Monday, August 31, 2009

As an adult you can make more brain cells !

Popular belief was that once your brain had finished it growth in the womb you didn't grow any more brain cells. Very recently this belief and was proved to be inaccurate. The great news is that you can grow more brain cells as an adult. This process unsurprisingly called Neurogenesis - the birth of neurons.

There is at least two different places that neurogenesis occurs. These are described below:

Dentate gyrus. This section of the brain is part of the hippocampus. The hippocampus is shown as the blue section of the graphic. The dentate gyrus is involved in memory formation and the formation of new memories. Damage to this part of the brain can create Déjà vu.

Interestingly enough stress and depression can inhibit the neurogenesis that occurs. It is known when you are stressed about an examination you struggle to memorize material. I wonder if this is the explanation. Also antidepressants helps increase the neurogenesis in this area.

Preliminary studies have indicated that exercise can increase the neurogenesis in this area. I also find that when I go for a run my memories of the run can be very vivid, especially when I see or experience something new or unusual. I often have strong positive memories about how wonderful creation really is.

Preliminary studies also indicate that poor glucose control (diabetes) can impair neurogenesis. This might explain things like alzheimer's are high in the high sugar western diet. Also kids learning is difficult when they have taken in sugar. I wonder if it is due to the shut down of this neurogenesis. I have found it much easier to understand things when I have not had sugary food. When I am intensely focused on grappling with information I will avoid all sugar as this messes up with the understanding.

Subventricular zone. This is the area of the brain which runs down the "tunnel" in the middle of the brain. See the circle next to "LV" in the figure. It is still being explored what happens to the cells that are generated and where they go. What is known is that five types of cells are created:

Fluid creating/circulateing cells. These cycles circulate the fluid in which the brain sits, acting like a cushion holding and protecting the brain.

Another type of cell is created. It is thought that they migrate to the olfactory bulb which is the part of the brain that deals with smell. However evidence is conflicting on this.

"Type B" cell, which does stuff that is still be figured out (it's over my head), could be associated with brain repair.

"Type C" cell like above is over my head, and not altogether understood

It doesn't really surprise me that brain cells are made, because so many people peice their lives back togeather after a brain/head injury. People who are written off by the doctors come back to lead normal lives.

Figures: Thanks to Wikipedia

Sunday, August 30, 2009

For scientists/engineers/mathematicians only

For those rather eccentric scientists like myself who occasional wonder about the mathematics of cooking, Mental Masala has undertaken an analysis of the perfect chocolate chip biscuit recipe !

Have some coal with your cuppa ?

Reading an article are some interesting pointers about pregnancy and diet:
  • That mother does not need to "eat for two". Aparently there is very little extra energy needed for growing baby - this does not cover micro nutrients though.
  • Caffeine is bad for you. Yes one cup of high quality is not a problem, but more is not necessarily better. More than eight cups a day increased the risk of malformation, low birth weight and possibly miscarriages.
  • That 90% of pregnant woman believed diet to be important, where as 33% found compliance difficult. No a surprise most people think diet is important and most people struggle to eat healthy, so I expect that the 33% should be a higher number.
  • In 1936 514 women who had cravings in pregnancy had a total of 991 cravings. These were for Fruit (261), vegetables (187), confectionery (79), pickles (66), cereals (65) and 187 cravings for non food substances such as coal, disinfectant, toothpaste and chalk. It would be fascinating to do a similar survey 75 years on. Would people still crave fruits and vegetables the most, and would a significant number want pickles?
Reference:Barbara Knoxa, John Kremera and Jack Pearceb Food preference during human pregnancy: A review Food Quality and Preference Volume 2, Issue 3, 1990, Pages 131-154

Saturday, August 29, 2009

A garden growing up the wall !

You have to check out these pictures / story about a guy who designs and plants on the outside of buildings. So his garden is vertically not horizontal ! More info is found on his web site. I wonder if you could somehow grow vegetables or fruit trees in this way. Think about how much fresh fruits and vegetables could be grown for people who live in these areas.

Thursday, August 27, 2009

Vegetarian fish oil !

The other day I blogged about essential fatty acids (EFA's) and fungi. One thing that caught my mind was there was a marine fungi that produced DHA. I know that oily fish get their oil from the plankton they eat. Hence depending on which study you read farmed salmon have half the ETA content as wild salmon, or the wild salmon have less than the farmed salmon.

So I thought it would be a great idea to grow the plankton or fungus harvest this for its oil. This has a number of advantages. I would think that growing a bunch of slime would be easier and cost less than farming fish (although sometimes they wouldn't be). It has less pollution - salmon farms often are detrimental to the environment and with wild salmon that pass buy. It is likely a more consistent EFA live would be produced as well.

Well when I was blogging about the concentrated fruit and vegetable powder yesterday, the same sight sells a vegetarian DHA supplement. This is made from marine algae. Now I assume that the algae they are using are plankton that uses sun to grow, not zooplankton as these are animals that eat the plant plankton!

Fruits and vege’s are good for you – dooh

Are vitamins every found by them selves in nature? Have you ever seen a vitamin C tree, that produces 100% vitamin C, covered by a thin layer of skin. Of course not! Then why do we think that having high levels of one nutrient would work miracles? Common sense tells us that vitamins are always found in combination with other important nutrients.

But aren’t you the guy who is writing a book about optimal vitamin content? Yes I am and I believe passionately that you need more vitamins than you are currently getting. However I also believe that you should eat like you are not taking any supplements and supplement like you are eating no nutrients. I also strongly recommend where possible you have whole food supplements. That is food which has had the moister and cellulose (fiber) removed, as well as removal of sugar(s).

