What are the real differences between EPA and DHA?

The first casualty of marketing is usually the truth. The reality is that the two key omega-3 fatty acids (EPA and DHA) do a lot of different things, and as a result the benefits of EPA and DHA are often very different. That’s why you need them both. But as to why, let me go into more detail.

Benefits of EPA

The ultimate goal of using omega-3 fatty acids is the reduction of cellular inflammation. Since eicosanoids derived from arachidonic acid (AA), an omega-6 fatty acid, are the primary mediators of cellular inflammation, EPA is the most important of the omega-3 fatty acids to reduce cellular inflammation for a number of reasons. First, EPA is an inhibitor of the enzyme delta-5-desaturase (D5D) that produces AA (1). The more EPA you have in the diet, the less AA you produce. This essentially chokes off the supply of AA necessary for the production of pro-inflammatory eicosanoids (prostaglandins, thromboxanes, leukotrienes, etc.)

DHA is not an inhibitor of this enzyme because it can’t fit into the active catalytic site of the enzyme due to its larger spatial size. As an additional insurance policy, EPA also competes with AA for the enzyme phospholipase A2 necessary to release AA from the membrane phospholipids (where it is stored). Inhibition of this enzyme is the mechanism of action used by corticosteroids. If you have adequate levels of EPA to compete with AA (i.e. a low AA/EPA ratio), you can realize many of the benefits of corticosteroids but without their side effects. That’s because if you don’t release AA from the cell membrane, you can’t make inflammatory eicosanoids. Because of its increased spatial dimensions, DHA is not a good competitor of phospholipase A2 relative to EPA. On the other hand, EPA and AA are very similar spatially so they are in constant competition for the phospholipase A2 enzyme, just as both fatty acids are in constant competition for the delta-5 desaturase enzyme. This is why measuring the AA/EPA ratio is such a powerful predictor of the state of cellular inflammation in your body.

The various enzymes (COX and LOX) that make inflammatory eicosanoids can accommodate both AA and EPA, but again due to the greater spatial size of DHA, these enzymes will have difficulty-converting DHA into eicosanoids. This makes DHA a poor substrate for these key inflammatory enzymes. Thus DHA again has little effect on cellular inflammation, whereas EPA can have a powerful impact.

Finally, it is often assumed since there are not high levels of EPA in the brain, that it is not important for neurological function. Actually, it is key for reducing neuro-inflammation by competing against AA for access to the same enzymes needed to produce inflammatory eicosanoids. However, once EPA enters into the brain, it is rapidly oxidized (2,3). This is not the case with DHA (4). The only way to control cellular inflammation in the brain is to maintain high levels of EPA in the blood. This is why all the work on depression, ADHD, brain trauma, etc., has demonstrated that EPA is superior to DHA (5).

Benefits of DHA

At this point, you might think that DHA is useless. Just the opposite, because DHA can do a lot of different things than EPA and some of them even better.

First is in the area of omega-6 fatty acid metabolism. Whereas EPA is the inhibitor of the enzyme (D5D) that directly produces AA, DHA is an inhibitor of another key enzyme, delta-6-desaturase (D6D), that produces the first metabolite from linoleic acid known as gamma linolenic acid or GLA (6). However, this is not exactly an advantage. Even though reduction of GLA will eventually decrease AA production, it also has the more immediate effect of reducing the production of the next metabolite known as dihomo gamma linolenic acid or DGLA. This can be a disaster as a great number of powerful anti-inflammatory eicosanoids are derived from DGLA. This is why if you use high-dose DHA, it is essential to add back trace amounts of GLA to maintain sufficient levels of DGLA to continue to make anti-inflammatory eicosanoids.

In my opinion, the key benefit of DHA lies in its unique spatial characteristics. As mentioned earlier, the extra double bonds and length of DHA compared to EPA means it takes up a lot more space in the membrane. Although this increase in spatial volume makes DHA a poor substrate for phospholipase A2 as well as the COX and LOX enzymes, it does a great job of making membranes (especially those in the brain) a lot more fluid as the DHA sweeps out a much greater volume in the membrane than EPA. This increase in membrane fluidity is critical for synaptic vesicles and the retina of the eye because it allows receptors to rotate more effectively, thus increasing the transmission of signals from the surface of the membrane to the interior of the nerve cells. This is why DHA is a critical component of these parts of the nerves (7). On the other hand, the myelin membrane is essentially an insulator so that relatively little DHA is found in that part of the membrane.

This constant sweeping motion of DHA also causes the breakup of lipid rafts in membranes (8). Disruption of these islands of relatively solid lipids makes it more difficult for cancer cells to continue to survive and more difficult for inflammatory cytokines to initiate the signaling responses to turn on inflammatory genes (9). In addition, these greater spatial characteristics of DHA increase the size of LDL particles to a greater extent compared to EPA. As a result DHA helps reduce the entry of these enlarged LDL particles into the muscle cells that line the artery, thus reducing the likelihood of developing atherosclerotic lesions (10). Thus the increased spatial territory swept out by DHA is good news for making certain areas of membranes more fluid or lipoprotein particles larger, even though it reduces the benefits of DHA in competing with AA for key enzymes important in the development of cellular inflammation.

Common Effects for Both EPA and DHA

Not surprisingly, there are some areas in which both EPA and DHA appear to be equally beneficial. For example, both are equally effective in reducing triglyceride levels (10). This is probably due to the relatively equivalent activation of the gene transcription factor (PPAR alpha) that causes the enhanced synthesis of the enzymes that oxidize fats in lipoprotein particles. There is also apparently equal activation of the anti-inflammatory gene transcription factor PPAR-gamma (11). Both seem to be equally effective in making powerful anti-inflammatory eicosanoids known as resolvins (12). Finally, although both have no effect on total cholesterol levels, DHA can increase the size of LDL particle to a greater extent than EPA can (10).

Summary

EPA and DHA do different things, so you need them both. If your goal is reducing cellular inflammation, then you probably need more EPA than DHA. How much more? Probably twice the levels, but you always cover your bets with omega-3 fatty acids by using both at the same time.

