Dietary Dogma: Has America’s dietary advice been successful? A review of USDA guidelines:

 

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“Thus we should beware of clinging to vulgar opinions, and judge things by reason’s way, not by popular say.”   -Montaigne  (1533-1592)

It wouldn’t be very uncommon to immediately and even subconsciously correlate issues such as heart disease, obesity and diabetes whenever we hear the word ‘fat’. Diabetes being a bit of head scratcher considering it is a blood sugar disorder biochemically, but occasionally incorporated none the less.  In fact,  this is such a well-known and indisputable subject, that questioning it seems aimless. After all, if fat doesn’t make you fat, than what the heck possibly could, right?  It’s portrayed as so elementary, and has been for years-all the way back to the 1950s when a researcher by the name of Ancel Keys found a relationship between the amount of saturated fats and cholesterol in the diet and incidence of heart disease. (1) This theory-known as the diet-heart hypothesis-would soon set the stage for numerous margarine, vegetable oil, and various mono-culturing practices to take on the task of making our food supply both healthy and safe.  In 1992 when I was in grade school we were blessed with the USDA food pyramid, assuring us that eating diets consisting of ‘six to eleven servings bread, cereal, rice and pasta’, and ‘consuming fats sparingly’ will salvage our health and longevity. We were now equipped with guidelines and a universal formula designed to get us all ‘back on track’.  This idea; currently experiencing its ‘mid-life crisis’ known as the MyPlate, has a new look, a hip new website embracing all the fabulous social media outlets, plus now they even have calorie charts where you can track all of your favorites-from pizza to lasagna to egg rolls-as well.  Not that they would be embracing these foods, of course! 😉  Here’s what they do embrace regarding dietary guidelines for Americans, however, this may sound familiar: “Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk products.  Includes lean meats, poultry, fish, beans, eggs, and nuts; and is low in saturated fats, trans fats, cholesterol, salt (sodium) and added sugars.”  (2)  Hmm…you know, this time I think their advice will work in our favor, it just gots ‘ta!  So the question now becomes, how have these recommendations held up the last sixty-some odd years?  Before this analysis, let’s take a brief look at some of the roles fat initiates in the body and even, dare I say, some benefits of fats:

  • Building cell membranes
  • Help receptor sites operate sufficiently (including insulin receptors)  (3)
  • Can protect against cancer (through inter-cellular communication)   (4)
  • Fats carry vitamins A, D, E and K to the cell (fat soluble vitamins)
  • Short and medium chain fats have antimicrobial properties.       (5)
  • Fats are needed for brain development and optimal function (DHA).
  • Fats have been shown to be capable of regulating inflammation (hat tip to EPA)
  • Fatty acids can be used to synthesize glucose when blood sugar is low. (Through gluconeogenesis in the liver).
  • EPA and DHA (found in fish oil or algal oil) have shown significant protective effects against allergy development as well as therapeutic effects in double-blind clinical trials.  (6,7)
  • Insufficient amounts of long-chain omega-3 fatty acids (EPA and DHA) have been linked to depression.  (8)
  • Higher levels of long-chain omega-3 fatty acids (EPA and DHA) actually reduce the risk of heart attack.  (9)

And the list goes on and on.  With all this in mind, let’s evaluate the MyPlate nutrition advice above, delivered courtesy of industrialized agriculture:

“Emphasizes fruits, vegetables and whole grains”.  Alright, good start.  Nothing too out of the ordinary here.  Although-which whole grains are they referring to?  Is whole wheat considered healthy?  Gluten and its derived peptides found in not only wheat, but barley and rye as well, have been shown to be problematic.  (10)   In fact, studies have shown that gluten can affect the brain (schizophrenia, epilepsy), skin (acne, psoriasis, dermatitis), endocrine system (thyroid, type 1 diabetes), stomach, liver, blood vessels, etc. etc. the list goes on and on.  (11) So not only does this not address those who are gluten sensitive (estimated 83% of the population) (12) and/or suffer from Celiac disease (estimated 1% of all Americans, although it remains largely undiagnosed) (13) but whole grains have also been shown to have a higher content of phytate, which studies suggest prevent proper mineral absorption.  (14)  To add insult to injury, whole grains are actually quite nutrient-poor. Using the USDA National Nutrient Database as a reference, Harvard University chemist Dr. Mat Lalonde found that overall grains scored second to last on average regarding availability of various micronutrients, such as vitamin A, vitamin C, and vitamin B12, plus remember minerals like iron, calcium, selenium, zinc and magnesium are not fully absorbed due to the phytates.  Because of variables such as these, one can’t help but question should these whole grains still be suggested as the foundation of a healthy diet?  I’m not saying everyone needs to abandon these foods, but if we don’t need them and we can get a more rich and bioavailable source of these nutrients elsewhere-why place so much emphasis on them?

