Dispelling nutrition myths, ranting, and occasionally, raving


1 Comment

Aloe vera: healing or harmful?

8463896997_566a475485_z

Image by Andreas Issleib on flickr. Used under a Creative Commons Licence.

A little while ago when I was looking for blogspiration a friend told me to take a look at a certain “nutritionist” on twitter. Since then, I’ve had her on my back burner because she certainly looked like she would have some good blog fodder (cured her incurable illness through diet) but I couldn’t be bothered to look through all her posts. Well, today’s the day I move her to the front burner.

I was reading her post on the healing properties of aloe. I found myself hoping that she would provide a balanced picture because I didn’t really want to write about aloe. Sadly, she did not, so here we are. As I feel that simply extolling the virtues of a food, without providing cautions is irresponsible, even if you don’t have a regulatory body protecting the public from you. Sorry, sorry, I digress.

In her post she writes about the magical properties of aloe: anti-viral, anti-bacterial, anti-inflammatory. Unfortunately, there she didn’t link to any research so I can’t comment on the quality of the studies used to make these claims. As far as I can tell, to date there’s been very little (if any) research on human subjects. However, some in vitro studies and animal have shown some promise when it comes to the anti-viral (1, 2) and anti-microbial (3, 4) properties of aloe vera. Of course, based on the current research, there’s no way to know what dose or form of aloe would (if at all) be effective in humans. It’s entirely possible that oral ingestion of aloe would not have any positive benefits in relation to viruses and bacteria.

Some mouse studies and in vitro have shown promising wound healing and anti-inflammatory effects of aloe vera (when administered both topically and orally) (5, 6). Again, there has yet to be any conclusive research done in humans.

Okay, it sounds a bit promising but… Then come the concerns. Before you start adding a handful of aloe vera plant to your smoothie you should be aware that the exterior portion of the leaf has a laxative effect. There are other longer lasting concerns about aloe vera consumption than diarrhea. My friend Helen has written about many of them on her blog Food and Nonsense. These include a risk of cancer and impaired liver function. Over at Examine, the only conclusive research they’ve found so far for aloe supplementation is for increased intestinal motility (i.e. to combat constipation). The Mayo Clinic provides a long list of cautions against the ingestion of aloe vera products, including the risk of inducing uterine contractions in pregnant women. I’ve also blogged about the consumption of aloe vera juice in the past.

I believe that my final statement in that post stands the test of time: Just because it’s “natural” doesn’t mean it’s good for you.

 


2 Comments

DDT and obesity

url

You know how I feel about mouse studies. It’s very difficult to create circumstances that accurately mimic real life in the lab. It’s even more difficult to create circumstances using mice that can be assumed to be the same for humans. A recent study reported that perinatal exposure to DDT caused an increase in diabetes and insulin resistance in mice.

It was quite interesting that the only difference between the mice exposed to DDT in the womb, and those not exposed, appeared to be a decrease in body temperature. They ate the same amount of food, exercised the same amount, and yet they gained weight, apparently because of decreased thermogenesis.

What are the implications of this for those of us who are human though? Well, if you live in a country where DDT is not banned as a pesticide, or is used to control malaria, it may be a concern. It may also be a factor in women (apparently the DDT did not have the same effect on male mice as it did on the females) who were exposed to DDT in the womb before DDT was banned (1972 in Canada and the US). However, it does nothing to explain the current rise in obesity rates and rates of type 2 diabetes in North Americans of all ages. Type 2 diabetes rates in children continue to rise. This study does bring more validity to the argument that pesticide exposure may be playing a role in the obesity epidemic. However, DDT is certainly not the culprit in our neck of the woods.


1 Comment

From mice and CGA to humans and coffee: I won’t be forsaking my Bodum just yet

url

Now that everybody’s all in a tizzy about the latest evidence that coffee is bad for us maybe it’s time to actually look at the study. News reports are stating that “five cups of coffee or more per day linked to weight gain, increased diabetes risk”. Not exactly.

The study used mice as subjects. As discussed before, mice are not humans and results in mice may differ significantly from results in humans. In addition to this, the study didn’t actually look at coffee consumption. No, they looked at the effect of one component present in coffee. That’s like taking sugar out of an orange, giving it to mice, and then stating that oranges are making us obese. One of the greatest obstacles for the supplement industry is that individual nutrients and other substances contained in foods do not have the same effects when they’re consumed in isolation. That’s why us dietitians are always yammering on about it being best to get as many of your nutrients as you can from whole foods.

Yet another issue with the study is that they used three groups of mice: one fed a “normal diet”, a second fed a “high-fat diet”, and the third fed “a high-fat diet + CGA” (CGA is chlorogenic acid, the component in coffee that they were studying). They only looked at the effects of the CGA on mice consuming a high-fat diet. Thus, we don’t know what effects of CGA might have been on mice consuming other types of diets. Admittedly, the mice taking the CGA fared worse than the mice on the high-fat diet alone. However, as the headline pointed out, the negative consequences of CGA consumption were only seen in mice consuming the equivalent of CGA from five or more cups of coffee a day.

This study tells me that CGA in isolation, in relatively high quantities, in mice consuming high-fat diets, may contribute to weight gain and associated risks. A great deal more research is needed before we can draw any similar conclusions regarding human consumption of coffee. For now, take this dose of reality and wash it down with a good cup of coffee.