Throw away total cholesterol!

Richard's total cholesterol without treatment was 186 mg/dl. "That's great!" his doctor declared, referring to the conventional dictum that total cholesterols less than 200 carry low risk. Several fingersticks in a mall kiosk set up by a local hospital to check total cholesterols confirmed Richard's low number.

But after Richard's unexpected hospitalization and two stents for severe coronary blockages, he demanded better answers.

Tragically, the answer was there all along: Despite a "favorable" total cholesterol, his HDL ("good") cholesterol was a miserable 32 mg (ideal >60 mg).

Total cholesterol is actually the sum total of HDL cholesterol, LDL cholesterol, with a contribution from triglycerides. That's why a low total cholesterol can conceal a low HDL.

This situation is quite common. And low HDL is accompanied by a constellation of other undesirable causes of heart disease, most notably small LDL.

Don't accept total cholesterol as your sole measure of risk. It's nearly worthless. If you live in Bangladesh or a third world country, well perhaps that's the best you can get. But if you live in the U.S. or developed world, it's absurd to rely on total cholesterol.

Smart Start not so smart




Kellogg's has crafted a campaign to support the American Heart Association featuring acress Sela Ward. Her attractive face, familiar to many TV and movie viewers, does add a comforting face to their efforts.

What's in this cereal made by the manufacturers of Pop-Tarts, Cheez-It, Rice Krispies, and Chips Deluxe cookies?

There are, indeed, some healthy ingredients: oat bran, potassium; you can even get a version made with soy protein. But there's sugar listed as the second ingredient. High-fructose corn syrup is also listed prominently. (Remember this issue? High-fructose corn syrup causes overwhelming sugar cravings, causes your triglycerides to skyrocket, and is probably among the principal food ingredients that make you obese.)

Upon detailed questioning of my patients struggling to lose weight, this and products like it are often among the "healthy" foods they've gravitated towards. We spend a great deal of time dissuading them of this idea.

A one-cup serving of Smart Start is low in fat (1 gram) but contains 43 grams of carbohydates, of which there are 14 grams of sugar. There are a meager 3 grams of fiber. To me, this sounds like a cupcake.

The Kellogg's people are exceptionally clever marketers. Partner with the American Heart Association and movie stars? Brilliant!

You should trust food manufacturer advertising about as much as you trust drug manufacturer advertising, which is to say not at all.

Kellogg's sold $10 billion dollars of food products last year. They are the world's leading producer of breakfast cereals. They are a leading producer of convenience foods: cookies, crackers, cereal bars, and frozen waffles under the brands Keebler, Pop-Tarts, Eggo, Cheez-It, Nutri-Grain, Rice Krispies, Famous Amos, and Kashi.

Can they cash in on healthy trends? They'll certainly try.

Does anybody have a normal vitamin D level?

We now routinely check everyone's vitamin D blood level at the start of the program. (The measure to obtain is 25-OH-Vitamin D3. This is not to be confused with 1,25-OH2-vitamin D3, which is a kidney function measure.)

Of the 10 people with levels drawn today, none were even close to normal levels (which we define as 50 ng/ml)--not a single one.

The majority were in the range of severe deficiency (<20 ng/ml). Only two had levels in the 30s. None had higher. (Remember: I'm talking about people in Wisconsin, a terribly sunlight-deprived area much of the year. This might not apply quite as vigorously to Florida residents or others in sun-exposed regions.)

Curiously, I've also seen several people this week who had extraordinary quantities of coronary plaque on their heart scans (scores >1000), all of whom had extremely low vitamin D levels. One of these people had fairly unimpressive lipoproteins, with very minimal abnormalities identified. (This is quite unusual, by the way.) It makes you wonder if a profound deficiency of vitamin D is sufficient to act on its own as an instigator of coronary plaque.

The more we examine the issue of vitamin D deficiency, the more fascinating it gets. I suspect we've just scratched the surface and there's a lot more to learn about this tremendously interesting nutrient. Nonetheless, with what we're seeing in our experience, I'm urging everyone to get a blood vitamin D level.

