Food Bytes: Weekly Nibbles from Mar 25 - Apr 4

Food Bytes is a weekly blog post of “nibbles” of information on all things food and nutrition science, policy and culture.

This week’s food bytes focuses on the complications of understanding what is a healthy diet because there seems to be much havoc and confusion in the space. The more havoc, the more people want to dissect the havoc or relish in it. And we seemed to be inundated these last two weeks with diet news.

Tamar Haspel is a fantastic food columnist for the Washington Post. There was a lot of twittering and conversation, which she does not shy away from, about her recent article entitled “Here’s what the government’s dietary guidelines should really say.” She hauls the science of nutrition over the coals leaving no one left standing. In her article, she presents two main criticisms. Her first issue is the flawed nature of nutritional sciences. Errors abound in the way diet data is collected, the way observational studies assess impacts of those diets on outcomes, and the ways in which confounding factors are taken into account. Her second issue is the conflicts of interest in nutritional science. She highlights not just perverse industry-funded research, but also, the nutrition experts’ often ideological world views, or “fanatical opinions that abound in nutrition” which shape interpretations of the data in misleading ways. These two issues, the imperfect science and the conflicts of interest, interact and influence each other.

Following her merciless critique, Haspel concludes that “In the two decades I’ve been writing about nutrition, my confidence in what we know about food and health has eroded.” She is not alone. Many people are very confused about what is healthy and what is not. What will kill you and what will keep you alive. What is sustainable, and what will ruin the planet. She is left feeling certain about three simple things: (1) eat a wide variety of foods with their nutrients intact; (2) keep your weight down; and (3) get some exercise. Sounds about right.

Timeline of the nutrition science field

Timeline of the nutrition science field

Do former New York Times writer Mark Bittman and Yale Professor David Katz agree with these sentiments? Largely yes. They argue, “eating well remains difficult not because it’s complicated but because the choices are hard even when they’re clear.” But they have answers. Lots of them. They thought of every question imaginable about diets and health and tried to answer them. Many of the answers are a bit “take my word for it,” but I give them the benefit of the doubt. Although some could wonder why we trust Bittman over credible scientists, but I digress. They argue that future conversations are no longer needed. Yeah, if it were only that easy boys…

Katz also delves deep into why we are eating as if we know less about food than ever before. He argues that humans have been bamboozled by prominent ideologues in the field of nutrition who have built careers defending just one point of view. Similar sentiments to what Haspel highlighted. He argues:

“Where humans practice any reasonable variant on the theme of wholesome foods, mostly plants, in a balanced, time-honored assembly; wherever they eat mostly vegetables, fruits, whole grains, beans, lentils, nuts and seeds, and drink mostly water, they tend to live long, prosper with vitality, and go late and gentle into that good night.  It is not the job of “science” to tear down this established foundation: It is the job of science to build upon it.”

I think what Katz is getting at is that the science of nutrition has come a long way, and there is lot of agreement about the science, but we need to build further on that evidence base. At least, I hope that is what he means. Well-respected Dariush Mozaffarian (Dean and Jean Mayer Professor at the Tufts Friedman School of Nutrition Science and Policy) and colleagues have shown a timeline of the nutrition field and how far the science has come. In the final piece of their timeline - the future - they argue, “Public health future nutrition policy must unite modern scientific advances on dietary priorities with creative new approaches for trusted public communication and modern evidence on effective systems level behavior change.” Trusted public communication. Sounds quite similar to what is being argued by Katz and Haspel. The question is, how do we ensure the science and the way it is communicated by scientists, media and journalists, is trustworthy?

Global Burden of Disease Lancet study: impact of diets on mortality

Global Burden of Disease Lancet study: impact of diets on mortality

But the chug and churn of nutritional sciences continues amidst the havoc. Here are three studies published these past two weeks that show the impact of diets on health, at three different levels: at the dietary pattern/whole diet level, the food group level and the individual nutrient level.

  1. The Global Burden of Disease project out of the University of Washington just published a Lancet paper on the impact of suboptimal diet on noncommunicable disease mortality and morbidity (Full discloser: The Food Archive archiver is an author on this paper). The estimates (and modeled data) show that 11 million deaths and 255 million disability adjusted life years (DALYs) were attributable to dietary risk factors. High intake of sodium (3 million deaths and 70 million DALYs), low intake of whole grains (3 million deaths and 83 million DALYs), and low intake of fruits (2 million deaths and 65 million DALYs) were the leading dietary risk factors for deaths and DALYs globally and in many countries.  

