All posts by Dr. AnthonyP

Cardiologist, blogger, musician

Smoothies: Kings of Sugar Masquerading As Healthy Food Choice

I have had a vague interaction with smoothies in the past, but after a recent jam session with my bassist daughter and drummer son, my daughter enthusiastically recommended we get a smoothie. “Smoothie” was entered into the Apple map app and a remarkable number of establishments serving this concoction popped up.

Smoothie sales have taken off in the last decade as consumers are apparently seeking healthier alternatives to carbonated beverages.

This was my first experience with Smoothie King which is the biggest and oldest chain of smoothie purveyors. According to their web site:

Since Steve Kuhnau created the first Smoothie Bar in 1973, Smoothie King has grown to over 650 locations across three continents. From the US to the Republic of Korea, Singapore and the Cayman Islands, our purpose continues to impact millions of lives around the globe.

Our quest is simple: Make living a healthier more active lifestyle delicious and nutritious. Whether you’re trying to lose a few pounds, have a little more energy at the end of the day or simply feel better about your diet, each and every Smoothie we make is blended for a specific purpose. Which is why we call them “Smoothies With A Purpose.”

This sounds spectacularly good: who wouldn’t want to lose a few pounds, have more energy at the end of the day and feel better about their diet.

Smoothie-King-New-Store-Design-interiorThe Smoothie King store was disturbingly sterile with an intense corporate feeling and had a bewildering array of choices. I could choose from Fitness Blends, Energy Blends, Slim Blends, Wellness Blends or Take a Break Blends.

 

There are 17 “Slim Blends” to choose from. The Angel Food  (“treat your body like an angel”(I have no idea what that means)) Slim Blend contains 350 calories, 84 grams of carbohydrates, 75 grams of sugar, 4 grams of protein, and 6 grams of fiber. This comes from strawberries (I saw no real strawberries behind the counter),bananas, non-fat milk (when I asked about getting whole milk the girl behind the counter told me that they didn’t even use real non-fat milk just a powder), vanilla, turbinado (fancy and deceptive word for brown sugar) and soy protein.

What’s wrong with this? A smoothie from SmoothieKing marketed as a Slim Blend contains 75 grams of sugar, the equivalent of 19 cubes of sugar. There only 39 grams of sugar in a 12 ounce coca-cola thus the small 20 oz “Slim Blend” contains the equivalent of two cans of coca-cola in sugar. There may be some useful nutrients in this monstrosity but predominantly you are getting loads of sugar in a highly concentrated form.

As I’ve pointed out here and here, there is reason to believe that sugar contributes more to obesity and heart disease than fat. Its hard to understand how this Slim Blend would contribute to weight loss in any way. It is just another stealth dessert similar to what Starbucks promotes as I’ve discussed here. What the food industry has done to smoothies is eerily similar to what happened to yogurt which I call the no fat  yogurt scam.

Most people have figured out for good weight control and health they should avoid sodas and sugar-sweetened beverages (even my 19 year old daughter has) but smoothies are masquerading as healthy choices for slimming, for fitness or wellness when they are (in the case of ones from SmoothieKing and presumably most similar chains) an absolutely horrible dietary choice.

What we have here is the classic food industry approach to marketing: Take real food ingredients like fruits, which are healthy choices when consumed in their original state, process  them, industrialize them, add sugar and promote them as healthier dietary choices.

Add in the veneer of promoting fitness or weight loss or wellness by adding magically powerful elixirs or powders and  the duped public will line up and sales will skyrocket. Unfortunately, despite claims of health benefits, consumers will end up less healthy.

 

 

 

 

 

Searching for Subclinical Atherosclerosis: Vascular Age

I’ve discussed in a previous post the importance of detecting subclinical atherosclerosis.

The process of atherosclerosis (the build up of fatty plaques in all arteries) occurs silently and often the first symptom is sudden death due to a heart attack.

Examining the large arteries in the neck (the carotids) with ultrasound for early fatty  plaques helps establish whether atherosclerosis is present or not.

If there is plaque in the carotids this is a strong indicator that atherosclerosis is present throughout the large arteries of the body including the coronary arteries supplying blood to the heart.

Ruptured plaques in the coronary arteries are what cause heart attacks and most cases of sudden cardiac death are due to heart attacks.

If we can identify those who have subclinical (i.e. before significant blockages and symptoms develop) atherosclerosis, we can better target aggressive therapy to those at the highest risk.