Don't believe your LDL cholesterol!

Harry's case is typical. For years, his doctor told him his LDL cholesterol of 123 mg was okay. But a heart scan score of 490 (90th percentile at age 52) made him question just where his coronary plaque came from.

Lipoprotein analysis told a very different story: His LDL particle number was 2400 nmol, meaning his trueLDL was more like 240 mg, nearly double the value of LDL obtained through his doctor. Harry had other sources of risk, too, but the LDL particle number was a clear stand-out.

Why does this happen? How can LDL cholesterol be so terribly inaccurate?

LDL cholesterols obtained in virtually all labs are not measured, they're calculated. The calculation was developed in the 1960s by Dr. Friedewald at the National Institutes of Health and therefore goes by his name (the Friedewald calculation). Dr. Friedewald derived this simple calculation to permit doctors across the U.S. to obtain LDL cholesterols, which were technically difficult to measure in those days by using measured HDL, total cholesterol and triglycerides.

Doctors were told that the only time that the Friedewald calculated LDL was inaccurate was when triglycerides exceeded 400 mg. So most family practitioners and internists still believe that calculated LDL's are, for the most part, quite accurate.

Nothing could be further from the truth. When LDL's are actually meaured, you find that LDL is rarely accurate. In fact, in our experience, inaccuracy of 30-50% is the rule, sometimes 100%. The one telltale hint that calculated LDL is wrong is when HDL is <50 mg--that's nearly everybody.

So what's your LDL? You won't really know unless it's measured. Our preferred method is NMR (LipoScience) LDL particle number, probably the most accurate of all. Second best: apoprotein B, direct measured LDL, and non-HDL. (We'll cover this issue much more extensively in an upcoming report on the www.cureality.com website in an extensive Special Report.)

Are you the exception?


I read about 40 heart scans this morning. In the stack was a 41-year old man with a heart scan score of 841.

That's terribly high for anyone, let alone a 41-year old person. He's lucky to find out about this before catastrophe strikes.

People like this worry me. In general, we advise men to consider a heart scan age 40 and older; women 50 and older. If there's anything exceptional about your family history or your own history, then you might notch these numbers down another 5-10 years. For instance, if your Dad had a heart attack at age 43, you might consider a scan at age 35. Or, if you've had diabetes for several years and you're a 42-year old woman, you might think about a scan. (Men tend to develop measurable plaque by heart scans 10 years before women.)

There are no hard and fast rules. It's unusual for a male to have a score >0 before age 40. Likewise, it's very uncommon for a woman to have a score >0 before age 50. But there are occasional exceptions--but they can be very important exceptions.

Our 41-year old man with the score of 841, for instance, probably had a high score since his mid-30s. I've seen several women without any obvious risk factors with scores in the several hundred range in their early 40s.

My rule: When in doubt, opt for safety. Every day, I still read about people in their 30s, 40s, and 50s dying of heart attacks. It shouldn't happen.

When in doubt, get the heart scan. The most you'll lose is the cost of the scan and a modest exposure to radiation. If your score is zero, you know you're safe for the next 5 or more years. But if you have an exceptional score at a young age, take preventive action.

Self-empowerment in health: The new wave in health care

Track Your Plaque is just one facet of the broad and powerful emerging wave of self-empowerment in health.

Hospitals, drug and device manufacturers, and the medical establishment don't like this idea. People managing their own health? That's ridiculous! Dangerous! But mostly unprofitable.

Self-empowerment means having easy access to simple, safe, and inexpensive diagnostic tests like heart scans, carotid scans, bone densitometry (for osteoporosis), cholesterol tests, abdominal ultrasound, even brain scans (e.g., CT or MRI) for people with a family history of brain aneurysm.

