Track Your Plaque: Safer at any score

Imagine two people.

Tom is a 50-year old man. Tom's initial heart scan score was 500--a concerning score that carries a 5% risk for heart attack per year.

Harry is also 50 years old. His heart scan score is 100--also a concerning score, but not to the same degree as Tom's much higher score.

Tom follows the Track Your Plaque program. He achieves the 60:60:60 lipid targets; chooses healthy foods, including elimination of wheat; takes fish oil at a therapeutic dose; increase his blood vitamin D level to 60-70 ng/ml, etc. One year later, Tom's heart scan score is 400, representing a 20% reduction from his starting score.

Harry, on the other hand, doesn't understand the implications of his score. Neither does his doctor. He's casually provided a prescription for a cholesterol drug by his doctor, a brief admonition to follow a low-fat diet, and little else. One year later, Harry's heart scan score is 200, a doubling (100% increase) of the original score.

At this point, we're left with Tom having a score of 400, Harry with a score of 200. That is, Tom has twice Harry's score, 200 points higher. Who's better off?

Tom with the score of 400 is better off. Even though he has a significantly higher score, Tom's plaque is regressing. Tom's plaque is therefore quiescent with active components being extracted, inflammation subsiding, the artery in a more relaxed state, etc.

Harry's plaque, in contrast, is active and growing: inflammatory cells are abundant and producing enzymes that degrade supportive tissue, constrictive factors are released that cause the artery to pinch partially closed, fatty materials accumulate and trigger a cascade of abnormal responses.

So it's not just the score--the quantity of atherosclerotic plaque present--but the state of activity of the plaque: Is it growing, is it being reduced? Is there escalating or subsiding inflammation? Is plaque filled with degradative enzymes or quiescent?

Following the Track Your Plaque program therefore leads us to the notion that it's not the score that's most important; the most important thing is what you're doing about it. We sometimes say that Track Your Plaque makes you safer at any score.

Triglyceride and chylomicron "stacking"

Continuing the comments started in Grazing is for cattle, here's an interesting study from the Oxford Center for Diabetes, Endocrinology and Metabolism.

Volunteers were fed a test meal breakfast of Rice Krispies, a banana, and a chocolate milkshake (76.4 grams carbohydrates, 51.9 grams fat, 12.2 grams protein). Lunch was served 5 hours later and consisted of a cheese sandwich and a second chocolate milkshake 43.4 grams carbohydrates, 49.6 grams fat, 24.0 grams protein). Frequent blood samples were then assessed over the day. (Don't try this at home: These are obviously very dangerous foods!)

Here's the pattern of triglycerides that was observed (1st dotted vertical line = breakfast, 2nd dotted vertical line = lunch):



Note that triglycerides only begin to decline 3-4 hours after breakfast, only to peak higher after lunch.


Here's the pattern observed for chylomicrons, the "granddaddy" of lipoproteins that derives from intestinal absorption of fatty acids:



Both graphs from Heath RB et al Am J Phyiol Endocrinol Metab 2006.


With chylomicrons, note a similar pattern to triglycerides: Chylomicrons begin to decline at 3-4 hours, only to peak higher after lunch.

This is the first study to examine the effect of sequential meals on such postprandial (after-eating) patterns. But it makes the graphic point that, if insufficient time is permitted between meals, both triglycerides and chylomicrons will "stack" themselves higher and higher. (Chylomicrons are subjected to processing by the enzyme, lipoprotein lipase, to form highly atherogenic, or plaque-causing, chylomicron remnants.)

While not examined in this study, my bet is that "grazing," i.e., eating small meals or snacks frequently, is an extreme instance of triglyceride, chylomicron, and chylomicron remnant stacking. That can only lead to one thing: accelerated heart and vascular plaque.

What is a healthy vitamin D blood level?

When measuring blood levels of vitamin D (as 25-hydroxy vitamin D), what constitutes a desirable level?

There's no study that directly examines this question, no study that enrolled thousands of people and assigned a placebo group and groups receiving escalating doses of vitamin D and/or achieved higher levels of vitamin D, then observed for development of cancer, diabetes, depression, heart disease, multiple sclerosis, osteoporosis, osteoarthritis, etc. Such a study would requires many thousands of participants (particularly to observe cancer and multiple sclerosis incidence), many years of observation, and many tens of millions of dollars. Nope, only a drug company could afford such costs.

So we have to piece together various observations and extrapolate what we believe to be the ideal level of vitamin D. Epidemiologic observations in several cancers (breast, colon, prostate, and bladder) suggest that a 25-hydroxy vitamin D level of 30 ng/ml or higher is desirable (with less cancer incidence above this level). Other data suggest a level of 52 ng/ml or greater is desirable. Unfortunately, much cancer research looked at intake of vitamin D from food and supplement sources, rather than actual blood levels. We also have to factor in the great individual variation in vitamin D metabolism, with a single dose yielding variable blood levels (as much as a 10-fold difference). There's also the variation introduced by vitamin D-receptor variation (genetic polymorphisms).

A new study using vitamin D administration helps chart the desirable levels of vitamin D.