Carotid IMT: The window to your vascular age

There is a second technique which uses carotid ultrasound  available to evaluate an individual’s longer term risk of heart disease even before plaque develops.

This technique is termed carotid IMT. IMT (intimal-medial thickness ) refers to the thickness of the wall of the artery which includes the thin layer of cells lining the inside of arteries or intima and the smooth muscle in the wall of the artery (media).

The Carotid IMT has been shown to be related to all of the risk factors that medical science knows for atherosclerosis. It progressively increases with normal aging and we have data on what the normal value is for white and black  men and women between the ages of 40 and 70.

By making multiple precise and careful measurements of an individual’s CIMT we can determine where that individual stands in comparison to normal individuals of the same age, gender and race.

Individuals whose CIMT is great than that of 75% of individuals of the same age and gender are at significantly higher risk of heart attack and stroke even if no carotid plaque is discovered.

Thus, the CIMT serves somewhat as an early warning signal for unhealthy arteries.

We can also determine a so-called vascular age from this technique.

 

Carotid IMT is the distance between the lines the two arrows point at
Carotid IMT is the distance between the lines the two arrows point at

An example of this is shown to the left. . The individual was an asymptomatic young man. He had no plaque but his CIMT measured 0.770, which is significantly higher than the normal CIMT for a similarly aged white male of 0.598.  This is thicker than 80% of normal individuals of the same age and gender. It is normal for an individual who is 65 years old. Thus, this individual’s vascular age is 65 years, 20 years greater than his chronological age.

In my office I usually recommend a combination of CIMT and carotid plaque be performed in individuals in whom I am trying to assess risk of cardiovascular disease between the ages of 40 and 70.

There is no reason to do CIMT in patients who have documented coronary heart disease (heart attack/stroke/stent/bypass surgery), carotid disease (stroke/carotid surgery), or peripheral arterial disease. These patients have already passed the early warning phase of atherosclerosis.

This technique should only be done by physicians/technicians who have been adequately trained and have dedicated themselves to performing the meticulous tiny measurements required in an accurate manner.

Major cardiovascular organizations differ on recommending  CIMT for screening purposes.  Well-respected scientific papers have clearly established CIMT as reproducible and highly predictive of vascular events but there is no randomized , controlled trial which establishes that utilizing it in conjunction with treatment decisions based on the results will improve cardiovascular outcomes.

For this reason, even though it is cheap, painless, harmless and quick insurance companies do not reimburse for the costs.

Some caveats:

*We don’t have good data sets on individuals under the age of 40 years. I offer CIMT to this group and extrapolate the good data  but more studies are needed in this age range.

*We don’t have good data sets on ethnicities other than the African-americans and European and American whites.

*Multiple methods of CIMT recording and measurement  have been published.

*I don’t find CIMT useful in individuals over the age of 70. Carotid plaque is much more helpful. Most men have carotid plaque by this age. If you don’t have any carotid plaque over the age of 70 years then you are in a very low risk category and are unlikely to benefit from statin or aspirin therapy.

Next post we’ll discuss the third noninvasive tool at cardiologists disposal to assess individuals for subclinical atherosclerosis: a direct look at calcium in the coronary arteries

N.B. As noted here.

The full process underlying intimal thickening is not fully understood but is thought to be similar, though not identical, to that underlying atherosclerosis. The hypothesis that IMT represents subclinical vascular disease may be supported by the finding of graded associations between IMT and concurrent atherosclerotic change visualized in the coronary arteries during angiography. It is important to note, however, that whilst in many cases thickening of the intima–media does represent atherosclerotic change, in other cases it may represent non-atherosclerotic lesions such as hypertrophy in response to shear stress on the artery wall.

 

 

 

 

 

 

 

 

You’re The Titanium Dioxide In My Coffee

What do you put in your coffee?

Apparently 2/3 of Americans put either a sweetener or a creamer/whitener in their cup.

For the longest time I put skim milk in my coffee

When I was doing my cardiology training in the mid 1980s at Saint Louis University, one of the cardiology faculty was obsessed with the dangers of putting cream in coffee. He and mainstream nutritional guidelines convinced me  that putting this dangerous liquid in my coffee would clog my coronary arteries and give me a heart attack.  This was during the hey-day of the “saturated fat is bad so it’s better to substitute anything for it even if it was made in a factory and contains umpteen chemicals whose effects on the body are unknown” era.

