Cholesterol, Cancer, and Depression
Tuesday, March 27, 2012 at 09:52AM
Plant Positive

Running a Cholesterol Confusionist Gauntlet, Part 9 – Cancer and Depression

Cholesterol confusionists say low cholesterol will increase your chances of suffering from depression or cancer. Therefore, they think you should eat fatty animal foods so your cholesterol will be high. It’s pretty hard to find an expert opinion from the domains of cancer or depression research who would endorse this strategy.

Let’s first consider cancer. Apparently, Mr Colpo buys in on the idea that low cholesterol somehow promotes cancer.

In his blog about me, Mr Colpo refers to the Los Angeles Veterans study, as you can see in the second line from the bottom on this slide. I’ve included an excerpt from a magazine article so you can see how the confusionists try to make this study about cancer. A trial was conducted which placed some men on a control diet high in saturated fat and others on an experimental diet lower in saturated fat and higher in polyunsaturated fat. Mr Colpo says the men on the low saturated fat diet had a higher mortality rate. At least the magazine article informs us that over the five years of the study the men on that diet were less likely to die of cardiovascular disease. Unfortunately, that group also had extra deaths from cancer. So just from looking at these two confusionist references, we can see that two separate issues have been raised. The first is that a diet lower in saturated fat seemed to protect cardiovascular health. Anthony Colpo had lower standards of truth telling here than Men’s Health because he decided you didn’t need to know that on the topic he is actually writing about, namely the lipid hypothesis, this study hurts his argument. The second issue is the question of whether either a diet high in polyunsaturated oils or low cholesterol will shorten your life despite your healthier heart by giving you cancer. These are two separate issues which the confusionists would like to conflate. They want to conflate them because it’s so clear that saturated fats and high cholesterol will hurt your heart. They need to attach a phony concern about cancer to distract you from that.

Here is a portion of the summary for this study. We see that the experimental diet did lower the cholesterol levels of the men who ate it.

And we can see that this translated into an avoidance of cardiovascular events. The lipid hypothesis is supported again. We also see here that, sure enough, there was a higher death rate in this group. Now that’s a problem. The researchers conducting the study said they did not believe the experimental diet was responsible for this.

Two of the original Los Angeles researchers reported a higher rate of cancer over an eight-year period in the experimental group.

This difference in cancer death rate was studied by other researchers. Yes, this one study in Los Angeles showed a higher rate of cancer on a higher polyunsaturated fat diet. But in other studies of this kind this trend did not continue. Other studies showed the opposite result. Overall mortality was not higher in the other studies, either.

Upon closer examination, more than half of the cancer deaths in the experimental group in Los Angeles occurred in men who did not adhere closely to the diet, so one can hardly connect their deaths to the experimental diet.

Here is the result of a recent huge study covering over 19 years that examined the relationship between cholesterol and cancer incidence. It was found that only a short-term relationship between cancer and cholesterol existed. Over time periods longer than five months, the association disappeared. I want to say as an aside, I cover a lot of ground fast in my videos. Some of these studies really deserve to be read carefully and understood and this is one of those studies. It’s a great one. You should look it up.

These researchers concluded that any association between cancer and cholesterol reflected – say it with me – reverse causation. They noted that some cancer cells were sucking up the LDL from the blood faster than normal cells, lowering cholesterol concentrations. This is one way cancer lowers cholesterol. They also made a very important observation. Subjects with high cholesterol would appear to have lower rates of cancer because their cholesterol levels were killing them through cardiovascular disease before their cancer had a chance to develop enough to be noticed. In other words, the people with high cholesterol were too dead to get cancer. That’s pretty obvious, isn’t it? If you aren’t dying of heart disease, you’ll end up dying later of something else, something like cancer.

Mr Colpo, this is an example of something called survivor bias.

If the confusionists were right that low cholesterol caused cancer, you would expect to see low rates of cancer in countries that eat lots of saturated fat and have high cholesterol. When you look at the countries that have the highest rates of cancer, it becomes obvious that this is not the case.

Of course, T Colin Campbell and his colleagues observed both low cholesterol AND low rates of cancer among the Chinese people they studied. This pretty much blows up that confusionist hypothesis. Campbell’s work is so inconvenient for the confusionists, it’s easy to see why they want to discredit him.

The cholesterol confusionists might want to retire this particular line of attack. This recent paper states that high cholesterol is strongly linked to prostate cancer progression. The authors consider cholesterol-lowering to be a way to slow down this particular cancer.

In this study, patients with esophageal cancer who had high cholesterol were more likely to have tumor cells enter their lymphatic system. That’s very bad news for them.

