Saturday, February 3, 2007

Omega-3 Fats: The Right Ratio


There has been some interest of late in omega-3 fatty acids or, as some people know them by, fish oils. This is due to the interesting things that science has found about these oils.

First and foremost as almost anyone who has grown-up in the last 40 years knows, fat is bad for you and should be avoided at all cost. WRONG!

Not only are some fats good for you but some are essential. That's right, like some vitamins, minerals, and amino acids (proteins) some fats are needed by our body yet cannot be produced by our body thus they must come from our diet making them "essential". This fact alone should radically alter the view most people have of fats.

Some Fats Are Essential

Fat is used by the body in many ways. The way that most people think of is as a means to store energy. This is why you gain fat when you eat more calories than you burn. Your body converts those extra calories into fat because fat is a highly efficient means of storage (more calories stored per gram).

But fat is also used in the construction of cells, their walls and interiors. The brain itself is largely constructed with fat. Fat is also used as a means to communicate between cells where the types of fat exchanged can play a role in how those cells behave. This point, though seemingly innocuous, can have serious health consequences. If your cells, say pancreas cells, get the wrong information on how to behave (due to exchange of the wrong kind of fat, maybe due to dietary restriction of essential fats) this could eventually lead to health problems.

The essential fats, omega-3 and omega-6 fatty acids, are also known as omega fats. There are also omega-9 fatty acids but they are not essential in that our bodies have the enzymes to produce these as needed. The term omega is used to distinguish the naming system (nomenclature) used to identify the carbon at which the first double-bond (unsaturation) is encountered (see figure). The need for the term is an artifact of the different carbon counting systems used by chemists and physiologists. With regards to diet and the body the physiological nomenclature makes sense since the body interacts with these molecules from the omega end of the molecule.

Chemical structure of alpha-linolenic acid (ALA), an essential omega-3 fatty acid, (18:3Δ9c,12c,15c). Although chemists count from the carbonyl carbon (blue numbering), physiologists count from the omega (ω) carbon (red numbering). Note that from the omega end (diagram right), the first double bond appears as the third carbon-carbon bond (line segment), hence the name "omega-3"
Chemical structure of alpha-linolenic acid (ALA), an essential omega-3 fatty acid, (18:3Δ9c,12c,15c).
Although chemists count from the carbonyl carbon (blue numbering), physiologists count from the omega (ω) carbon


Get the Right Ratio
In recent decades research on the two essential fats has begun to focus not only on the absolute quantity (how much) of the two fats consumed but also on the relative ratio (amounts of one relative to the other) of the two fats consumed. Using modern hunter-gatherer diets as aguide researchers have come to the conclusion that our ancestral diet, our paleo-diet, had a ratio of omega-3 to omega-6 fatty acids of about 1:1 or one omega-3 for each omega-6 consumed. Iin our modern diet this ratio has changed drastically. We now consume ratios of 1:10 with one study giving a 1:20 ratio between the two fats. The higher ratio of omega-6 to omega-3 is implicated in increased risk to heart disease as well as other inflammation diseases (Crohn's disease, insulin resistance and diabetes, as well as others) though the exact mechanism by which this ratio difference can impact the body is not yet fully realized. The impact that the ratio of the two fats has on the body is basically at the cutting edge of research. The take home message from that last sentence is, with regard to our understanding of diet, health, and the body, ideas derived from "cutting edge research" often change dramatically, as most anyone who follows such research is painfully aware.

In addition to the ratio of omega-3s to omega-6s there is also research looking into the impact of the three different types of omega-3 fatty acids, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). You can read more about the three different types in a previous post.

Avoid the Bad Fats
Now there is a lot of information here to keep track of. To add to that it should be remembered that saturated fats (solids at room temperature) such as butter and animal fats are still to be minimized and avoided as should hydrogenated fats found in margarine, many prepared foods, and most off the shelf snack foods. The hydrogenation process destroys the double bonds (adds hydrogens) which preferentially destroy the omega-3 bonds over the omega-6 bonds thus increasing the ratio. Though I am skeptical of the "worst fat" moniker that trans-fats have been given they are at best as bad as saturated fats and thus should be eliminated.

Recommendations:
Before changing your diet consult a physician and if you change your diet, consult your body. Listen to what it is telling you and adjust your diet to your body's needs. These needs will likely change over the course of a dietary change (and as you age) so make sure to keep listening.
  • Eat more vegetables (higher in omega-3s) the fresher the better.
  • Increase your consumption of good fats by replacing corn oil with canola oil or flax oil (don't fry with flax oil but baking is OK). You can also replace oil in recipes with flax meal in a 3:1 flax meal:oil ratio (you might need to adjust fluids but I have yet to do so.)
  • Do not get all your omega-3s from flax or other vegetable sources since this omega-3 (ALA) is not converted into "brain" omega-3 (DHA) by the body.
  • Eat more cold water fish, the lower on the food chain the better (due to bio-magnification process where heavy metals and PCBs are increasingly concentrated as you move up the food chain) this means more sardines but since eating sardines everyday really isn't tenable include salmon and other upper food chain fish in limited amounts (~ 1 or 2 servings a week).
  • Use fish oil supplements. Make sure they are purified to remove heavy metals and that they are third party certified.
  • Fish stocks globally are being harvested unsustainably. Please consider that you can now get DHA derived from algae from this site (note: I am not invested nor do I receive proceeds from this company. Full disclosure is that I plan to invest in this company in the future.)
  • Avoid saturated fats, processed foods (they contain hydrogenated fats to increase shelf life), and other hydrogenated fats.
  • Replace conventional dariy products with organics, there is some suggestion that organics have a higher ratio omega-3 to omega-6.
  • Eat grass fed meat products if you eat meat since these are higher in omega-3s.