 “Fat-free or low-fat milk products.”  As mentioned above in the list of roles fat plays in the body, among one of them is their job to deliver nutrients such as fat soluble vitamins A, D, E and K to the cells for utilization.  When people are told to consume dairy, the reasons are typically to obtain an adequate source of calcium or even vitamin D (most convention milk products are fortified with vitamin D).  It is now well-known that vitamin D stimulates the absorption of calcium, and studies have shown that higher blood levels of vitamin D are associated with a lower rate of fractures; whereas lower vitamin D levels are associated with a higher rate of fractures.  (15)  So if we need vitamin D to help us absorb calcium, and we need fats to absorb vitamin D (fat soluble), than it seems rational to conclude that these fat-free alternatives may not be all that beneficial-at least in regards to nutrient density.  Not to mention that pasteurization also kills off the beneficial bacteria, as well as destroys various enzymes-for instance lactase-which helps break down lactose sugars in milk. Vitamin K is another fat-soluble vitamin and K2, (found in fermented dairy such as cheeses, butter and also found in natto) is now understood to be responsible for the calcium (once absorbed) to be properly utilized by bone tissue, and prevents calcium from being deposited elsewhere, such as organs (kidneys) and arteries.  This again points out, that fat-free dairy products may actually not be all that beneficial, considering so many of the nutrients work synergistically with and depend on fat.

“Low in saturated fats”.  So again, this advice stemmed from the work of Ancel Keys’ diet-heart hypothesis which suggested that consuming saturated fat increases our risk for heart disease.  In a nut-shell, Keys found a correlation between saturated fat consumption and increased incidence of heart disease in certain countries, including the US.  It is important to understand that correlation does not equal causation, and although no study-including this one-should be overlooked, one with as minimal variables as his should be taken with a grain of salt.  For arguments sake, what about the countries that not just consume saturated fat, but large amounts of saturated fat and whom do NOT have high incidence of heart disease, if any at all?  Take the Maasai tribe of Kenya who subsist largely on milk, blood and beef and are free from heart disease AND have low cholesterol levels.  (16)  Or the Inuit who liberally consume animal fats from fish and marine life and are also free of heart disease.  (17)  A study comparing Jews when they lived in Yemen-whose diets were high in animal fats, to Yemenite Jews living in Israel-whose diets contained margarine and vegetable oils, showed that the animal fat group had little incidence of heart disease or diabetes while the vegetable oil group had high levels of both.  (18)  So you can see there is conflicting epidemiological evidence that support just the opposite of what we’ve always been told.  In fact, in 2010 a large review of twenty-one different studies covering over 350,000 subjects found that “…there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD (coronary heart disease) or CVD (cardiovascular disease).”  (19)  These, and the many more studies that have very similar conclusions should be enough to validate any questions or concerns regarding the suggestion to avoid saturated fat.  These are examples of how dietary dogma can not only be incorrect at times, but also unscientific.  To close, I would like to add that saturated fats also needed for the utilization of essential fatty acids- such as omega-3s, (20) they also play a role in enhancing the immune system (21) as well as protects the liver from alcohol and other toxins such as Tylenol.  (22)

What about cholesterol?  It is known that cholesterol makes up arterial plaque in people suffering from atherosclerosis, and the almost irreversible myths are that a) cholesterol is bad, b) avoiding saturated fat and animal fats will lower serum cholesterol, and c) low cholesterol in the blood leads to a lower risk for heart disease, and lower mortality.  I’m not going to jump too far down this rabbit hole-realistically more a tunnel to the center of the Earth-but I will address some of these myths.  First, let’s start with cholesterol’s roles in the body:

  • Cholesterol plays a critical role in forming cell membranes; which controls how the cell moves, as well as communicates with other cells.
  • Cholesterol is carried in transporters called ‘lipoproteins’ which transport cholesterol, fat soluble vitamins (A,D,E and K) and antioxidants to all the cells in the body.
  • Fifty percent of cell membranes are made up of cholesterol.
  • LDL cholesterol binds to and inactivates bacterial toxins.  (23)
  • Cholesterol is a precursor to ALL steroid hormones in the body; including sex hormones and adrenal hormones.
  • Babies and children ESPECIALLY need cholesterol to ensure proper growth and brain development.  In fact, babies fed formula only have been shown to have lower IQs and higher rates of infectious disease mortality.  (24, 25)  A breast-fed baby’s cholesterol intake is around 100-200 milligrams per day.  Scaled by body weight, that is ten times higher than the typical amount of cholesterol consumed by American adults!
  • Synapse formation in the brain is almost entirely dependent on cholesterol.
  • Cholesterol is an antioxidant that protects from free radical damage and oxidative stress.  (Both of which can actually promote heart disease).
  • Cholesterol helps maintain the integrity of the intestinal wall, which can protect us from food allergies, sensitivities and autoimmune disorders.