Thus, was born the dreaded industrial trans-fats, and a host of food transformed to be low fat by adding high fructose corn syrup.

As a result of nutritional advice to avoid all saturated fats, Americans feared cream in their coffee and a variety of Frankensteinian coffee additives was born.

I encountered such a monstrosity the other day, as I was waiting in a gargantuan, luxurious medical waiting room when i felt the urge to have a cup of coffee to stimulate me while I waited interminably for my name to be called. Coffee was offered free of charge to those of us in the waiting room, but there was no container of milk or cream, not even boring skim milk. Instead, I found in a drawer filled with packets of sugar and artificial sweeteners, a product that calls itself “Coffee Creamer”

coffecreaerMade by “Wholesome Farms” a creation of Sysco, the giant food conglomerate, Wholesome Farms (?more appropriately Unwholesome Factory Produced) Coffee Creamer contains a  long list of barely recognizable chemicals and industrially processed natural foods as follows

  • corn syrup solids
  • partially hydrogenated soybean oil
  • sodium caseinate ( a milk derivate)
  • dipotassiumphosphate
  • mono and diglycerides
  • sodium silicoaluminate
  • sodium tripoliphosphate
  • diacetyl tartaric acid esters of mono and di glycerides
  • artifical flavor
  • beta carotene
  • riboflavin
  • titanium dioxide
  • artifical colors

Wholesome Farms Coffee Creamer is a microcosm of the food industry reaction to misguided nutritional recommendations to cut back on saturated fat and cholesterol in the diet: substitute  industrially produced chemical, sugars and oils and add in factory processed vitamins to create the illusion of healthiness.

The obvious advantages of this coffee additive are that it can sit in a drawer, unrefrigerated for years without spoiling because there is no real food in it but why on earth would anyone willingly choose to adulterate a perfectly good cup of coffee with it?

After realizing that full fat dairy does not raise the risk of cardiovascular disease (see here and here) about two years ago I began using whole milk (from Trader’s Point Creamery’s happy, grass-fed cows) in my morning coffee and it is a lot more satisfying than the skim milk I used for 30 years. In most coffee shops I’m presented with half and half or skim milk as options and I have no heart health  concerns about cream as a coffee additive.

Indeed, we can now appreciate cream in coffee as a very good thing as Annette Henshaw sung in 1928.

Soon we shall have to discuss “the salt in my stew”.

 

 

 

Time to Eat Butter Without Guilt

A number of readers of The Skeptical Cardiologist have pointed out to me that Time Magazine’s latest issue has a picture of butter on the cover with the headline “IMG_2965Eat Butter. Scientists labeled fat the enemy. Why they were wrong.”

The lead  article summarizes a lot of the evidence I have been writing about which suggests that saturated fat has been inappropriately vilified (here) and that added sugar and processed food may be the real root cause of the obesity epidemic (here).

It is well-written and reasonably balanced and has some catchy graphics.  It doesn’t really specifically address issues with dairy fat or butter as the title implies. I have defended high fat dairy in numerous posts over the past two years.

Hopefully this article in a well-respected mainstream newsmagazine will help correct the misinformation about diet and nutrition that has become entrenched in the consciousness of Americans.

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In Defense of Real Cheese

Ah Cheese. A most wondrous and diverse real food.
wensleydaleOf the thousands of delightful varieties, let us consider Wensleydale, the 33rd type of cheese requested by John Cleese of Ye Olde Cheese Emporium proprietor, Henry Wensleydale (Purveyor of Fine Cheese to the Gentry and the Poverty Stricken Too) in the Monty Python sketch, Cheese Shop.

The cheese I have in front of me from Wensleydale creamery (which owes its continued existence to being the favorite cheese of  Wallace (of Wallace and Gromit fame)) lists  the following ingredients:

  • pasteurized cow’s milk
  • cheese cultures
  • salt
  • rennet
  • annato (a natural coloring that gives cheese and other foods a bright orange hue. It comes from the Bixa orellana, a tropical plant commonly known as achiote or lipstick tree (from one of its uses))

Other than annato, the above ingredients are components of all cheese and signify that it is a non processed, nonindustrial product.

A 1 oz serving of this cheese (28 grams), like cheddar cheese (“the single most popular cheese in the world”), provides 110 calories, 80 of which are from fat (9 grams total fat, 6 grams saturated fat), 25 grams of cholesterol, 170 mg of salt and around 200 mg of calcium.