Vitamin D supplementation reduces insulin resistance in South Asian women living in New Zealand who are insulin resistant and vitamin D deficient - a randomised, placebo-controlled trial.

In this New Zealand study, 42 women (23 to 68 years old) were given 4000 units vitamin D, 39 women given placebo. Median 25-hydroxy vitamin D levels increased from 21 nmol/L (8.4 ng/ml) to 75 nmol/L (30 ng/ml). Both HOMA (a measure of insulin sensitivity) and fasting insulin levels improved, with greatest improvement seen at 25-hydroxy vitamin D levels of 80-119 nmol/L (32-47.6 ng/ml) or greater.

We also know that a vacation on a Caribbean beach in a bathing suit will increase vitamin D blood levels to the 80-110 ng/ml range without ill-effect (at least in young people who maintain the capacity to activate vitamin D in the skin, a phenomenon that declines as we age).

So do we really know the truly ideal level of vitamin D to achieve? I believe that, given the above observations, it is reasonable to extrapolate that the ideal vitamin D blood level likely lies somewhere above 50 ng/ml. We also know that vitamin D toxicity (i.e., hypercalcemia) is virtually unheard of until vitamin D blood levels approach 150 ng/ml, and even then is inconsistent. The health benefits of vitamin D supplementation are so tremendous, that I am not willing to wait for the prospective data to explore this question fully. For now, I aim for a blood level of vitamin D of 60-70 ng/ml (150-175 nmol/L).

Grazing is for cattle

Many dietitians and nutritionists advise many people today to "graze," i.e., to eat small snacks every couple of hours. They argue that it blocks the drop in insulin and blood sugar that can trigger greater appetite and claim it can facilitate weight loss.



This is an absurd notion. Humans are not meant to graze. Humans are meant to find a wild boar or other animal, kill it, gorge on the meat, organs, and fat, then revert to berries, roots, leaves, and other foraged foods until the next kill. A human living in the wild does not have a cupboard or refrigerator full of ready-to-eat snacks to graze on.

The several hours after a meal is the most dangerous for creating coronary atherosclerotic plaque, i.e., the post-prandial period. In other words, eat dinner and, for the next 6-12 hours, your intestinal tract degrades the food; food byproducts are absorbed into the blood or lymph system. The blood is literally flooded with the byproducts of your meal.

Postprandial abnormalities are emerging to be a potent, and much underappreciated, means of causing heart disease and atherosclerosis in other vascular territories (especially carotid arteries and thoracic aorta).

Not eating--i.e., the fasting state--for extended periods is good for you. Encouraging people to graze amplifies atherosclerotic risk, since it creates an abnormal prolonged postprandial state.

The disastrous results of a low-fat diet

Rob was never that committed to following the program in the first place.

I met Rob because of a modest heart scan score and consultation for a cholesterol abnormality. Rob had been cycled through all the statin agents by his primary care physician, all of which resulted in terrible muscle aches that he found intolerable.

I started out, as usual, characterizing his cholesterol abnormality with lipoprotein testing (NMR):

LDL particle number 1489 nmol/L
LDL cholesterol (Friedewald calculation) 143 mg/dl
Small LDL 52% of total LDL
HDL 50 mg/dl
Triglycerides 82 mg/dl

(LDL particle number is the emerging gold standard for LDL quantification, superior to calculated or Friedewald LDL cholesterol for prediction of cardiovascular events.)

Rob is a busy guy. After only a couple of brief visits, life and work got in the way and Rob let his attentions drift away from heart health. Since the information I provided made little impact on his thinking, he reverted to the low-fat diet his primary care doctor had originally prescribed and that he read about in magazines and food packages. He also ran out of the basic supplements I had advised, including fish oil and vitamin D, and just never restarted them.

A couple of years passed and Rob decided that just poking around on his own might not cut it. So he came back to the office. We repeated his NMR lipoprotein analysis:

LDL particle number 2699 nmol/L
LDL cholesterol (Friedewald calculation) 229 mg/dl
Small LDL 81% of total LDL
HDL 53 mg/dl
Triglycerides 78 mg/dl


Two years of a low-fat diet had caused Rob's LDL particle number to skyrocket by 81%, nearly all due to an explosion of small LDL. Recall that small LDL is more susceptible to oxidation, more inflammation-provoking, more adhesive--the form of LDL particles most likely to cause heart disease.

Also, note that, despite the enormous increase in small LDL, HDL and triglycerides remained favorable. This counters the popular rule-of-thumb offered by some that small LDL is not present when HDL is "normal."

Low-fat diets as commonly practiced are enormously destructive. In Rob's case, a low-fat diet caused both calculated Friedewald LDL as well as LDL particle number to increase dramatically. In many other people, low-fat diets increase calculated Friedewald LDL modestly or not at all, but cause the more accurate LDL particle number to increase significantly, all due to small LDL.

I'm happy to say that, once Rob witnessed how far wrong he could go on the wrong program, he's back on Track. (Sorry, pun intended.) He has resumed his supplements and eliminated the food triggers of small LDL--wheat, cornstarch, and sugars.

Dr. David Grimes reminds us of vitamin D

In response to the Heart Scan Blog post, Fish oil makes you happy: Psychological distress and omega-3 index, Dr. David Grimes offered the following argument.