Opponents of this idea worry about the "false-positives" that come about with broad testing, i.e, detection of abnormalities that are artifactual. Our experience is that false-positives are only an occasional problem with any test. Instead, we find that most people have many true-positives. In CT heart scanning, for example, we find many unsuspected enlarged aortas (potential future aneurysms), valve disorders, and aortic calcium. These are all important in a preventive program. Unfortunately, your doctor's definition of false-positive often means that no corrective procedure or operation is required.

Other evidence that self-empowerment in health is growing:

--The nutritional supplement movement. What better example of power in managing your own health is there than the fabulous array of nutritional supplements available?

--Medications moving to over-the-counter status. Gradually, more and more medications are trickling into availability for you to obtain without a doctor's prescription.

--What I call "retail imaging", i.e. screening ultrasound, heart scans, full body scans, etc. that are available in most states without a doctor's order.

--The Internet. The rapidity and depth of information available on the Internet today is mind-boggling. It will fuel the self-empowerment movement by providing sophisticated information to the health care consumer previously available only through your physician.

--High-deductible health insurance plans. If health care consumers will bear more and more of the costs of health care, they will seize greater responsibility for early identification and prevention to minimize long-term costs.

There are more. But the movement is powerful and broad--and unstoppable. Let the establishment with vested interests in preserving the status quo fuss and complain, just like horse and buggy manufacturers did in the early 1900's when the autmobile came along.

Vitamin D deficiency is rampant

Today alone I've seen several people with severe deficiencies of vitamin D.

We're now checking everyone's blood vitamin D level at the start of the program. The measure that most accurately reflects your vitamin D status is 25-OH-vitamin D3. This is very confusing to many physicians, who traditionally have thought of 1,25-di-Hydroxy vitamin D3 as the standard test to measure. What they're failing to recognize is that this second measure is a kidney product, not a reflection of vitamin D status.

Using 25-OH-vitamin D3, several people today alone had levels of <10 ng/ml, clearly in the category of severe deficiency (generally regarded as <20ng/ml).

The majority of people we see in the office are Wisconsin residents. It's no wonder they're deficient. Although it's mid-May, we've seen the sun only a handful of days this year. And most of the days have been too chilly to wear short sleeves and shorts to permit sufficient surface area for UV exposure.

Living in a sunny climate, however, is no guarantee that you have sufficient blood vitamin D levels. Two recent studies have shown that 30-50% of the residents of sunny southern Florida and Hawaii are also deficient. (Why, I'm not sure.)

Although our experience thus far is anecdotal in several hundred people, my impression is that people who have normal blood levels of vitamin D (we regard normal as 45-50 ng/ml) have a far easier time of halting or regressing coronary plaque.

Vitamin D is among the most exciting nutritional tools we've come across in a long time. The conversation is making the media, which impresses me tremendously, given the fact that nobody stands to profit financially to any significant degree through vitamin D supplementation.

For a wonderful collection of discussions on vitamin D, go to Dr. John Cannell's website, www.vitaminDcouncil.com. You'll find a huge quantity of scientific background and conversation on the whole idea. I believe you will be thoroughly impressed with just how powerful the argument in favor of vitamin D has become.

What if wheat products were illegal?

Imagine if anything made of wheat were illegal: bread, bagels, crackers, pasta, pretzels, donuts, Shredded Wheat cereal, Raisin Bran, pastry, cookies, cakes, cupcakes. . . Your grocery store would then be unable to carry any of these products.

How empty would the grocery store shelves be?

There would be very little. The stores would be filled instead with vegetables and fruits, meats, and dairy products. But aisle after aisle would be empty. There'd be no cereal aisle. There'd be no snack chip aisle. The ordinarily overcrowded bread shelves wouldn't be there.

Bakery? Nope, not there either. Pasta and noodles? Empty. How about cakes and pastries? Also gone.

Getting the picture? American groceries are dominated by wheat products. What would happen to your health and the health of your family if wheat were abruptly removed from your choices? Would you be less healthy?

