h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I very often hear about being overweight increasing risk of heart disease, and as far as I'm aware heart disease is one of the main (possibly the biggest?) killers there is, and finally of course that certain foods cause heart disease and also increasing weight.

I am a very slim person, actually technically underweight according the the BMI although I'm not terribly worried because I think its partly down to generally having quite a thin body structure, no broad shoulders for me . I also have a pretty big appetite and most days I will eat one meal of red meat, butter, bread, pasta eggs, that sort of stuff. After that my appetite will change and the next meal will probably be fish, fruit, vegetables, rice, yoghurt etc. but I'm aware that a large plateful a day is quite a lot of fatty stuff. Should I be worrying? How much can I trust my tastebuds on this?

Pretty much the only things that have been proven in large trials to increase the risk of heart disease are these:

Being a male
Smoking
Getting older
Smoking
Diabetes
Smoking
Hypertension
Smoking
High cholesterol

Obesity itself is just a soft risk factor, because it leads to diabetes (and probably hypertension too), but just being fat without any of the above risk factors hasn't been PROVEN to be bad in and of itself.

Eating fat may eventually make you fat if you don't exercise enough, and will almost certainly increase your cholesterol long-term. So, the answer to your question is, you should be careful but not too worried at this stage. You can always get your cholesterol checked at your GP if you want to be sure, but if you're under 40 even that's not too urgent.

Matt

An adage I've repeated over and over again on this topic is as simple as it is wise: trust your body. If you listen to your body and give it what it wants, it won't steer you wrong. Eat when you are hungry, and stop when you are full. Give in to your cravings, because a craving often means your body is missing something.

Red meat gets a bad rap because of its fat and cholesterol content, but it's also a valuable source of proteins and iron. Eggs are the closest thing to a perfect food source for proteins. The health warnings are out on these things because a breakfast of steak and eggs every morning will lead to problems. But taken in moderation, they are excellent food sources. So long as you are adequately balancing these foods with other, leaner sources (and your description leads me to believe you are), you're doing quite well.

You can also greatly reduce the negative effects of red meat simply by trimming the fat.

So far all we've covered is the diet side of the equation, but another important side is exercise. The way to keep any part of the body is strong working order is to use it frequently, and the heart definitely follows the rule. Regular cardiovascular exercise will dramatically decrease your chances of developing hypertension and has been demonstrated to have a positive effect on cholesterol, by increasing HDL levels (the good kind of cholesterol), which will then clean out the bad stuff (LDL).

The third factor in the equation is genetic, and there isn't a damned thing you can do about that one. Healthy young professional athletes have dropped dead from heart conditions.

BTW... you mentioned pasta and bread in your list of fatty foods earlier. You want to stay away from the processed bleached flour crap, which is just empty calories with little more nutritional value than the package it comes in. But whole grain breads and pastas are quite low in fat and cholesterol, high in soluble fiber (which helps reduce LDL) and are an excellent source of carbohydrates, which your body needs for energy. It's only if you're eating too many carbs and being too sedentary that all those carbs would be converted to fat and raise your risk of heart disease, and this doesn't appear to be a problem for you.

Can some of our medical fraternity please enlighten me on cholesterol. Some years ago I used to have a conversation with a friend, who was also a medical consultant and a published researcher. Almost eminent in a small field. She maintained that the vast majority of people were born with their cholesterol level and that there was little you could do to change it. If you pigged out on a dozen eggs your body would wind down it's production of cholesterol and vice versa.

She maintained that cholesterol had gotten a bad name only because blood clots contained high level of it.

Recent advertisng campaigns would suggest that cholesterol is the bete noire of good health. Is it or is it just an indicator of other maladies?

The higher your cholesterol, the greater your risk of heart disease. And there is certainly genetic variation in the 'base' cholesterol level, but it can be reduced by a number of different medications (most notably statins). Trials have shown that older people using a statin can decrease their risk of heart attack by around 25%.

Matt

On pasta I've found that buying the posh durum wheat semolina pasta really makes a huge improvement in taste, and although twice as expensive is still only about £1.50 a kg. I highly recommend for others who are on a low food budget (or anyone really).

Anyway, all this about cholesterol clogging your arteries, is that just imagery to say that cholesterol makes your blood clot or does it actually happen? If so, can cholesterol build up in skinny people's arteries or would it get used for whatever it is the body uses fat for?

Being young, in good shape etc. I'm not genuinely worried but as heart disease is such a huge killer that I've never really paid attention to its probably worth finding out.

basically high levels of cholesterol (hypercholesterolemia) can lead to the formation and accumulation of plaque deposits on the walls of arteries. Plaque is composed of cholesterol, other fatty substances, fibrous tissue, calcium and some other things (not the same plaque as the stuff colgate and other toothpastes talk about). When it builds up in the arteries plaques can grow large enough to significantly reduce the blood's flow through an artery.

But most of the damage occurs when they become fragile and rupture.

Plaques that rupture cause blood clots to form that can block blood flow or break off and travel to another part of the body.

So basically these things are cumulative and multifactoral (not surprising since pratically everything in biology is)

Cholesterol can't dissolve in blood. So in order for cholesterol to move through your bloodstream to areas where it's needed, cholesterol must travel in protein packages called lipoproteins.

LDL is the protein package that carries most of the cholesterol in your blood.

The more LDL you have in your blood, the higher your risk of heart disease.

HDL is the protein package that carries 20% to 30% of the cholesterol in most people's blood. Unlike LDL packages, which are loaded with cholesterol, HDL packages contain mostly protein. HDL is known as good cholesterol because it acts as your body's garbage collector for cholesterol.