So ends the first myth, “cholesterol is bad”.  There are many, many more reasons why this is false, but there will be lots of future posts regarding this myth, so be sure to stay tuned!  It is also important to note that about 75% of the cholesterol in our bodies is actually manufactured in the liver, where the remaining 25% (some argue even less) comes from the diet.  So high cholesterol is geared more toward liver function, not so much dietary factors.  Feeding studies where they fed volunteers two to four eggs a day and measured their cholesterol, showed that dietary cholesterol had very little impact on blood cholesterol in majority of the population.  In the remaining small percentage of the population where dietary cholesterol does raise blood levels, studies show that both LDL and HDL (good cholesterol) were raised and there was no increase in heart disease risk.  (26)  Ancel Keys, the founder of the diet-heart hypothesis even came to terms in a letter to the New England Journal of Medicine in 1991 where he stated:  “Dietary cholesterol has an important effect on the cholesterol level in the blood of chickens and rabbits, but many controlled experiments have shown that dietary cholesterol has a limited effect in humans.  Adding cholesterol to a cholesterol-free diet raises blood levels in humans, but when added to an unrestricted diet, it has minimal effect.” (27)     But wait…I thought an increase in cholesterol in the blood meant a higher risk for heart disease?  Not according to a study of over 52,000 Norwegians.  Researchers found that women with total cholesterol levels below 195 mg/dL had a higher risk of death than women with cholesterol levels above the cut-off. (28)  In the Japanese Lipid Intervention Trial (J-LIT), involving 47,000 participants, the highest death rate was observed in those with the lowest cholesterol levels, and the lowest death rate was observed in those with cholesterol levels between 200-259 mg/dL, (29) which is considered “high” by US standards (100-199 mg/dL considered ‘healthy’ ranges).

“Low in salt (sodium).”  Just a brief segment here.  A study reported in the Journal of the American Medical Association measured salt intake via sodium excretion in urine and followed subjects for five years to assess their death rates.  The mortality rate was lowest when sodium intake was in the range of 4 to 6 grams per day.  Sodium intake below 3 grams per day significantly raised the mortality rate, however so did consuming 7 grams or more of sodium per day.  (30)  To put this in perspective, The American Heart Association advises consuming less than 1.5 grams of sodium per day (even though this study showed that consuming less than 3 grams per day increased mortality rate).

These are just a few examples of many that suggest the exact opposite of what we’ve always known to make up a “healthy” diet.  I should state, however, that we haven’t gotten it all wrong.  I do agree that emphasis on consuming good portions of vegetables and fruits, fish, lean meats (I would add fatty meats as well), poultry and eggs (so long as there is no immunogenic response) while avoiding trans fats and refined sugar appear to be good ‘general’ recommendations.  However general recommendations-especially these- don’t necessarily affect specific health conditions.  To state that dietarily all folks need to do is follow these guidelines is not only inconclusive in the scientific literature, but for some people it could be doing them a dis-service.  This is why when it comes to nutrition it’s important to work with a professional that can help you construct your own personal ‘MyPlate’ catered specifically to you and your individual needs.

In conclusion, the point I’m trying to get across in addressing the drawbacks to dietary dogma is not to promote another way of eating for the general population, but to get folks to understand that a healthy diet is not one prescription, but instead a complexity of individual biological ‘codes’.  I believe every code can be ‘cracked’, but much more efficiently on individual terms.  I hope folks found this both informative, and useful in their own personal health journeys!  Thanks for reading my rant on these almost religious, uniform dietary standards, and just remember: nobody knows your body better than you, and if somebody is going to give you advice on what to eat to be ‘healthy’ than they better know your “ins and outs” on a hormonal level, on a genetic level, on a lymphatic level, and on a spiritual level.  It’s been fun, until next time friends, be well!

