Sugar-Sweetened Beverages, Diet Coke & Health. Part I.

14 03 2010

At Medical and Technology of Joseph Kim, the upcoming Grand Rounds host, I saw the blog post “Need your help on Facebook to get Diet Coke to Donate $50,000 to the Foundation for NIH”.

National Heart Lung and Blood Institute has started a national campaign in the US, The Heart Truth®. They issued a challenge in support of heart health, raising awareness on the fact that  heart disease is the #1 killer of women, to identify risk factors and take action to lower them. Diet Coke is one of their corporate-partners, helping to spread the word through visibility on 6.7 billion packages of Diet Coke featuring The Heart Truth and Red Dress symbol. It has also started a Facebook cause: Diet Coke will donate $0.50 for every person that joins the cause and $1.00 for every person that donates $1, for a total donation of up to $50,000!

O.k. Donation Fine, NIH fine, but Coca Cola as a main sponsor to raise awareness against heart disease?? Its almost feels like a tobacco company raising awareness against lung cancer. It is as odd as McDonalds, Lego & Mars preaching online advertising awareness to kids...

You could object that any money to raise awareness is  a welcome bonus and that diet coke, unlike normal coke, doesn’t contain any calories. But then you could ask whether diet coke is really healthy… Plus Coca Cola does sell a lot of beverages with loads of sugar, with a possible adverse effect on health, including cardiovascular disease (see below). It looks a lot like hypocrisy to me, meant only to improve the BRAND.

Well, I was to write about sweetened beverages anyway, since I came across several interesting news items the last weeks.

Sugar-Sweetened Beverages Have Major Effects on Diabetes and Cardiovascular Health

During the joint EPI/NPAM Conference (Cardiovascular Disease Epidemiology and Prevention &- Nutrition, Physical Activity and Metabolism), Mar 2-5, 2010 (link), Litsa Lambrakos presented a posterSugar-Sweetened Beverage Consumption and the Attributable Burden to Diabetes and Coronary Heart Disease” that was covered in a press release and in the media (Elsevier Global Medical News; All Headline News)

Based on data from several large observational studies demonstrating a link between higher rates of sugar-sweetened beverages (SSB) consumption and subsequent risk of incident diabetes, Lambrakos and colleagues assumed that daily consumption of SSBs is associated with an increased risk of incident diabetes (RR 1.32 for those with daily consumption compared with adults consuming less than one sugar-sweetened beverage per month).  Next they estimated that the increased consumption of sugar-sweetened beverages (including sugar-sweetened soda, sport and fruit drinks) between 1990 and 2000 contributed to 130,000 new cases of diabetes, 14,000 new cases of coronary heart disease (CHD), and 50,000 additional life-years burdened by coronary heart disease over the past decade. They derived these data from the 1990-2000 National Health and Nutrition Examination Survey (NHANES) on consumption of sugar-sweetened beverages, combined  with the CHD Policy Model, a computer simulation of heart disease in U. S. adults aged 35-84 years.

Through the model, the researchers also estimated that the additional disease caused by the drinks has increased coronary heart disease healthcare costs by 300-550 million U.S. dollars between 2000-2010. This is probably an underestimation, because it does not account for the increased costs associated with the treatment and care of patients with diabetes alone.

How does this ($300.000.000-$550.000.000) compare to the $50,000 (max) that Coca Cola is willing to contribute to The Heart Truth?

Admitted, the comparison is not entirely fair. There are far more soft drinks than the sodas from Coca Cola. More importantly, the reliability of the  figures is highly dependent on the accuracy of the assumptions. Furthermore it is hard to review a study that is not yet published.

Other studies on possible harm of SSB consumption. 1. Effects on BMI, overweight & obesity.

To get an idea about the evidence on the ‘harm’ of SSB I did a quick search in PubMed (see PubMed tips).

First I searched for secondary (aggregated) sources.

((Dietary Sucrose AND beverages) OR soft drink* OR sugar-sweetened beverag* OR soda*[tiab]) AND “systematic”[Filter]

This yielded 27 hits.

Five Publications centered on the effect of beverages on weight, obesity or BMI.

The effect on overweight seems the most obvious side-effect of SSB’s. First the increase in obesity over time has been paralleled by an increase in soft drink consumption. Second the daily sweetener consumption in the United States increased by 83 kcal per person, of which 54 kcal/d  from soda. If these calories are added to the normal diet without reducing intake from other sources, 1 soda/d could lead to a weight gain of 6.75 kg in 1 year. [refs in 2]

Still the evidence is not that clear.