So, in short (I am a scientist and so do sometimes have trouble not being a little long winded, sorry)
Yes cholesterol (mainly that found in LDL) can clog arteries,
it doesn't really make a difference if you're skinny, it's all about how much LDL you have in your blood at any one time, if you eat a really greasy meal then you'll have more fat than you need and so it can start accumulating in blood vessles.

If you're young, active with a diet rich in HDL loaded foods than not worrying about it seems a fairly appropriate state.

I think this is the nub of my earlier question



Am I right in thinking that hypercholesterolemia only effects less than 1% of the UK population hence that is the only sector that is at risk from high chlolesterol levels?

not really, although as far as I know they are definitely at a much higher risk for developing artherosclerosis and all the things that brings on. Usually plaques build up on parts of the artery wall that have been damaged which is not that unusual, and so even if you don't suffer from chronic hypercholesterolemia you may get a plaque build up on these damaged areas. Although it would probably take decades before it got big enough to cause any major problems.

Yes, maybe it's just my perception but the current medical views out there, and the advertisng campaigns, seem to suggest that high cholesterol levels will lead to heart attacks and coronaries.

Isn't it more complicated in that high cholesterol is an indicator of heart disease and not the cause hence reducing cholesterol doesn't effect heart disease.

well now we really get into the wonders of medical science and the murky depts of distinguishing between links, causative agents and results. It is all very confusing really.

No, high cholesterol isn't really an indicator of heart disease, by which I mean heart disease comes first, high cholesterol second.
While every person with high cholesterol may not develop heart disease, studies have shown that they are much more likely to.
(there are loads of studies showing this but a reasonably simple summary can be found at http://www.irishhealth.com/clin/cholesterol/chol_heart.html).

The build up of plaque, beginning with cholesterol accumulation eventually damages the lining of the artery, causing blood cells called platelets to form of a clot around the damaged area. This can narrow the artery considerably and cause unstable angina (a form of chest pain).
Sometimes the plaque becomes covered by scar tissue, which can rupture under any sudden stress. This creates a wider area of damage to the wall of the artery. A much larger clot will then form, leading to complete blockage. This clot can also become detached and travel to different parts of the body resulting in stroke etc.

So rather than being a result of heart disease it's much more likely that having high cholesterol levels is a contributing factor to some cases (by no means all) of certain types of heart disease

Heart disease and high cholesterol are indeed related. As plaque builds up in the arteries, blood flow becomes restricted. When you restrict the flow of a pressurized liquid, the pressure of the liquid increases (think of what happens when you hold your thumb over the end of a garden hose). That pressure increase will be reflected at the heart, which has to work harder to overcome the resistance introduced by all that plaque. Over time the heart has to work harder and harder, and eventually it fails.

Another metaphor for understanding this process is a vacuum cleaner. The vacuum motor hums along nicely until you get a sock stuck on the end. As soon as that happens the motor changes pitch to a high whine, indicating that it's working too hard to overcome the blockage. If you didn't remove the sock, you'd burn up the motor in short order.

Heart failure of this nature is actually less common. What usually happens is that plaque deposits create clots in the tiny blood vessels around the outside of the heart that supply the heart tissues with oxygen. This is where triple-bypass surgery comes into play.

Sorry couldn't get the link to fire.



I think this hits the nail on the head. Does the rate of the build up of plaque depend on your cholesterol level. Does reducing or attempting to reduce your cholesterol level have any bearing on the risk of a clot forming.

That is what the advertising industry would have us believe, Flora, Yakult etc., and I don't think it's the full story. Not that the advertisng industry would stretch the truth of course.

advertising companies stretch the truth, good gracious what an idea!

Yes, the rate of plaque build up will relate to the levels of cholesterol in your blood (other stuff probably has an impact too), the more cholesterol, the faster plaques develop. So reducing your LDL will reduce the speed at which these things grow, and reduce the risk of clots.
There is also some preliminary studies that seem to show that HDL seems to be able to grab some of the cholesterol in plaques and take it away from the artery wall, which is nice and adds to it's good guy image.

All this cholesterol stuff is a long way from being the whole story of heart disease though, but it's one of the few things that we can actually control relatively easily through diet and excercise.
So while for young healthy individuals it's definitely a good idea to prevent future problems by reducing LDL and increasing HDL intake in the diet I wouldn't panic.

Most people are not going to drop from a heart attack after eating a bag of chips and forgetting to have their Benecol, unless fries are all you eat for 5 years and the nearest you get to HDL is watching Carol Vordeman on the ads for Benecol.

PS sorry about that link, but a google search of cholesterol and heart disease gives enough reading material on the topic to distract you from work for hours

Try this:

http://www.irishhealth.com/clin/cholesterol/chol_heart.html

Cholesterol is necessary for the body to maintain its function, i e building of bile acids. The body itself produces approximately one gram of cholesterol daily.

Another aspect of fats in the blood circulation is triglycerides. Triglycerides are fats that are connected in units of three. They are used as energy sources and as part of cell membranes.

We need fat to maintain ourselves, - but not as much as most of us eat! Some people have better ability to use and dispose dietary fat, and therfore can eat more crisps and fries than others, without raising their rate of atherosclerosis.

In the western part of the world excess intake of dietary fats causes heart disease in young ages. So called fatty streaks, the first stage in atheroscerosis, can be seen as early as in the mid twenties....

'm still a little sceptical. I don't believe there is only one major study that connects cholesterol and heart disease. Also the article itself seems to raise concerns and answers the question:-



Hmmm.

I found this article, published last week, that I hope will convince you. This is a link to a summary, and from there you can go to the full article
http://aje.oxfordjournals.org/cgi/content/abstract/kwi309v1