Let’s pull back from this odd focus on cancer to remember the big picture. Saturated fat is in animal foods, and there have been many studies that have pointed to an association between these foods and various cancers. Don’t let the confusionists confuse you when it comes to diet and cancer.

Let’s shift now to suicide and depression. Even if we decided to pretend there is a direct link between low cholesterol and suicide just as Colpo says, you would still be better off taking your chances with low cholesterol to avoid dying of heart disease. The mortality rate for heart disease is eighteen times higher than the mortality rate associated with suicide. Do you think Mr Colpo is really interested in saving lives with his conjecture about suicide and cholesterol? I don’t. Do you think the science linking low cholesterol to suicide is as strong as the science linking high cholesterol to heart disease? There is only one right answer to this question. Mr Colpo, like other Paleo cranks, does not apply his skepticism consistently. With his every argument he further demonstrates his bias. It’s all just a game to him. The evidence of a causal role for high cholesterol in heart disease is extremely robust while the evidence of a causal role for low cholesterol in depression and suicide is extremely weak.

As I said, in video 41, the epidemiology of depression does not seem to support this alleged relationship.

If we look at the whole of the 20th century we can see that it is claimed that rates of depression increased quite dramatically …

Just as the amounts of meat and dairy consumed increased dramatically…

Right along with the increase in heart disease.

Now don’t misunderstand me. I’m not saying saturated fat and cholesterol cause depression. As I said in video 41, depression is way too complicated to be explained this way. Also, I don’t necessarily believe that depression has increased over the 20th century. My point is that it’s hard to find epidemiological support for a connection between depression and cholesterol. Remember, the epidemiological research into heart disease, especially the Seven Countries Study of Ancel Keys, is one of the major pillars supporting the lipid hypothesis. If the link between low cholesterol and depression were so clear, there would be plenty of papers out there elucidating it. I’ve looked at the epidemiology of depression and I do not see a relationship with diet.

Mr Colpo’s claims about depression got me thinking about his buy-in on Paleologic and the uncomfortable contradictions that creates. Of course, humans evolved consuming certain foods, but of what use is that knowledge now? To Colpo, this means we should eat meat. But this creates a problem for him, a problem Loren Cordain intelligently anticipated and avoided. You see, for all his faults, Cordain does not rely on the typical denialist belief system.

Cordain looked around at the cholesterol numbers of hunter gatherers and realized that any diet fad based on human evolution would have to account for the low cholesterol levels that were likely the norm during the Paleolithic. Of course, he missed some of the most obvious reasons for this, such as low food energy consumption and parasitic infection.

If hunter gatherers have low cholesterol levels, then by Anthony Colpo’s logic they must be depressed and suicidal. But this does not seem to be true. Depression seems relatively rare among these people.

Here’s another reference for that. It names the !KungSan as being relatively free of depressive symptoms.

And the !KungSan had some nice low cholesterol scores. I think Colpo needs to choose between his belief in an evolved requirement for a meaty diet and his belief that high cholesterol somehow protects people from depression and cancer. Until he does, he seems to just be looking for any flimsy excuse he can find to eat meat and saturated fat.

There is plenty of reason to doubt that low cholesterol causes depression. I’m guessing most of you watching this know this paper. Vegetarian diets are said here to be associated with healthy mood states. That should be enough to dispel Colpo’s hypothesis but I have plenty more material than this.

The most obvious explanation for any perceived link between low cholesterol and depression is, of course, reverse causation. I showed you this slide in my video number 41. There are several plausible means by which depression might cause low cholesterol, and not the other way around. I won’t read this slide now to save time but you should read it.

Depression itself is believed to be responsible for a lowering of cholesterol for some.

The authors of this paper examining cholesterol and depression have no denialist agenda, so unlike Mr Colpo they did not ignore the multiple possibilities for reverse causation. These include poor health (which might lower cholesterol as well as mood) and poor appetite (which would reduce total calories and consequently cholesterol levels as well). They note that the evidence they’d seen from statin trials suggested that low cholesterol itself does not cause mental health problems.

Here’s another paper that found no association between cholesterol levels and depression.

Here is a 2008 meta-analysis looking at the relationship between cholesterol and depression. The results were all over the map. Higher total cholesterol was associated with lower depression. An inverse association with LDL was called non-significant. Higher HDL, which the low-carbers say protects them, was associated with more depression.

In these elderly subjects, men with low LDL and women with low HDL were more likely to be depressed, but these were elderly individuals who certainly had comorbidities. This is likely another example of reverse causation.

Here is a case study suggesting a link between low cholesterol and violent behavior but this has nothing to do with diet. Since genetic factors affect both cholesterol levels and mental health, it is possible some of the associations between cholesterol and mental health challenges observed in some studies are due to common genetic variants.