For the last 40 years, Americans have been mistakenly advised that all  saturated fat in the food is bad and contributes to heart disease. Since cheese contains such a high proportion of saturated fat, it has also been targeted. Dietary recommendations suggest limiting real cheese consumption and switching to low-fat cheese.

This concept is not supported by any recent analysis of data, and as I’ve pointed out in a previous post, saturated fat does not contribute to obesity, nor is it clearly associated with increased heart disease risk. There are many different saturated fats and they have varying effects on putative causes of heart disease such as bad/good cholesterol and inflammation. In addition, the milieu in which the fats are consumed plays a huge role in how they effect the body.

Cheese vary widely in taste, texture and color and the final ingredients depend on a host of different factors including:

  • the type of animal milk used
  • the the diet of the animal
  • the amount of butterfat
  • whether the product is pasteurized or not
  • the strain of bacteria active in the cheese
  • the strain of mold active in the cheese

As a result the bioactive ingredients in cheese will vary from type to type.

Recent scientific reviews of the topic note that dairy products such as cheese do not exert the negative effects on blood lipids as predicted solely by the content of saturated fat. Calcium and other bioactive components may modify the effects on LDL cholesterol and triglycerides.

In addition, we now know that the effect of diet on a single biomarker is insufficient evidence to assess CAD risk; a combination of multiple biomarkers and epidemiologic evidence using clinical endpoints is needed to substantiate the effects of diet on CAD risk.

Some points to consider in why dairy and cheese in particular are healthy:

  • Blood pressure lowering effects.  Calcium is thought to be one of the main nutrients responsible for the impact of dairy products on blood pressure. Other minerals such as magnesium, phosphate and potassium may also play a role. Casein and whey proteins are a rich source of specific bioactive peptides that  have an angiotensin-I-converting enzyme inhibitory effect, a key process in blood pressure control. Studies have also suggested that certain peptides derived from milk proteins may modulate endothelin-1 release by endothelial cells, thereby partly explaining the anti-hypertensive effect of milk proteins.
  • Inflammation and oxidative stress reduction. These are key  factors in the development of atherosclerosis and subsequent heart disease and stroke. Recent animal and human studies suggest that dairy components including calcium and or its unique proteins, the peptides they release, the phospholipids associated with milk fat or the stimulation of HDL by lipids themselves, may suppress adipose tissue oxidative and inflammatory response.

Government and health organization nutritional guidelines have had a huge and harmful impact on what the food industry presents to Americans to eat. The emphasis on reducing animal fats in food led to the creation of foods laden with processed vegetable oils containing harmful trans-fatty acids.  This mistake has been recognized and corrected, but the overall unsupported  concept of replacing naturally occurring saturated fats with processed carbohydrates and sugar is ongoing and arguably the root of the obesity epidemic in America.

Converting mistaken nutritional guidelines into law

The USDA in 2012 following an act of Congress stimulated by Michelle Obama, changed the standards for the national school lunch and breakfast guidelines, for the first time in 15 years.

The law was intended to increase consumption of fruits, vegetables, whole grains and promote the consumption of low-fat or nonfat milk. It seemed like a good idea and likely to counter increasing obesity in children. However, the original recommendations were modified by Congress, due to heavy food industry lobbying, to allow the small amount of tomato paste in pizza to qualify as a vegetable.

Unfortunately, the food industry has responded by providing products which meet the government’s criteria for healthy lunches, but in actuality are less healthy.

Dominos Pizza, as a recent New York Times article pointed out, is now providing a specially modified pizza to schools which is unavailable in their regular stores. Their so-called “Revolution in School Pizza” is a…

line of delicious, nutritious pizzas created specifically for schools delivered hot and fresh from your local Domino’s Pizza store. Domino’s Pizza Smart Slice is the nutritious food that kids will actually EAT and LOVE!

school_lunch_anatomyofsliceThis pizza, in contrast to the pizza sold in Domino’s stores, utilizes a “lite” Mozarella cheese to cut fat content, a pepperoni with lower sodium and fat content, and a crust that contains 51% whole grain flour.

This “smart slice” replaces dairy fat with carbohydrates; there is no evidence that this will improve obesity rate or reduce heart disease  In fact, this change may lead to less satiety and a tendency for the children to want to snack on further carbohydrate or sugar-laden products when they get home. Furthermore, as critics have suggested, it may promote the consumption of  “unhealthy” versions of pizza that are sold in stores.

