Tag: Diet

Worried about diet soda? Strokes are not likely.

diet cokeLate last week, the popular press began touting a paper by Matthew Pase and coworkers in the journal Stroke on the newfound risks of diet sodas, (artificially sweetened beverages, ASBs) as compared to sugar sweetened beverages (SSBs). Most of the articles have been pretty accurate, NBC, CNN and Arstechnica got it pretty much right. Only Meredith Bland, writing as Scary Mommy went a bit off the deep end. If you´re done drinking all of these sugary drinks, then here are some Healthy Drinks Tips.

What the researchers did was examine data on 2888 participants from the Framingham Heart Study Offspring Cohort, looking at their reported consumption of ASBs and SSBs, and the results of their regular examinations, which ended in 2001. Surveillance continued for 10 years, ending in 2011.

They found that “higher recent and cumulative consumption of ASBs were associated with an increased risk of ischemic stroke, all-cause dementia, and Alzheimer’s disease dementia.” Specifically, they found that stroke was 2.96 times as likely and dementia about 2.89 times as likely.

This sounds really worrisome, but bear in mind that this is a single study, and that they found a correlation, not any actual cause. In fact, they didn’t propose any cause, because these results are very difficult to explain medically. They do, of course, note that “future research is needed to replicate our findings and investigate the mechanisms…”

What many writers did not specifically mention, is that there is an accompanying editorial in this same journal by Wersching, Gardener and Sacco, that is quite critical of Pase’s paper. In addition to pointing out that they show correlation and not causation, the editorial notes that while Pase reported that those consuming SSBs did not seem to have strokes or dementia, they suggested that this could be because of selection bias because those consuming sugary beverages may have died earlier. They note that previous studies have indeed found negative outcomes from those consuming SSBs.

As regards those consuming diet beverages (ASBs), the editorial suggests that “reverse causation” cannot be ruled out. What they mean is that those who know they are at risk may have chosen to switch to diet beverages and thus their strokes and dementia were incorrectly being correlated with the diet beverages instead of their already existing risk. They specifically point out that “disentangling these effects” is “challenging” in such studies.

Finally, they note that there is no obvious biological pathway to explain these cardiovascular events in those consuming diet beverages. They suggest that the current body of research, including this paper, is inconclusive and that carefully designed studies, following subjects from childhood would be necessary to establish these effects for certain.

So, for the moment, it would seem that nothing has really been established concerning diet beverages, and you can go ahead and sip yours without new worries.

 

 

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Is coconut oil healthy or just a fad? We check with Doctor Oz.

Is coconut oil healthy or just a fad? We check with Doctor Oz.

Recently we were discussing approaches to weight loss with a group of friends in Wilton, and one pointed out that Dr Oz had said that coconut oil was good for weight loss. This seemed surprising since it is an oil made of saturated fats, so we looked into it. You can buy coconut oil  almost everywhere now and from quacks like Dr Mercola.

Dr Oz did indeed endorse coconut oil on a recent show, claiming that unspecified “recent research” said it was good for weight loss, skin conditions and treating ulcers. He didn’t claim it would walk your dog or fold your laundry, but that might be in the next segment.

Dr Oz trained as a medical doctor, and some of his straightforward medical advice can be pretty helpful, but he increasingly has moved to endorse alternative medicine, pseudo-science and even faith healing. Many scientists and physicians feel he has gone completely “over to the dark side,” eschewing science-based medicine for a lot of hokum.

Coconut oil may very well make a good skin treatment, as you often find it in suntan lotions and the like. But there really isn’t much peer-reviewed research to support Oz’s assertions. It has been linked to impaired memory performance in rats. But there are no studies linking coconut oil to the stomach ulcer bacteria h pylori. There are, however, a number of sites hawking coconut oil that make these claims, though.