References

  1. Sears B. “The Zone.” Regan Books. New York, NY (1995)
  2. Chen CT, Liu Z, Ouellet M, Calon F, and Bazinet RP. “Rapid beta-oxidation of eicosapentaenoic acid in mouse brain: an in situ study.” Prostaglandins Leukot Essent Fatty Acids 80:157-163 (2009)
  3. Chen CT, Liu Z, and Bazinet RP. “Rapid de-esterification and loss of eicosapentaenoic acid from rat brain phospholipids: an intracerebroventricular study. J Neurochem 116:363-373 (2011)
  4. Umhau JC, Zhou W, Carson RE, Rapoport SI, Polozova A, Demar J, Hussein N, Bhattacharjee AK, Ma K, Esposito G, Majchrzak S, Herscovitch P, Eckelman WC, Kurdziel KA, and Salem N. “Imaging incorporation of circulating docosahexaenoic acid into the human brain using positron emission tomography.” J Lipid Res 50:1259-1268 (2009)
  5. Martins JG. “EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials.” J Am Coll Nutr 28:525-542 (2009)
  6. Sato M, Adan Y, Shibata K, Shoji Y, Sato H, and Imaizumi K. “Cloning of rat delta 6-desaturase and its regulation by dietary eicosapentaenoic or docosahexaenoic acid.” World Rev Nutr Diet 88:196-199 (2001)
  7. Stillwell W and Wassall SR. “Docosahexaenoic acid: membrane properties of a unique fatty acid. Chem Phys Lipids 126:1-27 (2003)
  8. Chapkin RS, McMurray DN, Davidson LA, Patil BS, Fan YY, and Lupton JR. “Bioactive dietary long-chain fatty acids: emerging mechanisms of action.” Br J Nutr 100:1152-1157 (2008)
  9. Li Q, Wang M, Tan L, Wang C, Ma J, Li N, Li Y, Xu G, and Li J. “Docosahexaenoic acid changes lipid composition and interleukin-2 receptor signaling in membrane rafts.” J Lipid Res 46:1904-1913 (2005)
  10. Mori TA, Burke V, Puddey IB, Watts GF, O’Neal DN, Best JD, and Beilin LJ. “Purified eicosapentaenoic and docosahexaenoic acids have differential effects on serum lipids and lipoproteins, LDL particle size, glucose, and insulin in mildly hyperlipidemic men.” Am J Clin Nutr 71:1085-1094 (2000)
  11. Li H, Ruan XZ, Powis SH, Fernando R, Mon WY, Wheeler DC, Moorhead JF, and Varghese Z. “EPA and DHA reduce LPS-induced inflammation responses in HK-2 cells: evidence for a PPAR-gamma-dependent mechanism.” Kidney Int 67:867-874 (2005)
  12. Serhan CN, Hong S, Gronert K, Colgan SP, Devchand PR, Mirick G, and Moussignac RL. “Resolvins: a family of bioactive products of omega-3 fatty acid transformation circuits initiated by aspirin treatment that counter proinflammation signals.” J Exp Med 1996:1025-1037

Anxiety and Omega-3 Fatty Acids

Anxiety is one of most the common neurological disorders, but it also is one of the most difficult to understand. Simply stated, anxiety is an apprehension of the future, especially about an upcoming challenging task. This is normal. What is not normal is when the reaction is significantly out of proportion to what might be expected. Over the years, a number of specific terms, such as generalized anxiety disorder, panic disorder, phobia, social anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder, and separation anxiety disorder have emerged in an attempt to better categorize general anxiety. Any way you describe anxiety, it is a big problem with nearly 20% of Americans suffering from it, thus making anxiety the largest neurological disorder in the United States (1).

If anxiety is worrying about the future, then it has a fellow traveler, depression. Depression can be viewed as an over-reaction about regret associated with past events. Not surprisingly, almost an equal number of Americans suffer from this condition. This leads to the question: Is there a linkage between the two conditions? I believe the answer is yes and it may be caused by radical changes in the American diet in the past 40 years. These changes have resulted in what I term the Perfect Nutritional Storm (2). The result is an increase in the levels of inflammation throughout the body and particularly in the brain.

The brain is incredibly sensitive to inflammation, not the type you can feel but the type of inflammation that is below the perception of pain. I term this cellular inflammation. What makes this type of inflammation so disruptive is that it causes a breakdown in signaling between cells. What causes cellular inflammation is an increase in the omega-6 fatty acid known as arachidonic acid (AA). From this fatty acid comes a wide range of inflammatory hormones known as eicosanoids that are the usual suspects when it comes to inflammation. This is why anti-inflammatory drugs (aspirin, non-steroid anti-inflammatories, COX-2 inhibitions and corticosteroids) all have a single mode of action—to inhibit the formation of these inflammatory eicosanoids. These drugs, however, can’t cross the blood-brain barrier that isolates the brain from a lot of noxious materials in the blood stream. So when the brain becomes inflamed, its only protection is adequate levels of anti-inflammatory omega-3 fatty acids. But what happens when the levels of omega-3 fatty acids are low in the brain? The answer is increased neuro-inflammation and continual disruption of signaling between nerves.

There are two omega-3 fatty acids in the brain. The first is called docosahexaenoic acid or DHA. This is primarily a structural component for the brain. The other is called eicosapentaenoic acid or EPA. This is the primary anti-inflammatory omega-3 fatty acid for the brain. So if the levels of EPA are low in the blood, they are going to be low in the brain. To further complicate the matter, the lifetime of EPA in the brain is very limited (3,4). This means you have to have a constant supply in the blood stream to keep neuro-inflammation under control.

It is known from work with uni-polar and bi-polar depressed patients, that high-dose fish oil rich in EPA has remarkable benefits (5,6). On the other hand, supplementing the diet with oils rich in DHA have virtually no effects (7).

Since anxiety has a significant co-morbidity with depression, the obvious question becomes is it possible that high levels of EPA can reduce anxiety? The answer appears to be yes (8), according to a study conducted in 2008 using substance abusers. It is known that increased anxiety is one of the primary reasons why substance abusers and alcoholics tend to relapse (9,10). When these patients were given a high dose of EPA (greater than 2 grams of EPA per day), there was a statistically significant reduction in anxiety compared to those receiving a placebo. More importantly, the degree of anxiety reduced was highly correlated to the decrease of the ratio of AA to EPA in the blood (8). In other studies with normal individuals without clinical depression or anxiety, increased intake of EPA improved their ability to handle stress and generated significant improvements in mood (11-13). It may be that depression and anxiety are simply two sides of the same coin of increased cellular inflammation in the brain. Even for “normal” individuals, high dose EPA seems to make them happier and better able to handle stress.

So let’s go back to an earlier question and ask about the dietary changes in the American diet that may be factors in the growing prevalence of both depression and anxiety. As I outline in my book Toxic Fat, it is probably due to a growing imbalance of AA and EPA in our diets (2). What causes AA to increase is a combination of increased consumption of vegetable oils rich in omega-6 fatty acids coupled with an increase in the consumption of refined carbohydrates that generate insulin. When excess omega-6 fatty acids interact with increased insulin, you get a surge of AA production. At the same time, our consumption of fish rich in EPA has decreased. The end result is an increasing AA/EPA ratio in the blood, which means a corresponding increase in the same AA/EPA ratio in the brain creating more cellular inflammation.

