Gut microbiome science (or non-science)

Anna Maria Barry-Jester – Is Gut Science Biased?:

The vast majority of data on microbiomes across science is still mostly coming from people in the U.S., Canada and Europe, and having too narrow a sample of the population means we could be looking at the proverbial trees when what we need to understand is the whole forest.

Much of what we know about gut microbiomes is biased towards what can be easily measured – the guts of people in the western world. I’d take articles touting the benefits of this or that diet on gut microbiome with a grain of salt.

Gluten free diets aren’t quite what most people think they are

Norelle R. Reilly recently published an article in the Journal of Pediatrics – The Gluten-Free Diet: Recognizing Fact, Fiction and Fad:

Gluten-free packaged foods frequently contain a greater density of fat and sugar than their gluten-containing counterparts. Increased fat and calorie intake have been identified in individuals after a GFD. Obesity, overweight, and new-onset insulin resistance and metabolic syndrome have been identified after initiation of a GFD. A GFD also may lead to deficiencies in B vitamins, folate, and iron, given a lack of nutrient fortification of many gluten-free products.

Uh-oh. Not good for those people who are gluten-free for non-celiac reasons.

There is emerging evidence that those consuming gluten-free products without sufficient diversity may be at greater risk of exposure to certain toxins than those on an unrestricted diet. Arsenic is frequently present in inorganic form in rice, a concern for those on a GFD given that rice is a common ingredient in gluten-free processed foods.

A constant worry for us, since much of our diet is rice-based. Maybe 80% or so.

There also are noteworthy non-nutritional implications of a GFD. Worldwide, those purchasing gluten-free products will encounter far greater food costs than gluten containing competitors. Social isolation and inconvenience have been reported by children with CD requiring a GFD, and some with CD report a deterioration in their quality of life while on a GFD, linked in many cases to the diet itself.

We are lucky to be able to afford the time and expense of making much of our food from scratch in order to keep it as safe as we can from allergens. But it’s another worry for us in the future as our son grows up.

Added sugar labelling!

That exclamation point is not an accident. I’m looking forward to this. From the FDA:

Today, the FDA has finalized the new Nutrition Facts label on packaged foods with changes that will make it easier for consumers to make informed choices about what they’re eating.

Some groups aren’t too happy with the change:

The Sugar Association is disappointed by the Food and Drug Administration’s (FDA) ruling to require an “added sugars” declaration and daily reference value (DRV) on the Nutrition Facts Label (NFL). The extraordinary contradictions and irregularities, as well as the lack of scientific justification in this rulemaking process are unprecedented for the FDA.

But the FDA says:

And you can have confidence in the science on which it is based, including evidence used to support the Dietary Guidelines for Americans, nutrition intake recommendations from the Institute of Medicine, and nutrition intake information from the National Health and Nutrition Examination Survey (NHANES).

Whose interpretation of science is correct? Well, the Sugar Association is likely a little biased.

Fat vs sugar

Ian Leslie at the guardian – The sugar conspiracy:

The UN’s Food and Agriculture Organisation, in a 2008 analysis of all studies of the low-fat diet, found “no probable or convincing evidence” that a high level of dietary fat causes heart disease or cancer. Another landmark review, published in 2010, in the American Society for Nutrition, and authored by, among others, Ronald Krauss, a highly respected researcher and physician at the University of California, stated “there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD [coronary heart disease and cardiovascular disease]”.

Many nutritionists refused to accept these conclusions. The journal that published Krauss’s review, wary of outrage among its readers, prefaced it with a rebuttal by a former right-hand man of Ancel Keys, which implied that since Krauss’s findings contradicted every national and international dietary recommendation, they must be flawed. The circular logic is symptomatic of a field with an unusually high propensity for ignoring evidence that does not fit its conventional wisdom.

Exercise times on food labels?

Shirley Cramer, chief executive of the Royal Society for Public Health – Food should be labelled with the exercise needed to expend its calories:

The Royal Society for Public Health has called for the introduction of “activity equivalent” calorie labelling, with symbols showing how many minutes of several different physical activities are equivalent in the calories expended to those in the product. The aim is to prompt people to be more mindful of the energy they consume and how these calories relate to activities in their everyday lives, to encourage them to be more physically active.

