Question 2 - Jenn
When comparing the U.S. RDAs to various international standards (i.e. European and Italian RDA standards), what possible limitations do you foresee when generalizing nutrition research findings to individuals from other countries? For example, all participants from the Bolzetta study were recruited from Italy.
posted by Unknown @ 7:54 AM
11 comments
11 Comments:
I see the challenge in creating universal levels for micronutrients for the elderly population. Most people do have some chronic disease issue by that point in life in America. While in countries, where (seemingly) an unusually high number of people live past 100, a person the same age might not have any issues. With such wide discrepancies in how well people age, based on countries’ dietary culture and other cultural norms, you are looking at apples and oranges at this point in time.
Further, think about a vegetarian versus and omnivorous person, just on iron, and this is within the same country. With the nutrient interactions like competing calcium and iron absorption, tannins in coffee and tea, cultural norms for wine consumption, the ability of a diet very high in fiber to reduce absorption of some nutrients, and bioavailability differences depending on source, it just seems like there are too many confounding variables to make blanket recommendations. Environment plays a very big role in diet; the diet throughout life affects physiological functionality later in life. These are just a few examples.
If we have to specialize things within our own country based on how well the body is working how can we go back and say let’s make blanket recommendations? It sounds tedious, but I think the best research for each country will come from studying the physiological changes and lifestyle changes which would be pertinent for each country.
I agree with Gina about it being like comparing apples and oranges. I mean if you think about it, the RDA is the average amount needed to meet the needs of most "healthy people" of that given population. Can you compare a "healthy" American to a "healthy" Italian to a "healthy" Mexican? I feel as though each of these cultures have their very own view of health. To have a universal RDA level there would need to be a universal view of health, or at least a universal definition of it...and I don't know how realistic or necessary that is.
I don't know if generalizing an individual country's nutrition recommendations as "fit for all of the people in all of the countries" is something I would support, but I do believe that there should be a universal platform for sharing nutritional research and findings so that each individual country can be better informed of any potential "global best practices". A United Nutritional Nations if you will.
The limitation that I can think of is that different countries have different needs based on their cultures, geography, etc. For example, some countries (many European countries) have a high population of smokers. Smokers tend to have an increased need for antioxidants. So in these populations, it may be a recommendation for most "healthy people" of that population to have an increased RDA for vitamins A, C and E. Additionally, perhaps in some countries it's warm year-round, so people are unlikely to wear jackets or cover up their skin more frequently, thus having more exposure to the sun and wouldn't need as much vitamin D from food sources. On the other hand, some cultures have women covered up from head to toe, thus limiting their vitamin D conversion from the sun and would likely need an increased RDA for vitamin D.
I see obstacles of applying the same RDAs for people with different cultural habits or regional differences. However, we can see the same difference among the diverse population in the United States. Therefore, if we can generalize RDAs for the diverse American public, can't we do the same for "general" population worldwide?
Excellent point on the vitamin D. It can even be job related whether you spend all day in an office our outside on a construction site for example. I remember reading something about vitamin A supplementation causing increased mortality in smokers. They do need more vitamin C though. I think Des has it right with the universal platform to share best practices. As RDs it will be our responsibility to translate the available body of knowledge into usable information relevant for our clients and target populations.
As many above have mentioned, I think that the differing cultural norms present the biggest concern for this issue. Food norms vary from state to state let alone from country to country, so when this research is being completed, it is more than likely, for example, an American studying American subjects and these results would more than likely be more pertinent to Americans' nutritional needs than those of another nationality.
I think that Vivian touched on a great example with the Vitamin D. Individuals in more sunny areas of the world year round would have much lower nutritional needs for Vitamin D than a population living in a less sunny environment year round.
I agree with others that food intake will vary significantly from country to country. Food preferences and food availability will differ, but genetics will differ as well. It could be that people from Italy have certain strains of gut bacteria that people from America do not which can affect the breakdown and utilization of vitamins and minerals.
The dietitian at the Community Cancer Center was really knowledgeable about vitamin D. I watched a presentation that she recommended and I learned about an app that lets you know how long you have to be in the sun to get adequate vitamin D. It varies based on geographic location, cloud coverage, percentage skin exposure, time of day, and color of skin. That could be a helpful tool, but probably would not be ideal for reaching the elderly population.
I do not believe it would be appropriate to generalize findings from participants from another country. I definitely think the findings could be helpful and further direct research areas in the United States but making generalized recommendations from one certain population to another might not be useful. Each country has certain cultural norms regarding food and food that is more readily available so there could be a great variance on nutrition implications from country to country.
I do not think it is appropriate to generalize nutrition findings from individuals from another country because the "typical" diet for these countries all vary. The diets vary because of preference and availability and therefore I do not think generalizing nutrition findings from one country to another would be accurate. In addition vitamins and minerals can be lost in the manufactering processes of many foods. Americans typically consume more processed foods than other countries and therefore I would almost think RDAs for Americans would have to consider the amount of these vitmains that are accessible in the American food supply. I think Viv made a great point about climate variation among countries pretaining to vitamin D. I also think Gina brought up an excellent point about how some countries have a heavily plant based diet while others have a more meat based diet. All these factors should be taken into consideration when deciding if research from a study from one country can be generalized to another country.
Abby brought up a great point about different bacteria flora in our guts based on our diets and perhaps other cultural habits. Essentially, I don't think the diet differences between cultures justify why we can't have international nutritional guidelines. Regardless of a person's diet, their needs will be the same. I can have pizza one day and eat sushi the next day. My consumption of vitamins and minerals are different of course, however, my needs remain the same. The difference is that different diets would call for the need to supplement various vitamins and minerals based on the diets. These supplements may be food form via snacks or it could be liquid supplements or pill form. The only vitamin that I can think of that cannot be generalized is vitamin D since we receive amounts from our environment, not from our diets, which would lead to different needs based on geographic location and climate.
I definitely do not think that it would be appropriate to generalize nutritional findings from research studies without taking into consideration each country's unique population characteristics and cultural norms. I agree with Desiray that there most likely seems to be a vast difference between comparisons of "healthy" individuals from different countries as each one is so unique in their way of life. Another issue that I could foresee is the quality of the nation's food supply; whether a particular country receives primarily imported food goods or is self-reliant and relies heavily on a homegrown self-sustaining food supply also counts for something in my mind. I just feel that there are too many variables to consider when generalizing.
I think there would be much value in having all countries have the same nutrition standards. The primary reason I see benefit is because we could more easily draw comparisons between countries. When we do not have the same parameters, it is very difficult to be able to fully compare the nutritional status from country to country. I thought Gina made a very good point about just how helpful it would be for us to be able to evaluate the differences in countries and also pinpoint what environmental factors are correlated. This could help advance other countries who are not faring as well. I also liked the way Des explained how it doesn't really make sense to compare a "healthy" person of one country to that of another. I hadn't even thought about it that way. However, a healthy American could very well be different than what is thought of as a healthy Chinese person for example.
Post a Comment
<< Home