Cutting back vegetable oil and refined carbohydrate intake is difficult since they are now the most inexpensive source of calories. Not surprisingly, they are key ingredients for virtually every processed food product. So if changing your diet is too hard, then consider eating more fish to get adequate levels of EPA. Of course, the question is how much fish? If we use a daily intake level of 2 grams of EPA per day that was used the successful trials of using omega-3 fatty acids reduce anxiety, then this would translate into consuming 14 pounds of cod per day. If you prefer a more fatty fish like salmon, then you would only need about 2 pounds per day to get 2 grams of EPA. The Japanese are able to reach that level because they are the largest consumers of fish in the world. These are highly unlikely dietary changes for most Americans. However, it has been demonstrated that following a strict anti-inflammatory diet coupled with purified fish oil supplements can generate an AA/EPA ratio similar to that found in the Japanese population (11).

There is simply no easy way out of this problem created by the Perfect Nutritional Storm, which will only intensify with each succeeding generation due to the insidious effect of cellular inflammation on fetal programming in the womb. Unfortunately for most Americans this will require a dietary change of immense proportions. This probably means that Valium and other anti-anxiety medications are here to stay.

References

  1. Kessler RC, Chiu WT, Demler O, Merikangas KR, and Walters EE. “Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication”. Arch Gen Psychiatry 62:617–627 (2005)
  2. Sears B. Toxic Fat. Thomas Nelson. Nashville, TN (2008)
  3. Chen CT, Liu Z, Ouellet M, Calon F, and Bazinet RP. “Rapid beta-oxidation of eicosapentaenoic acid in mouse brain: an in situ study.” Prostaglandins Leukot Essent Fatty Acids 80:157-163 (2009)
  4. Chen CT, Liu Z, and Bazinet RP. “Rapid de-esterification and loss of eicosapentaenoic acid from rat brain phospholipids: an intracerebroventricular study.” J Neurochem 116:363-373 (2011)
  5. Nemets B, Stahl Z, and Belmaker RH. “Addition of omega-3 fatty acid to maintenance medication treatment for recurrent unipolar depressive disorder.” Am J Psychiatry 159:477-479 (2002)
  6. Stoll AL, Severus WE, Freeman MP, Rueter S, Zboyan HA, Diamond E, Cress KK, and Marangell LB. “Omega 3 fatty acids in bipolar disorder: a preliminary double-blind, placebo-controlled trial.” Arch Gen Psychiatry 56:407-412 (1999)
  7. Marangell LB, Martinez JM, Zboyan HA, Kertz B, Kim HF, and Puryear LJ. “A double-blind, placebo-controlled study of the omega-3 fatty acid docosahexaenoic acid in the treatment of major depression.” Am J Psychiatry 160:996-998 (2003)
  8. Buydens-Branchey L, Branchey M, and Hibbeln JR. “Associations between increases in plasma n-3 polyunsaturated fatty acids following supplementation and decreases in anger and anxiety in substance abusers.” Prog Neuropsychopharmacol Biol Psychiatry 32:568-575 (2008)
  9. Willinger U, Lenzinger E, Hornik K, Fischer G, Schonbeck G, Aschauer HN, and Meszaros K. “Anxiety as a predictor of relapse in detoxified alcohol-dependent patients.” Alcohol and Alcoholism 37:609-612 (2002)
  10. Kushner MG, Abrams K, Thuras P, Hanson KL, Brekke M, and Sletten S. “Follow-up study of anxiety disorder and alcohol dependence in comorbid alcoholism treatment patients.” Alcohol Clin Exp Res 29:1432-1443 (2005)
  11. Fontani G, Corradeschi F, Felici A, Alfatti F, Bugarini R, Fiaschi AI, Cerretani D, Montorfano G, Rizzo AM, and Berra B. “Blood profiles, body fat and mood state in healthy subjects on different diets supplemented with Omega-3 polyunsaturated fatty acids.” Eur J Clin Invest 35:499-507 (2005)
  12. Fontani G, Corradeschi F, Felici A, Alfatti F, Migliorini S, and Lodi L. “Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects. “Eur J Clin Invest 35:691-699 (2005)
  13. Kiecolt-Glaser JK, Belury MA, Andridge R, Malarkey WB, and Glaser R. “Omega-3 supplementation lowers inflammation and anxiety in medical students: A randomized controlled trial.” Brain Behav Immun 25:1725-1734 (2011)

What is Cellular Inflammation?

People (including virtually all physicians) are constantly confused what cellular inflammation is. So I decided to take the opportunity to explain the concept in more detail.

There are two types of inflammation. The first type is classical inflammation, which generates the inflammatory response we associate with pain such as, heat, redness, swelling, pain, and eventually loss of organ function. The other type is cellular inflammation, which is below the perception of pain. Cellular inflammation is the initiating cause of chronic disease because it disrupts hormonal signaling networks throughout the body.

Definition of Cellular Inflammation

The definition of cellular inflammation is increased activity of the gene transcription factor know as Nuclear Factor-kappaB (NF-κB). This is the gene transcription factor found in every cell, and it activates the inflammatory response of the innate immune system. Although the innate immune system is the most primitive part of our immune response, it has been resistant to study without recent breakthroughs in molecular biology. In fact, the 2011 Nobel Prize in Medicine was awarded for the earliest studies on the innate immune system and its implications in the development of chronic disease.

There are several extracellular events through which NF-κB can be activated by distinct mechanisms. These include microbial invasion recognized by toll-like receptors (TLR), generation of reactive oxygen species (ROS), cellular generation of inflammatory eicosanoids, and interaction with inflammatory cytokines via defined cell surface receptors. We also know that several of these initiating events are modulated by dietary factors. This also means that appropriate use of the diet can either turn on or turn off the activation of NF-κB. This new knowledge is the foundation of anti-inflammatory nutrition (1-3).

Understanding Cellular Inflammation

Although the innate immune system is exceptionally complex, it can be illustrated in a relatively simple diagram as shown below in Figure 1.

Figure 1. Simplified View of the Innate Immune System

Essential fatty acids are the most powerful modulators of NF-κB. In particular, the omega-6 fatty acid arachidonic acid (AA) activates NF-κB, whereas the omega-3 fatty acid eicosapentaenoic acid (EPA) does not (4). Recent work suggests that a subgroup of eicosanoids known as leukotrienes that are derived from AA may play a significant factor in NF-κB activation (5,6)

Extracellular inflammatory cytokines can also activate NF-κB by their interaction with specific receptors on the cell surface. The primary cytokine that activates NF-κB is tumor necrosis factor (TNF) (7). Toll-like receptors (TLR) are another starting point for the activation of NF-κB. In particular, TLR-4 is sensitive to dietary saturated fatty acids (8). The binding of saturated fatty acids to TLR-4 can be inhibited by omega-3 fatty acids such as EPA. Finally ROS either induced by ionizing radiation or by excess free radical formation are additional activators of NF-κB (9).