To your health and wellness,

Derek

References:

1)  http://jama.jamanetwork.com/article.aspx?articleid=321297

2)  http://www.choosemyplate.gov/dietary-guidelines.html

3)  Krishna Mohan I, Das UN.  Prevention of chemically induced diabetes mellitus in experimental animals by polyunsaturated fatty acids.  Nutrition 2001; 17: 126-151

4)  http://ajcn.nutrition.org/content/79/6/935.short

5)  http://link.springer.com/article/10.1007/s00253-009-2355-3

6)  Kremmyda LS, Vlachava M, Noakes PS, et al.  Atopy risk in infants and children in relation to early exposure to fish, oily fish, or long-chain omega-3 fatty acids: a systematic review.  Clinical Reviews in Allergy and Immunology 2011  Aug; 41(1): 36-66.

7)  Soyland E, Funk J, Rajka G, et al.  Dietary supplementation with very long-chain n-3 fatty acids in patients with atopic dermatitis.  A double-blind, multicenter study.  British Journal of Dermatology 1994;130:757-764.

8)  Freeman MP, Rapaport MH.  Omega-3 fatty acids and depression: from cellular mechanisms to clinical care.  Journal of Clinical Psychiatry 2011 Feb; 72(2):258-259.

9)  Siscovick DS, Raghunathan TE, King I, et al.  Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest.  The Journal of the American Medical Association, JAMA 1995 Nov 1; 274(17):1363-1367.

10) Dohan FC. Wheat “consumption” and hospital admissions for schizophrenia during World War II.  A preliminary report.  1966, Jan. 18

11) www.bmj.com/content/319/7204/236

12)  Bernardo D et al. Is gliadin really safe for non-coeliac individuals? Production of interleukin 15 in biopsy culture from non-coeliac individuals challenged with gliadin peptides. Gut 2007 Jun;56(6):889–90, http://pmid.us/17519496.

13)  Tack GJ, Verbeek WH, Schreurs MW, Mulder CJ.  The spectrum of celiac disease: epidemiology, clinical aspects and treatment.  Nature Reviews Gastroenterology & Hepatology 2010 Apr; 7(4):204-13

14)  Juliano BO. Rice in Human Nutrition. Rome: Food and Agriculture Organization of the United Nations, 1993, www.fao.org/docrep/t0567e/T0567E00.htm.

15)  Bischoff-Ferrari HA, Giovannucci E, Willett WC, et al.  Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes.  The American Journal of Clinical Nutrition 2006;84:18-26

16)  Kang-Jey Ho, et al.  Archeological Pathology, 1971, 91: 387; Mann, G V, et al.  American Journal of Epidemiology, 1972, 95: 26-37.

17)  Price, Weston, DDS, Nutrition and Physical Degeneration, 1945, Price-Pottenger Nutrition Foundation, San Diego, CA, 59-72.

18) Cohen, A, American Heart Journal, 1963, 65:291

19) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824152/

20) Garg, M L, et al, Federation of American Societies for Experimental Biology (FASEB) Journal, 1988, 2:4: A852; Oliart Ros, R M, et al, “Meeting Abstracts,”  American Oil Chemists Society Proceedings,” May 1998, 7, Chicago, IL.

21)  Kabara, JJ, The Pharmacological Effects of Lipids, The American Oil Chemists Society, Champaign, IL, 1978, 1-14; Cohen, L A et al, The Journal of the National cancer Institute 1986, 77:43

22) Nanji, A A et al, Gastroenterology, Aug 1995, 109(2):547-54; Cha, Y S and D S Sachan, Journal of the American College of Nutrition, Aug 1994, 13(4): 338-43; Hargrove, H L, et al. Federation of American Societies for Experimental Biology (FASEB) Journal, Meeting Abstracts, Mar 1999, #204. 1, p A222

23) http://www.ncbi.nlm.nih.gov/pubmed/8617867

24) Picaud JC et al. Incidence of infectious diseases in infants fed follow-on formula containing synbiotics: an observational study. Acta Paediatr. 2010 Nov;99(11):1695-700. http://pmid.us/20560895.

25) Victora CG et al. Evidence for protection by breast-feeding against infant deaths from infectious diseases in Brazil. Lancet. 1987 Aug 8;2(8554):319-22. http://pmid.us/2886775.

26) http://www.ncbi.nlm.nih.gov/pubmed/19852882

27) http://www.nejm.org/doi/full/10.1056/NEJM199108223250813

28) http://www.ncbi.nlm.nih.gov/pubmed/21951982

29)  http://ije.oxfordjournals.org/content/22/6/1038.abstract

30)  O’Donnell MJ et al. Urinary sodium and potassium excretion and risk of cardiovascular events. JAMA, The Journal of the American Medical Association 2011 Nov 23;306(20):2229–38, http://pmid.us/22110105.

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