Wednesday, February 12, 2014

Facts About Xylitol

Because of recent confusion and mis-statements by some bloggers, I'd like to report some facts about the sugar alcohol, Xylitol:

Like all sugar alcohols, unabsorbed (versus undigested) material is hygroscopic (attracts water) as it passes through the GI tract. This makes them potentially laxative at various doses; as always, moderation is the key.
o For xylitol, the common threshold is at 30-50 grams a day (1-2 ounces).
o For erythritol, an alternative sugar alcohol, there is practically no laxative effect since it is predominantly absorbed.

Xylitol is naturally found in plums, raspberries, and cauliflower; it is a naturally occurring sweetener that the body can handle.

Xylitol can be made from xylan; a fiber found in many plants including:
o corn husks, cobs, and stalks (corn bobs are the leading commercial source)
o certain hardwoods like birch and beech (relatively small commercial production is done in Europe for Scandinavian trees)
o rice, oat, wheat and cotton seed hulls (possible, but not a typical commercial source)
o various nut shells (possible, but not a typical commercial source)
o straw (possible, but not a typical commercial source)
o sugar cane (possible, but not a typical commercial source)

Xylitol does not require insulin.

Xylitol improves bone and tooth density, protects tooth enamel.

Xylitol has fewer calories than sugar; only about 2.4 calories per gram versus 4 for sugar.

Most xylitol is produced in China.
o However, GMO corn is not allowed for food production in China.
o There are some IP (documented as from non-GMO corn) supplies and others tested as non-GMO (the corn sources are tested before production, though IP is not in place yet).
o GMOs have not been found in xylitol from corn, despite unsubstantiated speculation from bloggers.
o China’s food safety laws have been expanded dramatically in recent years, and in some cases now exceed US standards.

Xylitol can be toxic to dogs, but so is chocolate. Pets can’t always eat our foods, but that doesn’t imply that these foods are somehow harmful to humans. This is a “straw man” argument that fades upon examination.

Monday, January 06, 2014

Most vitamin studies are flawed by poor methodology

In a new published analysis, researchers at the Linus Pauling Institute of Oregon State University report that many large clinical trials of vitamin supplements, especially antioxidants like vitamin C, have flawed methodologies that make them 'useless' in determining the real value of such nutrients.

It is on the basis of such flawed studies created by researchers that are uninformed as to the nature of nutrients that their studies may conclude that vitamins are of no value or may even be harmful.

Of course, common sense tells us that essential nutrients cannot be inherently useless or harmful in reasonable doses, but those are messages that we repeatedly hear in the media reports.  Such flawed science leads to the equally flawed calls for vitamins to be regulated as drugs, adding a new logical error in failing to consider the vast difference in safety between nutrients and drugs.

Drugs are typically synthetic, isolated substances that are foreign to the body and don't act like nutrients, and it is this foreignness of drug properties that make them inherently toxic to the body. That toxicity is the legal basis of regulating drugs as controlled substances, and the failure to demonstrate toxicity of nutrients, except in studies with such flawed methodogies as we are discussing, makes calls to regulate vitamins as drugs hollow and illogical.

A report on that article:

The original peer-reviewed publication in a peer-reviewed nutrition journal:

Thursday, December 26, 2013

The Top Ten Vitamin Myths of 2013

The Top Ten Vitamin Myths of 2013
  1. All multivitamins are exactly the same, so a study on any one product is applicable to all other multis (ignoring variations of number of nutrients, the dose and form of each one, any supporting substances, the delivery form and excipients is good science)
  2. People take multivitamins primarily to prevent/treat cancer and heart disease (therefore any lack of definitive proof of efficacy against these diseases means that people should immediately stop taking vitamins, and all research on multivitamins is futile and should be halted even though they still are proven to prevent deficiency diseases and supply nutrients needed to preserve joint health, eyesight, healthy cholesterol and blood lipids, reduce cardiovascular risk factors, prevent birth defects, etc.)
  3. Our food supply is perfect and unchanging, as are our eating habits, making multivitamins unnecessary (Although USDA food tables were drafted around 1940, it’s okay to ignore changes in soil, seed, agriculture, food processing, how much processed and fast food we consume, the detoxification burden of environmental contaminants, and our lifestyles when telling Americans that they don’t need to supplement their diets to ensure adequate basic nutrition)
  4. Definitive answers of nutrient safety/efficacy can be found by “data mining” older studies (the practice of another team applying a “secondary data analysis” to certain fields within previously published studies in which nutrient values were reported but were not the intended research subject (“lacking depth”), and therefore all relevant variables for the nutrient(s) were probably not identified nor properly controlled as they should be in primary research)
  5. Perfect classic control groups can exist in nutrient research (obviously, this would require subjects who don’t ingest any vitamins or minerals from food  or supplements (or sunlight for vitamin D), had their serum levels at the beginning of the study measured and equalized, and had identified/controlled all co-factors that influence those nutrient levels in the body)
  6. Editorials in medical journals accurately and impartially reflect the true state of science regarding nutrient research (by honestly addressing shortcomings and limitations of the reports instead of adding their spin to well-publicized controversial articles appearing in their journal)
  7. Media coverage of vitamin controversies is always  balanced and put into proper perspective (utilizing reporters and editors who know the topic, really research stories, and present comprehensive reports)
  8. Researchers who make political statements in their reports should still be regarded as unbiased experts in nutrient study design and execution (for example, when they inaccurately state that dietary supplements are “unregulated” simply because they are not regulated as drugs it raises questions of impartiality, as well as exposing basic ignorance of the topic they claim to be experts on)
  9. A single study, especially if blending data from several other studies, can be regarded as Definitive (especially data-mining secondary data analyses that look for possible associations but lack the depth of original design to control all variables)
  10. A single study can reasonably claim to contradict decades of rigorous research (especially when it is a preliminary study not designed to screen all relevant factors that would allow it to demonstrate cause-and-effect and dose-dependent relationships)
None of these statements are true, in my opinion, but in my experience still appear to be typical operating procedures in the brave new world of research and reporting that we live in today. Questionable studies may have been designed based on questionable models, often due to ignorance or unconscious bias - even if well-intentioned