Anti-inflammatory Nutrition To Inhibit Cellular Inflammation

Anti-inflammatory nutrition is based on the ability of certain nutrients to reduce the activation of NF-κB.

The most effective way to lower the activation of NF-κB is to reduce the levels of AA in the target cell membrane thus reducing the formation of leukotrienes that can activate NF-κB. Having the patient follow an anti-inflammatory diet, such as the Zone Diet coupled with the simultaneous lowering omega-6 fatty acid intake are the primary dietary strategies to accomplish this goal (1-3).

Another effective dietary approach (and often easier for the patient to comply with) is the dietary supplementation with adequate levels of high-dose fish oil rich in omega-3 fatty acids, such as EPA and DHA. These omega-3 fatty acids taken at high enough levels will lower AA levels and increase EPA levels. This change of the AA/EPA ratio in the cell membrane will reduce the likelihood of the formation of inflammatory leukotrienes that can activate NF-κB. This is because leukotrienes derived from AA are pro-inflammatory, whereas those from EPA are non-inflammatory. The increased intake of omega-3 fatty acids is also a dietary approach that can activate the anti-inflammatory gene transcription factor PPAR-γ (10-12), decrease the formation of ROS (13) and decrease the binding of saturated fatty acids to TLR-4 (14). This illustrates the multi-functional roles that omega-3 fatty acids have in controlling cellular inflammation.

A third dietary approach is the adequate intake of dietary polyphenols. These are compounds that give fruits and vegetables their color. At high levels they are powerful anti-oxidants to reduce the generation of ROS (15). They can also inhibit the activation of NF-κB (16).

Finally, the least effective dietary strategy (but still useful) is the reduction of dietary saturated fat intake. This is because saturated fatty acids will cause the activation of the TLR-4 receptor in the cell membrane (8,14).

Obviously, the greater the number of these dietary strategies implemented by the patient, the greater the overall effect on reducing cellular inflammation.

Clinical Measurement of Cellular Inflammation

Since cellular inflammation is confined to the cell itself, there are few blood markers that can be used to directly measure the levels of systemic cellular inflammation in a cell. However, the AA/EPA ratio in the blood appears to be a precise and reproducible marker of the levels of the same ratio of these essential fatty acids in the cell membrane.

As described above, the leukotrienes derived from AA are powerful modulators of NF-κB. Thus a reduction in the AA/EPA ratio in the target cell membrane will lead to a reduced activation of NF-κB by decreased formation of inflammatory leukotrienes. The cell membrane is constantly being supplied by AA and EPA from the blood. Therefore the AA/EPA ratio in the blood becomes an excellent marker of the same ratio in the cell membrane (17). Currently the best and most reproducible marker of cellular inflammation is the AA/EPA ratio in the blood as it represents an upstream control point for the control of NF-κB activation.

The most commonly used diagnostic marker of inflammation is C-reactive protein (CRP). Unlike the AA/EPA ratio, CRP is a very distant downstream marker of past NF-κB activation. This is because one of inflammatory mediators expressed in the target cell is IL-6. It must eventually reach a high enough level in the blood to eventually interact with the liver or the fat cells to produce CRP. This makes CRP a more long-lived marker in the blood stream compared to the primary inflammatory gene products (IL-1, IL-6, TNF, and COX-2) released after the activation of NF-κB. As a consequence, CRP is easier to measure than the most immediate inflammatory products generated by NF-κB activation. However, easier doesn’t necessarily translate into better. In fact, an increase AA/EPA ratio in the target cell membrane often precedes any increase of C-reactive protein by several years. An elevated AA/EPA ratio indicates that NF-κB is at the tipping point and the cell is primed for increased genetic expression of a wide variety of inflammatory mediators. The measurement of CRP indicates that NF-κB has been activated for a considerable period of time and that cellular inflammation is now causing systemic damage.

Summary

I believe the future of medicine lies in the control of cellular inflammation. This is most effectively accomplished by the constant application of anti-inflammatory nutrition. The success of such dietary interventions can be measured clinically by the reduction of the AA/EPA ratio in the blood.

References

  1. Sears B. The Anti-Inflammation Zone. Regan Books. New York, NY (2005)
  2. Sears B. Toxic Fat. Thomas Nelson. Nashville, TN (2008)
  3. Sears B and Riccordi C. “Anti-inflammatory nutrition as a pharmacological approach to treat obesity.” J Obesity doi:10.1155/2011/431985 (2011)
  4. Camandola S, Leonarduzzi G,Musso T, Varesio L, Carini R, Scavazza A, Chiarpotto E, Baeuerle PA, and Poli G. “Nuclear factor kB is activated by arachidonic acid but not by eicosapentaenoic acid.” Biochem Biophys Res Commun 229:643-647 (1996)
  5. Sears DD, Miles PD, Chapman J, Ofrecio JM, Almazan F, Thapar D, and Miller YI. “12/15-lipoxygenase is required for the early onset of high fat diet-induced adipose tissue inflammation and insulin resistance in mice.” PLoS One 4:e7250 (2009)
  6. Chakrabarti SK, Cole BK, Wen Y, Keller SR, and Nadler JL. “12/15-lipoxygenase products induce inflammation and impair insulin signaling in 3T3-L1 adipocytes.” Obesity 17:1657-1663 (2009)
  7. Min JK, Kim YM, Kim SW, Kwon MC, Kong YY, Hwang IK, Won MH, Rho J, and Kwon YG. “TNF-related activation-induced cytokine enhances leukocyte adhesiveness: induction of ICAM-1 and VCAM-1 via TNF receptor-associated factor and protein kinase C-dependent NF-kappaB activation in endothelial cells.” J Immunol 175: 531-540 (2005)
  8. Kim JJ and Sears DD. “TLR4 and Insulin Resistance.” Gastroenterol Res Pract doi:10./2010/212563 (2010)
  9. Bubici C, Papa S, Dean K, and Franzoso G. “Mutual cross-talk between reactive oxygen species and nuclear factor-kappa B: molecular basis and biological significance.” Oncogene 25: 6731-6748 (2006)
  10. Li H, Ruan XZ, Powis SH, Fernando R, Mon WY, Wheeler DC, Moorhead JF, and Varghese Z. “EPA and DHA reduce LPS-induced inflammation responses in HK-2 cells: Evidence for a PPAR-gamma-dependent mechanism.” Kidney Int 67: 867-874 (2005)
  11. Kawashima A, Harada T, Imada K, Yano T, and Mizuguchi K. “Eicosapentaenoic acid inhibits interleukin-6 production in interleukin-1beta-stimulated C6 glioma cells through peroxisome proliferator-activated receptor-gamma.” Prostaglandins LeukotEssent Fatty Acids 79: 59-65 (2008)
  12. Chambrier C, Bastard JP, Rieusset J, Chevillotte E, Bonnefont-Rousselot D, Therond P, Hainque B, Riou JP, Laville M, and Vidal H. “Eicosapentaenoic acid induces mRNA expression of peroxisome proliferator-activated receptor gamma.” Obes Res 10: 518-525 (2002)
  13. Mas E, Woodman RJ, Burke V, Puddey IB, Beilin LJ, Durand T, and Mori TA. “The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes.” Free Radic Res 44: 983-990 (2010)
  14. Lee JY, Plakidas A, Lee WH, Heikkinen A, Chanmugam P, Bray G, and Hwang DH. “Differential modulation of Toll-like receptors by fatty acids: preferential inhibition by n-3 polyunsaturated fatty acids.” J Lipid Res 44: 479-486 (2003)
  15. Crispo JA, Ansell DR, Piche M, Eibl JK, Khaper N, Ross GM, and Tai TC. “Protective effects of polyphenolic compounds on oxidative stress-induced cytotoxicity in PC12 cells.” Can J Physiol Pharmacol 88: 429-438 (2010)
  16. Romier B, Van De Walle J, During A, Larondelle Y, and Schneider YJ. “Modulation of signaling nuclear factor-kappaB activation pathway by polyphenols in human intestinal Caco-2 cells.” Br J Nutr 100: 542-551 (2008)
  17. Yee LD, Lester JL, Cole RM, Richardson JR, Hsu JC, Li Y, Lehman A, Belury MA, and Clinton SK. “Omega-3 fatty acid supplements in women at high risk of breast cancer have dose-dependent effects on breast adipose tissue fatty acid composition.” Am J Clin Nutr 91: 1185-1194 (2010)

