I’ve learned a lot this week. So much so, that I’m going to have to split this into 2 posts to avoid you getting reader’s-fatigue.
Last Monday I was asked for help by a member of my family. Her husband had just been told by his doctor that he had extremely high cholesterol and that in particular his LDL levels were very high. He had been sent home with some basic nutrition advice and been told that if diet changes hadn’t made a noticeable difference when he is retested in a few weeks time then he will be prescribed statins.
Being known as a bit of a nutrition nut by my family, I was given the challenge to get his cholesterol levels down through diet changes.
When I started speaking to them both, I was shocked by how little basic education the doctor had given them about cholesterol. How are you meant to make sensible dietary decisions when you are out of your usual surroundings (e.g. a dinner in a restaurant) if you don’t understand the background? An excellent starting point for anyone, is a recent article done by Ryan Andrews on Precision Nutrition.
Why do we need cholesterol?
Everyone seems to be against cholesterol but it has an important role in our bodies. It is produced and destroyed as necessary by our livers (they produce 1-2mg of cholesterol daily) and it is used:
- to produce vitamin D, steroid hormones and bile acids;
- as one of the components of cell membranes;
- to aid in muscle growth as a precursor to important anabolic hormones;
- as the basis of some reproductive hormones (including androgens and estrogens);
- to increase membrane viscosity, increasing the exposure of proteins to compounds coming in from outside the cell and possibly therefore maximising the use of nutrients by the body.
Given the liver’s key role in all of this, it is immediately clear to me that any action we can take to look after and support our liver, which carries out several major metabolic functions in addition to the synthesising of cholesterol and bile salts, will help in our quest for acceptable cholesterol levels.
The different cholesterol types
Cholesterol is fatty and in order for it to be carried around the body, it has to be given a protein coating, known as a lipoprotein. There are three different lipoproteins which determine the different types of cholesterol:
- High-density lipoprotein (‘HDL’ or “good cholesterol”): This mops up excess cholesterol and moves it to the liver for disposal.
- Low-density lipoprotein (‘LDL’ or “bad cholesterol”): This is used to transport cholesterol and fat from the liver to the rest of the body where the cholesterol can serve its purpose. Unfortunately it gets a bad name as it is fragile and prone to oxidation, therefore it is one of the main ingredients in vessel plaque.
- Lp(a): This can restore damaged blood vessels in a healthy body but if levels are too high then it can concentrate at damaged artery sites leading to plaque build-up.
Generally accepted principles (though disputed by many reputable researchers) are that you want to keep your total cholesterol under 200mg/dl, with LDL below 100mg/dl and HDL above 60mg/dl.
You might be wondering at this point, as I do, whether the problem with our health is not the level of cholesterol in the blood but instead the damage being done to the arteries in the first place that causes the cholesterol to build up in its attempts to mend the arteries. However, my goal this week was to provide support, not create doubt regarding the capability of the medical profession.
Trans fats, meat and the stealth oil
There has been lots of noise about trans fats. Studies have shown that they raise LDL and also that they may lower HDL. Therefore, to sort out your cholesterol levels you probably want to reduce your trans fats. But what are they? Trans fats seem to come in two main forms:
- Elaidic acid – converted from oleic acid and the main trans fat found in soy bean oil
- Vaccenic acid – formed in animal products by bacteria in the rumen, one of the four stomachs in ruminating animals. This hydrogenates polyunsaturated fats and converts them into saturated and trans fats.
Mike Roussell summarises in a brief article about trans fats that epidemiological data (studies where results are put together through observation, a common tool with nutritional studies but also, through the nature of them, inherently less reliable) shows that “natural” trans fats, such as those in animal products, don’t increase the risk of heart disease. In fact, humans can convert vaccenic acid into CLA (conjugated linoleic acid).
So we want to avoid the elaidic acid form of the trans fats. That’s ok, just avoid soy oil.
But that’s not so easy, as Dr Kaayla Daniel explains in an interview with Chris Shugart. Soy oil is produced in huge quantities and is in almost everything that is processed. In fact, it is so prevalent that it doesn’t always get labelled on the packet as a trans fat or as soy oil. Look for anything that has vegetable oil, margarine or shortening in it for a start. Apparently you can almost guarantee that in reality it has soy oil in it.
Saturated Fats and Dairy
I was asked specifically to find out about dairy. Mostly because I went off on a tirade about trans fats when they told me that the doctor had advised that they should use margarine rather than butter. I really can’t believe that they said that. It borders on malpractice, in my view.
So, to summarise, saturated fats are bad, because they increase LDL and inhibit the anti-inflammatory effects of HDL, but they are also better than other fats because they increase and maintain elevated HDL levels.
Where does that leave us? I advised the following:
- ignore the doctor’s advice to use margarine instead of butter (I’d rather have a helping of LDL and HDL increasing saturated fats than a dose of LDL increasing trans fats), but
- do follow advice to use skimmed milk instead of semi-skimmed or whole milk (at least in the short term), and
- use all dairy products as little as possible and when using them, take them in moderation.
As a reminder, I also mentioned that there were saturated fats in meat. This is therefore the basis for recommendations that you limit your meat intake on a cholesterol-reducing diet. I’m more relaxed about this, though I did agree that using more chicken and less beef might be a good idea for a while, to kick-start the diet.
The Egg Debate
I was also shocked to hear that the doctor had advised against eating eggs. The best summary of why this is hugely outdated advice comes from Poliquin who explains that yes, eggs raise cholesterol. However, there are two important pieces of information missing:
- The study was done by the cereal board – you should question the reliability of a group of people whose best interests are in getting you to replace eggs as your breakfast food.
- The study was done before they differentiated between different cholesterol types.
Eggs raise HDL, not LDL, so if you are trying to lower LDL and raise HDL then the logical answer is to eat more eggs, not fewer.
So for today we have learned that while it is generally accepted that we need to keep our total cholesterol below 200mg/dl, with emphasis on HDL, we do still need cholesterol as it plays an important role in our bodies.
We’ve also learned that there are three main forms of cholesterol, designated by the different lipoprotein coatings that they have to enable them to be carried around the body and which give each cholesterol type a unique characteristic.
We’ve found that different fats affect our cholesterol levels in different ways. Trans fats raise LDL and are found in almost any processed food, while saturated fats are more complex since they increase LDL and may reduce the anti-inflammatory effects of HDL but they do also keep HDL elevated. When faced with a choice, choose the saturated fat (so keep the butter and ditch the margarine).
And finally we’ve established that eggs are, as anyone who does weight training knows, good for you and not the evil foodstuff that the medical profession would have you believe.