There is one preliminary study on 20 obese Malaysian males that showed some reduction in waist circumference and another study showing increasing obesity upon ingestion of coconut oil and other saturated fats. Finally there is a study among Filipino women showing that coconut oil improved the lipid profile by increasing HDL (good cholesterol).

However, these are small and preliminary, and no definitive conclusions have been reached. On the web site sharecare.com, the Mt Sinai Medical Center answers a query about coconut oil, suggesting it is unlikely to be useful.

The bottom line, according to the Mayo Clinic and others is this: People on coconut oil diets showed higher arterial fat after just one meal, it can increase cholesterol and, if it is not reducing your caloric intake, coconut oil can actually lead to weight gain.

And the Mayo Clinic web site points out

Although eating coconut oil in moderation for a short-term diet probably won’t harm your health, it may not help you lose weight. At prodiets, you can assure to achieve what you want medically, you can compare both the programs if you want to. And keep in mind that coconut oil actually has more saturated fat than do butter and lard. For successful, long-term weight loss, stick to the basics — an overall healthy-eating plan and exercise.

There are some articles on Oz’s web site but mostly by blog contributors, many with only Naturopath training (which is not science based medicine) and even they come back to these same preliminary studies. There is also one by a board certified dermatologist touting essentially the same studies.

The only places strongly touting coconut oil are quack doctor Joe Mercola’s site and the even more suspect site at the Weston A Price Foundation. The paper Mercola appears to be referring to is also the 2009 Brazilian study where 2 groups of volunteers were fed either soybean oil or coconut oil over 12 weeks and instructed to walk 50 minutes a day and follow an otherwise balanced low calorie diet. Both groups lost weight, but HDL (good) cholesterol was higher in the coconut oil group.

In conclusion, there is a bit of preliminary evidence for some benefits,  but since it seems counter-intuitive that eating a high saturated fat diet can help you lose weight, it is probably better to follow the advice of the established experts such as WebMD and the American Heart Association who recommend against it.

 

Gary Taubes says sugar is poison

Gary Taubes says sugar is poison

Science writer Gary Taubes has been writing columns everywhere promoting his new book The Case Against Sugar. He has written columns in The Guardian, and  The New York TImes among other places, and has been reviewed somewhat critically in The Guardian, Food Insight and The Atlantic.

Taubes’ central argument is that calories from sugar are not the only reason for obesity, but argues that sugar itself is uniquely toxic.

Taubes: “If the research community had been doing its job and not assuming since the 1920s that a calorie is a calorie, perhaps we would have found such evidence long ago.”

In a nutshell, the flaw in his argument is revealed in the above statement in the Times article. There must be more to sugar’s causing obesity than just calories, but researchers haven’t been doing their job!

And, in fact, despite Taubes’ persuasive writing, this is most of his argument. He cites no research in his articles (I have not read his actual book) or even mentions researchers who agree with him.

His thesis echoes that of Dr Robert Lustig, who makes much the same arguments in his book Fat Chance, and in the movie Fed Up but both Lustig’s and Taubes’ similar ideas have been debunked in articles, such as this one in Science Based Medicine. And Food Insight called this “blind fealty to correlation as causation.” Scientific American pointed out the fallacies in this argument in 2013.

In fact, while obesity continues to increase, sugar intake in the US actually decreased from 1999-2008, mainly because of decreased consumption of sugary soft drinks.

Taubes’ other somewhat distressing argument is that the sugar industry has been influencing research outcomes for years by sponsoring research. This suggests that not only that scientists are unethical but that the journal peer-review process itself is corrupt, and that is hard to swallow. The idea that research funding influences outcomes had been thoroughly debunked in this article by van Eenenaam, who notes that such corrupt research is a sure path to a short academic career.

He cites this PLoS One paper which reviews papers for their findings, correlating them with the source of their support. The authors suggested that papers with no declared “conflict of interest” are more likely(83%) to find that sugar sweetened beverages could be a risk for weight gain, but for those “disclosing some financial conflict of interest” 83% found that there was no such correlation.

