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The facts and myths over 'good' and 'bad' fats as part of our daily diet

 

A study published in the Lancet journal made the front cover of many newspapers worldwide. The data is from the Prospective Urban Rural Epidemiology (PURE) study and was led by researchers at McMaster University and Hamilton Health Sciences. It followed more than 135,000 people from 18 low income, middle income and high income countries.

The study asked people about their diet and followed them for an average of seven-and-a-half years. They used food frequency questionnaires - they're not as accurate as we would like, but they're used a lot in research.

The study aimed to observe its participants over time to see if they can statistically find relationships between observations. This was not the type of study we use for cause and effect. It does serve as an excellent hypothesis-generating study that could lead on to other controlled studies.

So, what made this study so special?

1. First and foremost, this study considered more than just Europe. Up until now, dietary guidelines are based on results from studies which are mainly from Europe.

Obviously this means that the current guidelines would be more suited to us in the UK rather than those in North America.

This study was special as it considered countries in North America as well as Europe, including low, middle and high income countries. Therefore they feel that the world nutrition guidelines should be adjusted according to their results.

What may be better is to tailor the guidelines to the particular countries instead of trying to get a more general guideline to fit everybody. After all, we know that ethnicity as well as socio-economic status influence disease risk.

2. This particular paper suggested that instead of quarter of our calories coming from fat, one third of our calories should come from fat. If we did this, we would have a 23% lower risk of dying.

Now, while this is being touted as ground-breaking stuff, it's actually not. We knew this. Most food standard agencies have the reference intake for fat set at a little more than 30%. Yes, this study showed that adequate intake of fat was good for us. Well, duh... fat helps absorb the likes of vitamin A, D, K and E.

Fats also give us nutrients that are essential to life and if not eaten in sufficient quantity, our body can't make them, and thus health suffers. For example, the much discussed and much encouraged omega 3 fatty acids.

3. The next thing it suggested was that the likes of monounsaturated fats and polyunsaturated fats were good for us. It wasn't surprising that this study showed that these fats were the most protective of all. This is why the Mediterranean diet is constantly being encouraged as its rich in unsaturated fats such as olive oil, avocado, nuts and seeds.

4. This study encouraged us to avoid eating too many carbohydrates. Sure, haven't we all heard this before? In this study, 65% of the 135,000 participants ate very high carbohydrate diets where over 60% of their calorie intake was carbohydrates.

In fact, 33% of the participants consumed diets that were over 70% carbohydrate. Sure, we're not all endurance athletes, and even if we were, we wouldn't be having over 70% of calories from carbs on all days of the week.

So this study showed that by overeating this food group, you're at a 28% greater risk of dying.

5. Sticking to the carbohydrate results, the researchers noted that the people more prone to this style of diet were of lower socio-economic backgrounds and relied on the likes of white bread and white rice.

In other words, processed carbohydrates that are low in fibre.

Now, isn't it safe to say guidelines on healthy eating generally encourage limiting refined carbs and encourage the more natural varieties of wholegrains?

6. I guess what surprised many people was that saturated fat intake was shown to be protective and was even associated with lower risk of stroke. Saturated fat is the fat that's hard at room temperature and is found in the likes of animal produce (meat, dairy and eggs), palm oil and the very trendy, but over-hyped coconut oil.

If you look at the trend of research what we've learnt is that not all saturated fats are created equal. In fact the fats in milk and yoghurt have been shown by top-tier research papers to be protective against stroke. Some other scientists are pointing out that research from Harvard cohort studies are missing from this piece of research, which may have impacted the overall results as Harvard University cohort studies showed that by replacing saturated fat with polyunsaturated fat you had favourable results on risk of death.

7. The point above is precisely why the 'If It Fits Your Macros' movement is so flawed. Yes 'IIFYM' encourages the right quantity of macronutrients for your body, but it doesn't consider quality. Saturated fat isn't the same when it's found in less healthy processed food rather than in natural foods our planet provides.

