discussion group containing over 100 GPs, and is consistent with the advice we would usually give)

Healthcare professionals are very busy people with a wide range of responsibilities. Most healthcare professionals believed the evidence that stated that eating fats causes heart disease and therefore it’s a traditional approach to ‘prescribe’ a low fat diet for someone with CVD. They may however not have had the time to catch up with the wealth of evidence now emerging that we got this wrong, and that reducing carbohydrates (particularly refined carbohydrates) and processed foods can improve our lipid profile far better than a low-fat diet for many people.

Patient choice is essential. With this evidence that a high(er) fat approach can be beneficial you may wish to experiment with a real food diet with plenty of good fats and low(er) carbohydrates, and see if your lipid profile improves. For many there will be a clear benefit, and these results can then be shared with healthcare professionals who will be more likely to look into the benefits of this approach as a result. You may not want to experiment with this though and that is absolutely not a problem either! At the end of the day it is your life and you have ultimate responsibility for your own health, so you have to be comfortable with the decisions you make. Individuals can choose to do what they feel is best for themselves, it really is up to them.

When it comes to dietary advice we are in a stage of transition, and that is why there are conflicting messages. If you understand the different options available to you you can decide which approach you would like to take.

Where does the evidence to support the message that we don’t need to demonise saturated fat in natural, unprocessed foods come from?

There are a number of sources of evidence that suggest that saturated fat has been unfairly demonised, but the strongest source is a 2015 Cochrane systematic review and meta-analysis. Cochrane reviews are the best form of research evidence, so where possible it is better to use these rather than to cherry pick research papers. This review included 15 good quality randomised controlled trials (RCTS) which had a combined number of participants of over 58,000. When dietary saturated fat was reduced there was no change in overall mortality or the number of people who died of cardiovascular disease. The authors did report a 17% reduction in the number of cardiovascular events, but when only studies that significantly reduced saturated fat were included (the only studies we actually care about if we are investigating the effect of saturated fat) there was no difference in the number of these events either.

The bottom line of this review was that reducing saturated fat did not reduce mortality or cardiac events, so therefore there is not strong evidence that saturated fat should be avoided.

It is also worth noting that many natural, unprocessed foods which are considered healthy actually contain quite a lot of saturated fat. For example, olive oil contains about 14% saturated fat!

Which oil is best to use for cooking?

The best fats to cook with are saturated fats because they do not contain any double bonds. Double bonds are weak spots that easily become oxidised (damaged) forming free radicals, which are unstable chemicals that cause damage to body cells leading to inflammation in the body.

The most unhealthy oils are refined vegetable oils such as corn oil and sunflower oil as these contain a lot of polyunsaturated fats which contain multiple double bonds, causing the fat to be damaged by heat. These oils are heavily processed too, which can cause damage to some of the fats even before they are used for cooking.

It is, however, okay to cook with olive oil as it is predominately monounsaturated fat that only contains one weak spot, i.e. one double bond. Studies have been conducted on whether olive oil denatures at high temperatures, with results showing that the oil remains stable even when been exposed to heats of 180 degrees Celsius for 36 hours! Some studies have shown extra virgin olive oil to remain completely stable when used in deep frying.

However, the processing of most oils is ugly. There is nothing natural about the end product and so we don’t want to encourage people to buy them. We would only recommend the use of cold pressed oils, which avoids damaging of the unsaturated fats

How do nut oils and rice bran 100% oil compare to other oils used in cooking?

Nut oils are similar to olive oil, but with slightly more polyunsaturated fatty acids (16.9g vs 8g) and slightly less monounsaturated fatty acids (54.6g vs 73g). You can go onto any supermarket online to look at the nutritional breakdown of specific foods.

Overall, the fatty acid composition of rice bran oil is quite good. It contains approx. 21g saturated fat per 100g and an even mix between mono-unsaturated fat (MUFA) and polyunsaturated fat (PUFA) (approx. 35g per 100g). It is also quite stable when heated and has a high smoke point, which makes it suitable for frying at high temperatures. However, the biggest downside to rice bran oil is that it is not easy to make without high amounts of industrial processing. It is usually processed in a similar way to vegetable oils. An example of this process is as follows:
• The husk (outer layer) of the rice grain is removed leaving a brown rice grain
• The brown bran layer and rice germ are removed leaving behind a white rice grain
• Rice bran oil is extracted from the bran and germ which involves a highly industrialized and high pressure process (often including bleaching, high heats and the addition of chemicals such as sodium hydroxide solution)
• The resulting oil is then refined and separated into a clear liquid and solids (one particular brand (Alfa One) states that the ‘clear liquid is extra cold filtered for maximum purity’, which is why it claims to be 100% pure)

Which oils contain omega-6 fatty acids?