Hard times are ahead

Last month was a red-letter month for the future of mankind as the world population passed 7 billion. Unfortunately, this fact dovetails with recent research that indicates it is likely that one-half of all Americans will be diabetic by 2050 (1).

The combination of these two trends does not bode well for the future. To begin with, how are we going to feed all these people? Most of the arable land on the planet is already under cultivation. Furthermore, urbanization is destroying prime cropland at a rapid pace.

Added to these facts is that the diversity of most of the world’s calories is rapidly decreasing. Currently the five top sources of calories in the world are corn, soybeans, wheat, rice and potatoes (as well as its kissin’ cousin cassava, which is incredibly poor in protein and nutrients). The first two crops (corn and soy) are rich sources of omega-6 fatty acids. In addition, corn, wheat, and rice provide extremely high-glycemic carbohydrates that can be easily refined to last forever and make thus a wide variety of processed foods. (Potatoes and cassava tend to decompose rapidly and can’t be easily refined, except perhaps as potato chips). As a consequence, omega-6 fatty acids and refined carbohydrates are now the cheapest form of calories in the world. In fact, it is estimated that they are 400 times less expensive per calorie than fresh fruits and vegetables.

So how can you feed this growing population of more than 7 billion people? The answer is easy—produce even more refined carbohydrates and omega-6 fatty acids.

Unfortunately, feeding the growing population of the world with cheap omega-6 fatty acids and refined carbohydrates is exactly the best way to increase cellular inflammation and drive the development of diabetes (2). It is estimated that by 2050 diabetes will be the primary non-infectious disease on the planet. This is equally bad news as it is also the most expensive chronic disease to treat on a long-term basis.

Today, more than 26 percent of all Americans older than 65 has diabetes. If the estimates of increased diabetes are correct (1), then it is likely that the number of Americans older than 65 in 2050 with diabetes may be greater than 50 percent. The current level of diabetes is the primary reason why our health-care expenses are spiraling out of control. If you double number of older Americans with diabetes by 2050, there is no way the current health-care system, as we know it can possibly survive. Add to the fact that once you have diabetes, you are 2-4 times more likely to develop heart disease and Alzheimer’s. It is not a very pleasant picture of the future of health care in America.

What can you do about it? On a global basis, not much unless you would like to see an apocalyptic event that reduces the population from 7 billion to a more manageable 1-2 billion individuals. Of course, this is highly unlikely. However, on the individual basis there is a lot you can do to protect yourself in the future. Simply take control of your future by focusing on managing cellular inflammation for a lifetime by following an anti-inflammatory diet. This may be your only real health security in times of increasing demands on the planet’s resources to produce food. There is no question that we have other troubles brewing like climate change, decreasing water supplies, and decreasing cheap energy, all of which will also impact the cost of food, driving more individuals toward inexpensive sources of calories no matter what the health consequences. But the rise of diabetes will occur first.

Old folks like myself will probably be OK, but the future generations will take the brunt of trouble brewing ahead.

References

  1. Boyle JP , Thompson TJ, Gregg EW, Barker LE, and Williamson DF. “Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence.” Population Health Metrics 8:29 (2010)
  2. Sears B. “Toxic Fat.” Thomas Nelson. Nashville, TN (2008)

“Biggest Loser” or best Zoner?

A few weeks ago I spoke at the American Society of Bariatric Physicians. Later in the day I heard an interesting lecture from the lead dietician for the TV series “The Biggest Loser”. In this lecture, she disclosed all the keys for successful weight loss in the individuals on the show.

The first was incredibly careful screening just like you would do for a clinical trial. This is to make sure you have incredibly motivated people, who aren’t depressed or have other existing medical conditions, such as heart disease. In other words, you stack the deck. Considering that after the first pilot show in 2004, there were 225,000 applications for the 2005 series, there is no problem in recruiting motivated people. Just to make sure the motivation is maintained, the contestants get paid while they are on the show in addition to the big payoff for the winner at the end of the series.

Next contestants are isolated in a “camp”. Consider this to be like a metabolic ward where they only have access to good food for the next 10 to 16 weeks. This means no white carbohydrates and no artificial sweeteners other than stevia and all the meals made for them.

According to the speaker, the real secret is that they are fed a Zonelike Diet with 45 percent of the calories coming carbohydrates (primarily non-starchy vegetables and fruits) with a very limited amount of whole grains, 30 percent of the calories from low-fat protein, and 25 percent from good fats, such as olive oil or nuts. The typical calorie intake for the females is 1,200 to 1,600 and for the males about 1,800-2,400. The typical 300-pound contestant will consume about 1,750 calories per day. Finally, you spread the balanced calories over three meals and two snacks during the day.

Of course, you never see the contestants eating their Zone meals and snacks or the dietician discussing nutrition with them because that makes for boring TV. So most of the time you see them being yelled at by their trainers. That makes for exciting TV. In fact. the more tears they shed by being intimidated, the better the ratings.

So what happens to them after they leave the show, no longer get paid, and are surrounded by their favorite foods? About 50 percent regain the lost weight. But the other 50 percent have found out that the Zone Diet isn’t that hard, and now they have a clear dietary plan for a lifetime without being yelled at by drill sergeant-like trainers.