Thus were could predict that studies that dose high of one nutrient will likely not show large benefit, but studies that dose a range of nutrients, or even better concentrated fruits and vegetables should have a positive benefit.

Thus today’s blog post highlights a pilot study were they used concentrated fruits and vegetables in powder form on blood pressure and weight. The concentrated fruits and vegetables gave a equivalent of 10 fruit and vegetables servings a day.

The control group had no change in blood pressure or weight. Where as the test group after 90 days of supplementation had a drop in blood pressure and no weight change. For the tech’s
“The systolic blood pressure decreased from 140.4 ± 17.7 to 128 ± 14.2 mm Hg, and the diastolic blood pressure decreased from 90.2 ± 7.7 to 83.1 ± 7.4 mm Hg.”
Thus eating fruits in vegetables, even in powdered form is good for your health! I predict we are going to see more and more of these studies as people figure out that high doses of one vitamin is not going to help, yet high doses of multivitamins and plant extracts are going to be very beneficial.

Reference: Zhang et al The effect of fruit and vegetable powder mix on hypertensive subjects: a pilot study Journal of Chiropractic Medicine
Volume 8, Issue 3, September 2009, Pages 101-106

Wednesday, August 26, 2009

Purple beer !

In line with the previous post, and playing to my own brewing experiments, check out this purple beer!

Is the medication making your child drunk?

In 1986 the American Academy of Pediatrics recommended to "have alcohol removed from liquid preparations for children." Thirteen years later in 1999 some Italian researches found 103 drugs currently in pediatric (child) use that all had the potential to deliver a blood alcohol level of 20mg/100ml.

To put that is perspective adult drives in NZ are allowed 80mg/100ml but for drivers >20 years old the level is 30mg/100ml. This this level of 20mg/100ml is very close to the maximum alcohol level allowed for teenage drivers. So it is quite a significantly high level.

What is even more staggering is that the paper then states "it is worrisome that chronic passive exposure to this bioactive substrate and its metabolites without clinical need or benefit for therapy has not translated into antagonistic literature. " Say what?! In non techy speak they are saying that no body has ever looked at what effects there are feeding these levels of alcohol to kids! They go on to say "An effect on chronic exposure to ethanol and its potentially toxic metabolites has not been assessed in terms of safety or risk in a paediatric setting, although mounting such a study would be both ethical and feasible."

Some of these drugs were drugs that children were likely to be on long term such as cough mixtures and asthma medication. Thus they would be exposed to this high blood alcohol level over some considerable time. Yet on data exists on any negative effects that this has on kids.

They also looked at Over The Counter (OTC) medications. And and herbal unsurprisingly they found many cough syrups that could deliver high levels of blood alcohol. They also found many homeopathicpreparations with high alcohol levels. This is no surprise as homeopathic remedies contain almost no active ingredients, so are diluted down with water or alcohol. Herbal preparations called tinctures, are highly alcoholic as both water and fat soluble compounds are extracted from plants using alcohol.

So the moral of the story is read the label on any product you are prescibed or purchase for your child. (And this is a really go idea to do for any purchase!)

Interesting enough they found common soft drinks had alcohol in them, abit in very low concentrations. Sprite had 0.48ml of alcohol per 100mls and Coke had 0.13ml per 100ml. Now these levels are low. I suspect that they would come from disinfectants or cleaners using in the processing. However it shows how ubiquitous that alcohol has become.

They also found bread also contained alcohol. I was very surprised at this to start with until I figured out that the bread was created using yeast. And yeast is using to brew beer/wine etc. They are different types of yeast optimized for each function. However yeast in bread making obviously also creates alcohol giving levels in 1-2ml per 100g. So in NZ conditions were a typical loaf is 750g it would contain 7.5-15ml of alcohol. As this is pure ethanol, this would equivalent to about 1/2 a glass of wine.

Reference: Fiocchi, A., Ethanol in medicines and other products intended for children: Commentary on a medical paradox Nutrition Research Volume 19, Issue 3, March 1999, Pages 373-379

Monday, August 24, 2009

Iron out the iron wrinkles

I have never believed the hysteria about making sure your baby has enough iron because come 6 months old they cannot get enough iron from breast milk. Plane and simple mums have been feeding for millenniums without any issues, so why is it a problem today?

Well was doing some submission on the Food Relation Policy for Infant formula Products. It turns out that bioavailability of iron in breast milk is 8.12%. This seems like a very small amount, until you read that in whey dominate formula the bioavailability is 1.28%, casein formulas 0.48% and soy based formula 1.48%. (1)

This changes the argument somewhat! Because formula should have approximately 5 to 16 times the amount of iron as breast milk to get equivalent uptake.

Now what is the level in breast milk, the following graph (2) is very helpful
So the lowest iron level is approximately 0.3 micro g/ml. So using the absorption figure of 8% as mentioned above, the iron uptake is 0.3 x 8% which gives 0.072 micro g/ml. 

Low iron formula is milk which has iron levels below 6.7 micro grams per ml. These iron levels are typically much lower than 6.7 normally being 1-2 micro g/ml(3). Therefore the iron from whey formula would be 2 X 1.28% resulting in iron uptake of 0.027 micro g/ml.

Thus you can see that mothers milk, even at the lowest level or 0.3 micro g/ml can supply significantly more iron to baby than low iron formulas.

In America a high iron formula has iron levels >6.7 micro g/ml and in generally they have 10-12 micro g/ml. Thus in whey formula baby gets 0.13-0.15 in whey formula and 0.05-0.58 micro g/ml. The breast milk figures is still 0.072 micro g/ml. Therefore in high iron formula's mum is still providing more than the casein formula, and about half the iron in whey formula.