If we are going to make laws that promote healthy eating, we have to be absolutely certain that they are supported by scientific evidence. These School Lunch Program Standards are an example of how getting the science wrong or getting ahead of the science can lead to worse outcomes than if there were no laws regulating school diets.

Hopefully, you will continue to consume real full-fat cheese without concerns that cheese is “artery-clogging” and you will be more successful in obtaining the “fermented curd” than John Cleese’s Mr. Mousebender was below:

 

 

 

 

 

Still More Reasons Not to Take Worthless Vitamins and MultiVitamins

As I have pointed out in a previous post, there is no reason to take multivitamins or any individual vitamin or supplement to prevent cardiovascular disease.

The U.S. Preventive Services Task Force (USPSTF) has just  updated its 2003 recommendation on vitamin supplementation to prevent cardiovascular disease and cancer and published this analysis in the April 15, 2014  Annals of Internal Medicine issue.

Their recommendations agree with mine and those of the American Heart Association, the American Cancer Society and the Academy of Nutrition and Dietetics.

After analyzing all available studies they found insufficient evidence to support

  • the use of multivitamins to prevent cardiovascular disease or cancer
  • the use of single or paired nutrients (except β-carotene or vitamin E) for the prevention of cardiovascular disease or cancer (including Vitamins A, C, D, E, folic acid, selenium and beta-carotene)

About half the country is taking these worthless vitamins, supplements and multivitamins and spending 28 billion dollars per year on them.

This money would be much better spent on gym memberships or  on the purchase of real, unprocessed food which contains all the vitamins and nutrients you need.

 

 

Hot Dogs, Brats, Music, Nitrates and Your Risk of Cardiovascular Death

IMG_2690
The Skeptical Cardiologist observes the Dirt Leg Benders at Perche Creek Bridge

The skeptical cardiologist participated in the Pedaler’s Jamboree this Memorial Day weekend. This is an annual bicycling/music festival centered around a 30 mile bike ride from Columbia to Boonville, MO along the KT trail as it tracks the Missouri River. It ends at Kemper Park in Boonville with a concert and campout (the highlight of which for me was SHEL)

 

At various stops along the way we were treated to excellent roots/blues/folk

The significant other of the skeptical cardiologist (SOSC) and friend enjoying the bluesy slide guitar work of White Trash Blues Revival at the McBaine stop along the KT trail at the Pedaler's Jamboree
The significant other of the skeptical cardiologist (SOSC) and friend enjoying the bluesy slide guitar work of White Trash Blues Revival at the McBaine stop along the KT trail at the Pedaler’s Jamboree

music. Our favorite moment was listening to an awesome duo from Fort Wayne, Indiana, the White Trash Blues Revival, in a downpour at the McBaine stop. The lead singer/guitarist played a home-made lap steel (made from a skate board and a Red Stripe beer bottle) and the drummer played trash cans, a beer keg and a cardboard box with outstanding results.

During the day, I observed thousands of my fellow pedalers consuming hot dogs and bratwursts at the various stops. In America, during Memorial Day weekend, several million brats and dogs will be consumed which made me ponder: is this increasing Americans’ risk of dying from heart disease?

 

US dietary-guidelines recommend “eating less” red and processed meat. For cardiovascular disease, these recommendations are based largely on expected effects on blood cholesterol of saturated fat and dietary cholesterol in meats. However, multiple recent published analyses have found no relationships of meat intake with cardiometabolic disease outcomes, including coronary heart disease (CHD), stroke, and diabetes.

This is a really important fact to know when making food choices, so I’m going to highlight it and repeat it:

Scientific studies do not show an association between unprocessed red meat consumption and cardiovascular disease.

 “Red meat” is usually defined as unprocessed meat from beef, hamburgers, lamb, pork, or game, and excludes poultry, fish, or eggs.

“Processed meat” is any meat preserved by smoking, curing or salting, or addition of chemical preservatives, such as bacon, salami, sausages, hot dogs, or processed deli or luncheon meats, excluding fish or eggs.

A 2010 meta-analysis of American studies on this showed no increased risk of coronary heart disease for the highest consumers of unprocessed meat versus the lowest.

On the other hand, each serving per day of processed meat was associated with a 42% higher risk of coronary heart disease.  Restricted to US studies, each serving per day was associated with 53% higher risk of diabetes.

A recent European study of 448,000 people found no association between unprocessed red meat consumption and mortality. For processed meats, there was an 18% higher risk of death per 50 gm/day serving.

