Harvard strikes again.
The February 2008 issue of the Harvard Heart Letter (subscription only) contains an article titled Triglycerides: A Big Fat Problem. The article discusses the correlation of elevated triglyceride levels with the development of coronary artery disease, then lists eight methods for reducing elevated triglyceride levels. It’s this list I want to discuss, but first let’s consider what triglycerides are and what they do.
Triglycerides are storage fats composed of three fatty acid chains hooked onto a glycerol (a 3-carbon carbohydrate) molecule. Fats travel in the blood as triglycerides and are stored in the cells as triglycerides. Each time a triglyceride moves into or out of a cell, the three fatty acids must first be removed from the glycerol backbone. After the fatty acids move across the cell membrane into or out of the cell, the fatty acids are then reattached in a process called esterification. (The particular bond between the fatty acids and the glycerol molecule is called an ester bond.)
There is undoubtedly a correlation between elevated levels of triglycerides in a fasting blood sample and the risk for heart disease. But, remember, although correlation implies causation it doesn’t really prove causation. As far as I can tell there is no firm data showing precisely how elevated levels of triglycerides actually drive the development of heart disease, but there is a considerable body of data demonstrating a strong correlation between elevated triglycdride levels and heart disease. My opinion, for what it’s worth, is that elevated levels of triglycerides in fasting blood are a marker for heart disease, meaning that whatever really causes heart disease also causes an elevation of triglycerides. A ridiculous example of this would be large belt sizes and obesity. Obese people wear large belts, but the belts don’t cause the obesity.
If this is the case, then simply lowering triglycerides won’t really reduce the risk of heart disease unless however you reduce triglycerides also reduces the real risk. Focusing on reducing triglycerides only would be comparable to an obese person buying a smaller belt in an effort to reduce his bulk because, after all, non-obese people have smaller belts.
We know that chronically elevated blood sugar, even if it is within what is considered the normal range, is a risk factor for heart disease. (Despite the focus over the past several decades on cholesterol in it’s many forms being a risk factor, this has never been conclusively shown to be true. The correlation between elevated blood sugar and heart disease, although dismissed or ignored by lipid-hypothesis promoters is much more closely associated in a dose response manner by the data than is cholesterol. See this old post for an explanation.)
After years of low-carb dieting myself and of taking care of thousands of patients on low-carb diets, I can tell you one thing with pretty much certainty: Low-carb diets reduce triglyceride levels markedly. And I can tell you that low-carb diets reduce blood sugar levels as well. Most of the patients with the highest fasting triglyceride levels also have elevated fasting blood sugars. On a low-carb diet, these patients drop their triglyceride levels like a rock.
Now, having this history, let’s take a look at the eight methods the Harvard Heart Letter recommends to help people reduce their triglycerides.
1. Beware of bad fats. Cut back on saturated fat (found in red meat and full-fat dairy foods) and trans fat (in some fried and commercially prepared foods).
Always the first recommendation by those in the grip of saturated fat hysteria. In their minds, no matter what the problem, cutting saturated fat makes it better. You can eat saturated fat to your heart’s content and still markedly reduce your triglyceride levels as long as you rigidly reduce your carbs. Same with trans fat. Needless to say, I’m not a fan of trans fat, but many patients have brought about tremendous reduction of their triglyceride levels while eating a lot of processed food by simply restricting their carbs. This isn’t the ideal situation, but it does give the lie to the idea that simply reducing trans fat will reduce triglyceride levels.
2. Go for good carbs. Eat whole grains and cut back on sugary drinks and foods.
Cutting back on sugary drinks and foods is sound advice. But they have to be virtually eliminated, not just cut back on if you expect much triglyceride lowering. Unfortunately, ‘good’ carbs elevate triglycrides as much as ‘bad’ carbs. And here they go again with the whole grains nonsense. Do these people not realize that we humans can’t eat whole grains. If you don’t believe me, go get some wheat grains and try to eat them. These grains are in a protective shell that we can’t break through to get at the starch within. In order to make the much-beloved whole grains edible, they have to be processed. What these people mean by whole grains are grains that have been processed up to the very last stage that removes all the brown husks from the flour. Whole grains, as these people mean them, are processed grains. You can go out and increase your consumption of five-grain, whole-wheat bread out the wazoo and watch your triglycerides rise. I can tell you categorically that eating whole grains as intended by these people will absolutely not lower your triglycerides. Eating real whole grains probably wouldn’t have much impact because they would pass through undigested.
3. Check your alcohol. Moderate drinking is good for the heart, unless you are a “responder” in whom alcohol dramatically boosts triglycerides. To determine if you’re a responder, avoid alcohol for three weeks and have your triglycerides tested.
The responder business counts only if there is actual demonstrated causation between elevated triglycerides and heart disease, which there isn’t. I suspect something else is going on here, but in all honesty, if I were a ‘responder’ I would probably cut back on my alcohol consumption until I figured out what is really going on. Thank God I’m not.
4. Go fish. Omega-3 fats in some fish lower triglycerides. Have fish twice a week.
Omage-3s do indeed work to lower triglycerides and are protective against heart attack. But I would have fish twice per week only if I wanted to increase my mercury levels along with my omega-3s. A much better way is by taking mercury-free fish oil and/or krill oil in supplement form. If you insist upon eating fish, go for sardines. They are small, low on the food chain and haven’t had time to concentrate much mercury.
5. Aim for a healthy weight. If you are overweight, aim to lose at least 5% to 10% of your weight to lower triglycerides.
Weight loss will really help to lower your triglycerides if you accomplish it via a low-carb diet. In fact, if you go on a rigid low-carb diet, you will lower your triglycerides dramatically long before you lose much weight.
6. Get moving. Exercise lowers triglycerides and boosts HDL.
I don’t have a problem with this recommendation, although you can lower triglycerides and raise HDL levels much more quickly with diet than you can with exercise.
7. Stop smoking. Smoking isn’t good for triglyceride levels (or anything else).
From the data I’ve read on smoking, that habit seems to drive the forces of insulin resistance and the metabolic syndrome. I’m pretty sure that insulin resistance and hyperinsulinemia are the driving forces behind elevated triglycerides so anything you can do to reduce these underlying problems will reduce your triglycerides. Having said that, however, I’ve had a number of patients who smoked, refused to quit despite my nagging, and still lowered their triglycerides by eating low-carb. But don’t get me wrong – I believe everyone who smokes should quit.
8. Get help from a medication. Niacin, fibrates, fish oil, and cholesterol-lowering statins have all been shown to lower triglycerides.
Readers of this blog can, I’m sure, imagine my response to this recommendation.
If you want to lower your triglycerides, lower your carbs. It’s as simple as that. But you’ve got to really lower your carbs, not just make a half-hearted stab at a low-carb diet. If your idea of lowering your carbs is avoiding a dessert from time to time, but continuing to chow down on ‘good’ carbs all day long, you’re going to be disappointed. But if you eat a lot of meat, even red meat, accompanied by green and colorful vegetables and low-carb fruits, you should be rewarded with triglycerides that are almost always below the 150 mg/dl limit of what’s considered ‘normal,’ and you will more than likely find yourself with fasting triglycerides below 100 mg/dl, which is a very good place to have them.
On another note, I’m traveling today, so probably won’t be able to get comments posted until late tonight. I’m planning a post on the vitamin D situation that so many people have written questions about, and you won’t believe the latest from Anthony Colpo. All to come this week.