I wrote previously how learning that I had a family history of early heart disease prompted me to take a more proactive approach to managing my health. After getting tested for a number of markers associated with heart disease, and scoring in the high range for some of them, I began forming an action plan.
Of course I knew the basic plan would be to "eat well and exercise", as per the advice most doctors would offer. But I wanted more specifics. What's *my* optimal diet for preventing heart disease? Which has the greater effect, diet or exercise? Is focusing on one alone sufficient? How much should I be exercising?
Diet
I began by focusing on just diet. Generally I eat pretty well, avoiding sugar and refined carbs. This helps keep my weight under control (I have an endomorphic body type) but I do eat a fair amount of meat (minimum twice a day) and especially red meat (minimum twice a week). There seemed to be much literature advocating a plant-based diet as a means of not only preventing heart disease but reversing it. The physician behind much of this work, Dr Dean Ornish, worked with Bill Cinton to help him recover from his quadruple bypass in 2004.
I decided to try a modified version of the strict plant-based diet. I cut out all meat, fish, dairy and restricted eggs to a maximum of twice a week. I found this change much tougher than I'd expected, I felt gassy and low-energy after the second week. After one month I made a modification and switched to occasionally having lean, white meat or fish for dinner but still no red meat at all. I found this more workable and would still often go days without any meat at all.
After two months I ran another set of blood tests to see if my heart disease markers had changed:
| Marker | Change | Target |
|---|---|---|
| Total Cholesterol | 206 mg/dL (+/- 0%) | < 200 mg/dL |
| LDL (bad cholesterol) | 127 -> 119 mg/dL (- 6%) | < 100 mg/dL |
| HDL (good cholesterol) | 70 -> 77 mg/dL (+ 10%) | > 40 mg/dL |
I was happy to see improvement in the ratio of my LDL and HDL. Even though it'd only been two months, I was somewhat surprised that my total cholesterol hadn't changed at all though. This made me curious about the exact link between diet and cholesterol. I began looking into the research connecting them. I discovered something that stunned me. For 70% of people, diet supposedly has minimal effect on their cholesterol levels (more detailed explanation below).
More concerning to me was that my dietary change had negligible effect on two of the more advanced heart disease markers, in fact they showed a tiny increase:
| Marker | Change | Target |
|---|---|---|
| Apo(B) | 98 -> 102 mg/dL (+ 4%) | < 80 mg/dL |
| Lp(a) | 148 -> 151 nmol/L (+ 2%) | < 75 mg/dL |
I found there was considerable evidence that Apo(B) may actually be a more important predictor of heart disease risk than LDL cholesterol. The Canadian Cardiovascular Society has included Apo(B) in its heart disease management guideline since 2009. A quick explanation of the theory is that the number of cholesterol particles you have, is more important than your total amount of cholesterol. Apo(B) count is a proxy for the number of cholesterol particles because each particle has exactly one Apo(B) molecule.
There were some more notable changes in two of my other makers:
| Marker | Change | Target |
|---|---|---|
| Triglycerides (fat in your blood) | 80 -> 49 mg/dL (- 39%) | < 150 mg/dL |
| hs-CRP (Inflammation) | 3.1 -> 0.8 mg/L (- 77%) | <1 mg/L |
I was happy to get my triglycerides down but they were already in the healthy range, unlike my other markers. It was also hard to know what to make of the inflammation decrease, since it's a notoriously variable reading (intense exercise or a recovering from a cold could both raise it). Frankly, it was a surprise to me that I'd scored so highly in the first place and I suspect it could have just been a funky reading (human involvement in the testing process means there's an inevitable margin for error on these tests).
Exercise
During these two months I'd not been exercising at all. Now I kept the same diet and signed up for a crossfit gym, working out there 3x a week. Two months later I ran the tests again. This time I found even fewer changes in my cholesterol levels:
| Marker | Change | Target |
|---|---|---|
| Total Cholesterol | 206 md/dL (+/- 0%) | < 200 mg/dL |
| LDL (bad cholesterol) | 119 mg/dL (+/- 0%) | < 100 mg/dL |
| HDL (good cholesterol) | 77 -> 73 md/dL (- 5%) | > 40 mg/dL |
However I saw some significant movement in my other markers:
| Marker | Change | Target |
|---|---|---|
| Apo(B) | 102 - 90 mg/dL (- 12%) | < 80 mg/dL |
| Lp(a) | 151 -> 88 nmol/L (- 42%) | < 75 mg/dL |
Given the importance of Apo(B) in particular, as I mentioned above, this was really encouraging. My remaining markers showed some mixed results:
| Marker | Change | Target |
|---|---|---|
| Triglycerides | 49 -> 61 mg/dL (+ 25%) | < 150 mg/dL |
| hs-CRP (Inflammation) | 0.8 -> 0.5 mg/L (- 37.5%) | < 1 mg/L |
Conclusion
Given the importance of Apo(B) as a predictor of heart disease and its non-response to my diet-only modification, regular exercise is clearly an essential component of an effective heart disease prevention plan for me.
Looking at my LDL trend, the lack of change in the past two months is interesting. I can think of two explanations; 1) my body is sensitive to dietary cholesterol and I'd have to adopt a strict vegetarian/vegan diet over a longer period of time to bring it down into what's considered the healthy range, 2) my exercise regime increased my body's production of LDL and cancelled out any decrease from my diet modification (there is some precedent that increased muscle mass elevates LDL levels, and since starting crossfit I've gained just over 3lbs of muscle mass).
I plan to continue with my regime of limiting meat intake (I actually quite enjoy it now as it gives me a reason to explore new places and foods for lunch) and regular exercising. Hopefully in another couple of months my Apo(B) in particular will continue moving towards the healthy range.
I've always known that eating well and exercising are things I should be doing but tying them to specific data that affects how long I'm going to live for, gives me a level of motivation I've not felt before.
Thanks to Dr Mager for reading a draft of this.
HN discussion here.
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Notes
For the full explanation of how cholesterol works, I'd really recommend reading The Straight Dope on Cholesterol. It's an incredibly detailed set of articles though. This is a fairly good summary of the main points, though still a decent read itself. I'll attempt to give a super simple nutshell explanation here:
- Cholesterol comes both from the food you eat (only animal food products) and is also produced by your liver (it's present in every cell in your body).
- The type of cholesterol from food is typically too large in size for your cells to absorb it, so it just passes straight through.