In this study, the opposite of what Colpo’s hypothesis would predict was observed. Older people who were depressed tended to consume more saturated fat and cholesterol. Maybe they felt the need to eat more comfort food. For me, it’s easy to imagine how a high-saturated fat diet might make you depressed. This is pretty obvious…

Having a heart attack would certainly make you feel a bit down, don’t you think? In this study, depression was three times more common in patients after a heart attack. Knowing this, I think I will try to reduce my risk of being depressed after a heart attack by trying not to have a heart attack at all. That’s a good plan, don’t you think?

I have seen several studies that showed a drop in cholesterol levels after a heart attack. Maybe following Anthony Colpo’s advice to eat lots of saturated fats will actually lower both your cholesterol and your mood eventually, since you’re raising your chances of having a heart attack if you follow his advice.

Also, if you eat more calorie-dense, saturated-fat-laden animal foods, you’ll probably pack on the fat, and that’s another path to depression. In this study, as saturated fat consumption went up, LDL went up as well, and so did body mass index.

I doubt you’ll be surprised to learn that obesity and depression are often a package deal.

Along these lines, having metabolic syndrome might make you depressed, too. Having metabolic syndrome does suggest low HDL so maybe that’s from where some of the talk of low total cholesterol and depression comes.

What about the idea that low cholesterol causes hostile behavior, sort of like the hostile way Anthony Colpo writes about me? In this study, a low fat, high complex carbohydrate diet improved symptoms of depression and hostility at the same time as it lowered cholesterol levels. Does this study not destroy Colpo’s half-baked ideas about depression and cholesterol?

Here’s one of Colpo’s more laughable passages. He references a study in which monkeys fed a so-called “prudent” diet had lower cholesterol and displayed more aggressive behavior than those fed a so-called “luxury” diet. Anyone calling a high-fat diet a “luxury diet” is making clear his taste in food, so this indicates a subtle bias to me.  A diet of 43% fat doesn’t sound so much like a luxury diet to me as much as a lethargy diet. Before I went vegan, I used to feel like I needed a nap after eating a fatty meal. Come to think of it, a nap would have seemed pretty luxurious to me back then, so maybe the name is appropriate.

Here’s the study Colpo is writing about. Check out the diets fed to the monkeys at the right. The prudent diet, that is, the one that made the monkeys more aggressive, featured such natural and prudent monkey foods as casein, wheat flour, sucrose, Crisco, and a fiber supplement called Alphacel. Now let me ask you, if you were a monkey who belonged in a rainforest somewhere eating figs, but instead you had someone feed you this garbage in your cage, do you think it might make you a bit more aggressive? As for the other diet, you can be sure the monkeys really felt they were luxuriating in their fantasy luxury diet of lard, butter, egg yolk, beef tallow, and wheat flour. They received hardly any Alphacel to move that glop through their bowels. Maybe the monkeys were more low-key on this diet because they were constipated. If you are tempted to joke that the monkeys may have been smarter than the researchers who conducted this study, I can understand where you’re coming from.

All that sugar and empty calories made me think those aggressive monkeys were probably having glycemic problems from that synthetic and cruel diet. Mr Colpo, you may be completely unaware that refined carbs cause hypoglycemia and consequently can lead to aggressive behavior. Depression can result as well. This is probably what those poor monkeys were being put through. I know you think you’re a real expert in nutrition but this is pretty basic stuff.

Here’s a study showing that cholesterol lowering with a statin did not effect anger, impulsiveness, or depression. How do you explain that, Mr Colpo? I wonder what he’ll say. Let’s see… If lower cholesterol hurts your mood but statins don’t, then maybe Colpo will say that statins must compensate for the bad effects of lower cholesterol by pulling through with still more pleiotropic effects, effects that make you happier. Maybe that is one more benefit of statins he’ll add to his big list.

Lastly, I present to you this recent study which investigated the effects on mood of removing meats from the diet. Thirty-nine people were fed diets classified as omnivorous, fish, or vegetarian. The vegetarian group experienced improvements in various mood measurements well beyond those demonstrated on the other two diets. This was another damaging study for Colpo’s nonsense hypothesis about saturated fat and mood. This study allows us to look past the complicated issues of low cholesterol and its causes and effects and instead brings us back to the practical issue of diet. This result should cause you to doubt that you need fatty animal foods to maintain your emotional health. I’ll add that a plant-based diet may enhance your mood even further should you contemplate the violence you are sparing innocent animals.

We have arrived at the final segment of my response to Colpo, the many references he makes to pharmaceuticals to make his case against the lipid hypothesis. Please join me in the next video.

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