As reported by the CBC, not everyone is a fan of this approach:

Not everybody is sold on the idea. Dr. Yoni Freedhoff is the medical director of the Bariatric Medical Institute in Ottawa.

“People believe that exercise is the ticket to the weight loss express,” he said.

But, in fact, exercise doesn’t burn that many calories.

I believe Dr. Freedhoff is correct. Labelling foods with exercise equivalents is not the right message, and mixes up the idea of weight loss with exercise, when they are not well linked at all.

From what I’ve been reading, exercise is key for reducing your risk of dying early due to cadriovascular disease. With better fitness you also reduce your risk of physical injuries. However, the amount of exercise you do is not well correlated to your weight. Meaning that you cannot realistically exercise enough to reduce your weight if you are consuming the same amount of calories.

Generally:
– More exercise => better fitness and live longer
– Fewer calories => lose weight

See Dr. Freedhoff’s talk on the issue:

Canadian Senate Report on Obesity – on sugars

From page 6 of the report:

Sandra Marsden of the Canadian Sugar Institute testified that sugar consumption has declined in recent years, however, as that organization represent the sucrose industry (the sugar extracted from beet and sugar cane), this decline seems to be only associated with sucrose and not all sugars combined.

(Zing!)

The Canadian Sugar Institute says the estimated added sugars* consumption in Canada is approximately 51 – 53 g per day.

A number of witnesses also told the committee that sugary beverages are the primary source of added sugar in our diet and are the primary driver of obesity. They noted that these beverages have little or no nutrient value while being calorie-rich. Further they indicated that these are ‘invisible’ calories as they do not contribute to satiety and are simply added calories over and above food intake. Some witnesses offered testimony that sugar is addictive and that it promotes overconsumption.

Addictive? Interesting.

From page 12 of the report:

At the same time, Manuel Arango, of the Heart and Stroke Foundation of Canada, indicated that as much as 62% of the Canadian diet can be categorized as highly-processed, a percentage that has been rising in recent decades at the expense of whole foods. As a consequence of the increased intake of highly processed foods, sugar consumption has increased dramatically from 4 bounds annually per person 200 years ago to 151 pounds annually per person today.

151 pounds per person is huge. That’s nearly 1 cup of sugar per day. I’m not sure where they get that figure.

The Heart and Stroke Foundation of Canada’s position statement on sugar cites that total sugar intake is 110 g per day, or about 1/2 cup per day.

As mentioned previously, Health Canada’s proposed limit is 100 g per day of total sugars.

Footnotes:
*"Added sugars" is defined as follows:

Sugars and syrups (Statistics Canada Category - Sugar and sugar syrups (from sugar cane or sugar beets), maple sugars, honey. Does not include corn sweeteners.
Corn sweeteners: high fructose corn syrup ("glucose-fructose"), glucose syrup, and dextrose.
Fruit juce/concentrated fruit juice or other ingredients that act as a functional substitute for added sugars.

 

Report on Health in Children in Canada

Public Health Agency of Canada publication, published February 24, 2016 – Health Behaviour in School-aged Children in Canada: Focus on Relationships:

Key Finding #11: Healthy Eating

While some concerning dietary habits were reported, there were also some positive findings with respect to healthy eating.

Almost half (46%) of boys and more than one third (37%) of girls reported eating neither vegetables nor fruits once per day or more, while 34% of boys and 42% of girls reported eating both fruits and vegetables once per day or more. Some of these behaviours may be attributable to the food environments that surround young people and the availability and affordability of fruits and vegetables. More positively, reports of soft drink and candy consumption have decreased over time, and reported daily consumption of potato chips, diet soft drinks, and energy drinks was quite low. This lower frequency of consumption was consistent with the Canada Food Guide recommendations on reducing the intake of foods high in fats, sugar, sodium, or calories.

Boys and girls aren’t eating enough fruits or vegetables, but at least they have reduced their consumption of sugary drinks and snacks.

Key Finding #12: Healthy Weights

The epidemic of overweight and obesity is not declining in young Canadians.