Remember, a healthy diet includes fat, within limits, and that getting the ratio of omega-3s to omega-6s right as well as the right mix of the three types of omega-3s is important. Once again, a balanced diet is called for. For more information of the food sources of omega-3 follow this link.

Lastly, this isn't a lecture, this is a co-operative joint venture. I am very willing to tap into the collective knowledge-base that is the readership. The human body is a super complex mechanism so please, if you've read conflicting information or know of the latest research email me or add a comment.

DISCLAIMER: The information and advice contained in this article are intended as a general guide to healthy eating and are not specific to individuals or their particular circumstances. All content within this article is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional.


Technorati Tags: , , ,

Thursday, February 1, 2007

Good Fat: Omega-3s and Your Health

Omega-3s


The three different types

Omega-3
Definitions
ALA (sometimes LNA): alpha-linolenic acid
EPA:                         eicosapentaenoic acid
DHA:                        docosahexaenoic acid

http://en.wikipedia.org/wiki/Omega-3
Omega-3 fatty acids which are important in human nutrition are: alpha-linolenic acid (18:3, ALA), eicosapentaenoic acid (20:5, EPA), and docosahexaenoic acid (22:6, DHA). These three polyunsaturates have either 3, 5 or 6 double bonds in a carbon chain of 18, 20 or 22 carbon atoms, respectively. All double bonds are in the cis-configuration, i.e. the two hydrogen atoms are on the same side of the double bond.


What are the general findings?

  • Natural (human evolution) diet ratio of omega-3 to omega-6 fatty acids (omega3:omega6) was about 1:1 but present American diet is around 1:20 [4,5]

A diet rich in omega 3 fatty acids (such as the LNA from flax oil or the EPA and DHA from fish oils) not only provides the body with healthy fats, but it also lowers the blood level of potentially harmful ones, such as cholesterol and, possibly, even reversing the effects of excess trans fatty acids.

DHA is the primary structural component of brain tissue, so it stands to reason that a deficiency of DHA in the diet could translate into a deficiency in brain function. In fact, research is increasingly recognizing the possibility that DHA has a crucial influence on neurotransmitters in the brain, helping brain cells better communicate with each other. Asian cultures have long appreciated the brain-building effects of DHA. In Japan, DHA is considered such an important "health food" that it is used as a nutritional supplement to enrich some foods, and students frequently take DHA pills before examinations.

Journal article

  • Men are more efficient at converting ingested fat to energy than women [2,3].  For men ALA conversion was 33% versus 22% for women.
  • The conversion of ALA to EPA is strongly linear (what percent?) Thus increased consumption of ALA should lead to an equally large increase in the amount of EPA in the blood.
  • There is no relationship to the consumption of ALA and the blood levels of DHA.  Thus ALA consumption should not substitute for the consumption of DHA.  Unfortunately DHA is found widely in resources that are being harvested unsustainably.

Conversion percent
  • Role of gender in conversion
The article Compartmental modeling to quantify alpha-linolenic acid conversion after longer term intake of multiple tracer boluses says that the body incorporates about 7% of the ALA consumed and converts about 1% of that into DHA (eventually).  (That's 0.07% of ALA consumed becomes DHA - 1000mg ALA = 70mg of DHA for the body. Compare that to the amount (minimum ~150mg) in one DHA enriched egg.)  This conflicts with the previously mentioned study which found no conversion.  This study uses isotopic methods of investigation that the previous study mentioned as having some problems.  None-the-less neither study shows substantial conversion of ALA into DHA.


Health benefits of ala, epa, and dha
Omega-3s and
depression
Alzheimer's
Colon cancer

CiteULike link

 
[1] G.C. Burd, Metabolism of α-linolenic acid in humans  Prostaglandins, Leukotrienes and Essential Fatty Acids Volume 75, Issue 3 , September 2006, Pages 161-168
[2] A.E. Jones, J.L. Murphy, M. Stolinski and S.A. Wootton, The effect of age and gender on the metabolic disposal of 1-13C palmitic acid, Eur. J. Clin. Nutr. 52 (1998), pp. 22–28. Abstract-EMBASE | Abstract-MEDLINE   | Abstract + References in Scopus | Cited By in Scopus

[3] A.E. Jones, M. Stolinski, R.D. Smith, R.J.L. Murphy and S.A. Wootton, Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women, Br. J. Nutr. 81 (1999), pp. 37–43. Abstract-MEDLINE | Abstract-EMBASE   | Abstract + References in Scopus | Cited By in Scopus

