PepsiCo to reduce sugar and fat in products

I guess PepsiCo is moving ahead of the competition, but in a snail pace and in a very, very politically correct way. Will this help in any way? I doubt. It is just too little, too late. See article here.

The article states that:

The company also set two goals for the next 10 years: to cut the average added sugar per serving by 25 percent and saturated fat per serving by 15 percent, in addition to adding more whole grains, fruits, vegetables and low-fat dairy into its array of products.

While it is nice to see more of a focus on sugar than on saturated fat, I would have preferred to see something like this:

The company also set two goals for the next 5 years: to cut the average added sugar per serving by 95 percent and increase saturated fat per serving by 50 percent, in addition to adding more vegetables and full-fat dairy into its array of products.

What would happen? Well, Indra Nooyi is a very smart CEO, and the company has many competent people. They know that they would probably lose enough customers to go out of business … or become the Apple of their industry.

The bottom line is that, if you want to improve your health, you should generally avoid any food or liquid that is highly industrialized.

Maybe PepsiCo should add unprocessed coconut water to their portfolio of drinks.

Fatty Liver: It's not Just for Grown-ups Anymore

The epidemic of non-alcoholic fatty liver disease (NAFLD) is one of my favorite topics on this blog, due to the liver's role as the body's metabolic "grand central station", as Dr. Philip Wood puts it. The liver plays a critical part in the regulation of sugar, insulin, and lipid levels in the blood. Many of the routine blood tests administered in the doctor's office (blood glucose, cholesterol, etc.) partially reflect liver function.

NAFLD is an excessive accumulation of fat in the liver that impairs its function and can lead to severe liver inflammation (NASH), and in a small percentage of people, liver cancer. An estimated 20-30% of people in industrial nations suffer from NAFLD, a shockingly high prevalence (1).

I previously posted on dietary factors I believe are involved in NAFLD. In rodents, feeding a large amount of sugar or industrial seed oils (corn oil, etc.) promotes NAFLD, whereas fats such as butter and coconut oil do not (2). In human infants, enteric feeding with industrial seed oils causes severe liver damage, whereas the same amount of fat from fish oil doesn't, and can even reverse the damage done by seed oils (3). [2013 update: obesity is probably the main contributor to NAFLD.  Obesity is associated with ectopic fat deposition in a number of organs, including the liver]

So basically, I think excessive sugar and industrial oils could be involved NAFLD, and if you look at diet trends in the US over the last 40 years, they're consistent with the idea.

I recently came across a study that examined the diet of Canadian children with NAFLD (6). The children had a high sugar intake, a typical (i.e., high) omega-6 intake, and a low omega-3 intake. The authors claimed that the children also had a high saturated fat intake, but at 10.5% of calories, they were almost eating to the American Heart Association's "Step I" diet recommendations**! Total fat intake was also low.

High sugar consumption was associated with a larger waist circumference, insulin resistance, lower adiponectin and elevated markers of inflammation. High omega-6 intake was associated with markers of inflammation. Low omega-3 intake was associated with insulin resistance and elevated liver enzymes. Saturated fat intake presumably had no relation to any of these markers, since they didn't mention it in the text.

These children with NAFLD, who were all insulin resistant and mostly obese, had diets high in omega-6, high in sugar, and low in omega-3. This is consistent with the idea that these three factors, which have all been moving in the wrong direction in the last 40 years, contribute to NAFLD.


* Fatty liver was assessed by liver enzymes, admittedly not a perfect test. However, elevated liver enzymes do correlate fairly well with NAFLD.

** Steps I and II were replaced by new diet advice in 2000. The AHA now recommends keeping saturated fat below 7% of calories.  However, the new recommendations focus mostly on eating real food rather than avoiding saturated fat and cholesterol.

Online calculators to assess cardiovascular disease risk: No LDL needed

Researchers can build mathematical equations (sometimes referred to as structural equations) that predict health outcomes based on health factors. Those mathematical equations can then be used in online calculators.

This link takes you to a government-sponsored calculator based on the Framingham Heart Study. It estimates 10-year risk for “hard” coronary heart disease outcomes (myocardial infarction and coronary death).