The trouble with that paper is that there are only a few such studies: there were only 12 in the first category and 6 in the second category, and only 10/12 and 5/6 supported the author’s conclusions.

There are other reviews of sugar consumption that we need to consider. For example, Weed et al. studied reviews of health outcomes from sugar sweetene beverage (SSB) consumption, and rated the review quality using the AMSTAR review rating scheme, and found that most of them received moderately low quality scores, regardless of the conclusions of the paper. This would mean that the conclusions of these reviews are probably not entirely convincing, and basing Taubes’ sugar conspiracy theory on such weak data is not fully substantiated.

Moreover, this recent paper by Keller et al. reviews papers on sugar sweetened beverage consumption among children and adolescents, reporting that 9 reviews found a correlation between obesity and SSB consumption, while 4 did not. But that the quality scores of the reviews was low to moderate and that the two papers with highest quality scores reported discrepant (inconclusive) results.

The most important conclusion we can draw from reading Taubes’ many opinion pieces is we eat too much sugar, but that studies so far have not shown that sugar is more to blame than calories from any other source. No such research seems yet to exist.

Cleansing diets: are they right for you?

bottlesWith the start of each New Year, there have been several surveys of diet plans, explaining which are most effective, easiest to follow and most heart healthy. US News recently published their recommendations based on their expert panelists. WebMD has a summary of dozens of such diet plans, and has a good summary of the highly successful (and free) DASH Diet Plan.

But you may also have friends who decide that what they really need to do is “cleanse their systems.” The idea behind this is that a lot of nasty processed foods and the like build up in your colon, and need to be “cleansed.” If this sounds like purging, it is.

Nevertheless you don’t have to go very far to find people peddling their highly profitable “juice cleanses” and other detox diets. For example, Westport’s Kaia Yoga Café offers a 3-day juice cleanse program for $195. And the quack-bound Darien Center for Integrative Medicine offers cleansing and detoxification programs. This is an alternative medicine group. But remember that

alternative medicine is made up of things we don’t know work and things we know don’t work.

The whole cleansing idea is not well regarded by the medical community. For example Dr Eric Yoshida, head of gastroenterology at the University of British Columbia says:

… this is all bunk. The body’s systems just don’t work the way the proponents of the cleanses claim they do. Once in the colon, nothing but water gets reabsorbed, he says. The liver detoxes our food very efficiently.

If you consult WebMD, it expresses similar concerns:

The Master Cleanse Diet is supposed to “release years of built-up waste in just 10 days, while your energy soars.” Yet, experts point out, the liver already detoxifies the body. Further, there is no medical evidence that fasting or “cleansing” diets actually rid the body of any toxins not otherwise discarded in bodily waste.

And the Mayo Clinic web site says much the same thing:

There’s little evidence that detox diets actually remove toxins from the body. Most ingested toxins are efficiently and effectively removed by the kidneys and liver and excreted in urine and stool.

Finally, Robert Lambert, MD noted that Body Detoxification is a Hoax

  1. Your body is not “full of toxins.”  When it is, your liver and kidneys are designed to handle those “toxins” and will do so far better than anything someone tries to sell you.
    2. Diets only work when they restrict calories.
    3. Your colon is fine and does not deserve to be regularly “cleansed.”  Colonics have been around since the early 1900’s (maybe earlier) and the fact that they are still being used is only evidence of the gullibility of humans. Careful with certain exotic fruits claiming to cleanse also, make sure you read irvingia gabonensis side effects before consuming something you can’t pronounce. Just be smart.

You will find hundreds of web sites promoting these quack remedies, but they are snake oil: they are all out to take your money.

New Year’s is a great time to take stock of your weight and perhaps lose some holiday overage, but use one of the diets listed on the US News of WebMD sites above, and stay away from quackery.

This article was originally published in Examiner.com on January 9, 2012