Scientists really don’t know what it is about processed red meat that makes it associated with higher mortality.

As the table below indicates, the amount of saturated fat and cholesterocontents processed meatl is not higher, so that does not appear to be the cause.

Because sodium nitrite is used to cure most processed  meats, processed meats have about 4 times the amount of sodium as red meats.

High dietary sodium intake significantly increases blood pressure. Habitual consumption may also worsen arterial compliance and promote vascular stiffness, so It’s possible this is a factor.

Nitrate and nitrite levels are about 40% higher in processed meats and this has been suggested as a contributor to higher CVD and cancer rates.

However, 80-95% of dietary nitrates come from vegetables sources and a very significant source of nitrites is the breakdown of nitrates to nitrites by bacteria in saliva. Recent studies suggest that the blood pressure lowering effect of vegetables may be mediated by their nitrate content.

 A recent review concluded

At present, it seems that dietary nitrite and nitrate have cardiovascular protective effects. … the effects of nitrite and nitrate to enhance NO bioavailability, to improve endothelial function, to cause vasodilation, and to inhibit platelet aggregation may at least partly mediate their cardiovascular beneficial effects. … Taking the data presented above together with the failure of recent studies to show significant correlation between nitrite and nitrate exposure and cancer, we suggest that the benefits of dietary nitrite and nitrate will strongly outweigh any potential risks, particularly for cardiovascular disease patients.

So, there is a signal from observational data that processed meats may increase cardiovascular disease and death, but exactly which ones might be the culprits and how this might work is entirely unclear. I’m still consuming brats, sausages,  and hot dogs on occasion. Riding a bike, listening to music and drinking beer is a fine occasion for that.

I would advise the following

  • Don’t worry about nitrates/nitrites in processed meats. Science has not determined whether this is good or bad for you. Brands of bacon/sausage that claim no nitrates/nitrites are often using “natural” forms of nitrates that come from sources such as celery powder or sea salt.
  • Processed meats contain a lot of salt. Your body likely senses that and cuts back on salt consumption in other food choices during the day, especially if you indulge moderately. If you eat too much, too often, you put yourself at risk for high blood pressure and its attendant consequences. What is “too much” is uncertain, but the higher rates of heart disease and death don’t really seem to kick in until you eat the equivalent of greater than 80 grams per day.
  • Personally, I choose sustainably, humanely, “naturally” and locally raised processed meats whenever possible but there is no evidence-based medicine supporting this choice.

 

Are You Fed Up With Sugar?

A new documentary  movie, Fed UP, released May 9 and a   New York Times Editorial published  today are helping to focus the country’s attention on a new paradigm for what makes us fat and the importance of added sugar in causing obesity and chronic diseases. I highly recommend both viewing the movie and reading the editorial.

As I’ve pointed out here and here and as eloquently summarized by Gary Taubes in “Good Calories, Bad Calories” and “Why We Get Fat”, the concept of replacing fat with carbohydrates is not making America healthier.

The NY Times editorial and an article published by the same authors in JAMA focus on an alternative view of why people get fat. The generally accepted view is based on the (seemingly immutable)  first law of thermodynamics, that you gain weight because you have consumed more calories than you have burned with exercise. People get fat due to lack of willpower in either consuming too many calories or not exercising enough. In this paradigm, all calories are equal in their effects. To lose weight you merely need to cut back on how many calories you consume. Unfortunately, calorie restriction for weight loss fails almost all the time.

 

The alternative view of obesity posits that underlying genetic factors exacerbated by lifestyle factors such as inadequate sleep, stress and by poor quality of diet are the major reasons for obesity. These factors lead to increase in fat storage which , in turn, means less metabolic fuels available for activity. This causes an increase in hunger and a reduction in metabolic activity, muscular efficiency and physical activity.  The combination of increased energy intake and reduced energy expenditure causes obesity.

Insulin is the major hormone involved in fat metabolism and of all the things we eat highly refined and rapidly digestible carbohydrates cause the greatest insulin response. Thus, the authors write 

By this way of thinking, the increasing amount and processing of carbohydrates in the American diet has increased insulin levels, put fat cells into storage overdrive and elicited obesity-promoting biological responses in a large number of people. Like an infection that raises the body temperature set point, high consumption of refined carbohydrates — chips, crackers, cakes, soft drinks, sugary breakfast cereals and even white rice and bread — has increased body weights throughout the population.

