Today’s edition of Dear Mark  is a relatively brief two-parter, but it’s a good one. First, I answer a question about HDL. Is higher good? Is higher (sometimes) bad? How does a person make sense of all the seemingly conflicting information? Then I explain how two statements about exercise and weight loss can be simultaneously correct and apparently contradictory. Is weight loss effective or useless for weight loss, or what?
I’m not sure I understand the HDL one. So higher HDL could lead to cardiovascular issues, but higher HDL is a byproduct of a healthy lifestyle? I think I’m missing something. Does anyone understand this to explain it?
Allow me to provide more details.
Higher HDL is complicated, and before we can interpret its health implications we must understand the many roles it plays in immune and cardiovascular health.
HDL reduces and neutralizes oxidative, inflammatory agents that damage LDL particles and lead to atherosclerotic lesions in our arteries. They can even clear oxidized LDL particles themselves, shuttling them to the liver for processing.
HDL can also attack and destroy pathogens and their toxins. In some cases, HDL particles carry antimicrobial poisons and trick pathogens into consuming them. HDL also “grabs” bacterial endotoxins and neutralizes their toxicity .
Sometimes, high HDL indicates an ongoing inflammatory assault or infection. For instance, high omega-6/omega-3 ratios have been shown to increase HDL cholesterol , but they do not suppress atherosclerosis. How can this be?
Perhaps the high omega-6/low omega-3 intake is increasing the susceptibility of LDL to oxidative damage. That’s what other studies show, generally—eating more dietary omega-6 (linoleic acid) makes your lipoproteins more polyunsaturated, unstable, and prone to oxidative damage . And since one of HDL’s primary jobs is to clean up oxidized LDL and the agents that oxidize it, the body might ramp up HDL production as a response to increased omega-6s.
High HDL can be “bad” if it indicates an infection or high oxidative stress. But it’s also “good” because it means a person’s body is producing more HDL to deal with the infection or inflammation.
Previous attempts to brute-force high HDL via drugs like torcetrapib have failed miserably. Actually, they succeeded in boosting HDL to incredible heights, but they failed by killing the people who experienced the HDL boosts .
HDL testing could use some updating, I think. The HDL measurement we get at the doctor generally refers to the weight of the HDL. If your HDL has picked up toxins, it will weigh more and come up higher than a person whose HDL has not—even if you have the same number of HDL particles. Far more illuminating is the HDL particle number . When HDL particle testing becomes more routine, I think we’ll have a better idea of what’s going on.
Thanks for the question!
I’m taking the Primal Health Coaching Certification course and I just started Key Concept #7 this morning, titled Exercise is ineffective for weight management. Imagine my surprise when I read #10 above: Exercise is important for weight loss. Looking forward to reading more about this and getting some resolution around this topic so that I have a clear message for my clients.
Note the slight nuance: exercise can be both ineffective for weight management and important during weight loss.
Exercise is a major factor in Primal Health Coaching after all. If it weren’t important, we wouldn’t mention it. It’s just not enough for weight loss.
What we were trying to emphasize is that clients not rely on exercise for weight loss. Doing so leads to many negative outcomes:
- Promotes an “earn it, burn it” mindset, where bad food choices can be “paid off” by cranking out another hour or two on the treadmill or on the bike. This only encourages people to make those bad food choices.
- Introduces guilt. If exercise is the major determinant of weight loss and you’re not losing weight, it necessarily follows that you’re a lazy, good-for-nothing layabout who just needs to work harder. A small subset of people respond to this kind of motivation positively. Most will retreat into junk food and withdraw completely.
- Leads to burn-out, especially in women. You don’t want to get into the exercise rat race, where exercise becomes a miserable job you clock into day in and day out. Exercise should be joyous, intense, and, yes, challenging. It shouldn’t be drudgery. It shouldn’t be mind-numbing. It should be acutely stressful but not chronically so.
- Doesn’t really work all that well. Exercise can certainly enhance weight loss alongside diet and make weight gain harder, but as a standalone intervention it falls short. There are millions of examples of people who try to exercise their way to weight loss (watch for a bunch coming this January!) and fail miserably.
That’s different from using exercise to enhance and improve weight loss, however. Alongside a good diet, exercise can:
- Help you preferentially lose fat and retain/gain muscle. Diet helps you lose weight. Exercise affects what type of weight you lose.
- Create a glycogen debt and increase non insulin-dependent glycogen storage, so you can eat (post-workout) carbs without altering insulin levels by much and shutting off fat loss.
Those are the two most important roles exercise plays in fat loss, but there’s also more. If you want to know how exactly exercise can enhance fat loss, check out the post I wrote earlier this year . It contains lots of information you can use to improve your client outcomes.
Thanks for your question, by the way! It’s an important distinction that has to be made.
That’s it for this week, everyone. I hope you all had a fantastic holiday. Thanks for reading!