The journal Lancet Global Health has released a massive cross-sectional study which will be included in its September 2016 issue. The study is a global inquiry of the relationship between fruit and vegetable affordability, and their consumption. First author Victoria Miller and coworkers found that on average people around the globe are consuming less than WHO’s minimum recommended amounts of fruits and vegetables.
The study reveals the consumption of vegetables and fruits to be directly proportional to their affordability. As affordability increases in high income nations, so did the consumption. While the reverse holds for low income countries.
WHO recommends at least 2 servings of fruit and 3 servings of vegetables daily, the sum total of 5 servings should weigh 400 grams. The amounts of daily consumption of fruits and vegetables were gathered by the decade-long Prospective Urban Rural Epidemiology (PURE) study from 18 countries.
Researchers used PURE’s data and found that in low income countries, the servings averaged to 2.14 per day, while in high income countries, a person’s daily intake was 5.42 servings. Global average was calculated to be 3.76 servings which is below the WHO’s minimum recommendation of 5.
Annually 1.7 million deaths occur due to lack of fruits and vegetables in diet, around the globe. That makes up a significant 2.8% of all deaths annually. A lack of plant derived diet is often the basis of non-communicable diseases, like cardiovascular diseases and type 2 diabetes. The WHO highlights that potatoes and other starchy tubers should not be included when measuring daily vegetable consumption as they are a carbohydrate source.
The criterion for affordability was set by measuring the cost of the recommended amounts of fruit and vegetables, then estimating the percentage this sum equals to with regards to the total household income. Recommended amounts of fruits and vegetables cost a mean 51.97% of the total household income in low income countries and as less as 1.85% in high income countries.
The PURE study data observed food consumption behavior of 143,305 people. The researchers collected the data for household income from 130,402 themselves. The rates of fruits and vegetables were also probed by the researchers themselves as they collected them from 80 communities.
However, that is one of the limitations of this study as the PURE investigation was conducted in 667 communities. At best, these 80 communities can be fair ‘representatives’ of the 667 populations which are in turn supposed to be a representation for the world population.
Secondly, as pointed out by the nutritionist Amanda Lee in a comment paper accompanying the research by Victoria Miller, the serving size that the original PURE scientists used when collecting data was 125 grams. Five of such servings exceed the recommended 400 grams, to 625 grams.
Another important limitation of the study is that it is a cross-sectional one. Because the study collected its data from a single point in time and did not measure the trend of variables throughout the year, it can’t predict how affordability varies. This is especially true for this research because the price of fruits and vegetables are highly season dependent.
The ultimate shortcoming of the research, however, as admitted by the authors themselves and pointed by Amanda Lee again, has to do with the fact this is a cross-sectional study.
Since the study had such a large number of participants in several countries and findings previously unknown, it could have attained a grander position in the world of nutrition.
However, as it can’t be used to infer a temporal behavior of consumption of fruits and vegetables with respect to their affordability, Amanda comments it can’t be used by International Network for Food and Obesity/Non-Communicable Diseases Research, Monitoring and Action Support (INFORMAS) to make their policy.
Amanda further reveals in her comment paper that if the researchers repeat the readings and observe relationship between availability and consumption of fruits and vegetables at another instance, then it can be used as the gold standard by INFORMAS.
Whether it affects INFORMAS or not, this goliath of a research still has global consequences, especially for low income and lower middle income countries. The researchers concluded with their suggestion that there is a “need for policies that expand affordability and availability of these foods, which might improve the diet quality of many populations”.
This study also makes it possible for lower income countries to look at another layer of nutrition, not just regulate the food intake of their population with respect to the minimum daily calorie requirement.
Meanwhile, Amanda concluded her paper suggesting that in cases where the cost of recommended fruits and vegetables made a significant chunk out of the household income, awareness regarding the benefits of fruits and vegetables is of no use when trying to increasing the consumption.