In Europe the iron levels are typically 4-7 micro g/ml. This gives in whey formula a level between 0.05 - 0.89. This is very similar to the iron levels from the breast milk.

Thus we can conclude that breast milk delivers to baby more than any casein dominated formula. For whey casein formula is the iron level is below 7 micro g/ml, that is levels found in low iron formula, or formula for Europe it is the same, or less than iron from breast milk. The only formula that gives more iron than breast milk, is the high iron American formula that is made from whey (or soy, but I don't like soy milk, will blog about that one day)

It should be noted that the above information is not applicable if mother carrying the baby has not enough iron in the last trimester of pregnancy, thus baby post birth may have lower iron levels than what is optimal.

(1)Bosscher D, Van Caillie-Bertrand M, Robberecht H, Van Dyck K, Van Cauwenbergh R, Deelstra H. J. In vitro availability of calcium, iron, and zinc from first-age infant formulae and human milk. J. Pediatr Gastroenterol Nutr. 2001 Jan;32(1):54-8.
(2) Jensen (ed) Handbook of Milk Composition, Academic Press, 1995 pg 628
(3) Policy Statement Iron Fortification of Infant Formulas PEDIATRICS Vol. 104 No. 1 July 1999, pp. 119-123

Sunday, August 23, 2009

Fats from Fungi: GLA and DHA

Fungi fascinate me as a food. To be honest I don't really like the taste. So when I cook then I try to hide the taste by cooking them in wine, or with bacon. However they interest me because they don't use the sunlight for energy, like other plants. They break down the wood/soil material and use this for energy, and the bits that are above the ground are these plants "fruits". I only figured this out this year, that the fungi that we see are not there to make nutrients but to sow seeds.

With this unusual metabolic method, one would expect some very unusual compounds in fungi. This is why so many of them are poisons and can kills with such a small amount. This is why I don't eat any of the multitude of fungi that appear at our place (except for Taranaki Gold which is very distinctive). But I would love it if different types of fungi were cultivated and sold locally (I often contemplate setting up a shed out the back to do this, but I will be pleasantly surprised if I do this in the next 10 years).

Came across an article that was looking at fats in fungi. I would mentally not connect fungi with fats. However there seems to be a wide variety of fats produced by fungi.

One type of fungi Mucor javanicus produces a high level of GLA (a good omega 6 fatty acid). This can produce up to 18% of total fats produced. Intriguingly enough and enzyme from Mucor javanicus is proposed to be used in NZ cheese production. I am unsure if the application was approved, and if it is used commercially.

Fish get their DHA /EPA from the organisms that they eat. Therefore it is no surprise that the Marine fungi Thraustochytrium aureum which was discovered in 1963, turns out that in optimal conditions it can produce 50% of its fats as DHA. There is considerable interest in this because, one assumes, that it would be easier to produce in tanks than fish. And that is would be easier to process to extract the oil. Will be interesting to see over the next few years if supplements from this source appear on the market.

Reference: Kendrick and Ratledge Microbial lipid technology: microbial formation of polyunsaturated fatty acids. Lipid Technology Vol 2 no 3 pg 62 1990.

Found a new vegetable !

Somewhere in my mind I have linked Maori with Pork and Puha and boil ups using puha as a vegetable. Don't know if this is true, a cultural stereotype or just plan myth. It is included in Andrew Crowe's classic book about edible NZ plants as been eaten by the Maori. (picture ref.)

It is quite a common plant, also known as sow thistle, as when it is broken it exudes a sticky white sap that is incredibly bitter (is in theory a liver tonic). There are other plants that are similar such as Pickly Sow Thistle and Perennial Sow Thistle.

I could never figure out what anybody could bear to eat this most bitter plant, which raw tastes as bad as, if not worse than bitter lettuce. Over the weekend I spent time on my brewing hobby. Tasted a brew, hoping to bottle it, made from Myrtle and Puha. The Myrtle was supposed to be bitter, but it turns out that I should have been using Bog Myrtle! which is apparently a completely different plant! So when I tasted the beer there was no bitterness. I then and collected some Puha and other plants in this group. Boiled then up with some extra sugar (as to not weaken the beer). Tasted this brew, to my amazing no bitterness at all. I even ate some of the boiled leaves. No bitterness at all. In the end I picked a few dandelions (with roots attached) and this created a strong bitterness, so once boiled tipped it into the brewing carboy.

S0 once these plants are cooked they have no bitterness. So next time I boil vege's which is not something I tend to do, I will add in some Puha, as we often have it growing under the trampoline and along the hedge where the mower can't get it.

Friday, August 21, 2009

Sowing letteces the easy way

My lettuce patch is below. It looks like the lawn - well it is!
In some wonderful serendipity I discovered that if you let lettuces go to seed they create your next lettuce crop for you. Once I putted out my lettuces that had gone to seed. I through them on a section of my garden that was fallow and covered with mulch. I forgot about them and sometime later I picked them up and moved them off to the compost pile. Come along spring and this fallow garden was now covered in these lettuces.

Ever since this whenever possible I have let lettuces go to seed and create the next generation for me. It is wonderful as very little work is needed and it results in a massive lettuce crop. What happened in the picture above is that I put in a vege garden growing potatoes and some lettuces. It turned out it was one of the worst places for a vege garden as the top soil was less than 10 cm high! So I moved the garden over winter. However I did allow the lettuces to go to seed, and we know have a carpet of lettuces in the lawn. Below is two closer photos (clicking on them will enlarge them). If you look closely there are at least 3 lettuce variates

I have also done this in the original vege patch. This patch is in the process of transforming into a sub tropical garden. And in the last few weeks my lambs ear lettuces have grown. I love this work when you partner with nature, allowing it to do what it naturally wants to do thus saving you heaps of time. It also means that we have an excess of micro greens which are high in nutrients!