Fed Up, the movie, focuses on how American diets became awash in added sugar and what the consequences of that has been. Dr. Robert Lustig a pediatric endocrinologist at the University of California, San Francisco is an advisor to the film and has spoken and written eloquently on this new paradigm for obesity and the dangers of processed food, fructose and sugar as in this video.

.

 

Here’s the trailer for Fed Up.

The film has a limited release and may not be showing in your town,  but you can check out some actions the film’s web site proposes  (supporting a proposed tax on soda and  sugary beverages, investigating your school’s nutrition policy, taking a 10 day no-sugar challenge) here.

 

 

 

Urban Cycling Part I: Does Biking To Work Make You More or Less Likely to Die?

5Boro Bike Riders crossing the summit of the Queensboro aka 59th Street aka "Feelin Groovy" Bridge
5Boro Bike Riders crossing the summit of the Queensboro aka 59th Street aka “Feelin Groovy” Bridge. For some reason the significant other of the skeptical cardiologist (SOSC) has decided to stop here to look at her cell phone, thereby creating a traffic hazard.

The skeptical cardiologist recently participated in the 5 Boro New York City Bike Tour. It was quite cool.

This annual event allows 32,000 bike riders to stream from Manhattan to the Bronx to Queens, Brooklyn and Staten Island along 40 miles of traffic-free (except for thousands of cyclists) roads

Unlike my previous rides in Brooklyn and Manhattan (under the guidance of legendary Park Slope flaneur, NYC biking advocate, and old high school chum David Alquist) I was not in constant peril from automobile encounters because we cyclists had the mean streets of New York all to ourselves.

Take a look at this video to understand “why cyclists come from around the world for an experience of the Big Apple unlike any other”.

Urban Cycling as Transportation

The NYC event, and the fact that this is “bike to work week,” lead me to ponder aspects of urban bike riding, specifically, cycling as transportation.  Since cycling is physical exercise and there is scientific evidence (observational studies only) linking regular physical activity to a significant cardiovascular risk reduction, we might expect that it would help us live longer. 

A reasonable physical activity goal , endorsed by most authorities,  is to engage in moderate-intensity aerobic physical activity for a minimum of 30 min on 5 days each week or vigorous-intensity aerobic activity for a minimum of 20 min on 3 days each week. This level of exercise helps with weight control, fitness and is associated with lower mortality from cardiovascular disease .

METS:calories
METs and calories consumed per hour for various physical activities

The metabolic equivalent of task (MET) is a measure of the energy cost of physical activity. The chart to the left gives METs for various activities.  Individuals should be aiming for 500–1,000 MET min/week. Leisure cycling or cycling to work (15 km/hr) has a MET value of 4 and is characterized as a moderate activity  A person shifting from car to bicycle for a daily short distance of 7.5 km would meet the minimum recommendation (7.5 km at 15 km/hr = 30 min) for physical activity in 5 days (4 MET × 30 min × 5 days = 600 MET min/week).

 

Thus, cycling to work for many individuals would provide the daiy physical activity that is recommended for cardiovascular benefits. However, cycling in general, and urban cycling in particular, carries a significant risk of trauma and death from accidents and possibly greater exposure to urban pollutants.

bikversuscardeaths
from CBS (Statistics Netherlands) Traffic and Transport, 2008

This table shows the estimated numbers of traffic deaths per age category per billion passenger kilometers traveled by bicycle and by car (driver and passenger) in the Netherlands for 2008. These data suggest that there are about 5.5 times more traffic deaths per kilometer traveled by bicycle than by car for all ages. Interestingly, there is no increase in risk for individuals aged 15-30 years. On the other hand , those of us in the “baby-boomer” generation (?slowed reflexes, poor eyesight, impaired hearing) and older are at an 8 to 17 fold increase risk.

In the Netherlands, where a very large percentage of the population regularly rides bikes, there has been considerable scientific study of the overall health consequences of biking and we have reasonably good data on the question of relative safety of biking versus driving a car for short distances. You can watch the happy people of Groningen (“the world’s cycling city”, where 57% of the journeys in the city are made by bicycle) riding their bikes below.

Health Impact of Transition from Car to Bike for Short Trips

One study quantified the impact on all-cause mortality if 500,000  people made a  transition from car to bicycle for short trips on a daily basis in the Netherlands and concluded

For individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3–14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8–40 days lost) and the increase in traffic accidents (5–9 days lost). Societal benefits are even larger because of a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.