8. The other issue with not considering quality of nutrients is because it focuses solely on macronutrients and doesn't consider the other ingredients within our macronutrient foods like vitamins, minerals, phytocompounds and antioxidants. Of course they would make a difference to risk of death. Sure, you'd rarely go a week without reading about vitamin D, the fat soluble vitamin. Could the micronutrients have had an impact of the results encouraging moderate amounts of fat?

9. A hint at the importance of meeting our micronutrients as well as macronutrients is found when you consider the researchers second paper from the Pure study.

They showed that 375 to 500 grams of fruits, vegetables and legumes each day lead to the lowest risk of death. A portion of fruit and vegetables is 80 grams, therefore this paper encourages us to follow the common guidance of at least five a day.

In this study raw vegetable intake was more strongly associated with a lower risk of death compared to cooked vegetable intake.

This is similar to a different big review that showed salad was extremely protective against risk of death. Salad is good for us? Not too shocking.

10. What I'm surprised by is that not many people are talking ab out the fact that this paper showed that animal protein was inversely related to mortality or death, but plant protein had no impact.

Surely this should have been picked up by more people and then stimulated more discussions?

How to add healthy fat

There is no such thing as a 'bad fat'.

Breakfast: porridge made with oats, low-fat milk, banana and cinnamon

Tip: Add less oats but use regular milk and add pecans.

Snack: large apple

Tip: Choose a smaller apple but smear with peanut butter

Lunch: sandwich with brown bread, spinach, tomatoes, chicken breast

Tip: Why not have an open sandwich and swap a slice of bread for some avocado?

Snack: low-fat flavoured yoghurt

Tip: Opt for a natural yoghurt with a sprinkle of seeds

Dinner: chicken stir fry with rice

Tip: Why not eat less rice but add some cashews?

Nutrition and healthy eating isn't black and white. Generally speaking, there is no 'bad fat'.

A more accurate way of explaining it would be that a person is less healthy when they don't get the balance of fats within their diet right.

For example, someone may walk into my clinic and report only using coconut oil in meal preparation. The big issue here is that they are not eating a variety of fats.

Each fat is chemically different, making it act differently when inside the body. Additionally, each fat has its own mixture of nutrients within it, making it special and unique.

While it's known that we need to include some fat in our diet to remain healthy, and that we need to vary the sources of fats we eat.

Getting the balance right

Bad fats?

  •  Nutrition and healthy eating isn't black and white. Generally speaking, there is no 'bad fat'.

A more accurate way of explaining it would be that a person is less healthy when they don't get the balance of fats within their diet right.

For example, someone may walk into my clinic and report only using coconut oil in meal preparation. The big issue here is that they are not eating a variety of fats.

Each fat is chemically different, making it act differently when inside the body. Additionally, each fat has its own mixture of nutrients within it, making it special and unique.

Trans fats?

  • While it's known that we need to include some fat in our diet to remain healthy, and that we need to vary the sources of fats we eat, not all fats were created equal in terms of their positive effects on our health.
  •  A good example of these are 'trans fats'. There are small amounts of naturally-occurring trans fats within our diet.

For example cheese and cream, as well as beef and lamb. However, health concerns about these fatty acids have been flagged, resulting in many food companies reducing the amounts of trans fats in their products. To give you an example of this, until the Eighties, margarines contained 10-20% trans fats.

Due to reformulation, many margarines and spreads now have much lower trans fat content. Trans fats may also be produced when ordinary vegetable oils are heated to fry foods at very high temperatures.

  • This is one of the reasons takeaway foods can be the less healthy choice.

Additionally, foods that are produced using hardened vegetable oils typically contain some trans fats.

  • This is another reason why biscuits, pies, cakes and fried foods are less healthy.

To check the packet to see if the product contains trans fats, begin by looking at the ingredients.

  • A fully hydrogenated fat does not contain trans fat; only partially hydrogenated fat does.

If a food product contains partially hydrogenated fats or oils, it will almost certainly contain trans fats too, and the higher up the list the fat or oil appears, the more trans fats the product is likely to contain.

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