Wednesday, August 19, 2009

Misleading advertsing makes my blood boil

Some people hate baby formula companies and believe that they are the scourge of the earth. I am normally a bit more ambivalent to them, as sometime when we are so passionate about something we can become militant about it, and this ostracizes people. I personally don't think that formula companies are deliberately evil, just naive and misunderstand the issues.

However when I saw this add above in a magazine it mad me mad and I tore it out (lucky I wasn't browsing the mag in a store!). I have left of the bottom half of the ad which has words and a can of formula. It makes me mad because it is a half truth.

There two massive assumptions; that adding vitamins into milk powder will enable these vitamins to be used by baby/toddler/child. Secondly that all vegetables have in them in vitamins. Both of these are wrong.

Life is never as simple as it is made out. Vitamins are often found in plants and animals bound to carrier proteins which makes them much more bioavailable. Some examples are:

Vitamin B12
Vitamin B12 is carried by special protein haptocorrin. This has two functions, firstly it stops B12 from being digested in the stomach. Secondly it enables B12 to be uptaken by the stomach lining, and into the body. Adults make haptocorrin, so if you eat any B12 without it being naturally bound to haptocorrin, it can be attached to the B12 so the body can use it. However it is unknown if babies and infants can make haptocorrin! Cows milk is low in B12 so it is added into the powder as unbound vitamin B12. Therefore there is no evidence that babies get any B12 from the formula. Critic of course could argue that they must get enough otherwise clinical disease would show up.

Well lets have a look at clinical disease definitions. Vitamin B12 deficiency can cause ataxia. This shows up as lack of coordination, trouble walking and trouble with looking at objects. This sounds to me to be normal baby behavior and by time they are on solids at 2 years old they will be getting haptocorrin bound vitamin B12 from animal products.

Pallor can also be caused by vitamin B12 deficiency. This is when the skin is pale, again all my babies have always had pale skin!

So without a blood test it would be impossible to know vitamin B12 status in babies.

Folate is a very interesting vitamin. Folic acid is vitamin B9, however folic acid is not as common as folates in nature. Folates are the folic acid with additional chemicals bound to it. These different chemicals result is more, or less, uptake by the body.

In the body folates are transported around by a proteins called Folate Binding Proteins (FBP). This group of transport proteins are used for various functions in the body. Some are designed to resist digestion and tolerate a low pH as what would be found in stomach. Work with rat intestinal cells shows folate uptake higher than free folate, so these FBP play an important part with absorption of vitamin B9. In adults these functions are still being uncovered, so we really don't know if folic acid in formula can be absorbed by babies without the FBP's.

Again clinical signs are nebulous, a sore back, pallor as discussed above, and again a blood test is needed to determine any clinical defiancies.

The second assumption most people would now disagree with. Vegetables and colorful fruit are packed with micronutrients/flavonoids/phytochemicals. Even though these nutrients would be reduced due to modern day farming and storage. The more I read, the more I realise that the vitamins are the small tip of the iceberg when it comes to health benefits. Therefore it is better to eat your broccoli and carrots than take a vitamin A pill. The exception to this is if your supplements come from concentrated fruits/vegetables. But as these are expensive I can almost guarantee that the formula vitamins will be synthetic and contain no additional plant factors. I did once try and find this out from the formula manufactures and got a simple marketing fob off. And my contacts in the milk industry tell me that they are synthetic vitamins that are added.

In summary formula probably has enough vitamins in it that baby or child is unlikely to have a clinical vitamin deficiency. However they are extremely unlikely to absorb all the vitamins in the milk powder. We have no idea about how bioavailable these vitamins are.

Is your olive oil from irrigated or non irrigated trees?

Produce growers are paid on quality and quantity. Quality is typically defined as visual and/or sensory appeal. Modern growing methods have been focused on increasing production of "high" quality produce. As the nutritional content of the food is not seen as being important, often the increase in the yields results in a decrease of nutrients in the produce.

Here is yet another example of this - in olive oil. Unirrigated olive trees produced on average 987 and 980 olives per tree over two seasons. Irrigated olive trees produced 1489 and 2215 respectively. That is approximately a 50% and 100% increase in yield.

However this increase in yield diluted the oils polyphenols. Polyphenols are the "good stuff" in olive oil, the antioxidants and the other molecules are good for you. The concentration in the unirrigated trees oil was 253 and 227 parts per million (ppm) over the two seasons. The irrigated trees olive oil was only 166 and 150 ppm. That is the concentration of the healthy compounds in olive oil were only two thirds of the non irrigated olives.

Did this decrease result in decrease of "quality" that is the sensory aspects of the oil? No, using the sensory tests as specified by the International Olive Oil Council there was no decrease in quality between the oil from unirrigated and irrigated olives. Infact the irrigated olives had decreased bitterness so are seen as better.

So if you were are farmer would your irrigate? It increases your yield between 50-100% (depending on natural rain levels) and does not decrease the dollar value of your oil. Irrigation seems the logical choice. Have a closer look at the above picture, clicking on it will make it larger. What are those black lines on the ground?

Reference: Patum et al Olive and olive oil quality after intensive monocone olive growing (Olea europaea L., cv. Kalamata) in different irrigation regimes. Food Chemistry
Volume 77, Issue 1, May 2002, Pages 27-34

Monday, August 17, 2009

Pear's vitamin C decimated by cool storage

Found a very disturbing paper yesterday. One that show that vitamin C in pears is decimated by cool storage. The level of vitamin C upon picking was 43 mg/kg. However 15 days later it was only 15 mg/kg. That is a massive reduction to only 35% of the original level after 15 days. Yet I purchased pears the other week from the supermarket. These were NZ grown (I assume) and tasted OK. Yet these would have been harvested in June (or earlier!). So were at least 15 days since picking!

