Cholesterol: How low is too low?

How dangerous is low cholesterol? I’ve found a crap-load of sites but they all seem to say different things. Everyone agrees that some cholesterol is absolutely essential, since it’s needed to make some hormones. But how low is too low? The dangers of low cholesterol are said to be anxiety, depression, suicide, liver damage, certain types of cancer, and hemorrhagic stroke. Some aources, especially those promoting a vegetarian or low-meat diet, say 120-150 mg/dL is optimal. Others say 150 is too low, some say 160 is too low, some say 180 is too low.

I did some searches for hypocholesterolemia but the sites they returned seem to be mostly about undernourished elderly people or babies with birth defects. Is there a cutoff that defines hypocholesterolemia?

I’m curious, not worried. The cholesterol tests I’ve had in the past all fall in the range 167-190, and nobody told me that was anything to be concerned about. I certainly don’t feel anxious, depressed, suicidal, cancerous, or anything else but healthy.

AFAIK, there is no good medical consensus on this point. Nor any good studies.

Intriguing question, Bibliophage. From what I’ve read, conclusive evidence is not yet available.

FTR, I exercise a great deal and eat a reasonably low-fat diet. My cholesterol is in the 110-115 range and never has a physician diagnosed it as hypocholesterolemia or suggested I try to raise it. When I consulted a respected physician at NIH (actually we were dating) about it, she looked me over and said, “Don’t change a thing. These levels are ideal.”

A Japanese study in the early 90s suggested a link between very low cholesterol levels and certain cancers worried me, yet follow-up studies have not conclusively confirmed these findings. What I do know is that cholesterol levels among many Asians (those who haven’t adopted Western diets) fall in the 100-120 range, with no appreciable impact on health or longevity. Moreover, I’ve never heard a credible specialist claim that 167-190 is too low. Much the contrary, most medical specialists advise readings this low.

My husband’s is 16. He is doing ok, but boy does he have a wierd body chemistry.

Can it be to low? Doesn’t your body manufacture the cholesterol it needs? Can it not make enough?

If it really is 16, what is the break-down? What is the LDL and HDL? Tsunamisurfer says his down to 115. I wonder what is ratio is, too. My HDL is 90, which is almost his total cholesterol. The important thing is to keep a good ratio, at least 3:1. 4:1 has been given as OK. (That’s total cholesterol to HDL.) Mine is almost 2:1.

Your body will make cholesterol so unless you have some metabolic disorder, I don’t think this is a problem. I wonder, though, to hijack this thread, what is the minimal percentage of fat one should eat in a day. 30% is said to be ideal, with most of that being mono- or poly- unsaturated. I know someone who likes to keep it below 20%. To me, this seems too low. Fat, like cholesterol, is essential for many functions.

Lord, do I ever regret having posting my cholesterol level. Posting one’s VO2 max is one thing (which I posted before) but, frankly, I don’t want someone writing in with a late-breaking news report that says I’m destined for premature death. BTW, I cannot recall what my LDL/HDL levels are, but they are good.

Sixteen, of course, is impossible and a fairly lame joke.

I can’t recall the numbers exactly, but last time it was checked, mine was about 90 and the lipids (?) were around 31. My mother’s levels are also extrememly low; they told me it’s an inherited situation. I read that women with abnormally low cholesterol were at risk of having a certain kind of stroke during their 40’s, but sorry, I can’t find a cite for that just now. Anyway, after seeing the numbers the doctor told me - with a straight face - to go to Hardee’s posthaste! HA! I’m 20 lbs overweight as it is! There must be a way to raise cholesterol without eating a lot of fatty foods.

I’m not at work so I don’t have the references I’d like nearby. Still, I’ll offer a few comments.

Newborn humans and non-human primate adults in the wild have much lower cholesterol levels than do (Western) human adults. The former two groups are hardly the picture of poor health. My point, of course, is that most of us would likely still do quite well if our cholesterol levels dropped precipitously.

It is also worth emphasizing that the body doesn’t really “care” what the level of circulating cholesterol is, whether it’s low or high. What counts is the level inside the cells. In the classic genetic cause of hypercholesterolemia (i.e. familial hypercholeterolemia, a la Brown and Goldstein), you’d be right in some sense to state that the reason the blood cholesterol is high, is because the intracellular level is low.

It has been shown in population studies that individuals with the lowest cholesterol levels have a higher mortality rate than those whose cholesterol levels are somewhat higher (if you graphed mortality vs. cholesterol level, the curve would be J shaped*). Many people believe that this phenomenon is due to the fact many of the people who have the lowest cholesterol levels have cancer. (They are malnourished and this malnutrition can occur even before the cancer is otherwise manifest.) Further, people with chronic lung conditions (especially emphysema) and other serious diseases also tend to have low cholesterol levels. This too affects the linear relationship between cholesterol and mortality.

[sub][sup]* a similar J-shaped relation exists between blood pressure and mortality and between alcohol consumption and mortality.[/sup][/sub]

It is not a joke, and I do not care to have my veracity challenged so.

As I said, he has a wierd body chemistry. It was 31 the time before last when it was taken, but then he had been eating eggs everyday and a lot of seafood. I do not recall the break down. Doctors have hypothosized that it is so low due to an auto-immune problem, maybe the same one that took out his prostate. They aren’t sure, and since he seems to be in better health generally than they would expect, they don’t bother him too much trying to figure it out. His blood pressure and heart rate are typically on the extreme lower edge of what is considered normal. All this and he weighs around 270 lbs. He has an active job though and gets regular exercise. He also has odd allergies, such as fabric dye and nylon. He does not have that much debated “multiple environmental sensitivity”, just some very specific and odd allergies.

Don’t mistake this all for hypochondria either. If anything he is less sick than the doctors insist. For one thing, he walks (without a brace too, they had nylon in them) despite having 2 of the ligaments in his knee severed. Doctors have told him that it isn’t possible, but then they read the medical records and scratch their heads.

It is important to remember that very little of the health reccomendations made concerning cholesterol, weight, etc. are based on well understood disease mechanisms. They are mostly made based on statistical analysis. Many of the disease mechanisms are hypothesized, not observed. It is not like saying anthrax is caused by bacteria introduced into a subject. For one thing, you can’t reliably give a specific individual heart disease by making them fat, or raising their cholesterol level.

My husband has extremely low cholesterol levels. No one knows exactly why.

My sincere apologies and condolences. As “rather lame jokes” are often posted to serious questions in GQ, I thought this was yet another one. I’ve never heard of a cholesterol reading of only 16 and thought it physically impossible.