Matt Metzgar

Vitamin D and The Holy Grail

In a recent Vitamin D newsletter, there was this interesting quote:

"While I am on the subject, remember, that vitamin D will not prevent all cancer or heart disease, or respiratory infections. True, evidence is accumulating that it will help, but you can still develop cancer, heart disease, and respiratory infections with adequate blood levels of vitamin D. That's why I believe in complementary, not alternative, medicine."

Good.  I'm glad this was said.  Too many people think Vitamin D will cure all their problems.  It is an important factor in health, but not the primary one in my opinion.

In this recent study, the focus was on how Vitamin D interacts with gut flora in modulating inflammation.  The conclusion was that both probiotics and Vitamin D were needed - not just Vitamin D. 

The Gut Bacteria Hypothesis

At this point, I see all signs pointing to the gut bacteria as the basis for almost all metabolic problems.  I continue to find evidence to support this theory, and I continue to see how other evidence fits within this theory. 

The amount of research being done in this area is astounding.  There are major studies popping up all the time.  For example, this study found that simulating inflammation in the gut led to obesity and diabetes.  This study shows that those with higher levels of inflammation consume more calories.

The good news is that I think companies are scrambling to develop safe probiotics and prebiotics that will help people balance their gut bacteria and lose weight.

Blue Zones

I flipped through the book "Blue Zones" at the bookstore the other day.  It shows how people in certain geographical regions live longer.  It lists out a bunch of common sense ideas - sunlight, diet, social support, etc., - but nothing earth-shattering.

Instead, I would look at blue zones in terms of the gut bacteria hypothesis.  For example, one of the first things that came to mind flipping through the book was breastfeeding.  I would bet that it is higher in these regions.  Let's take the first Blue Zone: Sardinia, Italy.  According to this study, Sardinia has the highest rate of breastfeeding across regions of Italy.  So maybe it's not just the sun and the olive oil - maybe it's the breastfeeding that's the key in this region.

You could also look at antibiotic use and see its prevalence in the Blue Zones.  You could look at a number of gut-related issues and see if there's a connection.  My bet is that these factors are even more powerful than the ones listed in the book.

Whole Grains as Prebiotics

I came across one other interesting study on prebiotics.  This study found that whole grains have a prebiotic effect on the gut flora.  Consumption of whole grains (but not wheat bran) significantly increased the amount of bifidobacteria and lactobacilli in the gut.

Obviously, grains are not a Paleo food.  When humans switched from hunter-gatherers to farmers, health declined.  However, widespread obesity didn't come about until the 20th century.  Consumption of refined grains correlates with this.

Usually, the switch from whole grains to refined grains is viewed as negative in terms of higher calories and a higher glycemic index.  Instead, if you look at the change in terms of gut bacteria, the switch may have eliminated a source of prebiotics in the diet.  It could be this resulting change in gut bacteria that led to metabolic problems, and not necessarily the calories from refined grains.

Prebiotics and Diabetes

Recently, I wrote about the potential connection between gut bacteria and diabetes.  I came across a study that tested the effects of prebiotics on type 2 diabetes.

The study used xylooligosaccharides, which are a prebiotic that is found in certain fruits and vegetables.  The prebiotic had significant effects, lowering glucose, total cholesterol, and oxidized-LDL.

Unfortunately, xylooligosaccharides are not readily available yet, but I expect they will be in a year or two.

Antibiotics and Obesity

I have been writing a lot about probiotics and health lately, but there is another side to the issue.  Antibiotics are coming under increased scutiny as far as their impact on weight.

This study discusses how the rise of antibiotics correlates with the increase in obesity.  This study (full-text) studies specific antibiotics and finds that they can lead to weight gain.  With one particular antibiotic, 7 out of 11 patients had an increase of at least 10% in their BMI after taking the antibiotic.  This is quite a change!  The authors hypothesize that the antibiotic use led to increased colonization of lactobacillus, which ultimately led to the weight gain.

Gut Bacteria and Diabetes

Here's a new study that looks at gut bacteria and diabetes in adults.  It shows that there are significant differences in the gut bacteria in subjects with diabetes versus healthy controls.

This follows up on a rat study that showed how altered gut bacteria correlated with the onset of diabetes.

I expect to see future studies on whether probiotics/prebiotics can help treat diabetes.

Long-Term Low-Carb

I've written before about the lack of studies showing any benefits to low-carb diets in the long-term.  Now a brand new study on heart disease compares low-fat, low-carb, and Mediterranean diets for two years.  Guess what?  There was no significant differences between the three diets.  On average, the diets reversed artery thickness by 5%.

Let's see, Dr. Atkin's book was first published in 1972.  Now it's 2010, so that's been almost 40 years.  And yet there are still no long-term studies showing low-carb is more effective than any other diet combination.  40 years, that's a long time to keep saying something is true without any evidence, right?

Anyways, it looks like the weight loss was minimal on this diet.  I am in the process of getting the full-text of the study.  I'm sure some will say that this wasn't a true low-carb diet for some reason, that people didn't comply, etc.  Same excuses.

I just hope that a long-term Paleo diet study is in the works somewhere.

Hair and Heart Disease

Male pattern baldness (alopecia) is being linked to a number of health conditions.  Last year, this study found that alopecia was linked with insulin resistance.  Another recent study links alopecia to heart disease.  My guess is that inflammation is at the root of both these conditions.

This also connects some other things I've been looking into.  For example, I previously wrote how a form of Vitamin E (tocotrienol) supposedly improves male pattern baldness.  Now they are studying this same supplement to see if it can reverse heart disease.  If hair loss and heart disease are indeed linked, then this makes perfect sense.

Gut Bacteria in Time Magazine

There was a nice article in Time magazine about gut bacteria the other week.  The article really hits all the major points, so I will just repost some quotes here:

"We don't think the bacteria are directly making the mice eat more, but the bacteria are causing low-grade inflammation, which causes insulin resistance and then makes the mice eat more."

"We know that to gain weight and become obese, [it] requires you to eat more. The question is, Why do people eat more? Our results suggest that one reason people might be eating more is because of changes in their intestinal bacteria."

"Our results suggest that the tendency to eat more may not only be driven by the fact that food is cheaper and more available, but by a change in the bacteria in the intestines," he says. "People may be eating too much because their appetite is stronger due to a low-grade inflammation they have, which could be due to changes in their gut bacteria relative to what their grandparents or someone else might have had 50 years ago."

Exactly.