No. In fact, your health would be hugely improved. You'd lose a significant quantity of weight. Extraordinary numbers of people would lose diabetic or pre-diabetic tendencies. Feelings of sluggishness, sleepiness, and moodiness would dissolve. Blood pressure would be reduced. The incidence of cancer, skin disease, and inflammatory diseases would plumet.

From a plaque control perspective, your HDL cholesterol would rise, triglycerides drop. Small LDL would improve dramatically.

The message: Slash wheat products from your diet. Yes, you'll miss the smell and taste of freshly baked bread. But you'll do it for many more healthy years. And you may do it without a 14 inch scar in your chest.

The sobering tale of small LDL

Every day, I learn to respect small LDL more and more.

Small LDL particles, and its evil partner, low HDL, is among the most common reasons why someone fails to fully gain control of coronary plaque and heart disease risk.

Just yesterday, I saw a slender businessman (6 feet 1 inch in height, 186 lb.) whose small pattern persisted despite niacin, fish oil, oat bran, and raw almonds. We generally think of small LDL as an overweight person's pattern, but in some people the genetics are quite powerful and it can be expressed even in slender people.

The solution: More physical activity and exercise; cut back on processed carbohydrates, particularly wheat products like breads, pasta, crackers, breakfast cereals; think about magnesium (see our two recent reports on magnesium on the www.cureality.com membership website, the latest report to be posted this week); be sure sleep is adequate (gauge this by whether you're energetic during the day and don't fall asleep watching TV or movies). Lack of sufficient physical activity in people with sedentary jobs is probably among the most common reason the small LDL pattern persists.

Ignore small LDL and it can be like a hidden cancer in your body, growing and metastasizing (not literally, of course), fueling coronary plaque growth. Be sure your doctor assesses whether you have small LDL if you hope to gain control of your coronary risk.

Burn off the fat

If you've ever wondered just how many calories you're burning with various activities like yard work, driving, climbing stairs, etc. go to this great website that will calculate it for you: http://www.caloriecontrol.org/exercalc.html.

Here are some examples:


Dancing for 30 minutes(fast, e.g., tango): 193 calories
Yoga for 30 minutes: 204 calories
Washing the car for 30 minutes: 173 calories
Vacuuming for 30 minutes: 88 calories

(All are for a 170 lb person.)

As you see, physical activity does not necessarily have to consist of exercise. It doesn't require fancy equipment or expensive outfits. But it does require you to keep moving. Sedentary work is among the most common reasons I see in my patients for failing to control weight and its associated lipoprotein patterns, like low HDL and small LDL.

If your work is sedentary, then a minimum of 60 minutes of physical activity per day is necessary to begin to correct weight-related patterns. If you gauge by calories burned, then a useful goal is 500 calories per day in physical activity--at a minimum.
All posts by william-davis

Statin stupid

If we followed the lead of the pharmaceutical industry and my cardiology colleagues, we would all subscribe to the "statins for all" philosophy. There is now $2 billion of clinical "research" to back up this "evidence-based" practice.

I do not endorse this "statins for all" philosophy. I believe it is a product of the raw profiteering of the pharmaceutical industry, who are adept at recruiting physicians to their cause.

But lost in the confusion of tainted studies and over-the-top media saturation is the fact that there are small groups of people who likely do obtain benefit from statin drugs. They would certainly benefit from better informed scrutiny of their lipoprotein and metabolic abnormalities. But treatment may involve statins.

This is entirely distinct from the "statins for all" argument, the simpleminded rule that primary care physicians and cardiologist are told to follow.

Groups who may indeed benefit from statin therapy include:

Homozygous or heterozygous familial hypercholesterolemia--Lacking a receptor for LDL particles, LDL piles up to very high levels in these people. LDLs of 300+ are common and lead to heart disease and stroke at relatively young ages.

Combined mixed hyperlipidemia--Among the one or more genetic defects underlying this condition involves excessive production of apoprotein B and VLDL particles. This leads to high risk for heart disease.