Approximately 1 in 3 boys and approximately 1 in 4 girls were classified as overweight or obese by Body Mass Index (BMI; calculated from self-reported height and weight). Up to 25% of girls and 10% of boys were, or thought they should be, on a diet to lose weight. The percentage of young people who perceived that their body was too fat has increased from 28% in 2002 to 32% in 2014. Despite ongoing public health efforts, the prevalence of youth obesity, and the behaviours and feelings surrounding it, remain high and have increased over time.

We need to teach kids about growing food, cooking food and eating food, healthfully.

Food deserts

Julie Beck at The Atlantic – The Instagrams of Food Deserts:

In every region of the United States, the foods shown in Instagrams posted from food deserts had higher cholesterol, sugar, and fat than the posts from non-food deserts. Popular foods differed by region: In the southeast U.S., food-desert dwellers posted a lot of bacon, brisket, and grits, while non-food-desert dwellers posted more peaches, beans, and collard greens. In the Midwest, food deserts were full of hamburgers, hot dogs, and the generic descriptor “meat,” while kale, turkey, and spinach were more popular outside of food deserts.

 

Canadian Senate report on obesity – first thoughts

The Canadian Senate report – Obesity in Canada – A While-of-Society Approach for a Healthier Canada was released last week:

There is an obesity crisis in this country. Canadians are paying for it with their wallets — and with their lives.

Harsh and sobering. The infographic is good.

Among the more controversial recommendations:

  • Consider a tax on sugar- and artificially-sweetened drinks
  • Ban the advertising of food and beverages to children
  • Immediately update the food guide without industry influence

Sugar Tax?

The Canadian Taxpayer Federation and the Canadian Beverage Association both denounce the recommended sugar tax, claiming that it doesn’t work. Three comments:

  1. The discussion and promotion of such a tax is very helpful and brings some awareness to the issue of high sugar consumption, whether the tax is implemented or not.
  2. We need to look at the sugar content of all processed foods and see if such a tax should be expanded to cover foods with added sugars/sweeteners, natural or artificial. Even foods such as fruit juices, which give us the liquid without any of the fibre of the fruit, need to be reviewed for inclusion.
  3. As with salt, we need guidelines on the recommended maximum daily intake of added sugars, and the report suggests this in the text.

The CBC hosted a short forum discussion on the sugar tax last week.

Restricting food advertising to children

As for advertising, currently the Quebec Consumer Protections Act protects children (under the age of 13) from any commercial advertising:

248. Subject to what is provided in the regulations, no person may make use of commercial advertising directed at persons under thirteen years of age.

1978, c. 9, s. 248.

249. To determine whether or not an advertisement is directed at persons under thirteen years of age, account must be taken of the context of its presentation, and in particular of

(a) the nature and intended purpose of the goods advertised;
(b) the manner of presenting such advertisement;

(c) the time and place it is shown.

The fact that such advertisement may be contained in printed matter intended for persons thirteen years of age and over or intended both for persons under thirteen years of age and for persons thirteen years of age and over, or that it may be broadcast during air time intended for persons thirteen years of age and over or intended both for persons under thirteen years of age and for persons thirteen years of age and over does not create a presumption that it is not directed at persons under thirteen years of age.
1978, c. 9, s. 249.
The Senate report calls for a study on the effects of this restriction in Quebec, and for implementation of a similar restriction for all of Canada.

Updating the food guide

The call for updating the food without industry influence is fantastic. I’m not sure how realistic this could be, since many non-industry researchers in academia are funded by industry, so does this mean they can’t be involved? The removal of politics from the food guide is one of the questions I’ve always had, in light of the huge ‘push’ for milk/dairy products as our main recommended calcium intake method.

On contradictory food studies

Paul Taylor at the Globe and Mail – Why do researchers churn out so many contradictory food studies?:

Food studies frustrate me. One week a study says one thing. The next week another study says the opposite. Why do researchers churn out so many contradictory studies – and why does the news media keep covering them?

Taylor covers the various research methods well, but doesn’t discuss the media’s culpability in promoting findings that aren’t really there.

Dr. Donald Redelmeier gives good advice:

For that reason, Redelmeier says the best thing to do is focus on having a lot of variety in your diet – “everything in moderation” – and don’t get distracted by contradictory studies and the latest food fads.