And after 6 months in modified atmosphere storage was a measly 2 mg/kg. That is 4.5% of the original level.

As a small aside the literature review pears could have 72 mg/kg or 26-45 mg/kg. Thus you can see that food tables are really lacking in concrete data!

Interesting enough there was variation between the pears picked from low or high on the tree. The low trees had 1/2 to 1/3 level of vitamin C than the high ones. So make sure next time you go to the fruit shop / supermarket that you ask for the pears harvested from the top of the tree. (sorry couldn't help it, I know that this information is unavailable). Also one harvest was twice the level of another harvest (there was only three harvests altogether!).

Now pears are typically stored between 0 - 2°C so the -0.5°C maybe a bit lower than expected (fruit dues to higher sugar content do not necessarily freeze at 0.0°C)

Reference: Rizzolo et al Evaluation of sampling and extraction procedures for the analysis of ascorbic acid from pear fruit tissue Food Chemistry Volume 77, Issue 2, May 2002, Pages 257-262

Sunday, August 16, 2009

Selenium - how much do you need?

Selenium is a very important micro nutrient. I have been doing some reading about selenium and vitamin E and vitamin C and stumbled across this very important information. It was my understanding that the RDI for selenium was set to give a selenium level of 1.0 micro mol per liter in blood. This level was supposed to give maximum levels of glutathione peroxidase. However as the graph below shows, blood levels of more than 1.0 μmol per litre can often result in higher levels of glutathione peroxidase (GPx).

So when I found out that selenoprotein-P was a better indicator of selenium levels in the body, thus making it a better indicator of selenium status I was not surpised. The key results from this study was that:
  • NZers have low levels of selenium. Even though our bread is mostly made from Australian wheat which has increased our selenium levels, our intake is still low being an average of 28μg a day (the US RDI is 55μg).
  • That selenium iun Selenomethionine is almost twice as bioavailable than selenite. This shouldn't surpirse us as selenomthionine is selenium bound to a protein (methionine) and this is the form that is found in plants and animals. Where as selenite is a rock.
  • Glutathione peroxidase is maximized in blood with 50 μg of selenomethionine but took 80μg of selenite
  • That intake at 70 μg selenomethionine (10μg in diet at 60μg in suppliment) did not maximize the selenoprotein-P levels in blood.
  • You can measure your selenium status with a blood test. If your total selenium in your blood is appromiatly 80 μg/l then your body has enough selenium.
So if taking this data an applying it to NZ situation. We on average eat 28μg of selenium a day, so we need to suppliment with 40 μg a day. (I would be slightly more than this to maxamize the blood levels, however can't conclude from this study what that level would be). Make sure you suppliment with a chelated (protein bound) form of selenium eg selenomthionine.

Picture credit: Unfortuately I can't find the paper that this was orginally taken from! When I find it in my filing system I will upload the credit.
Paper credit: Xia,Y., Effectiveness of selenium supplements in a low-selenium area of ChinaAmerican Journal of Clinical Nutrition, Vol. 81, No. 4, 829-834, April 2005
© 2005 American Society for Clinical Nutrition

Friday, August 14, 2009

Why some people find it hard to lose weight - there could be a scientific reason

This article hopefully removes some of the burden of trying to loose weight. Here is some scientific facts as to why for some people it is such a uphill battle.

Firstly we have to take responsible for our weight and secondly to loose weight you need eat less energy than you give out. It is simple but not easy! We all know people who struggle to lose weight. They put lots of effort into exercise and focus on healthy eating but they seem to unable to easily slim down.

Due to personal experience of seeing this occur I have always wondered why some find weight management easy and some find it very difficult. I have always suspected that there is more going on at a cellular level than we understand. Well this week in browsing my personal journal collection I uncovered an amazing paper. The bottom line is that some people who are obese have less ability to turn fat into energy. Thus it is harder to burn off the fat. Their body at a biochemistry level does not help, and even restricts their ability to lose weight.

For those interested I will unpack the science:

Non Esterified Fatty Acids (NEFA) "float" around in your blood, making up about 10% of fat in the blood. They are also known as Free Fatty Acids (FFA) which seems a simpler name so I will used FFA for the rest of the article. In fasting these fats increase in the blood as FFA is pumped into the blood from fat stores, so that cells can absorb them and then use the for energy.

Muscles of obese men and obese women who have fat on their stomachs (viscerally-obese) when injected with a substance (beta- adrenergic) that should promote cells uptaking FFA does not promote any FFA uptake. This is despite the blood FFA's being the same level as non obese people whose muscles do take up FFA after injection. This implies that their bodies restrict fat burning at a cell level.

Even more disturbing is that weight reduction does not seem to reverse this lack of fat uptake. That is if an obese person has impaired FFA uptake, loosing weight does not cause the muscle cells to return to "normal" and absorb fats properly. This could be of the reasons that people who loose weight find it hard to keep it off, as the body doesn't use up fat as well as others.

Another study showed that 50% of the fat uptaken by a cell is burned as energy when beta-adrenergic is injected nto forearm muscles. However people with type II diabetes none of the fat taken up by the cell was used in producing energy, thus the fat was stored in the muscle. It would appear that in insulin resistance that cells loose the ability to switch fuels from carbohydrate to fat burning. And this inability seems to continue even after weight loss in diabetics. This is why diabetics find it hard to loose weight, and keep weight off.