People unable to follow a diet to correct their lipid disorder--I have 80+-year old patients, for instance, who say, "I've eaten this way for 82 years. I'm not going to change now!" In the absence of diet and other efforts (e.g., omega-3 fatty acids from fish oil), drugs may be the answer.

In other words, of the $27 billion annual bill for statin drugs, perhaps a tiny fraction is truly necessary. The majority of people taking statin drugs would not really need them if they had the real answers. But don't let that confuse us: There are some people who do indeed benefit.

Butter and insulin

In a previous post, Atkins Diet: Common Errors, I commented on butter's unusual ability to provoke insulin responses. I offer this as a possible reason why, after a period of effective weight loss on a low-carbohydrate program, inclusion of some foods, such as butter, will trigger weight gain or stall weight loss efforts.

This develops because of butter's insulin-triggering effect, doubling or tripling insulin responses (postprandial area-under-the-curve). If insulin is triggered, fat gain follows.

Here's one such study documenting this effect: Distinctive postprandial modulation of ß cell function and insulin sensitivity by dietary fats: monounsaturated compared with saturated fatty acids

López et al 2008


From Lopez et al 2008. Mean (± SD) plasma glucose, insulin, triglyceride, and free fatty acid (FFA) concentrations during glucose and triglyceride tolerance test meal (GTTTM) with no fat (control), enriched in monounsaturated fatty acids (MUFAs) from refined olive oil (ROO meal), with added butter, with a mixture of vegetable and fish oils (VEFO) or with high-palmitic sunflower oil (HPSO). N = 14.

The postprandial (after-eating) area-under-the-curve is substantially greater when butter is included in the mixed composition meal. This effect is not unique to butter, but is shared by most other dairy products.

Fat, in general, does not make you fat. But butter makes you fat.

Vitamin D as a cardiovascular risk factor gains ground

If you were reading The Heart Scan Blog back in 2007, or read my Life Extension article on vitamin D deficiency as a cardiovascular risk factor, you already knew that vitamin D deficiency is rampant and adds to cardiovascular risk.

Results of a study from the Intermountain Medical Center Heart Institute in Utah bolster the concept that vitamin D deficiency is a cardiovascular risk factor, vitamin D normalization/supplementation reduces cardiovascular risk.

Science Daily reported:

For the first study, researchers followed two groups of patients for an average of one year each. In the first study group, over 9,400 patients, mostly female, reported low initial vitamin D levels, and had at least one follow up exam during that time period. Researchers found that 47 percent of the patients who increased their levels of vitamin D between the two visits showed a reduced risk for cardiovascular disease.


In the second study, researchers placed over 31,000 patients into three categories based on their levels of vitamin D. The patients in each category who increased their vitamin D levels to 43 nanograms per milliliter of blood or higher had lower rates of death, diabetes, cardiovascular disease, myocardial infarction, heart failure, high blood pressure, depression, and kidney failure. Currently, a level of 30 nanograms per milliliter is considered "normal."


Over the past 4 years, people in our program have been enjoying the extravagant benefits of vitamin D restoration. Cardiovascular benefits are becoming better documented and the bone health, cancer-preventing, insulin-normalizing, mood-adjusting, and anti-inflammatory effects likewise.

Atkins Diet: Common errors

No doubt: The diet approach advocated by the late Dr. Robert Atkins was a heck of a lot closer to an ideal diet than the knuckleheaded advice emitting from the USDA, American Heart Association, American Diabetes Association, and the Surgeon General's office.

But having just spent a week with Atkins low-carbers, here are some common errors that I see many make, errors that I believe have long-term health consequences, including impairment of weight loss.

Excessive consumption of animal products--Non-restriction of fat often leads to over-reliance on animal products. Higher intakes of red meats (heme proteins?) have been strongly associated with increased risk for colon and other gastrointestinal tract cancers. It is not a fat issue; it is an animal product issue. We should consume less meat, more vegetables and other plant-sourced foods.

