Are artificial sweeteners the enemy?

There is no question, the word in the street is - stay away from artificial sweeteners.  Kurt Harris, a leading paleo source writes: " Artificial sweeteners, I believe, condition you to crave sweets. I have only personal and anecdotal clinical experience to support this, but it seems reasonable."

Really? That sounded strange to me. This is one of the most studied topic of the last fifty years - it seems so unlikely we wouldn't be able to have a way to measure the sweeteners effect on hunger.  So I went looking.

And here you go:

1. "Aspartame has not been found to increase food intake; indeed, both short-term and long-term studies have shown that consumption of aspartame-sweetened foods or drinks is associated with either no change or a reduction in food intake." [here]
2. "The addition of NNS [non-nutritive sweetener] to diets poses no benefit for weight loss or reduced weight gain without energy restriction. There are long-standing and recent concerns that inclusion of NNS in the diet promotes energy intake and contributes to obesity. Most of the purported mechanisms by which this occurs are not supported by the available evidence, although some warrant further consideration." [here]

As I browsed through the variety of studies, I found out that, predictably, consuming  sugary beverages will temporarily make you feel full.  Non-calorie sweeteners will not do that. However, there is little difference between drinking non-sweetened water and artificially-sweetened water when it comes to hunger. In fact, part of the problem with high fructose corn syrup may be that it does not make you feel full like sugar does.

While the internet at-large is filled with vicious propaganda against artificial sweeteners, I failed to find a medical study that confirmed their truth. My thought is that it is reasonable to assume, based on the strong sentiment against artificial sweeteners, there is plenty of motivation to prove these claims. Lack of evidence suggests just that - lack of existing available evidence in reality.

Dispelling the dogma: saturated fats

"Kate, I can't eat like you do. My cardiologist is going to kill me! I can practically feel my arteries getting clogged up with every bite."

Another discussion about fat is getting started between me and my mother-in-law. I sympathize with her. For 40+ years we've been talking about the dangers of saturated fats and the risk of disagreeing with the dogma carries dire consequences.

"We are extremely good at test-tube science," maintains my husband every time I lash out against the establishment. He is right, of course. We really are! We learn so much each day about how to further optimize treatments, how various micro-nutrients impact our bodies, we even figured out that sugar is bad for you. Go us! Yet, when it comes to fats, I can't buy it.

So, I am finally getting off my butt and figuring out what's wrong with the world of nutritional science and how it got to be that way.

I recently blogged in my personal journal about an article published by the Journal of the American Medical Association in which a real-life modern-time western-scientist says, nah... fats are ok (as I learned from this commentary). We've been retarded for all this time. I got very excited, but found that I could not access a copy of this article without paying. I would happily pay $40 to access a study, but this was just commentary. I figured, i'd rather look for something that has numbers.

I dug just a little further, and - voila - The American Journal of Clinical Nutrition is full of studies that overturn the claim that fats cause heart disease.  Unfortunately, I do not have full access to the majority of what's available there (though I think it's time to get my credit card out), here are some points I pulled out of the abstracts:

• "there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD [coronary heart disease] CVD [cardiovascular disease]" [here]
• "replacement [of saturated fat] with a higher carbohydrate intake, particularly refined carbohydrate, can exacerbate the atherogenic dyslipidemia associated with insulin resistance and obesity that includes increased triglycerides, small LDL particles, and reduced HDL cholesterol. [here]
• Though the same article points out that "Clinical trials that replaced saturated fat with polyunsaturated fat have generally shown a reduction in CVD events".  

Here is how I would summarize findings for today:

There is no significant evidence that saturated fat is bad.  However, you are better off eating polyunsaturated fat (the essential fatty acids).  But whatever you do, don't limit fat and replace it with pasta! Now, that's the one that will clog up your arteries as we speak, mom!  :-)

Stretching going out of vogue?

Get this: Stretching before running does not prevent injury according to a study published at the USA Track & Field website.  However, enthusiasm matters!

The study found a slight increase in "reported" injuries in the non-stretching group. However, "serious" injuries measured by a week or more off practice, did not increase.  Why?

So you are a runner who volunteered to participate. If you were used to stretching, and were randomly assigned to a non-stretching group, you'd be pretty scared, right?  Yeah, so 22% of such people reported an injury to a medical professional.  Only 11% of those who were not used to stretching did.
Bottom line, though it's hard to believe given what we have been hearing since middle school, a warm-up is just that: an increase in your body temperature. Stretching feels good and is a worthwhile exercise in and of itself. However, it is highly optional.





A note of caution: This study used a specific stretch regiment that looks right about what most people do: 10 second hold like this, 20 sec like that, so many reps, so many things.  It does not address yoga-style stretching alternatives and also does not examine long-term effect of stretching (like if you've been doing it for years - are you less likely to be hurt in general? Yeah, probably.)

I love finding these bits and pieces.  Thanks to NY Times article by Tara Pope for bringing this information.

Fructose malabsorption

Fructose malabsorption, formerly named "dietary fructose intolerance," is a digestive disorder in which absorption of fructose is impaired by deficient fructose carriers in the small intestine's enterocytes. This results in an increased concentration of fructose in the entire intestine. - Wikipedia

Turns out, this problem exists in 30-40% of women in central europe. Don't know what that says about americans, but most of us are from somewhere over there, right? Well, that's not the interesting part (wait, is apple juice flowing through the veins uninteresting??)

The amazing thing is that fructose malabsorption appears to lead to depression in women according to an Austrian study. Ironically, men appear to be unaffected - perhaps because of different chemical composition as Emily Deans explains in Evolutionary Psychiatry blog.

I always say that the Paleo diet has changed my life. It gave me energy, emotional stability, thereby making me a better parent, and allowing me to enjoy life. But the truth is, I don't know how it did it. Was I lacking protein on my low-fat high-carb diet? Was iron defficiency a problem? Was my body in a perpetual emotional yo-yo as my sugar swung wildly at each meal and snack? OK, I won't look a gift horse in the mouth - but nevertheless I tend to skip a heart beat every time I see yet another possible correlation between nutrient consumption and emotional state.

Carbohydrates: Food for muscle?

My husband and I got into an argument: is low-carb really healthy? My Paleo exploits have caused him to take an audio course on nutrition, which impressed both of us with its solid grounding. Surprisingly, many conclusions coincide with common wisdom among the Paleo folk, but there are some differences.

 Today I would like to examine the idea that carbohydrates are necessary for proper muscle function. There are two "basic truths" everyone who works out has heard:

1. We need carbohydrates in order to expend energy. All athletes "carb up" for the big marathons and according to mainstream nutritional science, protein can be converted to carbs if needed. However, that's slower and hard on your liver. So if you really want to impress your friends, better start your workout with an oatmeal.
2. Even my Crossfit coach agrees with this one: carbs are great for a post-workout recovery.

I started, as I often do at the old Mark's Daily Apple.  Sure enough,  he doesn't buy it. Have a high-protein snack after your workout and say hello to another great day.  The most interesting thing that came out of that article was a link to a study, which proves that consuming carbohydrates after a workout does not indeed help muscles rebuild.

When I reviewed studies citing this one - I learned that

• Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis
• Protein coingestion stimulates muscle protein synthesis during resistance-type exercise

OK. Back to beef jerky post-workout. But what about the other end of it? Do we need to consume heavy carbs in order to get out of the chair?

Word of mouth among Crossfit trainers says, no. But thus far I have not been able to find very much evidence. Can you point me in a good direction?