RSS

Tag Archives: miracle

Because it was on Dr. Oz, I’m more likely to think it’s a scam

doctor-ozI got something interesting in my inbox the other day. Something that I assume was a  friend’s email address getting hacked – although it’s the least offensive (apparent) hack I’ve ever seen (he says as the viruses circulate around his computer’s RAM).

It was a nearly blank email with a link to a Dr. Oz clip about the weight-loss promoting effects of green coffee extract, which contains high concentrations of chlorogenic acids. These molecules are said to promote weight loss through increasing metabolism.

Being a scientist means being a skeptic. In this case, because I already feel like it must be BS due to its connection with Dr. Oz (an Oprah-elevated proponent of many untested, ‘alternative’ therapies), the challenge for me is to admit the possibility that this stuff may work. So, rather than looking through the data to see if there’s anything to deny the claim, I’m really trying hard to look at the data to see any glimmer  of possibility.

Here’s a link to the Dr. Oz article online. The article was published in the January 2012  Diabetes, Metabolic Syndrome and Obesity, and happily the entire article is available free of charge. So let’s look at the data…

The article examines a “22-week crossover study was conducted to examine the efficacy and safety of a commercial green coffee extract product GCA™ at reducing weight and body mass in 16 overweight adults.” Half of the participants were male and half female – a typical study setup (although I do worry about how data is handled when looking at both sexes together, so let’s pay attention to that.)

Dr. Oz’s website indicates that “The subjects (taking the supplement) lost an average of almost 18 pounds – this was 10% of their overall body weight and 4.4% of their overall body fat.” These are pretty hefty claims, but I could use losing 18lbs, so let’s see where this goes.

The study followed those eight men and eight women for 22 weeks. At the beginning of the study, the average body mass index (BMI) at the start of the study was 28.22 ±  0.91 kg/m2 . Determine your own BMI here.

Note that BMI < 18.5 is underweight

18.5  –  25     healthy weight

25   –   30      overweight

30+               obese

This puts the study participants at the high end of overweight, but ‘preobese’.

Dosages of the green coffee extract and placebo were as follows:

“This study utilized two dosage levels of GCA, as well as a placebo. The high-dose condition was 350 mg of GCA taken orally three times daily. The low-dose condition was 350 mg of GCA taken orally twice daily. The placebo condition consisted of a 350 mg inert capsule of an inactive substance taken orally three times daily.”

I don’t think I’m the first one to point out that it’s hard to have a double blind trial when the dosages are distinguishable (two times vs three times daily). At least the placebo should be indistinguishable from the high dose.

One early eye-catching piece of data is from Table I, that summarizes the data of all precipitants as

BMI (kg/m2) pre study:28.22 ± 0.91        post study:25.25 ± 1.19     change-2.92 ± 0.85**, -10.3%

On average, all subjects lost weight during the study. But this really tells us nothing because we could see a 10% drop in BMI if the test arm lost 20% and then placebo arm stayed the same, or we could see the same thing if the weight loss occurred during ALL arms of the study.

Perhaps this reporting of data is justified by the next statement that participants all rotated through being on high dose, lose dose or placebo with intervening washout periods. Presumably, this makes the most of a small sampling of people, but I do find it harder to be confident about the data. Then again, I have never been involved in any human trial of this kind.

here’s the data:

High Dose arm:

start    BMI (kg/m2) 26.78 ± 1.55  –>    end 26.03 ± 1.36

Low Dose arm:

start    BMI (kg/m2) 26.25 ± 1.37  –>    end 25.66 ± 1.20

placebo arm:

start    BMI (kg/m2) 25.66 ± 1.20  –>  and 26.67 ± 1.72

At first glance this might appear to be pretty good. But let’s graph it out:

Image

the data continue to look great.

Now, with error bars:

ImageHuh. Not so hot anymore.

Also, I’m not how sure this was done, but they get p values for HD p = 0.002, LD p = 0.003, placebo p = 0.384. These stats mean that the HD and LD groups are showing very significant differences, while the placebo group is not. You should be able to see this in the graph with error bars (as an approximation of significance). Unfortunately, I see a whole lot of no nothing. But, perhaps BMI is not the appropriate way to observe weight change (we are, after all not seeing specific weight changes, but changes within a group, i.e. diversity)

Another way to try to see what’s going on is to take a look at the weight data:

Image

The data were presented in a number of other ways, but each of these was confusing and didn’t illustrate any clear conclusion (my interpretation).If the individuals’ data were visualized as a scatter plot, this might show us something – or data for each individuals change while in each group… As it is, we see unclear data with spectacular statistics, but we don’t get to see enough to be convinced of the changes.