  2. Sabrina Schlesinger and authors published a systematic review looking at the impact of food groups on risk of overweight, obesity and weight gain. They found that increased consumption of whole-grains, fruits, nuts, legumes and fish consumption had a negative association with overweight and obesity. Positive associations were found for refined grains, red meat, and and sugar sweetened beverages and overweight, obesity and weight gain. 

  3. And last, a Nature paper examined the impact of carbohydrate, a macronutrient, quality on health. They argue that the quality of carbohydrate-rich foods (high in fiber and whole grains) rather than quantity has the strongest effect on decreased mortality and reduced incidence of cardiovascular diseases, type 2 diabetes mellitus and colorectal cancer.

Still confused? Everyone is sort of saying the same thing that Michael Pollan said so simply a decade ago, now a mantra for many: Eat food, mostly plants and not too much.

Food Bytes: Weekly Nibbles from Jan 21 - 27

Food Bytes is a weekly blog post of “nibbles” of information on all things food and nutrition science, policy and culture.

Environmental effects per serving of food produced

Environmental effects per serving of food produced

The EAT Lancet Commission report entitled: “Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems” came out this week. It was both praised and demonized but regardless, it made a big splash across many media outlets. I was part of the Commission and I must say, I felt pretty worn out with interviews and podcasts after the first week of its release. So what is the report? It was made up of 37 scientists that came together to do three things: The first was to quantitively describes a universal healthy reference diet that would provide major health benefits, and also increase the likelihood of attainment of the Sustainable Development Goals. The second was to define six scientific boundaries for food systems that would ensure a safe operating space within six Earth systems, towards sustaining a healthy planet. The third outlined five strategies needed for the “Great Food Transformation.” Establishing targets has its benefits but it also breeds controversy. I will write in some detail on the politics of the report at a later date, but for now, the link above has all the deets including a podcast I did with Professor Tim Lang.

On the same week as the EAT Lancet, a paper was quietly published in the New England Journal of Medicine by Andy Haines urging for a renewed focus on climate and health. The authors argue that “climate change is expected to alter…climate-sensitive health outcomes and to affect the functioning of public health and health care systems.” One could argue, we know this, but the fact that it was in a clinical medical journal shows the breadth of how climate change will impact all facets and medical professionals need to be thinking about how this will impact their patient populations, particularly the more vulnerable.

What wasn’t discussed much in the EAT Lancet were “food environments.” These are the places where consumers make a decision about what to buy, order or have delivered. Food environments are markets or cafeterias, or restaurants or food trucks. They look different everywhere. My colleague, Shauna Downs and I published an article in Public Health Nutrition looking at consumers’ perceptions of their food environments and their food consumption patterns and preferences in urban and rural Myanmar. The study shows that the availability of diverse foods had increased over time, while the quality of foods had decreased. Most consumers greatest concern about the foods available was the safety. Consumers preferred fruits, vegetables and red meat compared with highly processed snack foods/beverages. Although consumers reported low intakes of highly processed snack foods, Burmese street food was consumed in high quantities.

One food environment that could improve is the office. A study done by the CDC shows that nearly a quarter of respondents ate food obtained directly at their office. And the foods they ate were not necessarily healthy. Think the leftover pizza, the corporate snack bar, the candy in the jar, the cake for someone’s birthday. The study found that what they officemates ate during work hours was “high in empty calories, sodium, and refined grains, and low in whole grains and fruit.” Shocker? Not really but I do think work places need to stop making it so hard for their colleagues to eat healthy.

Enough with the studies! How about a podcast? A great one has just been started by our friends at NPR. It is called Life Kit and they “help you cut through all the nutrition noise” and provide guidance on how to eat healthy. And there is indeed a lot of noise out there. I listened to three of their podcasts - only about 20 minutes long - and they had some stellar nutrition experts including Dary Mozaffarrian who is the Dean of Tufts Friedman School and Doctors David Katz and David Ludwig. They are great, and I think provide sound advice on nutrition and what to eat. Listen to them on your way to work or even better, while exercising!

And speaking of eating healthy, here is an old video of Andy Warhol, eating a hamburger. Took him about 4 minutes.