Quick introduction - based on my last few blood tests at annual check-ups, I have high cholesterol. I’m trying to lower that cholesterol with diet and exercise, so far with mixed results. Please note - I’m not asking for medical advice; any change in tactics will be between my MD and me.
My understanding is that there are foods that are high in cholesterol per se: for example, egg yolks. As a part of the regimen to reduce cholesterol, one should cut back on foods that are high in cholesterol. But the liver also makes cholesterol out of dietary fat, so a huge part of the game is to reduce the intake of calories from fat above the recommended daily limit. Cholesterol is not bad in and of itself - it is used by the body to create cell membranes - but past a certain age the body doesn’t need to create as many new cells, and that’s when the excess cholesterol in the blood stream starts to accumulate against the walls of the blood vessels.
My approach to fighting high cholesterol involves - reducing overall caloric intake, reducing fat in my diet (avoiding fatty foods and no added fat; steamed or poached rather than sauteed, for instance.) and increasing my exercise level. The idea is to use more calories in aerobic activity than I take in eating, causing the body to burn fat.
That’s my current understanding and I’m open to correction or clarification. What I don’t fully understand is what happens to the body fat that is burned during exercise? Does the liver use it to produce cholesterol the same way it would use dietary fat? I’m wondering if, for the next little while until I’m at a more ideal weight, my body fat is a source of cholesterol in the blood stream. Enlighten me, please.
I don’t have any direct answers, but there are a few other bits of info I can add to your knowledge. First, the fat that you burn away exercising is quite literally burned away. It’s broken down to give energy, eventually producing nothing but CO2 and water.
Also, you can lower cholesterol by eating more fiber. The mechanism here is refreshingly direct: the more fiber you eat, the more bile your liver produces to keep everything emulsified in your intestine. Cholesterol is a major component of bile, along with all sorts of other lipids. So some of it just ends up flushed down the toilet…
Lipid biochemistry is one of the more impenetrable research topics these days.
High cholesterol levels run on my dad’s side of the family and I inherited that trait. What I recall from conversations with my doctor is that the cholesterol you eat doesn’t necessarily get turned into the cholesterol in your bloodstream - that is actually more due to the saturated fats that you ingest. Generally speaking cholesterol comes from animal sources (like meat) but saturated fats can be found in all kinds of plant-based products - e.g. that bag of chips. Which is why those “No Cholesterol!” labels are misleading; while the two can go together (a big drippy burger) they don’t have to (palm oil).
Regarding “Where does the fat go when I exercise” we just had a thread on that the other month and someone explained the exact metabolic process; IIRC it worked out to your body burns fat to get the energy to move your muscles, and the byproducts of the reaction are water (which you get rid of through urination and sweating) and CO2 (which you exhale). I’ll see if I can find the thread.
Many thanks for that. I’m particularly gratified for the information on fibre - I knew higher fibre was a good idea, but I didn’t know that it had a bearing on cholesterol levels as well. I thought it was purely about roughage and satisfying bowel movements.
So then, in simple terms, body fat is the ‘easiest’ lipid for the body to make, to store and to burn?
I’m on a real Atkins diet, not that all bacon all the time diet with extra sugar alcohols that some people call Atkins. Over the last eight years or so I’ve lost eighty pounds and reduced my cholesterol from 200 mg/dl to 164 mg/dl on a diet consisting of 65% dietary fat and including over a dozen eggs every week. In my case at least, dietary fat is not a cause of high cholesterol.
Dietary cholesterol has minimal effect on blood cholesterol (i.e. LDL) levels. The proof of this statement follows from the rather old observation that even eating large quantities of cholesterol-rich food such as eggs leads to very little, if any, change in cholesterol levels.
What does matter with respect to changing blood levels (of LDL cholesterol) is how much saturated and trans fat is in the diet. So, if you boil your eggs, there’s unlikely to be much effect on cholesterol levels. On the other hand, if you fry them in a saturated fat like butter, your LDL will be affected (and will rise).
Notwithstanding the above, the major determinant of blood cholesterol level is genetic, not dietary (although dietary changes such as reducing saturated fat will help lower LDL levels). As a general rule, about 75% of a person’s cholesterol level is due to genetic influences (and produced in and by the body itself), with diet having a smaller effect, around 25% (don’t take these figures too literally, they’re just illustrative guidelines). By and large, people with high cholesterol have a genetic cause. Further, their percent of blood cholesterol from diet is less than 25%, perhaps 10% or so. The rest is produced by the body (liver).
I have come to the very reluctant conclusion that nearly everything doctors tell you about diet is wrong. There is a reason for this. They base their conclusions on studies using surrogate outcomes. This means that they decide that if high blood cholesterol is bad, then something that reduces blood cholesterol is good. The trouble is that the true outcome is do you live longer and have a better quality of life. Studying that is harder.
As has been often pointed out, Americans started out using fat-restricted diets 20 or 30 years ago and obesity levels shot up. Cause and effect? Who knows? I certainly don’t. I have been on a sodium-restricted diet for at least a decade.
Three days ago I read in the Science Times that serious questions have been raised about the benefits of low-salt diets. Researchers from Copenhagen University stated in 2003 that the evidence that low-salt diets are beneficial is inconsistent and small. A recent study in Italy, showed that a rigorous study of different diets on heart patients showed more hospitalizations and deaths among the low-salt group than the control. WTF?
Getting back to cholesterol, even the available evidence on statin drugs (which do extend life of those people who do not have bad liver reactions) suggests that the positive effect may actually be from reducing inflammation, rather than lowering cholesterol.
Yes, I’m with you on dietary cholesterol vs. cholesterol produced by the body, but if there’s no dietary source of saturated fats, doesn’t the body’s production of cholesterol decrease?
Yes, it’s too bad that Atkins has been so extensively mis-represented. While it isn’t my personal diet of choice, there are many things about it (‘increasing the quality of your carbohydrates’ seems to get overlooked in favour of the sensationalism of ‘eat more gravy’, which I don’t think was actually in any of his literature…) that are quite sensible.
And somehow, his ‘increased activity’ advice never seems to make the papers, either…