As you will notice, the link above does not take family history of disease into consideration. A different risk calculator, linked here, estimates a risk score called the Reynold Risk Score. It takes hsCRP (high sensitivity C-reactive protein, an inflammation marker) and family history in addition to the Framingham parameters in its risk score calculation.

Neither calculator asks for LDL cholesterol levels. I wonder why.

Standard deviation is not the same as range of variation

Often research results are expressed in means and standard deviations. For example, in the study reviewed in this post, it is stated that the weight of participants in a 12-week weight loss study varied from: 87.9 plus or minus 15.4 kg (at baseline, or before the 12-week intervention) to 81.7 plus or minus 16.2 kg (after the 12-week intervention).

The 87.9 and 81.7 are the average weights (a.k.a. “mean” weights), in kilograms, before and after the 12-week intervention. However, the 15.4 and 16.2 are NOT the range of variation in weights around the means before and after 12-week intervention. They are actually the ranges around the means encompassing approximately 68 percent of all of the values measured (see figure below, from www.electrical-res.com).

In the figure above, the minus and plus 15.4 and 16.2 values would be the “mean(x) – s” and “mean(x) + s” points on the horizontal axis of histograms of weights plotted before and after the 12-week intervention. This assumes that the distributions of weights are normal, or quasi-normal (i.e., similar to a bell-shaped, or normal, curve); a common assumption in this type of research.

The larger the standard deviation, the wider is the variation in the measures, and the flatter is the associated histogram (the bell-shaped curve). This property has a number of interesting implications, some of which will be discussed in other posts.

Sometimes another measure of dispersion, the variance, is reported instead of the standard deviation. The variance is the standard deviation squared.

The reason why standard deviations are reported instead of ranges of variation is that outliers (unusually high or low values) can dramatically widen the ranges. The standard deviation coefficient is much less sensitive to outliers.

Book Review: The Primal Blueprint

Mark Sisson has been a central figure in the evolutionary health community since he began his weblog Mark's Daily Apple in 2006. He and his staff have been posting daily on his blog ever since. He has also written several other books, edited the Optimum Health newsletter, competed as a high-level endurance athlete, and served on the International Triathlon Union as the anti-doping chairman, all of which you can read about on his biography page. Mark is a practice-what-you-preach kind of guy, and if physical appearance means anything, he's on to something.

In 2009, Mark published his long-awaited book The Primal Blueprint. He self-published the book, which has advantages and disadvantages. The big advantage is that you aren't subject to the sometimes onerous demands of publishers, who attempt to maximize sales at Barnes and Noble. The front cover sports a simple picture of Mark, rather than a sunbaked swimsuit model, and the back cover offers no ridiculous claims of instant beauty and fat loss.

The drawback of self-publishing is it's more difficult to break into a wider market. That's why Mark has asked me to publish my review of his book today. He's trying to push it up in the Amazon.com rankings so that it gets a broader exposure. If you've been thinking about buying Mark's book, now is a good time to do it. If you order it from Amazon.com on March 17th, Mark is offering to sweeten the deal with some freebies on his site Mark's Daily Apple. Full disclosure: I'm not getting anything out of this, I'm simply mentioning it because I was reviewing Mark's book anyway and I thought some readers might enjoy it.

The Primal Blueprint is not a weight loss or diet book, it's a lifestyle program with an evolutionary slant. Mark uses the example of historical and contemporary hunter-gatherers as a model, and attempts to apply those lessons to life in the 21st century. He does it in a way that's empowering accessible to nearly everyone. To illustrate his points, he uses the example of an archetypal hunter-gatherer called Grok, and his 21st century mirror image, the Korg family.

The diet section will be familiar to anyone who has read about "paleolithic"-type diets. He advocates eating meats including organs, seafood, eggs, nuts, abundant vegetables, and fruit. He also suggests avoiding grains, legumes, dairy (although he's not very militant about this one), processed food in general, and reducing carbohydrate to less than 150 grams per day. I like his diet suggestions because they focus on real food. Mark is not a drill sergeant. He tries to create a plan that will be sustainable in the long run, by staying positive and allowing for cheats.