Malik [2], and an almost overlapping systematic review [3] conclude that large cross-sectional studies, well-powered prospective cohort studies with long follow-up, and short-term experimental studies (including 2 RCT’s), show a positive association between greater intakes of SSBs and weight gain and obesity in both children and adults and yield sufficient evidence for public health strategies to discourage consumption of sugary drinks as part of a healthy lifestyle.

Two later reviews [4,5] point out that Malik et al. had erroneously concluded that the evidence was ‘strong’, because “several studies were reported as positive when only a selected sub-group had a positive result, or classified as ‘positive non-significant’ where coefficients are near zero and P values in excess of 0·2. Furthermore, the results of two studies were confounded by the inclusion of diet soft drinks.”[4]

On the contrary, Forshee et al [4] conclude that the  association between SSB consumption and BMI was near zero. Interestingly, the funnel plot analysis was consistent with publication bias against studies that do not report statistically significant findings!

Gibson [5] concludes that that the effect of SSB on body weight is small except in susceptible individuals or at high levels of intake. She also points out that the totality of evidence is dominated by American studies (including the positive NHANES study), “that may be less applicable to the European context where consumption is substantially lower and composition or formulation may differ (high-fructose corn syrup v. sucrose, proportion of diet v. non-diet, etc).”
Indeed in a systematic review primarily including European studies [6], overweight was not associated with the intake of soft drinks, but with lower physical activity and more tv watching time.

Thus the effect of SSB (alone) on BMI and overweight is inconclusive, based on the current body of evidence.

It is not excluded though that high intake of SSB alone or regular consumption of SSB in combination with other unhealthy lifestyle factors (unsaturated fat, lower physical activity) do contribute to obesity.

Since lack of sleep is also unhealthy (and possibly obesogen), I will leave it here.

Next time I will discuss any cardiovascular or other harmful effects of sugar sweetened beverages ànd diet sodas.

Meanwhile enjoy the sugar and coca cola video below.

Whatever the evidence, daily consumption of SSB, with many calories and no nutritional value, doesn’t seem overtly healthy to me. I won’t allow my kids to drink soda as a habit.

ResearchBlogging.org

References

  1. Litsa K Lambrakos, Pamela Coxson, Lee Goldman, Kirsten Bibbins-Domingo (2010). Sugar-Sweetened Beverage Consumption and the Attributable Burden to Diabetes and Coronary Heart Disease, poster  365, Joint Cardiovascular Disease Epidemiology and Prevention &- Nutrition, Physical Activity and Metabolism – Conference Mar 2-5, 2010.
  2. Malik VS, Schulze MB, & Hu FB (2006). Intake of sugar-sweetened beverages and weight gain: a systematic review. The American journal of clinical nutrition, 84 (2), 274-88 PMID: 16895873
  3. Wolff E, & Dansinger ML (2008). Soft drinks and weight gain: how strong is the link? Medscape journal of medicine, 10 (8) PMID: 18924641
  4. Forshee RA, Anderson PA, & Storey ML (2008). Sugar-sweetened beverages and body mass index in children and adolescents: a meta-analysis. The American journal of clinical nutrition, 87 (6), 1662-71 PMID: 18541554
  5. Gibson S (2008). Sugar-sweetened soft drinks and obesity: a systematic review of the evidence from observational studies and interventions. Nutrition research reviews, 21 (2), 134-47 PMID: 19087367
  6. Janssen I, Katzmarzyk PT, Boyce WF, Vereecken C, Mulvihill C, Roberts C, Currie C, Pickett W, & Health Behaviour in School-Aged Children Obesity Working Group (2005). Comparison of overweight and obesity prevalence in school-aged youth from 34 countries and their relationships with physical activity and dietary patterns. Obesity reviews : an official journal of the International Association for the Study of Obesity, 6 (2), 123-32 PMID: 15836463

Photo Credits

  1. Diet Coke: http://en.wikipedia.org/wiki/File:Diet_Coke_can_US_1982.jpg
  2. Sugar in Coca Cola: http://www.sugarstacks.com/
They used data from the 1990-2000 National Health and Nutrition Examination Survey (NHANES) on consumption of sugar-sweetened beverages. She combined that with the Coronary Heart Disease Policy Model, a computer simulation of heart disease in U. S. adults aged 35-84 years.
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