Peer reviewers for medical journals may have their own biases, ignorance, or motives for allowing statistically significant reports based on fundamentally flawed designs to be published, or for not questioning some studies' conclusions for poorly matching the reported data. 

For example, I have actually seen supplement studies reporting a conclusion that the supplements weren't effective even when the subgroup that actually followed protocol and took the supplements had success. If the overall failure of the supplements in the study were actually attributable to non-compliance subjects, that shouldn't be interpreted as the supplements being ineffective, failing the test. 

Some controversial studies are heavily marketed, even enlisting reporters to write stories based partially on sound bites and press releases in advance of embargoed reports' publication dates. Authors of controversial studies may become celebrity "experts" in the field, with their famous work widely cited by succeeding authors and being sought for media interviews during future controversies. Often, expert criticism of their work - and even failure to replicate the results in subsequent reports, a hallmark of the Scientific Method self-correcting the scientific record - typically is ignored; perhaps in light of their celebrity status.   

©2013 by Neil E. Levin, CCN, DANLA; may be cited with full attribution

Wednesday, November 06, 2013

How Important is it to have "Human Strain" Probiotics?

“Human Strain” Probiotics

The origin of a strain simply specifies from what source that particular strain - often part of a blend - was first isolated. Its origin is related to establishing intellectual property and a chain of custody, but not to any possible health benefits. There are all kinds of organisms, both desirable and undesirable, in our guts, but microbiologists do not consider the first identified/isolated source to be predictive of the health benefits that any particular strain (substrain) will provide to people.

So touting a “human source” or “soil organism” is actually a marketing game, not a valid scientific argument, and in fact is an anti-scientific message. Just because an organism was obtained from human feces (or rarely, saliva), perhaps because the person actually obtained it by eating fermented foods or even from contact with soil, doesn’t mean that it has probiotic properties…or even different properties than eating it in that yogurt or directly consuming those soil organisms. We all probably have some small quantity of E coli and Salmonella in our bowels; should they therefore be promoted as “human strain” probiotic bacteria? Obviously not…

In the scientific literature the benefits of a probiotic strain (or blend) depends solely on its technical qualities: proper identification of the specific strain (substrain), its stability in a consumer product, its bile and acid resistance, its ability to colonize and persist in the human GI tract, and any specific health effects it provides as measured in both test tube and human clinical trials when given to a human being. None of these qualities depend on its original sourcing. Specific label claims relating to substrains of probiotics depend totally on the body of clinical evidence of how that substrain provides benefits to people.

Look for the addition of a third name to the Latin binomial (2-word Latin name) of a strain to indicate a specific substrain, as in “Lactobacillus acidophilus La-14” or “Bifidobacterium lactis BL-04”.

If a company is touting the origin of their strain(s) rather than their proven clinical health benefits, then they may have no clinically validated strains and are just trying to promote theoretical rather than demonstrated benefits. Why would they promote strains based on irrelevant historical factors related to the strain's discovery rather than providing evidence of their product's demonstrated health benefits if they do have clinically relevant strains?

Smart consumers will look for evidence-based label claims, such as clinical trials utilizing their particular strain to assure that a probiotic product will have some credible evidence of being health promoting.