We part ways on the issue of carbohydrate. He suggests that eating more than 150 grams of carbohydrate per day leads to fat gain and disease, whereas I feel that position is untenable in light of what we know of non-industrial cultures (including some relatively high-carbohydrate hunter-gatherers). Although carbohydrate restriction (or at least wheat and sugar restriction) does have its place in treating obesity and metabolic dysfunction in modern populations, ultimately I don't think it's necessary for the prevention of those same problems, and it can even be counterproductive in some cases. Mark does acknowledge that refined carbohydrates are the main culprits.

The book's diet section also recommends nutritional supplements, including a multivitamin/mineral, antioxidant supplement, probiotics, protein powder and fish oil. I'm not a big proponent of supplementation. I'm also a bit of a hypocrite because I do take small doses of fish oil (when I haven't had seafood recently), and vitamin D in wintertime. But I can't get behind protein powders and antioxidant supplements.

Mark's suggestions for exercise, sun exposure, sleep and stress management make good sense to me. In a nutshell: do all three, but keep the exercise varied and don't overdo it. As a former high-level endurance athlete, he has a lot of credibility here. He puts everything in a format that's practical, accessible and empowering.

I think The Primal Blueprint is a useful book for a person who wants to maintain or improve her health. Although we disagree on the issue of carbohydrate, the diet and lifestyle advice is solid and will definitely be a vast improvement over what the average person is doing. The Primal Blueprint is not an academic book, nor does it attempt to be. It doesn't contain many references (although it does contain some), and it won't satisfy someone looking for an in-depth discussion of the scientific literature. However, it's perfect for someone who's getting started and needs guidance, or who simply wants a more comprehensive source than reading blog snippets. It would make a great gift for that family member or friend who's been asking how you stay in such good shape.

Ketosis, methylglyoxal, and accelerated aging: Probably more fiction than fact

This is a follow up on this post. Just to recap, an interesting hypothesis has been around for quite some time about a possible negative effect of ketosis. This hypothesis argues that ketosis leads to the production of an organic compound called methylglyoxal, which is believed to be a powerful agent in the formation of advanced glycation endproducts (AGEs).

In vitro research, and research with animals (e.g., mice and cows), indeed suggests negative short-term effects of increased ketosis-induced methylglyoxal production. These studies typically deal with what appears to be severe ketosis, not the mild type induced in healthy people by very low carbohydrate diets.

However, the bulk of methylglyoxal is produced via glycolysis, a multi-step metabolic process that uses sugar to produce the body’s main energy currency – adenosine triphosphate (ATP). Ketosis is a state whereby ketones are used as a source of energy instead of glucose.

(Ketones also provide an energy source that is distinct from lipoprotein-bound fatty acids and albumin-bound free fat acids. Those fatty acids appear to be preferred vehicles for the use of dietary or body fat as a source of energy. Yet it seems that small amounts of ketones are almost always present in the blood, even if they do not show up in the urine.)

Thus it follows that ketosis is associated with reduced glycolysis and, consequently, reduced methylglyoxal production, since the bulk of this substance (i.e., methylglyoxal) is produced through glycolysis.

So, how can one argue that ketosis is “a recipe for accelerated AGEing”?

One guess is that ketosis is being confused with ketoacidosis, a pathological condition in which the level of circulating ketones can be as much as 40 to 80 times that found in ketosis. De Grey (2007) refers to “diabetic patients” when he talks about this possibility (i.e., the connection with accelerated AGEing), and ketoacidosis is an unfortunately common condition among those with uncontrolled diabetes.

A gentle body massage is relaxing, and thus health-promoting. Add 40 times to the pressure, and the massage will become a form of physical torture; certainly unhealthy. That does not mean that a gentle body massage is unhealthy.

Interestingly, ketoacidosis often happens together with hyperglycemia, so at least part of the damage associated with ketoacidosis is likely to be caused by high blood sugar levels. Ketosis, on the other hand, is not associated with hyperglycemia.

Finally, if ketosis led to accelerated AGEing to the same extent as, or worse than, chronic hyperglycemia does, where is the long-term evidence?

Since the late 1800s people have been experimenting with ketosis-inducing diets, and documenting the results. The Inuit and other groups have adopted ketosis-inducing diets for much longer, although evolution via selection might have played a role in these cases.