Consumption of cured meats--Cured, processed meats, such as sausage, hot dogs, salami, bologna, and bacon, have a color fixative called sodium nitrite, an additive that has been confidently linked to gastrointestinal cancers. Risk is likely dose-dependent: The more you ingest, the greater the long-term risk.

Overconsumption of dairy products--Dairy products, especially milk, yogurt, cottage cheese, and butter, are potent insulinotropic foods, i.e., foods that trigger insulin release. There can be up to a tripling of insulin (area-under-the-curve) levels. This is not good in a world populated with tired, overworked pancreases, exhausted from a lifetime of high-carbohydrate eating.

Too many calories--While I agree that "a calorie is a calorie" and "calories in, calories out" are faulty concepts, I have anecdotally observed that long-time low-carbers often trend towards unlimited consumption of food, a phenomenon that seems to result in weight gain, especially in the sedentary. I wonder if this is a reflection of the insulinotropic action of dairy products and other proteins, compounded by the poor insulin responsiveness that develops with lack of physical activity. Factor into this conversation that lower calorie intake extends life, probably substantially (Sirt-2 activation and related phenomena, a la resveratrol). If lower calorie intake extends life, unlimited calorie intake likely shortens life.

Please don't hear this as low-carb bashing--it is not. It is a call to improve diets and not stumble into common traps that can impair heart health, weight loss, and longevity.

Fat Head: Tom Naughton's manifesto for low-carb eating

I just got back from Jimmy Moore's low-carb cruise to the Bahamas.

Among the many interesting people I met on the cruise was the creator of the documentary film, Fat Head, Tom Naughton.

Tom brings both creative insights into low-carbohydrate eating as well as humor. Low-carb eating can be a pretty contentious issue, but Tom made it fun. He will make you laugh about many of the odd notions we have about diet.

Among the best parts of Fat Head is Tom's portrayal of the effects of carbohydrates on insulin and fat metabolism:






Fat Head joins the ranks of films like Food, Inc, that make nutrition information entertaining. For anyone interested in a unvarnished look at diet, weight loss, along with a few laughs along the way, Tom Naughton's Fat Head is worth viewing.

Oatmeal: Good or bad?


You've heard it before: oatmeal reduces cholesterol. Oatmeal producers have obtained permission from the FDA to use a cholesterol-reducing claim. The American Heart Association provides a (paid) endorsement of Quaker Oats.

I've lost count of the times I've asked someone whether they ate a healthy breakfast and the answer was "Sure. I had oatmeal."

Is this true? Is oatmeal heart healthy because it reduces LDL cholesterol?

I don't think so. Try this: Have a serving of slow-cooked (e.g., steel-cut, Irish, etc.) oatmeal. Most people will consume oatmeal with skim or 1% milk and some dried or fresh fruit. Wait an hour, then check your blood sugar.

If you are not diabetic and have a fasting blood sugar in the "normal" range (<100 mg/dl), you will typically have a 1-hour blood glucose of 150-180 mg/dl--very high. If you have mildly increased fasting blood sugars between 100 and 126 mg/dl, postprandial (after-eating) blood sugars will easily exceed 180 mg/dl. If you have diabetes, hold onto your hat because, even if you take medications, blood sugar one hour after oatmeal will usually be between 200 and 300 mg/dl.

This is because oatmeal is converted rapidly to sugar, and a lot of it. Even if you were to repeat the experiment with no dried or fresh fruit, you will still witness high blood sugars in these ranges. Do like some people and pile on the raisins, dried cranberries, or brown sugar, and you will see blood sugars go even higher.

Blood sugars this high, experienced repetitively, will damage the delicate insulin-producing beta cells of your pancreas (glucose toxicity). It also glycates proteins of the eyes and vascular walls. The blood glucose effects of oatmeal really don't differ much from a large Snickers bar or bowl of jelly beans.

If you are like most people, you too will show high blood sugars after oatmeal. It's easy to find out . . . check your postprandial blood sugar.

