Pleased to be giving a seminar as an Adjunct Professor on “Personalizing Nutrition Guidance and Career Development” in the Department of Human Health & Nutritional Sciences, University of Guelph on Monday, Nov 19 at 1:00! HHNS at UofG http://ow.ly/i/JAWnz
Standardization of methods so that research studies conducted in different labs can be compared ALWAYS helps science advance. This paper applies to doubly water labeling studies to measure energy expenditure & body composition http://ow.ly/45gD30mE0Dl
In an insightful paper, Archer, Lavie and Hill (2018) argue that controversies regarding the health effects of dietary sugar, salt, fat and cholesterol are not driven by legitimate observations.
They discuss the fatal flaws of Memory-Based Dietary Assessment Methods (M-BMs):
- Dietary intake estimates are ‘mere guesswork’ and not accurate measurements of dietary intake.
- Human memory and dietary recall are not valid tools for objective data collection because people are forgetful, often intentionally misreport and change their responses to offer socially desirable responses.
- Conversion of abstract concepts/answers to categorical data is pseudo-scientific and misleading.
- M-BMs rely upon Food Frequency Questionnaires (FFQ) listing only 75-200 items or 24 hour recall data, both reliant upon incomplete food databases (the largest contains about 8,000 of >85,000 food items found in the marketplace) with varying degrees of analytical accuracy
- Studies using quantitative tools, e.g. doubly-labelled water, have found proxy estimates determined by M-BMs to be physiologically implausible
In short, the authors write:
“Thus, we posit that while dietary intake is an obvious and essential component of health, it is a trivial risk factor for obesity, metabolic, and chronic diseases.”
They go on to say:
“In fact, these estimates are so trivial, “crude and imprecise” that most diet-disease associations may be considered spurious (141). As such, we posit that measuring “diet” per se is tangential if not irrelevant to the major public health issues faced by industrialized nations.”
Archer, Lavie and Hill suggest that the answer may lie in metabolic differences among individuals, i.e. our ‘metabolic phenotype’. They acknowledge the resources required for metabolic phenotyping.
There may be an interim, more achievable nutrition goal.
Let’s shift our focus to objective measures of micronutrient status on chronic disease and away from an obsession with dietary sugar, fat, salt and cholesterol intake.
The fortification of food staples beginning in the 1940s (iodized salt, vitamin D fortified milk, B-vitamin fortification of cereal grains) has had a tremendous public health impact. However, society has changed. With >85,000 food items in the market, people eating on the go, and a diet-disease discourse that creates confusion and increases distrust of the agri-food industry, dietary patterns are becoming increasingly diverse. While overeating may be prevalent, lifestyle choices may increase risk of over- and underconsumption of essential nutrients.
Hidden hunger, a lack of essential vitamins and minerals to maintain health, occurs in people who are underweight, normal weight, or overweight/obese. Reports on the prevalence of hidden hunger often rely upon B-MBs. They need not. We should be adopting objective measures of nutritional status, i.e. serum 25(OH)D, serum ferritin, EPA+DHA, macular pigment density for lutein, etc.
Vitamin D is the poster nutrient for my recommendation. The National Institute of Standards and Technology (NIST) and National Institutes of Health established a Vitamin D Metabolites Quality Assurance Program. Based on this, nutrition and medical researchers have begun unravelling important relationships between vitamin D status and health (see two examples below).
It is possible to objectively monitor health status using many objective biomarkers: body weight, blood pressure, blood vitamin levels, blood (or red blood cell membrane) fatty acids EPA+DHA, serum cholesterol, glycosylated hemoglobin, C-reactive protein, serun ferritin for iron, etc).
As seen in the figure below, we know that individual responses to a standardized vitamin D dosage differ. We can speculate about vitamin D-related polymorphisms but we still do not know why; mostly because individual responses have not been studied very broadly.
A ‘metabolic phenotype’ may mean some individuals can consume more (or less) of a nutrient to maintain optimal micronutrient status. For most micronutrients, ‘optimal status’ is a vague term that needs to be defined further. However, if it is the availability of vitamins to cells, i.e. vitamin status, that affects cellular function and disease risk, then the dietary objective is to maintain ‘optimal status’ regardless of genetics. This hypothesis needs testing.
By adopting objective measures of nutritional status, nutrition scientists and medical scientists can unravel diet-disease relationships and help end our obsession with food. It is time to move forward…..
In the USA, 28% of adults use multivitamin-mineral supplements (MVMS) to increase nutrient intake (Blumberg et al, 2017). New research from China finds <1.8% using MVMS https://t.co/Ok9BrNNapX #MissedOpportunity #StatusMatters
In the USA, 28% of adults regularly uses (>21d/mo) multivitamin-mineral supplement (MVMS) to increase nutrient intake (Blumberg et al, 2017). New data from China finds <1.8% using MVMS http://ow.ly/DF7330mApv6 #MissedOpportunity #StatusMatters http://ow.ly/i/JuwRA
Working toward a PhD, or ready to reflect on your own experience? Then you should read these 20 recommendations by Lucy A Taylor.
Number 8 is always a challenge for me. The thought of writing a thesis, a book chapter, or a research paper is daunting. In fact, it leads to LOTS of procrastination. It is so much easier to start with a small component.
When writing a research paper, I always start with the methods, then compile my data into tables and figures. Now I have the narrative for the results section. Then I write my conclusions. Now out of the 100 plus ways I could begin the introduction, only one really leads through the rationale and to the conclusions.
With respect to book chapters, it helps me to create an outline. Then I can write it section by section. The struggle of sequencing the sections and linking them is always the most difficult for me.
Blogging I find easier because the format is shorter. I focus on ‘what’ I want to say, the ‘why’ am I writing this. Who do I hope will read it? Why? What are they hoping to learn.
Today, there isn’t much to learn from my blog. It was best said by Lucy Taylor.
Researchers find immigration to the US changes microbiome. Of course, there are many factors (diet, physical activity, sanitation, etc) but anticipation of today’s mid-term elections are also probably affecting microbiome in many individuals! http://ow.ly/dmLS30mwa7j