Changing gene expression

I have often stated that the real power of the Zone Diet is to change gene expression, especially the expression of anti-inflammatory genes. What I never realized is how rapid gene expression could occur. Now, new research from Norway gives me the answer (1). It takes about 24 hours!

This pilot study is on the effect of diet on gene expression in healthy obese individuals. Interestingly, when the researchers calculated the estimated daily calorie requirements for these subjects necessary to maintain their weight, they were surprised that they were already eating 250 fewer calories per day than predicted to maintain their current weight. So much for the “fact” that obese individuals are fat because they eat more calories than they need to maintain their weight. In fact, this observation was confirmed in an earlier study in which the number of calories consumed by obese and lean individuals did not vary, but the obese individuals consumed fewer meals consisting of larger servings (2).

So what the Norwegian researchers did was simply maintain the same number of calories the subjects were already eating and change the macronutrient balance to be very close to the Zone Diet (30 percent carbohydrates, 30 percent protein, and 40 percent fat). Then the subjects consumed six meals containing about 460 calories evenly spaced throughout the day so that the total calories consumed at any one time was moderate. Just making those two simple dietary changes resulted in more than an eight-pound weight loss in 28 days. The levels of body fat didn’t change since the number of calories consumed was exactly the same as they were previously consuming. However, it appears that evenly spacing the meals and reducing the calorie size of the meals resulted in less insulin production and therefore less retained water.

Then they looked to see if they could find any changes in gene expression in both the fat cells and the blood with the dietary changes. Amazingly they found dramatic changes in only 24 hours. Of the 16,000 genes they could identify, about 60 percent remained unchanged in their expression, but 40 percent were either turned on (i.e., up-regulated) or turned down (i.e., down-regulated). Interestingly, the changes seen in the first 24 hours were held constant throughout the 28 days of the experiment.

Upon further analysis, the up-regulated genes corresponded to those that had anti-inflammatory properties, and the down-regulated genes were those associated with chronic disease conditions, such as diabetes and heart disease. Furthermore, since these changes in gene expression occurred within 24 hours of the dietary change, they could not be attributed to any change in body weight and fat loss.

Fortunately, I had the opportunity to have dinner with the lead author of the study to discuss her work while I was in Europe last week. She told me that she has expanded the number of subjects in several new trials, and the results remain the same. I also found out that she has been following my work for many years.

This type of study only confirms the power of genetic analysis to demonstrate how a highly structured diet with the correct macronutrient content can rapidly alter genetic expression and hence controls your future health. But the door swings both ways. An unbalanced diet will have just the opposite genetic effects. While I have always been impressed by the power of the Zone Diet, this new experimental data takes my respect for the Zone Diet to a new level of awe, even by me.

References

  1. Brattbakk H-R, Arbo I, Aagaard S, Lindseth I, de Soysa AK, Langaas M, Kulseng B, Lindberg, and Johansen B. “Balanced caloric macronutrient composition down regulates immunological gene expression in human blood cells-adipose tissue diverges.” OMICS 15: doi:1089/omi.2010.0124 (2011)
  2. Berg C, Lappas G, Wolk A, Strandhagen E, Toren K, Rosengren A, Rosengren A, Thelle D, and Lissner L. “Eating patterns and portion size associated with obesity in a Swedish population.” Appetite 52: 21-26 (2009)

Eat Less, Get Hungry

Telling an obese person simply to eat less rarely succeeds. Is it because they are weak-willed individuals or is there something more complex going on? New research indicates the latter. A new article in Cell Metabolism showed that during extreme calorie restriction, the levels of fatty acids begin to rapidly rise in the blood as the body begins breaking down stored fat for energy. These newly released fatty acids from the fat cells can then enter into the brain (the hypothalamus to be exact) and cause the self-digestion of cells in the hunger neurons (1). This self-digestion of the cells in the hunger neurons produces a rise in the very powerful hunger hormone (AgRP) from the same bundle of neurons. Not surprisingly, the urge to eat becomes almost overpowering. This begins to explain why very low calorie diets can cause rapid weight loss, but are rarely successful in keeping the weight off.

This is why very low calorie diets that promise quick weight loss invariably cause the rapid release of stored fatty acids that promotes constant hunger. This is clearly not a sustainable way to maintain long-term weight management.

Of course the question might be whether it is all fatty acids or just one that causes the problem of cellular death in the hunger neurons? I believe the answer comes back to the usual suspect, arachidonic acid (2). It has been known for 20 years that when you put obese individuals on a very low calorie diet there is a rapid increase in the levels of arachidonic acid levels in the blood (3). Arachidonic acid can easily cross the blood brain barrier and enter into the hypothalamus. Since arachidonic acid is a powerful promoter of cell death (4), increased concentrations inside the hypothalamus may be the primary accelerator of the death of the hunger neurons. Increased levels of arachidionic acid in the blood are also the underlying cause of insulin resistance because of its effect on the generation of cellular inflammation (2). So as you build up the levels of stored arachidonic acid in the fat cells, caused by the Perfect Nutritional Storm (2), you are almost ensuring constant hunger when you try to lose weight quickly by following very low calorie diets. To make matters even worse, as arachidonic acid levels also build up in the brain increasing the production of endocannabinoids (5). These are the hormones that give you the continual munchies (they are related to the active ingredient in marijuana).

So is there any good news in all of this research? Yes as long as you develop a lifetime dietary strategy for reducing arachidonic acid and the cellular inflammation it causes as well as following a reasonable low calorie diet that supplies adequate levels of fat to moderate the release of stored fatty acids from the fat cells. It means following an anti-inflammatory diet with adequate protein using low-glycemic load carbohydrates and fats very low in omega-6 fatty acids, but adequate in monounsaturated and omega-3 fats.

That’s why you never want to start any type of weight loss program without adding omega-3 fatty acids to counteract the released of stored arachidonic acid from the fat cells. Not only will these omega-3 fatty acids reduce the degradation of the hunger neurons thereby reducing the release of powerful hunger hormones during calorie restriction, but they will also inhibit the release of endocannabinoids in the brain (6). The combination of the two events will ensure weight loss without hunger and that’s sustainable.

References

  1. Kaushik S,Rodriguez-Navarro JA, Arias E, Kiffin R, Sahu S, Schwartz GJ, Cuervo AM, and Singh R. “Autophagy in hypothalamic AgRP neurons regulates food intake and energy balance.” Cell Metabolism 14: 173-183 (2011)
  2. Sears B. Toxic Fat. Thomas Nelson. Nashville, TN (2008)
  3. Phinney SD, Davis PG, Johnson SB, and Holman RT. “Obesity and weight loss alter serum polyunsaturated lipids in humans.” Amer J Clin Nutr 53: 831-838 (1991)
  4. Pompeia C, Lima T, and Curi R. “Arachidonic acid cytotoxicity: can arachidonic acid be a physiological mediator of cell death?” Cell Biochemistry and Function 21:97-104 (2003)
  5. Kim J, Li Y, and Watkins BA. “Endocannabinoid signaling and energy metabolism: A target for dietary intervention.” Nutrition 27: 624-632 (2011)
  6. Oda E. “n-3 Fatty acids and the endocannabinoid system.” Am J Clin Nutr 85: 919 (2007)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.