The question then flows - is it obesity that causes the muscles cells not to absorb fat? Or is it that cells not absorbing fat that makes people obese?

Data would seem to indicate that it is the cells not burning fat makes people obese. The Respiratory Quotient (RQ) looks at how much carbon dioxide you breath out, compared to the oxygen you breath in. This can tell what type of fuel your body is burning. RQ is 1.0 when you are burning carbohydrates, and is approximately 0.70 when you burn fat. A study looked RQ and risk of obesity at Pima Indians in Arizona. They found people with a higher RQ more likely to be obese than those with lower RQ. That is people who more likely to burn carbohydrates than fat, are more likely to be obese.

It also appears that it is not only the difference between between using fat or carbohydrates, but also from where the fat is taken from. The data is only preliminary, but would indicate obese people are more likely to use the fat in their muscles for their energy source than fat deposited in their fat deposits. Thus retaining fat in fat storage areas, which are the areas that people want to remove from their bodies.

So hopefully this removes some of the burden of struggling to reduce weight. And frees you from that negative self talk that beats you up about your inability to loose weight. Thus ultimately helping you to loose weight as you feel better about yourself.

Blaak. E., Basic disturbances in skeletal muscle fatty acid metabolism in obesity and type II diabetes mellitus, Proceedings of the nutrition society (2004) vol 63 pg 323-330 2004.

Wednesday, August 12, 2009

Vitamin E and PUFA avoid the cruel twist of irony

You may heard that the amount of vitamin E that you need is proportional to your fat intake. This is some what true. It is related to Poly Unsaturated Fatty Acids (PUFA). Lets break down what a PUFA is:
  • Poly - this means more than one, in this case more than one double bond
  • Unsaturated - this means at least one double bond on a fat change (eg not completely saturated with hydrogen)
  • Fatty - means a length of fat!
  • Acid - the end of the length of fat as some other atoms that make it an acid, typically a carbon and two oxygen atoms.
Thus PUFA are basically long lengths of fats that have at least two double bonds.
One of the difficulties encountered in determining the amount of vitamin E needed by humans is that the dietary requirement is influenced to a large extent by other nutrients. In both laboratory animals and humans the primary determinate appears to be the amount of PUFA in tissues. Vitamin E is the bodies most important protection and the oxidization of PUFA.
What this means is that the higher the PUFA in tissue, the higher the need for vitamin E as vitamin E is very important to stop PUFA "going off" eg getting oxidized.
Over a period of time the PUFA content in the tissues reaches equilibrium with the dietary intake os that vitamin E requirement can be associated with the consumption of dietary fatty acids. Although it is clear that a higher dietary intake of PUFA increase the demand of vitamin E, an exact quantitative relationship between these factors has not been established.
Great, we know we should have a higher intake of vitamin E, but don't know exactly what level. I should point out that most people, myself included, have no idea about our PUFA intake!

In a cruel twist of irony people at risk of heart disease eg high cholesterol, are advised to increase their intake of PUFA. However in doing so they need more vitamin E. Unless they have this vitamin E the PUFA will oxidize. It is the oxidization of the PUFA which is the root cause of heart disease. So all you on a higher PUFA diet to get your cholesterol down could well be increasing your risk of heart disease.

So if you are increasing your PUFA intake, you need to also increase your vitamin E intake.

Reference: Shukla, V., Dietary essential fatty acids and antioxidants. Lipid Technology vol2 no 1 1990 pg 14

Why Soy oil is everywhere

In 1989 soybean was the "most wildely used ebidle oil int he world, supplying 24 percent of the worlds edible fat and oil consumption." *

Nearly 15 years later not much had changed "In the 2002–2003 growing season, 30.6 million tons of soybean oil were produced worldwide, constituting about half of worldwide edible vegetable oil production, and thirty percent of all fats and oils produced, including animal fats and oils derived from tropical plants" (ref)

I find it extremely fascinating to know why we do the things we take for granted. Sometimes the most mundane for example the space shuttle and horses ass. The reason that soy oil is used so much is it was a "waste" produce in making high protein feeds for American animals. America barn feeds there dairy cows, and often beef as well. Chickens also need a high protein diet and soy is also added to pet foods to boost the protein levels. soy was used to do this because it has a very high protein content, and post processing has approximately 50% protein.

To create these high protein feeds the oil first need to be extracted. So as the market for high protein feeds increased, so did the volume of soy oil. So today soy oil is the biggest oil produced for human consumption.

* Wiedermann, L., Soybean oil, commentary and insights. Lipid Technology vol 1 no 1 1989 pg 7

It'll make you weep

No we are not talking about onions. It is the "advice" that is being given to my community. I assume, as I have never met one, that dietitians are wonderful caring people who got involved in diet because the care for people, just like doctors and nurses. Unfortunately the get taught that the RDI for vitamins is all that people need, and that the food tables are correct. This results in a major focus being energy intake (fat/carbo's) instead of maximizing "minor" nutrients like vitamins.

Thus some very unusual recommendations occur. Sport Waikato has a project called Team Energize. They have tips that are put into our school newsletter. Yesterday's newsletter had "Sports Nutrition Tip #10" and it stated
"After your game try to eat something straight away to help your body star its recovery.

Try a ripe banana, jam sandwich with white bread, small can of creamed rice, crumpets of fruit smoothies And remember to drink lots of water to replace what you lost."
I find it abhorrent that these people are recommending a jam sandwich with white bread! Don't think you could get any more unhealthy than this. Same as a can of creamed rice or crumpet. They are suggesting these things as they are high in carbohydrates and you use up carbohydrates in exercise, so on the face of it these recomendations seem logical. However they are not.