Rather than go on and get more and more skeptical, let’s say, although we don’t see a lot here, the data,as reported, would make us want to see a larger study with some revisions for control of diet, exercise monitoring and a change in the way osage is administered so as to maintain the ‘blindness’ of the study.

 
4 Comments

Posted by on July 22, 2013 in Uncategorized

 

Tags: , , , , , , , , ,

Penicillin

A great old government film touting the discovery and promise of Penicillin:

Penicillins are a group of drugs naturally produced by penicillium molds. The antibiotic activity of penicillium was first observed by Alexander Fleming in 1928. He recognized the value of what he was seeing, but was unable to isolate the molecule that mediated the activity and therefore could not perform appropriate trials. It was not until Howard Florey and a team of researchers including Ernst Boris Chain and others from the Sir William Dunn School of Pathology, University of Oxford managed to isolate and purify the substance that its great promise became evident. (later Fleming, Florey and Chain shared the Nobel Prize in Medicine for their work)

Alexander_FlemingA number of naturally occurring penicillins exist, each characterized by a beta-lactam ring joined to a variable R-group. These drugs may be effective in the treatment of certain, susceptible (mostly) gram positive bacteria. The mechanism of action is the inhibition of peptidoglycan crosslinks in the bacterial cell wall, such that organisms cannot produce new cell wall and wind up shedding the wall during division. Without the cell wall, the bacteria is highly susceptible to immunological mechanisms and is readily killed.

ImageUnfortunately, many otherwise susceptible bacteria produce an enzyme (penicillinase / beta-lactamase) that cleaves the beta lactam ring structure leaving it ineffective. This single enzyme can be easily passed from one bacteria to another via a sex pilus or transformation rendering them non-susceptible to the antibiotic.

 Image

This enzyme breaks the β-lactam ring and deactivates it’s antibacterial properties. Because beta-lactam is central to the activity of penicillins, cephamycins, and carbapenems, all of these antibiotics can be rendered ineffective by organisms possessing this enzyme.

To counter this beta-lactamase activity, Clavulanic Acid can be used as an inhibitor of this enzyme. Clavulanic acid acts as a competitive ‘suicide inhibitor’, covalently bonding to the active site of the β-lactamase and irreversibly inactivating it. Compounds of the drug (Penicillin) and the enzyme inhibitor (Clavulanic Acid) are available as Amoxicillin under a number of brand names.

 
Leave a comment

Posted by on May 21, 2013 in Uncategorized

 

Tags: , , , , , , , , ,

You will soon witness a miracle

On friday I had lunch at Panda – something -or-other at the mall. Along with my orange chicken and spring roll I got a fortune cookie with fortune the likes of which I have never before seen: “You will soon witness a miracle.” That’s a little off-putting. I mean, miracles only seem warranted when something really bad has happened. I crossed my fingers and hoped for the best.

Then, I totally forgot about it. However, last night, I was reminded of that amazingly powerful cookie when the weatherman showed the extended forecast. Rain, cool days with high temperatures that might allow some time outside. Amazing!

I’ve made so much noise here complaining about the heat and lack of rain leading to the end of the world as I saw it that I thought it was my duty to write now.

There is a change in the air. The weathervane has spun about and a cool breeze is settling across our little patch of the midwest. Mary Poppins has floated into town with her miracle-filled carpet bag stuffed chock with cool mornings, thunderstorms and the chance of a drenching rain later in the week.

With a spoon full of sugar she is attempting to nurse our lifeless grass and trees back to health. I only hope that she has magic enough to bring back the dead (I can’t recall any resurrections in the original) But I did have a dream last night that there was a hint of green grass poking through the ground in our yard, so I have my fingers crossed.

I still have a horribly dreary outlook for the region here and all the dead trees and miserably large landscaping I am imagining, but there is light at the end of the tunnel in the form of a dark stormcloud on the horizon.

 

 

 
2 Comments

Posted by on August 13, 2012 in Uncategorized

 

Tags: , , , , , , , ,