Dr. Grimes is a physician in northwest England at the Blackburn Royal Infirmary, Lancashire. He is author of the wonderfully cheeky 2006 Lancet editorial, Are statins analogues of vitamin D?, questioning whether the benefits of statin drugs simply work by way of increased vitamin D blood levels.


There is a fashionable interest in Omega-3 fatty acids, and these become equated with fish oil.

But fish oil is much more. Plankton synthesise the related squalene (shark oil) which, in turn, is converted into 7-dehydrocholesterol (7-DHC). The sun now comes into play and it converts 7-DHC into vitamin D (a physico-chemical process).

Small fish eat plankton, large fish eat small fish, and we eat large fish. So vitamin D passes through the food chain.

This has been a vital source of vitamin D for the the Inuits and also for the Scots and other dwellers of northwest Europe. (Edinburgh is on the same latitude as Hudson Bay and Alaska, further north than anywhere in China). In these locations there is not adequate sunlight energy to guarantee synthesis of adequate amounts of vitamin D, again by the action of sunlight on 7-DHC in the skin.

When the Scots moved from coastal fishing villages to industrial cities such as Glasgow, they became seriously deficient in vitamin D, and so the emergence of rickets. This was followed by a variety of other diseases resulting from vitamin D deficiency: tuberculosis, dental decay, coronary heart disease, and even multiple sclerosis and depression (the Glasgow syndrome).

And so it was with the Inuits. When their diet changed from fish for breakfast, fish for lunch, fish for dinner, they became deficient of vitamin D and they developed diseases characteristic of industrial cities, where there is indoor work for long hours, indoor activities, and atmospheric pollution.

It is the vitamin D component of fish and fish oils that is important.

I recently saw an elderly lady from Bangladesh living in northwest England. I would have expected her to have a very low blood level of vitamin D, as her exposure to the sun was minimal. However the blood level was 47ng/ml, not 4 as expected. She eats oily fish from Bangladesh every day, showing its value as a source of vitamin D with subsequent good health. I expect her blood levels of omega-3 fatty acids would also be high.

But it is unfashionable vitamin D that is important, not fashionable omega-3.

David Grimes
www.vitamindandcholesterol.com


Excellent point. The health effects of omega-3 and vitamin D are intimately intertwined when examining populations that consume fish.

In this study of Inuits, it is indeed impossible to dissect out how much psychological distress was due to reduced vitamin D, how much due to reduced omega-3s. My bet is that it's both. Thankfully, we also have data examining the use of pure omega-3 fatty acids in capsule (not intact fish) form, including studies like GISSI Prevenzione.

Nonetheless, Dr. Grimes reminds us that both vitamin D and omega-3 fatty acids from fish oil play crucial roles in mental health and other aspects of health, and that it's the combination that may account for the extravagant health effects previously ascribed only to omega-3s.

Why does fish oil reduce triglycerides?

Beyond its ability to slash risk for cardiovascular events, omega-3 fatty acids from fish oil also reduce triglycerides.

There's no remaining question that omega-3s do this quite effectively. After all, the FDA approved prescription fish oil, Lovaza, to treat a condition called familial hypertriglyceridemia, an inherited condition in which very high triglycerides in the 100s or 1000s of milligrams typically develop.

The omega-3 fraction of fatty acids are unique for their triglyceride-reducing property. No other fraction of fatty acids, such as omega-6 or saturated, can match the triglyceride-reducing effect of omega-3s.

But why does fish oil reduce triglycerides?

First of all, what are triglycerides? As their name suggests, triglycerides consist of three ("tri-") fatty acids lined up along a glycerol (sugar) "backbone." Triglycerides are the form in which most fatty acids occur in the bloodstream, liver, and other organs. (Fatty acids, like omega-3, omega-6, mono- or polyunsaturated, or saturated, rarely occur as free fatty acids unbound to glycerol.) In various lipoproteins in the blood, like LDL, VLDL, and HDL, fatty acids occur as triglycerides.

Of all lipoproteins, chylomicrons (the large particle formed through intestinal absorption of fatty acids and transported to the liver via the lymph system) and VLDL (very low-density lipoprotein, very low-density because they are mostly fat and little protein) particles are richest in triglycerides. Thus, we would expect that omega-3s exert their triglyceride-reducing effect via reductions in either chylomicrons or VLDL.

Indeed, that seems to be the case. The emerging evidence suggests that omega-3 fatty acids from fish oil reduce triglycerides through:

--Reduced VLDL production by the liver (Harris 1989)
--Accelerating chylomicron and VLDL elimination from the blood
--Activation of peroxisome proliferator-activated receptor gamma (PPAR-gamma)--Omega-3s ramp up the cellular equipment used to convert fatty acids to energy (oxidation) (Gani 2008)

Combine omega-3 fatty acids from fish oil with wheat elimination and you have an extremely potent means of reducing triglycerides. Read a previous Heart Scan Blog post here to read how a patient reduced triglycerides 93.5% from 3100 mg/dl to 210 mg/dl in just a few weeks using fish oil and wheat elimination.