Monday, May 12, 2014

Research Update: Sugar Consumption And Cardiovascular Disease

Added sugar intake and cardiovascular diseases mortality among US adults. JAMA Internal Medicine 2014; 174:516-24.

Objective
To investigate the association between sugar consumption and risk of cardiovascular disease.

Methods
1988-94 National Health and Nutrition Examination Survey (NHANES) data was used for this investigation. NHANES is a nationally representative sample of the U.S. population. Each participant completed a household interview and a physical examination at a mobile examination center. Diet was measured by means of a 24 hour dietary recall that was conducted through a personal interview. Sugar consumption was measured, and subjects were followed for 14 years for incidence of cardiovascular disease.

Results
In this cohort, 71.4 percent of subjects consumed more than 10% of their calories as sugar. The average sugar consumption was 15.7% of calories. When compared to subjects consuming the lowest amount of sugar (7.4% of calories), subjects consuming the most sugar (25.2% of calories) had more than double the risk of cardiovascular disease. This was after controlling for all known risk factors for cardiovascular disease, and even after controlling for overall diet quality.

Comment
Studies showing the risk of a high sugar diet are really starting to mount. There have been reported associations between sugar and risk of obesity, type 2 diabetes, hypertension, dyslipidemia, and now even stronger evidence that sugar consumption is associated with cardiovascular disease.

What makes this study interesting is that it controlled for the Healthy Eating Index score in the statistical modelling. This score measures overall diet quality. It is easy to argue in an epidemiological study such as this, that sugar is simply a marker for an unhealthy diet, so of course it will be associated with cardiovascular disease. Since this study controlled for overall diet quality, it focuses in a bit more on sugar as the culprit.

As for the mechanisms, the authors propose several possibilities:

1) Sugar has been shown in animal studies to increase hypertension.

2) Excess sugar has been shown to increase triglycerides and LDL cholesterol while lowering HDL cholesterol.

3) Sugar has been shown to increase inflammation, which is a big part of developing cardiovascular disease.

Take Home Message
If you work with me or have read any of my books you already know I am an anti-sugar guy. Sugar is everywhere and the percentages can creep up on you quickly. One soda has 35 grams of sugar, and at 140 calories, makes up 7% of total calories on a 2000 calorie diet.

Strictly limiting sugar, or better yet completely avoided it, should be a high priority for anyone who is looking to manage their weight or reduce their risk of chronic disease. The most common sources of sugar in this cohort were sugar sweetened beverages, grain based desserts (like cookies and cakes), fruit drinks, dairy based desserts (like ice cream), and candy.  Limiting these foods is an awesome place to start.  

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