Tuesday, August 06, 2013

Supplements vs. Food to Obtain Key Nutrients

Supplements vs Food

Supplements vs Food [Infographic] by the team at Supplement Centre

Monday, July 15, 2013

The Facts About Omega-3 Fatty Acids and Increased Prostate Cancer Risk

A study released this week, “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial,” published in the Journal of the National Cancer Institute (JNCI)) suggests that the omega-3 essential fatty acids EPA, DPA, and DHA - but not the omega-3 fatty acid ALA, found in flax, chia, hemp seeds, and nuts that have repeatedly been shown to lower prostate cancer rates - are somehow associated with increased risks of high-grade prostate cancer. At the same time, higher amounts of normally harmful trans fats in these subjects were associated with lower rates of advanced prostate cancer. [1] Because of the known limitations of this particular kind of study, all of these reported results were completely unproven, highly questionable, and highly unlikely to be true.

What kind of study was this? It is data mining of a previously published population study in which important variables and endpoints for fish oil's relationship to prostate cancer were not controlled, nor any cause and effect demonstrated. Because it is a secondary analysis of a largely epidemiological (population) study, it represents the lowest level of evidence in human studies because most relevant variables, confounding factors, and clinical endpoints are not systematically collected for proper analysis as they would be in an actual controlled clinical trial. Instead, the limited goal was to look for possible associations that were admittedly not rigorous enough to be considered as actual evidence of a causal relationship. As a preliminary study, it was consciously designed only to raise questions, rather than to provide answers, and it did accomplish that goal but also created a messy splash of misleading and over-emphatic headlines inaccurately suggesting that this one study somehow trumps many more robust clinical trials. So much for the media knowing of and respecting the Scientific Method. [2]

Dr Marilyn Glenville PhD, the UK’s leading nutritionist specializing in women’s health and former President of the Food and Health Forum at the Royal Society of Medicine, has noted some deficiencies in the current JNCI report; some examples: [3]
  • “This is not a randomised controlled trial but a trial comparing Omega 3 levels in men with prostate cancer with healthy men. The men with prostate cancer had higher levels of Omega 3. But you cannot extrapolate cause and effect from this finding. It is like saying that if the majority of men with prostate cancer played tennis compared to healthy controls then tennis could trigger prostate cancer.”
  • In 2009 the Harvard School of Public Health reported that “Omega 3 deficient diets cause up to 96,000 preventable deaths a year in the US. The researchers estimated the number of deaths resulting from 12 preventable causes and Omega 3 deficiency ranked as the sixth highest killer of Americans. A deficiency in these fats was classed as a bigger killer than high intake of trans fats.” [4]
  • “…there are many cultures such as the Japanese who eat high amounts of oily fish containing Omega 3 fatty acids and yet have one of the lowest prostate cancer death rates in the world.”
Duffy MacKay, N.D., vice president, scientific and regulatory affairs of the Council for Responsible Nutrition, also noted some concerns with the report: [5]
  • “Hundreds of studies over the past two decades have shown omega-3 fatty acids to have positive effects associated with cardiovascular health, perinatal health, inflammation, cognitive function, or cancer. Collectively, this body of research serves as the basis for numerous recommendations from respected organizations, scientific boards and healthcare practitioners that Americans get omega-3 fatty acids in their diets.”
  • “While we encourage researchers to continue to study omega-3 fatty acids with an open mind, it is counterproductive when studying nutrition for researchers to promote their study as if it were the only piece of research that counts. In this case in particular, it is especially disingenuous for the researchers to make the kinds of assertions we've seen in the press, given their results are in stark contrast to previous epidemiologic studies that not only demonstrate no correlation between omega-3 consumption through fish and/or supplementation and the risk of prostate cancer, but in many cases also showed a protective effect against prostate cancer.”
  • “One should also consider whether this study could have simply been measuring a biomarker reflecting recent intake of fish or fish oil supplements in a group of high risk cancer patients that had been told to increase their EPA and DHA levels, as compared to a group of non-cancer patients that had not been told to consume more EPA and DHA. Plasma levels of EPA and DHA reflect very recent intake and are considered a poor biomarker of long term omega-3 intake especially when compared to red blood cell levels, which reflect medium term intake. A single fish oil dose (or hearty serving of fish at lunch) results in >100 percent increase in plasma omega-3 levels. So looking at plasma levels in healthy and sick people may only provide insight into the recent habits of these individuals.”
  • “The American Heart Association, the World Health Organization (WHO), the U.S. Institute of Medicine’s Food Nutrition Board (IOM FNB) and the 2010 Dietary Guidelines all have current policies advising Americans to eat more fatty fish to get the benefits of omega-3 fish oils. It is highly unlikely this one study will change that advice. Omega-3s can also be obtained by taking one of the many supplement products on the market. For those consumers who have concerns about prostate cancer or other questions about omega-3 fatty acids, we recommend speaking with your doctor or other healthcare practitioner.”
If you are a man and believe this report, then you’ll probably want to eat partially hydrogenated artificial trans fats instead of omega-3 fats for prostate health; though that change would greatly increase your risk of suffering far deadlier cardiovascular diseases, based on evidence from many clinical trials. But that would be ridiculous. In fact, many cultures around the world consume far more fish oil than Americans without having increased risks of aggressive prostate cancer; these include the Inuit people ("Eskimos"), Scandinavians, Southeast Asians, Pacific Islanders, Japanese, Filipinos, and others. 