To make matters worse most of the suggestions are all high glycemic foods. That is foods that should not be eaten by diabetics because they cause blood sugar spikes. In non diabetics these foods cause blood sugar spikes just they don't kill you like a blood sugar spikes can do to a diabetic. No wonder our nation is crippled with an obesity and diabetic epidemic.

Let us become more rational and look at some facts.
  1. Firstly you don't need to eat to replace energy loss during exercise. You body uses the glucose (technically it is glucose 6-phosphate but let not split hairs) to drive your cell. Once all the glucose is used up additional glucose is supplied by the liver. This is because the liver stores glucose ready to distribute under exercise. This storage in the liver is called glycogen. Also once the oxygen in used up the cell instead of producing carbon dioxide as waste produces lactic acid. Post exercise the glycogen is rebuilt in the liver. It is either rebuilt from the lactic acid, or from changing fat into carbohydrates to be stored as glycogen. Fat is a very efficient storage of energy. It only takes the energy in 1 gram of fat to power the body to run 100km. Most people have a fat gram or two that could be consumed by the body without any problems. Thus you do not need to eat post exercise.
  2. I would suggest the need to eat after exercise is because we don't eat before hand. We get the stitch if we exercise on a full stomach. Thus when we finish our exercise our stomach is empty so we are hungry. When it comes to kids they are aways hungry !
  3. What your body needs post exercise is nutrients. To make energy you have to use B vitamins. Just like anything you use enough times, B vitamins wear out. Therefore post exercise you should replenish these vitamins. (You can use this trick in endurace events. I always take lots of B's when tramping it enables me to go further and faster than I normally would)
  4. Antioxidants. During exercise you body uses antioxidants to protect the body from the negative side effects of exercise. The higher oxygen use results in high oxidation, high oxidation means more rapid use of antioxidants
  5. Therefore the best thing to eat after exercise are high nutrient foods. For example a green vegetable juice (high in B's) mixed with high antioxidant foods eg berries, really fresh fruit (what ever is in season). These foods have plenty of carbohydrates that would help rebuild glycogen, and high in nutrients.
  6. Lastly if you are having fruits and vegetables these are mostly made up of water, so water intake does not need to be as high post exercise.

Monday, August 10, 2009

Knowledge doesn't change behaviour

We all can think of people who are "bright" or have "talent" that have not been successful in life due to some character flaw or other issue. We all know that success in life is not about how many facts you know, but how you behave.

Therefore it should be no surprise that:
"General nutritional knowledge has been shown to relate to consumption only to a very limited degree."

"The correlation between.... knowledge and behavior was only 0.10" [in simple terms means that there was no correlation between knowledge and behavior.
My life is classic, I know a lot more about nutrition than most people. Yet my lifestyle is not more healthy than most people. My head knowledge doesn't translate into a healthy lifestyle. It would appear that beliefs about the sensory aspects of food are more important than nutritional benefits. That is how the food tastes, smells, texture, etc is more important than nutritional benefits.

Thus this shows the futility of public health campaigns to eat better. We seem awash with pamphlets, posters, ads all about how we should be living healthier lifestyles, eating more vegetables etc etc etc. However I have not seen any statistics about peoples lives being changed by this data. And I now know why I have not seen statistics - because if they exists they will show the futility of wasting money in this education campaign.

I personally think the money would be better spent on personal trainers who would work with people who have indicated they want to make lifestyle changes. These trainers would only impact a small number of people, but this would make a significant impact. Thus friends, relatives and family would be encouraged to embrace a healthier lifestyle.

Shepherd Behavioural modelling of fat consumption Food Quality and Preference
Volume 2, Issue 2, 1990, Pages 89-94

Grappling with the truth

Small post to say I am grappling with two papers that are full of science speak and gobbledygook. But if I am understanding the papers correctly they seem to be saying that obese people and/or type two diabetes people physiologically find it harder to loose weight. It would appear that at a cellular level they burn energy differently than normal, with normal people burning up fat when they exercise, but the obese/type II diabetes do not.

Once I have wrestled with the papers some more I will attempt to explain this is easier understandable words!

Thursday, August 6, 2009

Spirulina - not so super?

Spirulina, the green/blue bug that grows in water has some wonderful health benefits. This is hardly surprising as it is a plant, and most plants have wonderful health benefits if you eat them in large amounts, and minimal processing.
Technically Spirulina is two different types of cyanobacteria: Arthrospira platensis, and Arthrospira maxima. Cyanobacteria are group of pond scum bacteria. They are colored green to blue and get their energy from photosynthesis like green plants.

There is another cyanbacteria called Anabena flos-aquae which is not healthy for you at all. It produces Anatoxin-a neurotoxin with some very nasty effects. This neurotoxin can kill within minutes and sometimes wipes out groups of animals who drink from the same contaminated pond. In saying all this I have never heard of animals dieing in NZ from this toxin.

A study looked at Anatoxin-a in spirulina drinks and supplements (in the US market). They found 3 of the 39 Spirulina products (7.7%) where contaminated with Anatoxin-a. This may hit the headlines around the world as the papers like to report anything negative about supplements.

Reading the study more closely the anatoxin-a levels were between 2.50 to 33 μg / g. Mice die when 385 μg of anatoxin-a per kg of body weight is injected into their bodies. Therefore assuming same toxity level in humans and the average human being 75kg, you would need to injest 28.9 mg of anatoxin-a to die. With the highest food/supplement levels of 33 μg / g you would need to eat 875 kg of contaminated spirulina! (This assumes that all toxin eaten makes it into your blood stream.)

Have you ever eaten 875 kg in a meal? Thus rest assured that your spirulina is not going to poison you!