Preventing obesity through prenatal nutrition

It is obvious that pediatric obesity is a growing problem. However, compared to adult obesity, it is a relatively new problem. In a new article to be published in the Journal of Adolescent Health, it is pointed out that while childhood obesity has increased some 300 percent since 1960, most of that increase only began in the mid 1990s (1). This is well after the beginning of the climb of adult obesity, which started in the 1980s. Why the lag time? I believe it may have been caused by the amplification of any genetic predisposition to obesity by prenatal programming in the womb. That means you had to have obese mothers whose own hormonal changes and diet were altering the fetal programming of their children, thus amplifying their likelihood for obesity after birth.

This possibility makes sense based on results from another recent article that demonstrates that the lower the omega-3 fatty acid status in the mother, the more likely the child would be obese by the age of 3 (2). In this particular study, researchers found that by age 3 about 10 percent of the children were already obese. What they also analyzed was even though virtually all the women were consuming very low levels of omega-3 fatty acids during pregnancy, the higher the levels of the omega-3 fatty acids in mother’s diet, or her blood, and especially in the blood from the umbilical cord to the fetus, the lower the levels of obesity in the child three years later after birth.

Of course, lower levels of omega-3 fatty acids usually indicate higher levels of omega-6 fatty acids, giving rise to an unbalanced ratio of omega-3 to omega-6 fatty acids. This is why the highest correlation with increased childhood obesity was found with an increasing ratio of arachidonic acid to EPA and DHA in the blood of the mother and also in the umbilical cord of the fetus. This makes perfect sense since it is known from animal studies that the higher the omega-6 to omega-3 ratio in the diet of the mother, the greater the obesity in the offspring (3-5).

So if you want to begin to decrease childhood obesity, it is probably best to start in the womb of the mother with appropriate prenatal nutrition using appropriate levels of omega-3 fatty acids. This would prevent the fetal programming of the unborn child that would lead to rapid accumulation of excess body fat after birth. I think this makes a lot more sense than telling obese children to “eat less and exercise more” after their genetic expression has been altered in the womb. And if this makes sense, then doesn’t it also strongly suggest that feeding children more omega-3 and less omega-6 fatty acids after birth will silence the activation of ancient genes that make them fat and keep them fat (6).

References

  1. Lee H, Lee D, Guo G, and Harris KM. “Trends in body mass index in adolescence and young adulthood in the United States: 1959-2002.” J Adolescent Heath DOI:10.1016/jadolheath2011.04.019 (2011)
  2. Donahue SMA, Rifas-Shiman SL, Gold DR, Jouni ZE, Gilman MW, and Oken E. “Prenatal fatty acid status and child adiposity at age 3.” Am J Clin Nutr 93: 780-788 (2011)
  3. Korotkova M, Gabrielsson BG, Holmang, A, Larrson BM, Hanson LA, and Strandvik B. “Gender-related long-term effects in adult rats by perinatal dietary ratio of n-6/n-3 fatty acids.” Am J Physiol Regul Integr Comp Physiol 288: R575-579 (2005)
  4. Ailhaud G, Guesnet P, and Cannane SC. “An emerging risk factor for obesity: does disequilibrium of polyunsaturated fatty acid metabolism contribute to excessive adipose tissue development?” Br J Nutr 100: 461-470 (2008)
  5. Massiera L, Barbry P, Guesnet P, Joly A, Luquet S, Moreihon-Brest C, Moshen-Kanson T, Amri E-Z, and Ailhaud G. “A western-like fat diet is sufficient to induce a gradual enhancement in fat mass over generations.” J Lipid Res 51: 2352-2361 (2010)
  6. Massiera Saint-Marc P, Seydoux J, Murata T, Kobayshi T, Narumiya S, Guesnet P, Amri E-Z, Negrel R, and Alhaud G. “Arachidonic acid and prostacyclin signaling promote adipose tissue development: a human health concern?’ J Lipid Res 44: 271-279 (2003)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.

How to eliminate 50 percent of all coronary events

The European Society of Cardiology estimates a 50 percent reduction of coronary events if you can stabilize soft, vulnerable plaques (1). We are often led to believe that plaques you can see on an angiogram are “killer” plaques. It’s true that if they are large enough to obstruct blood flow, they will decrease oxygen transfer to the heart muscle cells making them more tired with less effort.

This is the definition of stable angina. It simply means it takes less effort to over-exert the heart muscles before they fatigue. However, you need approximately a 90 percent total obstruction of the blood vessel to develop stable angina. These plaques account for most of the plaques you might find in an angiogram. This is why if you take an angiogram, you are often immediately wheeled into the operating room to have a stent put into the artery with the belief you are only seconds away from an immediate heart attack and death.

However, the same angiogram can’t see a few plaques (because they are so small), known as the soft, vulnerable ones. When soft, vulnerable plaques rupture (like a pimple), then you have the death and disability (i.e., damaged heart tissue) that truly characterize heart disease. Technically, this is called an acute coronary event, and it has very little to do with the stable plaques that can cause angina. It is this small number of “rogue” soft, vulnerable plaques that are the true killers in heart disease (2,3).

The ultimate cause of plaque rupture is cellular inflammation inside the plaque. Cellular inflammation degrades the fibrous external coating of the plaque. Usually inside these soft, vulnerable plaques are also a lot of macrophages engorged with lipids. This is called the “necrotic core”. When the plaque bursts, these lipid pools are released into the bloodstream causing platelet aggregation and the rapid blockage of the artery resulting in a complete restriction of blood flow (as opposed to a limited restriction of blood flow with a typical stable plaque that will never rupture). It is estimated that about 75 percent of all coronary events are caused by ruptures of the soft, vulnerable plaques (2).

As I mentioned above, the really scary part of this story is that there is no type of imaging technology that can detect dangerous soft, vulnerable plaques. In essence, you don’t know if you have them or not. This is why the prediction of impeding cardiovascular events remains a guessing game. Even more interesting is that these soft, vulnerable plaques seem to form rather quickly (in about 10 years) as opposed to growing slowly over a lifetime (4). Moreover, the rate of growth of these soft, vulnerable plaques is strongly correlated with increasing insulin levels in the blood (4).