No one seems to have lived to be 150 years of age, but where are the reports of conditions akin to those caused by chronic hyperglycemia among the many that went “banting” in a more strict way since the late 1800s?

The arctic explorer Vilhjalmur Stefansson, who is reported to have lived much of his adult life in ketosis, died in 1962, in his early 80s. After reading about his life, few would disagree that he lived a rough life, with long periods without access to medical care. I doubt that Stefansson would have lived that long if he had suffered from untreated diabetes.

Severe ketosis, to the point of large amounts of ketones being present in the urine, may not be a natural state in which our Paleolithic ancestors lived most of the time. In modern humans, even a 24 h water fast, during an already low carbohydrate diet, may not induce ketosis of this type. Milder ketosis states, with slightly elevated concentrations of ketones showing up in blood tests, can be achieved much more easily.

In conclusion, the notion that ketosis causes accelerated aging to the same extent as chronic hyperglycemia seems more like fiction than fact.

Reference:

De Grey, A. (2007). Ending aging: The rejuvenation breakthroughs that could reverse human aging in our lifetime. New York: NY: St. Martin’s Press.

Ketosis, methylglyoxal, and accelerated aging: Fact or fiction?

Ketosis is a state typically associated with very low carbohydrate diets, such as the Atkins diet. In this state, the liver produces ketones based on fat (body fat or dietary fat). Unlike fats, ketones are water soluble and used by many tissues (including brain tissues) as a source of energy.

Unlike glucose and lipoprotein-bound fats (in VLDL, for example), unused ketones cannot be converted back to substances that can be stored by the body. Thus excess ketones are eliminated in the urine; leading to their detection by various tests, e.g., Ketostix tests.

This elimination of unused ketones in the urine is one of the reasons why very low carbohydrate diets are believed to lead to enhanced body fat loss.

From an evolutionary perspective, one could argue that a ketosis state that involves the elimination of ketones in the urine is an inefficient and unnatural emergency mechanism. For our Paleolithic ancestors, dying of starvation was a much bigger problem than dying of obesity complications.

An interesting hypothesis has been around for quite some time about a possible negative effect of ketosis. It goes more or less like this. Ketosis leads to the production of an organic compound called methylglyoxal, which is believed to be a powerful agent of glycation (a misnomer; see note below).

Glycation is a process whereby sugar molecules “stick” to protein or fat molecules, impairing their function. Glycation leads to the formation of advanced glycation endproducts (AGEs), which appear to be associated with a host of diseases, including diabetes, and to be implicated in accelerated aging (or “ageing”, with British spelling).

In short: ketosis leads to the production of methylglyoxal, which leads to the formation of AGEs, which in turn cause diseases and accelerated aging.

Note: Since glycation refers to “sugar” molecules sticking to protein and fats, its use in the context of methylglyoxal is arguably incorrect. Methylglyoxal is not a sugar, but an aldehyde.

One of the strongest indictments of ketosis, in relation to methylglyoxal, is made in a fairly well referenced book by De Grey (2007); the full reference to the book is at the end of this post. De Grey’s book is about aging, and how to stop or at least delay it. Overall, it is an excellent book. Here is some relevant text, from page 173 of the book:

… one established effect of very low-carbohydrate diets of the Atkins type is to bring down both triglyceride levels and the body’s total exposure to carbohydrates, so some advocates have hypothesized that these diets world reduce a person’s AGE burden. Unfortunately, it turns out that the metabolic state that these diets induce (the notorious “ketosis”) has the unfortunate side effect of causing a jump in the production of the oxoaldehyde methylglyoxal, a major precursor of AGEs that is also, ironically, produced within cells of diabetic patients when they are forced to take in more glucose than they can immediately process … methylglyoxal is far more chemically reactive than blood sugar (up to 40,000 times more reactive, in fact), and is known to cause wide-ranging damage in the body, of which AGE cross-links are but one example. This potentially makes the Atkins diet a recipe for accelerated AGEing …

Is this notion that ketosis, through methylglyoxal, can cause accelerated aging fact or fiction?

Sorry, but I need to consult with my guru before I post my answer.

Reference:

De Grey, A. (2007). Ending aging: The rejuvenation breakthroughs that could reverse human aging in our lifetime. New York: NY: St. Martin’s Press.