Apart from the highest average distance cycled per person, the Netherlands is also one of the safest countries in terms of fatal traffic accidents so it’s reasonable to ask whether these data apply to other countries. This study concluded

 When  traffic accident calculations for the United Kingdom were utilized, where the risk of dying per 100 million km for a cyclist is about 2.5 times higher, the overall benefits of cycling were still 7 times larger than the risks.

If you decide to bike to work this week, braving the elements , the possible automobile collisions and the automobile exhaust you can rest comfortably with the thought that not only are you  prolonging your own life but by reducing greenhouse gas emissions and air pollution you are contributing to the health of everyone around you.

Should I Take Aspirin To Prevent Stroke or Heart Attack?

 

Aspirin is a unique drug, the prototypical  two-edged sword of pharmaceuticals.  It has the capability of stopping platelets, the sticky elements in our blood, from forming clots that cause strokes and heart attacks when arterial plaques rupture, but it increases the risk of serious bleeding into the brain or from the GI tract. Despite these powerful properties, aspirin is available over the counter and is very cheap, thus anyone can take it in any dosage they want. 

Who Should Take Aspirin?

For the last five years I’ve been advising my patients who have no evidence of atherosclerotic vascular disease against taking aspirin to prevent heart attack and stroke. Several comprehensive reviews of all the randomized trials of aspirin had concluded by 2011 that

The current totality of evidence provides only modest support for a benefit of aspirin in patients without clinical cardiovascular disease, which is offset by its risk. For every 1,000 subjects treated with aspirin over a 5-year period, aspirin would prevent 2.9 MCE and cause 2.8 major bleeds.

(MCE=major cardiovascular events, e.g. stroke, heart attack, death from cardiovascular disease)

Dr. Oz, on the other hand, came to St. Louis in 2011 to have  lunch with five hundred women and advised them all to take a baby aspirin daily (and fish oil, which is not indicated for primary prevention as I have discussed here). When I saw these women subsequently in my office I had to spend a fair amount of our visit explaining why they didn’t need to take aspirin and fish oil.

After reviewing available data, the FDA this week issued a statement recommending against aspirin use for the prevention of a first heart attack or stroke in patients with no history of cardiovascular disease (i.e. for primary prevention). The FDA pointed out that aspirin use is associated with “serious risks,” including increased risk of bleeding in the stomach and brain. As for secondary prevention for people with cardiovascular disease or those who have had a previous heart attack or stroke (secondary prevention), the available evidence continues to support aspirin use.

Subclinical Atherosclerosis and Aspirin usage

As I’ve discussed previously, however, many individuals who have not had a stroke or heart attack are walking around with a substantial burden of atherosclerosis in their arteries. Fatty plaques can become quite advanced in the arteries to the brain and heart before they obstruct blood flow and cause symptoms. In such individuals with subclinical atherosclerosis aspirin is going to be much more beneficial.

 

Guided Use of Aspirin

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Large, complex atherosclerotic plaque in the carotid artery found by vascular screening in an individual with no history of stroke, heart attack, or vascular disease. This patient will definitely benefit from daily aspirin to prevent stroke or heart attack
We have the tools available to look for atherosclerotic plaques before they rupture and cause heart attacks or stroke. Ultrasound screening of the carotid artery, as I discussed here, is one such tool: vascular screening is an accurate, harmless and painless way to assess for subclinical atherosclerosis.

In my practice, the answer to the question of who should or should not take aspirin is based on whether my patient has or does not have significant atherosclerosis. If they have had a clinical event due to atherosclerotic cardiovascular disease (stroke, heart attack, coronary stent, coronary bypass surgery, documented blocked arteries to the legs) I recommend they take one 81 milligram (baby) uncoated aspirin daily. If they have not had a clinical event but I have documented by either

  • vascular screening (significant carotid plaque)
  • coronary calcium score (high score (cut-off is debatable, more on this in a subsequent post)
  • Incidentally discovered plaque in the aorta or peripheral arteries (found by CT or ultrasound done for other reasons)

then I recommend a daily baby aspirin (assuming no high risk of bleeding).

There are no randomized trials testing this approach but in the next few years several large aspirin trials will be completed and hopefully we will get a better understanding of who benefits most from aspirin for primary prevention.

Until then remember that aspirin is a powerful drug with potential for good and bad effects on your body. Only take it if you and your health care provider have decided the benefits outweigh the risks after careful consideration of your particular situation.