In past, I recommended oat products, specifically oat bran, to reduce LDL, especially small LDL. I've changed my mind: I now no longer recommend any oat product due to its blood sugar-increasing effects.

Better choices: eggs, ground flaxseed as a hot cereal, cheese (the one dairy product that does not excessively trigger insulin), raw nuts, salads, leftovers from last evening's dinner.

Mustard: Super health food?

Could mustard--yes, the yellow condiment you smear on hot dogs--be a super heart healthy food in disguise?

Consider that mustard contains:

Vinegar

Turmeric

No appreciable sugar


The vinegar slows gastric emptying, resulting in slower absorption of any carbohydrates and a reduced glucose area-under-the-curve. Of the little fats contained (about 3 grams per 1/4 cup), most are desirable monounsaturates. Mustards are relatively rich in selenium, with 20 mcg per 1/4 cup, helpful for protection against cancer and thyroid disease, and magnesium, 31 mg per 1/4 cup.

Turmeric is added to most mustards. One of the constituents of turmeric, curcumin, the substance that confers the bright yellow color, has been a focus of interest for its anti-inflammatory effects. Curcumin has been documented to reduce activity of the inflammatory enzymes cyclooxygenase-2 (COX-2), lipoxygenase, and reduce activity of inflammatory signal molecules, tumor necrosis factor-alpha (TNF-a), interleukin (IL)-1,2,6,8, and 12, and monocyte chemoattractant protein (MCP). Curcumin also has been shown to reduce LDL oxidation, a potentially important step in atherosclerotic plaque formation. Turmeric is used as a tea by Okinawans. (Hmmmm . . . )

Turmeric content of mustard can vary, of course. Likewise, sugar content. Look for mustards that are not sweetened, so avoid honey mustard in particular. Look for hot, brown, horseradish, Dijon, etc. If there is a downside to mustard, it's sodium content, though the 709 mg per 1/4 cup should only be a problem for those who are sodium-sensitive (African Americans, in particular).

So perhaps mustard isn't exactly a super health food. But it may have some bona fide health effects and should be used generously especially if you are concerned about blood sugar and inflammatory phenomena.

Exercise and blood sugar

There is no doubt that exercise yields benefits across a spectrum of health: reduced blood pressure,  reduced inflammation, reduced blood coagulation, better weight control, stronger bones, less depression, reduced risk for heart attack.

Exercise also influences blood sugar. Diabetics understand this best: Exercise reduces blood sugar 20, 30, 50 or more milligrams. A starting blood sugar, for instance, of 160 mg/dl can be reduced to 80 mg/dl by jogging or riding a bicycle. (I recently had brunch at an Indian restaurant with my family. Blood sugar one-hour postprandial: 134 mg/dl. I was sleepy and foggy. I got on my stationary bike and pedalled at a moderate clip for 60 minutes. Blood sugar: 90 mg/dl.)

Could the reduction of blood sugar with exercise be THE reason that exercise and physical activity provide such substantial benefits?

Think about it. Reduced blood sugar:

1) Reduces risk for future cardiovascular events.
2) Reduces glycation of proteins, i.e., reduced glucose binding to proteins like the ones in artery walls and the lenses of your eyes.
3) Reduces blood coagulation
4) Reduces endothelial dysfunction (abnormal artery constriction that leads to atherosclerosis)

This might explain why it doesn't require high levels of aerobic activity to derive benefit from exercise, since even modest efforts (e.g., a 15-minute walk after eating) reduce blood sugar substantially.

The incredible 33-year, 18,000-participant Whitehall study tells us that a postprandial (after-eating) blood sugar of an impossibly-difficult 83 mg/dl is required to erase the excess cardiovascular risk of blood sugar. Could this simply be telling us that physical activity or exercise is required to suppress blood sugars to these low levels?

It makes me wonder if an index of the adequacy of exercise is your post-exercise blood glucose.