So what does this mean for people who don’t want to die from a sudden rupture of soft, vulnerable plaques that can’t be detected? The first thing is to reduce the inflammation within the plaque. Surprisingly, there is only one clinical study that has ever been published that addressed this question, and it used fish oil (5). This study indicated that if you give patients relatively high doses of fish oil, you could see a definite remodeling of the soft, vulnerable plaques in about 40 days compared to subjects taking a placebo composed of safflower oil. The plaques in the subjects taking the fish oil became less inflamed, had higher levels of omega-3 fatty acids, fewer macrophages and more well-formed fibrous caps compared to those taking the placebo. So taking a therapeutic level of fish oil for a lifetime seems to be a good way to reduce the rupture of these plaques.

Another way to potentially reduce their formation in the first place is lower insulin levels. The reason insulin levels are elevated is because organs, such as the adipose tissue, the liver and the muscles, are also inflamed (6). The best way to reduce that systemic inflammation is to follow the anti-inflammatory diet and take therapeutic levels of fish oil for a lifetime. Your success is best measured by the AA/EPA ratio in the blood. Call me crazy, but I think that’s what I have been recommending for the past 16 years (7).

References

  1. Yia-Herttulala S, Bentzon JF, Daemen M, Falk E, Garcia-Garcia HM, Merrmann J, Hoefer IM, Juekma JW, Krams R, Kwak BR, Marx N, Maruszeqica M, Newby A, Pasterkamp G, Serruys PWJC, Waltenberger J, Weber C, and Tokgozoglu L. “Stabilization of atherosclerotic plaques.” Thomobosis and Haemostasis 106: 1-19 (2011)
  2. Schaar JA, Muller JE, Falk E, Virmani R, Fuster V, Serruys PW, Colombo A, Stefanadis C, Ward Casscells S, Moreno PR, Maseri A, and van der Steen AF. “Terminology for high-risk and vulnerable coronary artery plaques. Report of a meeting on the vulnerable plaque.” Eur Heart J 25: 1077-1082 (2004)
  3. Lloyd-Jones D, Adams R, Carnethon M, De Simone G, Ferguson TB, Flegal K, Ford E, Furie K, Go A, Greenlund K, Haase N, Hailpern S, Ho M, Howard V, Kissela B, Kittner S, Lackland D, Lisabeth L, Marelli A, McDermott M, Meigs J, Mozaffarian D, Nichol G, O’Donnell C, Roger V, Rosamond W, Sacco R, Sorlie P, Stafford R, Steinberger J, Thom T, Wasserthiel-Smoller S, Wong N, Wylie-Rosett J, and Hong Y. “Heart disease and stroke statistics–2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee.” Circulation 119:480-486 (2009)
  4. Hagg S, Salehpour M, Noori P, Lundstrom J, Possnert G, Takolander R, Konrad P, Rosfors S, Ruusalepp A, Skogsberg J, Tegner J, and Bjorkegren J. “Carotid plaque age is a feature of plaque stability inversely related to levels of plasma insulin.” PLoS One 6: e1824 (2011)
  5. Thies F, Garry JM, Yaqoob P, Rerkasem K, Williams J, Shearman CP, Gallagher PJ, Calder PC, and Grimble RF. “Association of n-3 polyunsaturated fatty acids with stability of atherosclerotic plaques: a randomized controlled trial.” Lancet 2003 361: 477-485 (2003)
  6. Sears, B. “Toxic Fat.” Thomas Nelson. Nashville, TN (2008)
  7. Sears B. “The Zone.” Regan Books. New York, NY (1995)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.

Pass the salt please?

One of the great “truths” in cardiovascular medicine is that to prevent stroke and cardiovascular death you reduce your salt intake. But is it true? A new analysis of the existing literature from the Cochrane Library indicates this may not be the case (1). Analyzing a great number of published studies, researchers came to the conclusion that there is no strong evidence to support the idea that salt restriction reduces cardiovascular disease or all-cause mortality in people with either normal or increased blood pressure. Furthermore, they found that while reducing salt intake did decrease blood pressure, it also increased the risk of all-cause death in people with existing congestive heart failure.

If that wasn’t enough, an article in the May 4 issue of the Journal of the American Heart Association found that low salt increased the risk of death from heart attacks and stokes, while not reducing blood pressure (2). This study was done with middle-aged Europeans and followed them for nearly eight years. During this time, the less salt they consumed, the greater the number who died of heart disease.

Needless to say, the American Heart Association (the same people who recommend eating lots of omega-6 fats) was enraged, similar to the Wizard of Oz telling Dorothy to ignore the man behind the curtain.

So why might restriction of salt consumption cause increased heart attacks? The reason may be due to increased insulin resistance induced by salt restriction (3). Insulin resistance increases insulin levels, and if that is combined with increased consumption of omega-6 fatty acids (remember the American Heart Association), you now have a sure-fire prescription to produce more arachidonic acid. It’s the inflammatory eicosanoids derived from arachidionic acid that would cause inflammation in the arterial wall leading to a heart attack.

This is not to say that some people are not salt-sensitive (African-Americans are particularly so), but I believe the problem is more a matter of balance. You need some sodium, but you also need potassium to balance it. This is confirmed by a recent study from Harvard Medical School that demonstrates that the higher the sodium-to-potassium ratio in the blood, the greater the likelihood of cardiovascular mortality (4). The relationship for increased death was significantly greater for a high sodium-to-potassium level than simply the sodium level itself.

Getting sodium in your diet is easy (sprinkle salt on your food), but getting adequate levels of potassium means eating a lot of fruits and vegetables. So rather than restricting salt intake or taking drugs (i.e. diuretics) to reduce the levels of sodium in the body, think about eating more fruits and vegetables if your goal is to reduce the likelihood of a heart attack. Oh, yes, also ignore the advice of American Heart Association and take more omega-3 and less omega-6 fatty acids.

References

  1. Taylor, RS, Ashton KE, Moxham T, Hooper L and Ebrahim S. “Reduced dietary salt for the prevention of cardiovascular disease.” Cochrane Database of Systematic Reviews DOI: 10.1002/14651858.CD009217 (2011)
  2. Stolarz-Skrzypek K, Kuznetsova T, Thijs L, Tikhonoff V, Seidlerova J, Richart T, Jin Y, Olszanecka A, Malyutina S, Casiglia E, Filipovsky J, Kawecka-Jaszcz K, Nikitin Y, and Staessen JA. “Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion.” JAMA 305: 1777-1785 (2011)
  3. Alderman MH. “Evidence relating dietary sodium to cardiovascular disease.” J Am Coll Nutr 25: 256S-261S (2006)
  4. Yang Q, Liu T, Kuklina EV, Flanders WD, Hong Y, Gillespie C, Chang M-H, Gwinn M, Dowling N, Khoury MJ, and Hu FB. “Sodium and potassium intake and morality among US adults.” Arch Intern Med 171: 1183-1191 (2011)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.