Reference: Rellán et al First detection of anatoxin-a in human and animal dietary supplements containing cyanobacteria Food and Chemical Toxicology
Volume 47, Issue 9, September 2009, Pages 2189-2195

What is it about vege's?

In general studies have found consumption of vegetables has wondrous effect on your health and wellbeing. However fruit has had mixed results, with some studies saying fruit consumption does not have a health benefit, and others say that it does. Part of the complexities is that most people would call a tomato and a green pepper/capsicum a vegetable, but the are actually fruit. So you can see some of the confusion that could arise.

Back to vege's, are great for your health, the more you eat and the larger variety the better for your health. I wonder what properties vegetables have that give them their health benefits. I have come up with a few theories, and knowing how complex life and nature is it highly likely that it is a combination of these things, not just one characteristic.
  1. Phytochemicals. This includes all the wonderful nutrients that the plants make. Vitamins is only a very small part of phytochemcials. Its seems like every week some scientist finds a new chemical in a vegetable that is great for your health. For a comprehensive list of phytochemicals see wikipedia. Commonly known ones would be Lycopene which makes tomatoes red, or sulforaphanes in cruciferous vegetables.This is the things that give cabbage and broccoli there distinctive taste
  2. Fibre. Vegetables contain oodles and oodles of fibre. This wonderful fibre both slows things down, and speed things up. It slows down the absorption of food, thus reducing blood sugar level spikes and dips. The fibre speeds up the travel of food and waste out of your body. Thus hopefully removing waste before it can have any adverse effect on your body
  3. Reduction of bad food. I have observed that people who eat lots of vegetables tend not to eat lots of "bad" food as they find our modern food processing (eg increasing sugar and fat) produces food that they do not like the taste of. For instance when I was eating very healthy I didn't like the taste of fast food or junk food because the fat made me feel sick and high sugar products tasted far to sweet.

Thus there are at least three ways that vegetables can make you healthy.

Tuesday, August 4, 2009

First things first - overcoming Imposter Syndrom

Went to a seminar about "Impostor" syndrome. It is basically when you don't believe you are worth your accomplishments, or you are a fake or fraud in being successful.

I have it really bad! Especially in the health area. I know all the things that we as a family should be doing to live in optimal health. And as I struggle to live this I feel afraid that someday someone will find out how unhealthy our lives are, and I will loose all creditability.

So I am learning to appreciate myself and my efforts, instead of telling myself how I don't measure up. For instance on Monday we were still recovering from a mammoth and wonderful celebration of life and marriage. So on paper I didn't achieve much, and in terms of billable hours (ie income) zilch. However what I did do was important. I did exercise, I juiced, we eat well and I nurtured our marriage as helped Tiffany clean up for her tupperware party (they bake things using the tupperware so the kitchen had to be quickly tided up after dinner. )

So I did important things. So instead of telling yourself that you are not doing enough for your health, celebrate the journey you are towards wellness. Rejoice in the small and important things that you do, feel good, give yourself a pat on the back instead of a monkey on your shoulder.

Monday, August 3, 2009

Not all fruit ripen post harvest - why home grown strawberris taste better

We all know that fruits are picked when they are unripe so that they are less damaged in transport to market and they can be "fresh" when they arrive ie not rotten.

I have just discovered that this is only true for some fruits. Fruits that ripen post harvest are call climacteric. And unsurprisingly fruit that does not ripen are called non-climacteric. Climacteric fruits that ripen post harvest like bananas and tomatoes release ethylene thus ripening. Ethylene is a plant hormone and is made inside plants. And yes this is the same gas that is used in some welding, and it is the same as the ethylene used as a anesthetic.

The no-climacteric fruit includes citrus, grapes, litchi's and strawberries.

This explains to me why strawberries purchased from shops always taste sour compared to home grown ones. It is the final ripening process that release sugars. Thus strawberries picked before they are 100% lock in their sugar levels at a lower level. This may also explain why I don't like the taste of imported citrus. It always tastes funny, although this could be due to the difference growing conditions in California than NZ!

Interesting enough the non-climacteric fruits do have ethylene receptors that are active. So in theory you could store strawberries with a climacteric fruit such as banana's and the strawberries might ripen. I will try this when strawberry season comes around again.

What part is best to eat?

One of the more perplexing issues is determining when to harvest your food and what part is the most nutritious part.

From memory lettuce leaves on the outside of the plant have higher nutrition. This is thought to be in response to the higher sunlight. However other plants (which I can't remember now) have higher nutrition when they are sprouts.

Then comes the next question, let us say broccoli is highest nutrient level when small. However it is the smallest by mass then, so when would be the best time to pick broccoli when you want to feed your family, but still feed high nutrient levels.

This is no simple answer for these questions. But there are pointers that hint at solutions.

One of these studies looked at two different grasses for their nutrient levels of the various parts, with relation to their usefulness for cattle feeding. One grass is commonly called "Timothy-grass" the other Switchgrass. Unfortunately the study didn't look at vitamin levels, but did look at minor metal concentrations. In the same soil Timothy grass had much high mineral levels across all minerals measured. This is shown graphically below:

So it would seem clear if you were going to sew grass for your cow you would choose Switch grass. On the other hand Aluminum which we would all agree is not a mineral you should eat if you can avoid it, had much higher Aluminum levels, so maybe it wouldn't be as good.

They also broke down the mineral level by different plant areas, however I couldn't draw any conclusions as the data became to complex.

As an aside here we have the classic issue of food tables. If you were to look up grass in a food table - what level would you get told?

Reference: Smith & Greenfield
Distribution of chemical constituents among shoot parts of timothy and switchgrass at anthesis Journal of Plant Nutrition, Volume 1, Issue 1 1979 , pages 81 - 99