Vegetable oils rich in omega-6 fatty acids include sunflower, safflower, sesame, corn & soya.

Is coconut oil bad for my health?

Coconut oil is often discouraged due to its saturated fat content (around 90%). We know that this is not necessary however, particularly as saturated fat is a stable fat to cook with and has not been proven to increase the risk of CVD. A useful article about coconut oil can be found here.

Coconut oil may have beneficial properties, but there is a lack of studies in humans which makes the drawing of firm conclusions difficult. There are some strong potential mechanisms of action behind these proposed benefits, primarily the fact that it is comprised of medium-chain triglycerides (MCTs). MCT ingestion leads to elevated ketone levels which in-turn may decrease appetite. MCT consumption may also lead to immediate improvements in cognitive function in Alzheimer’s patients, and so may be useful as a therapeutic intervention in this population.

There are however several limitations to the heavily cited studies supporting the health benefits of coconut oil. All these studies are relatively short term (less than 12 weeks) and most of the participants are classified as ‘healthy’. This raises questions as to the applicability of this research to obese people and/or people who are hyperinsulinaemic (i.e. people with high insulin levels, like those with prediabetes or Type 2 diabetes). Lastly, very few studies actually use coconut oil in its pure form ; with most using isolated MCT oil. More work is needed with larger sample sizes, including persons of all body compositions and health statuses, and using coconut oil in isolation. In the meantime, there is no clear evidence that coconut oil is detrimental to health and there may well be some benefits. Thus there is no reason to think it cannot be included as part of a healthy diet.

Is olive oil really healthy or is it just the latest fad?

This oil, traditionally part of the Mediterranean diet, has been a dietary staple for some of the world’s healthiest populations. Studies show that the fats and antioxidants in it have some powerful health benefits, such as reducing inflammation and the risk of heart disease. Olive oil is pressed from olives, the fruits of the olive tree. However, some lower quality versions can be extracted using chemicals, or even diluted with other cheaper oils. Extra virgin olive oil is best because it is extracted using natural methods and no chemicals are used or heat applied. There is a lot of fraud in the olive oil market and it is essential to buy from a reputable seller to prevent getting olive oil that has been mixed with cheaper oils.

Which is healthier, butter or margarine spreads such as Flora?

Spreads are highly processed and often have a lot of additional ingredients added in. For example:
Flora ingredients = Water, Vegetable Oils in varying proportions (45%) (Sunflower, Linseed, Palm, Rapeseed), Buttermilk, Salt (1.4%), Emulsifiers (Mono- and Diglycerides of Fatty Acids, Sunflower Lecithin), Natural Flavouring (contains Milk), Preservative (Potassium Sorbate), Acid (Citric Acid), Vitamins A and D, Colour (Carotene)
Whereas butter is minimally processed and contains few ingredients: Butter ingredients = Cream, Salt (1.8%)

Spreads are also made from vegetable oils, which are high in omega-6 polyunsaturated fats and are often heavily processed (see FAQ about oils above).

We would therefore encourage you to choose natural, unprocessed foods where possible and not to worry about the natural fat content of these foods!

Should I consume ‘whole fat’ or ‘low fat’ milk & dairy?

Recent research supports the consumption of whole fat dairy products such as whole milk, full fat natural yoghurt and cheese in the prevention and management of obesity, Type 2 diabetes and heart disease. They also promote beneficial bacteria that keep our gut healthy. Whole fat products are less processed and are more nutrient dense, containing healthy stable fats and protein that create a feeling of fullness. They are a rich source of many vitamins and minerals such as calcium, zinc and the vitamins A, B and K2. Therefore, whole fat products are encouraged when adopting a Mediterranean or low carb dietary approach. Low fat yoghurts should be avoided as the fat tends to be replaced with sugar to maintain flavour and texture.

Eggs are a rich source of dietary cholesterol, so should I only eat two eggs per week?

It was previously thought that cholesterol containing foods increase blood cholesterol and the risk of heart disease and strokes. However, this has not been shown to be the case and dietary cholesterol does not need to be restricted. Eggs are among the most nutritious foods on the planet providing good quality protein as well as being loaded with vitamins and minerals. A recent clinical study demonstrated that eating 12 eggs per week is not detrimental compared to eating less than two eggs per week. Free range eggs are healthier than eggs from caged hens. Two eggs are classed as one portion of protein. Consume as part of a healthy balanced diet cooking them in a manner to suit your chosen dietary approach.

THE FAQ FORUM IS “READ-ONLY”, SO YOU WILL NOT BE ABLE TO ADD COMMENTS TO THIS THREAD. IF YOU HAVE ANY ADDITIONAL QUESTIONS OR WOULD LIKE TO DISCUSS ANYTHING RELATED TO WHAT YOU HAVE READ HERE THEN PLEASE RETURN TO THE MAIN FORUM