[4] Omega-3 fatty acids in health and disease and in growth and development

Am J Clin Nutr, Vol. 54, No. 3. (1 September 1991), pp. 438-463.
by Simopoulos A
[5] Human requirement for N-3 polyunsaturated fatty acids.
Poult Sci, Vol. 79, No. 7. (July 2000), pp. 961-970.
by Simopoulos AP

 







Technorati Tags: , , ,

Thursday, December 28, 2006

Memory Moments

For many, a bed, blankets, pillows, and pajamas are all traditionally associated with sleep.
  • Sleep (~7 hours) helps with consolidation of memories (placement of memories in "long term storage" within their meaningful context.)
  • There maybe wakeful moments when memory consolidation occurs as well.
The link that sleep helps with memory has been getting some more attention in the media recently. This is due to some recent science work that has shown a strong link between getting a decent nights rest (minimum of ~7 hours thus my memory problem) and ability to redo a task that was learned the previous day [1]. Though there are some doubts about what period in the sleep pattern such consolidation occurs [2].

Yet sleep may not be the only time period in our lives that such an important task takes place. If you listen between the lines in the NPR Science Friday podcast (mp3 download) you will hear that there are moments during waking hours where the brain also consolidates and processes memories. These are the moments where we sometimes catch ourselves or others "zoning out".

Zoning out is when someone seems to be just staring off into space (usually for shorter periods than daydreaming but daydreaming may well be a a form of this) for a few seconds or so before re-emerging into the present moment. My three year old does that, it seems, a lot. I've been starting to call those moments her zombie moment. She'll be engauged with us in conversation or interaction of some sort then freeze, staring off into space. I think, now that I have heard this podcast, that I'll call them memory moments.

I will research this further to see what scientific evidence there is to support the idea and will write a follow-up.

So remember the next time your son or daughter or your partner is just staringing into space when you were talking to them, it may be that they are doing something healthful and helpful for themselves. Or it may just be that they don't want to take out the trash.



A note to readers. If you have any ideas on health and diet that you would like to see researched in the scientific literature and addressed in a maner you might understand please email me at macclune (at) gmail.com. I cannot promise that I will address every question but I will try.



Technorati Tags: , ,

Tuesday, December 26, 2006

Turmeric and cancer

Cancer can be a really difficult disease to fight using conventional methods. The cells in your body are in a state of flux. They are constantly dieing-off (senescence) and being replaced with new cells. The body needs to replace with new cells though only those that have been lost through cell death. Sometimes though that is not what happens.

Cancer cells are cells that have a faulty mechanism for turning themselves off. Both the replacement of healthy cells that have specific functions with cancer cells that do not perform those functions and the physical presence of the cancer mass have an impact on the body's functions such that death can occur if the cancerous mass is not removed either through surgery (not all cancers can be removed physically) or with chemical (chemo) therapy and/or radiation. Often a combination of these approaches are used.

Unfortunately not all cancers can be fought off in this way. Some are resistant (have faulty apoptotic pathways) and can even lead to increased malignancy with treatment over time. This tendency can either be inherent in the cancer type (shows no response to chemo/radiation therapy) or be acquired over time (initial response that is later lost.) But recent work on shows there may be some hope for future treatments on these resistant cancers.

There is a process of cell death termed mitotic catastrophe which in mammalian cells is caused by aberrant mitosis. This is sciencese for death of cells by dividing into various other (non-viable) forms. A mitotic catastrophe causes massive die-off of the affected cells. This process is generally prevented from occuring in cells due to a body chemical given the name of survivin (how creative! I guess that's better than zercoxinol or something like that.). It turns out survivn is found in all growing cell locations but not in mature tissue. Here is where things get interesting...

Turns out there is a way to interfere with survivin (remember servivin helps keep cancer cells alive by preventing mitotic catastrophe) and it is derived from turmeric.

From wikipedia:
Turmeric (Curcuma longa, also called tumeric or kunyit in some Asian countries) is a spice commonly used in curries and other South Asian cuisine.
An active ingredient in turmeric is a compound called curcumin. In a recent article in the journal International Journal of Cancer (Volume 119, Issue 8, Pages 1811-1818 23 May 2006) titled Resistance to apoptosis of HCW-2 cells can be overcome by curcumin- or vincristine-induced mitotic catastrophe Magalska et al state:
It has been very recently shown that curcumin (diferuloylmethane), a natural dye from the rhizome of Curcuma longa [turmeric] and a known apoptotic inducer, downregulates survivin. In other experiments, it has been shown that curcumin arrests MCF-7 cells in G2/M, disrupts mitotic spindle structure and induces micronucleation in MCF-7 breast cancer,[9] displaying cell morphology that fits very well to the mitotic catastrophe picture.
Well there is a lot of sciencese but the short of it is that this compound in turmeric may well play a future role in cancer suppression. This of course does not mean that you should expect that eating this turmeric will prevent cancer or help you if you have it. The body is far too complex a system to jump to that conclusion.

I will write more later about turmeric and a role it might have in helping older people keep mental acuity.

Technorati Tags: , ,

Sunday, December 24, 2006