In any case, in the absence of proper controls or any evidence of causation, we actually can’t know what these study results really mean. For example:
  • Were DHA levels related to diet, supplementation, or both?
  • Were fish and/or fish oils perhaps consumed as a deliberate health choice because of prior knowledge of prostate issues, rather than actually causing or aggravating those issues? In other words, could the consumption represent an attempt to improve a pre-existing condition by improving one’s nutritional status and be unrelated to the disease itself? Perhaps even suggested by medical teams as potentially helpful for patients' diet?
  • If they had been collected, what would key inflammatory and oxidative markers, that are much likelier to be related to prostate health problems than long-chain omega-3 fatty acids such as DHA, have told us about these men’s state of health and disease?
  • Where is the biochemical evidence that DHA itself may negatively contribute to prostate concerns? None is presented, even theoretically.
The Global Organization for EPA and DHA Omega-3s (GOED) also criticized these and numerous other some aspects of the JNCI report, among them these important points: [6]
  • “The difference in mean blood plasma phospholipid fatty acids blood level for omega-3s was 4.66% in the combined cancer group versus 4.48% in the control. They are basing their results on just ca. 0.2% difference in omega-3 levels.”
  • “Plasma phospholipid fatty acids as measured in this study are not a good index of long term intake and are influenced dramatically by a single meal, or even timing of a fish oil dose. A single fish oil dose massively increases LC omega 3 (typically increasing levels by 100% or more) in about 4-12 hours and then washes out around 48 hours.”
  • “The study was not designed to look at omega-3 and confounded with selenium and Vitamin E used in the treatment arms.”
  • “The test cohort included sick and healthy people. It is possible that sick people were taking fish oil supplements at a higher rate than the healthy individuals.”
  • “A recent meta-analysis of fish consumption and prostate cancer by Szymanski et al. (2010) reported a large reduction in late stage or fatal prostate cancer among cohort studies." [7]
  • "Several population based studies have shown a benefit of increased omega-3 fatty acid intakes to reducing prostate cancer risk.” [8], [9]
As I said earlier, this type of study raises questions about possible associations; but due to its built-in limitations, and results conflicting with most other related studies, provides no real answers.  Unfortunately, its counter-intuitive results generate sensational press coverage rarely accompanied by any true perspective on what this new study really means (not much).

In real life, most Americans and others in Western societies no longer consume the ideal amount or ratio of omega-3 fatty acids in their diet as our ancestors did a century or two ago. This reduction reportedly contributes to the large increase in chronic health problems that plague these societies. It is a public disservice to inappropriately scare people away from healthy foods and supplements, which help balance the diet in these many cases where the lack of essential nutrients is actually causing harm, based solely on such flimsy “evidence”. 

After reviewing this study I, a vegetarian, will continue to take my vegan DHA supplement twice a day with absolutely no concerns that it will negatively affect my own prostate health. Why am I not at all concerned? Because there is still no hard evidence explaining how long-chain omega-3 fatty acids like EPA and DHA may promote prostate cancer. There is still no demonstrated mode of action for this concern, and there are still no plausible explanations of any biological mechanisms that could justify the theory that long-chain omega-3 fatty acids may promote prostate cancer. My lack of concern is evidence based, after carefully reviewing the studies in question. Contrast this with the fear-mongering about fish, fish oil, and omega-3 fatty acids in foods and supplements that is overwhelmingly based on speculation, flimsy data, ignorance (on several levels), and maybe even some bias.

By Neil E. Levin, CCN, DANLA


[4] The Preventable Causes of Death in the United States: Comparative Risk Assessment of Dietary, Lifestyle, and Metabolic Risk Factors" study, April 2009, PLoS Medicine
[7] Szymanski KM, Wheeler DC, Mucci LA. Fish consumption and prostate cancer risk: a review and meta-analysis. Am J Clin Nutr. 2010;92(5):1223–1233
[8] Terry P, Lichtenstein P, Feychting M, et al. Fatty fish consumption and risk or prostate cancer. Lancet, 2001,357:1764-6.
[9] Lietzman MF, Stampfer MJ, Michaud DS, et al. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr 2004;80:204-216.

Tuesday, May 28, 2013

Is Canola Oil Better than Olive Oil for Cardiovascular Health?

Canola oil has less oleic (omega-9) and more ALA (omega-3) than olive oil and been shown to:

• improve lipid measurements greater than olive oil in human subjects in a randomized, double-blinded trial:

• improve cardiovascular health more than olive oil in a rat model: