Matt Metzgar

The Winter Metabolism

I feel that this is a pretty significant post, tying some things together that I haven't seen anywhere else.  Earlier, I was reading through this paper, that speculates that Vitamin D deficiency is the cause of common obesity.  I think the paper is on the right track, but it doesn't go far enough.

Before I make my argument, I need to make some other points.  If you look at different variables, you see seasonal variations.  First, there is a seasonal variation to inflammation.  Second, there is a seasonal variation for testosterone in men.  Third, there is a seasonal variation in body fat.  And of course, there is a seasonal variation in Vitamin D status, barring supplementation.  In all these studies, the negative results are highest in the winter and lowest in the summer.

In the paper I initially cited above, the author feels that a lack of Vitamin D is connected to all of these conditions.  The idea is that the body senses less sunlight via internal Vitamin D levels and shifts into winter metabolism.  Winter metabolism is equivalent to the metabolic sydrome.  Therefore, obesity results when a person is in a continual winter metabolism.

I think this argument is mostly correct, but it doesn't go far enough.  If you look at diet and inflammation, you start to see some other connections.  Specific types of fruit, like citrus fruit and berries, lower inflammation.  Of course, fruit is only naturally available in the summer time.

Next, you see that flavonoids and phytochemicals in plant food also lower inflammation (here and here).  So what causes the development of flavonoids and phytochemicals in plant food?  Sunlight (see here and here).

Here's my thoughts: in Paleolithic times, less sunlight in the autumn triggered the winter metabolism.  This led to a whole host of things - accumulation of body fat, declining hormone levels, increased inflammation, etc.  These are all things that are associated with the modern metabolic syndrome.

In the springtime, these conditions began to naturally reverse themselves.  However, this was due to an increase in sunlight AND an increase in anti-inflammatory plant foods that became available.

You can even take this further and look at how certain plant foods protect the skin from sun damage.  This new study shows that foods containing phytochemcials and polyphenols (which are generated from sunlight) appear to protect human skin from sun damage. 

In modern times, people can get trapped in a permanent winter metabolism due to lack of sun exposure and lack of plant food in their diet.  What is supposed to be a transient state of the metabolism for a few months becomes a permanent condition.  You also have children now being born with a "winter metabolism" due to poor maternal diets.

To escape this cycle, people need sun exposure and these plant foods that contain flavonoids and phytochemicals.  As I talked about in a previous post, I'm not sure if Vitamin D supplements are equivalent to sun exposure.  In the wintertime, people may want to use phototherapy or even tanning beds to increase Vitamin D levels.  Combining this with anti-inflammatory plant foods may allow a person to break out of the metabolic syndrome.

Phototherapy and Allergies

Phototherapy has been successfully used for skin conditions like eczema and psoriasis.  Now I am seeing some studies that show it may be effective for allergies as well.

This study reviews the topic.  This study uses a device that directly points light into the nasal cavity to reduce allergies.  Also, this study shows that phototherapy in general improves the quality of life for allergy patients.

Vitamin D and Sunlight

Even though I take Vitamin D supplements, I continue to be skeptical that they are equivalent to sunlight.  A couple new studies have brought up this point.  This study mentions that outcomes for UV radiation and Vitamin D supplements may be different. 

I also read through this study that looks into other benefits of sunlight.  It also discussed how sunlight and Vitamin D supplements are not equivalent.  This study points out that even if Vitamin d supplements and sunlight do both affect serum Vitamin D levels, there may be other benefits to sunlight apart from Vitamin D synthesis.  They state:

"It is important to recognize that all of the beneficial effects of UVR exposure may not occur only through UVR-induced vitamin D synthesis. Thus maintaining current sun avoidance policies while supplementing food with vitamin D may not be sufficient to avoid the risks of insufficient exposure to UVR."

You can also look at two new studies on Vitamin D supplements that showed they had no real effect.  In this study, subjects took Vitamin D for a year and had no decrease in inflammation.  In this study, supplementing with Vitamin D had no impact on quality of life or physical function.

Honestly, I just don't think you can get the true benefits of sunlight in a Vitamin D pill.  At this point, I am about ready to ditch the Vitamin D supplements and buy one of those goofy full spectrum lights.  At least this way, I will actually be getting light and not just a pill!

Phototherapy has actually been shown to have solid benefits.  For example, a couple of studies have looked at phototherapy in the treatment of psoriasis.  This study says home phototherapy should be the first-line treatment option for psoriasis.

I will be digging more into phototherapy over the coming weeks.

Benefits of Prebiotics

I was doing some research on prebiotics, and found a surprising benefit.  Apparently, prebiotics help with constipation.  If you look at older research on constipation, the conclusions are all vague as to what helps: more fiber, more vegetables, more magnesium, etc.  Now the newer research shows that it's a specific type of nondigestible carbohdyrate (prebiotic fiber) that appears to be the key.

This was tested in children a few years back.  Prebiotics were added to cereal and significantly the children.  They've also tested this in adults, and specifically those with irratable bowel syndrome.

You can also get prebiotic fiber from food, though it can be tricky.  From another website, here are the top prebiotic-containing foods:

• Chicory root: 64.6% prebiotic fiber by weight
• Jerusalem artichoke: 31.5% prebiotic fiber by weight (NOTE: Jerusalem artichoke is NOT the green globe artichoke you see at the store. It's a totally different plant.)
• Dandelion greens: 24.3% prebiotic fiber by weight
• Garlic: 17.5% prebiotic fiber by weight
• Leek: 11.7% prebiotic fiber by weight
• Raw Onion: 8.6% prebiotic fiber by weight
• Cooked Onion: 5% prebiotic fiber by weight
• Asparagus: 5% prebiotic fiber by weight
• Wheat bran: 5% prebiotic fiber by weight
• Wheat flour, baked: 4.8% prebiotic fiber by weight
• Banana: 1% prebiotic fiber by weight

As you can see, all of these aren't commonly consumed foods.  Therefore, it can be easier to get some prebiotics through a supplement.

Vitamin A and D

I just read through this study(full-text) which links Vitamin D intake to allergies in children.  It shows that infants who supplemented with Vitamin D had slightly more allergic conditions six years later.

This could be thought of as a blow against Vitamin D supplementation, but the details are important.  They gave the children both Vitamin D and Vitamin A together.  From the study,

"In addition, all children were prescribed vitamin A and D supplements containing 1000 Vitamin A (retinol palmitate) and 400 IU Vitamin D3 daily from 6 weeks to 24 months of age."

So in this study, why is Vitamin D to blame but not Vitamin A?  Based on the previous post, it seems just as likely that the pre-formed Vitamin A is causing the problems.

Vitamin A

I keep seeing weird connections between vitamin supplementation and links to allergy/asthma.  For example, I wrote earlier about the possible connection between Vitamin D supplements and allergies in children.

Now I am seeing the same thing with Vitamin A.  This study found that the way Vitamin A is given affects outcomes.  Vitamin A was either given through peanut oil or in water-soluble form.  The group given Vitamin A in water-soluble form actually ended up with more allergies.

Next, this study shows that Vitamin A at high doses may lead to immune suppression.  This study also shows that high Vitamin A intake can actually make asthma worse.  Yet this study shows that children with lower blood Vitamin A levels actually have more asthma symptoms.

Further, you have the issue of what form the Vitamin A is in.  You have the pre-formed Vitamin A (retinol) like that in cod liver oil, and then you have beta-carotene from plant foods which is converted into Vitamin A in the body.  Too much pre-formed Vitamin A has been linked to birth defects.  Also, this study hypothesizes that asthma is the result of "retinoid intoxication" or too much pre-formed Vitamin A.  It should be noted that milk is usually fortified with pre-formed Vitamin A.

What's going on here?  There are a lot of variables, but I am becoming more suspicious about any type of Vitamin A supplementation.

Vitamin E

I been seeing a number of new studies on Vitamin E lately.  In the past, the results from the various Vitamin E studies were mixed - sometimes there are benefits and sometimes not.  A number of new studies look at only certain components of Vitamin E and their health effects.

Researchers have been looking at tocotrienol, which is a certain type of Vitamin E.  A new study proclaims that tocotrienol is effective in treating male patten baldness.  The same group is doing a followup study that looks at tocotrienol and heart disease.

Tocotrienols are found in palm fruit, but the concentrations are very low.  More information about all this is available here.

Better Running

Barefoot Ralph: Training from Terra Plana on Vimeo.

The above video features Lee Saxby from Wild Fitness teaching barefoot running.  I think is a fantastic video that shows a large change in running form after only a small amount of time.

Inflammation Starts Very Early

Previously, I wrote about how children as young as 2 or 3 can show signs of inflammation.  Now a new study traces things back even further.

This study measured the amniotic fluid of pregnant women to check for levels of inflammation.  Women were divided into three groups: normal weight, overweight, and obese.  The researchers found that as the woman's weight went up, so did the level of cytokines in the amniotic fluid.

The researchers conclude that:

"Amniotic fluid CRP and TNF-alpha levels are increased in obese women, and both are related to maternal BMI, which suggests in utero exposure to higher proinflammatory cytokines and mediators in fetuses of these women."

All this looks like another way in which children can be born with a predisposition to inflammation.

Exercise and Weight Loss

I wanted to further discuss a study I mentioned in the last post.  In this study, subjects exercised 60 minutes a day, 6 days a week for a year, but only lost 4 pounds.  However, in a study I've mentioned before, subjects exercised for roughly 60 minutes a day, 7 days a week for 3 months.  Subjects lost 16 pounds over the 3 months.

So why did subjects lose weight in one study and not the other?  You can probably guess the answer: diet.  In the 12 month study, subjects were free to eat what they wanted.  In the 3 month study, subjects were told to consume the amount of calories per day that they were consuming prior to the study.  In other words, their calorie intake was kept constant while their calorie expenditure was increased.  This led to the weight loss.

These results show a couple things.  First, if exercise is increased with no regard to diet, it is likely that the body will compensate with increased hunger/eating and therefore the result will be minimal weight loss.  Second, the good news is that the subjects who exercised an hour a day did not gain weight, regardless of what they were eating. 

Fasted exercise may be effective because it's an easy way to create a calorie deficit on the day a person exercises.  If you fast, workout, fast some more, and then eat, it's likely that the net result for a day will be a calorie deficit.  A person might be able to achieve the same result by consuming the same amount of calories over the course of the day but without the fast.  This would make a good research study!