What Has 100 Years of Nutrition Science Taught Us ?

Vitamin Synthesis

Like any other sciences, the study of nutrition has evolved over time; however, it is still in it’s infancy. Some of the first discoveries in the field of nutrition were the identification and synthesis of vitamins such as vitamin B12 and vitamin C (identified on a sailing ship in 1930s to cure scurvy). This led to a new tactic of fortifying staple foods to prevent deficiencies such as rickets, goitre and anaemia. We can still see many cereal products being fortified with iron, calcium and other specific vitamins today. This is interesting to note as these nutritional scientists understood the danger of developing these deficiencies, therefore, they aimed to prevent them from happening.

Recommended Daily Allowance

With the threat of the second world war, scientists began to look into calories, protein, fats and sugar in a similarly isolated way to create the basis for the ‘recommended daily allowance’ (RDA) that we are familiar with today to prevent malnutrition in populations. RDA’s were created with the insight to decrease deficiencies by encouraging the population to take in the upper limits of these nutrients. These new guidelines were announced in 1941 at the National Nutrition Conference on Defence. This set the benchmark for public policy and nutrition research which we know today.

Whole Dietary Patterns

Following, there was a shift in the perspective of nutrition when scientists shifted from single nutrient experiments and began looking at dietary patterns of the population. This strategy encouraged scientists to look at the complex interactions between nutrients and the biological effects they have in the body. The basis of this shift was that we do not consume single nutrients, but instead we eat an array of food holding a variety of nutrient benefits. Importantly, they began to distinguish between types of nutrients such as the quality of carbohydrates (glycemic index and fibre content), the type of protein being consumed, additives (sodium) and the preparation of food. The reductionist view of nutrition has shifted to a more holistic view of the overall dietary pattern of the population.

However, the issue with researching entire dietary patterns is the difficulty in studying them. In terms of the type of experiments that can be run it is rather limiting. Randomized control trials (fn1) are seen as the gold standard of hypothesis testing in science. Participants are restricted to strict parameters to ensure that the experiment tests exactly what the scientists are hoping to test. The issue with this type of testing when it comes to nutrition is, it is very difficult to completely control a participant's entire diet. If they do manage to do it, it is very costly and strenuous on the researchers. Therefore, many trials seek to use surveys and observation studies to seek answers. This is problematic when you rely on human memory or trust that people will tell you the truth as it is never usually that easy. This makes understanding how entire dietary patterns affect individuals very difficult.

Interpreting new scientific research

Finally, there is much controversy over who funds these projects. Generally, these projects are not free and there are many costs involved especially when you are running long-term, comparative studies (the best we can hope for). The money needs to come from somewhere. Many institutions or governing organizations offer funding to these types of projects but only if they are interested in their results or if there is a need for this research. Alternatively, large food organizations can fund research that they are interested in or that might affect their business. Obviously, this is a serious conflict of interest as the people who are supplying the funding, may have a say in how the results of the study are interpreted. Unfortunately, many large corporations use this shortcut to acquire the ‘scientific backing’ that they need to make a claim on their product or launch a new project, when it is not necessarily true.

Therefore, the information we receive from these studies must be dissected in a detailed way and viewed from an unbiased lens. ‘Don’t believe everything you read’ comes to mind and a much more detailed examination is necessary to understand the full story.

Nutrition policy and the future

The final chapter of our nutrition history brings us back in a circular way to prevention strategies that we say in the early 20th century. The growing burden of obesity and malnutrition on health systems has seen a shift from secondary prevention measures to primary prevention of the obesity epidemic. There is a call for governments to improve nutrition policies in countries for the benefit of their countries population. This approach, in conjunction with increased nutrition research and effective communication with the population will see effective systemic changes. Nonetheless, there is an abundance of other factors to also be considered including economic issues, food insecurity, education and supply especially in low-income countries. I am confident that 100 more years of nutrition research and policy will see an impactful change on the health of our populations.

Footnote

Randomized control trials are considered to be the gold standard of scientific testing. It is used to compare groups to one another under strict rules. There is usually an ‘experiment’ group who might adopt the new idea (eg. only eating fruit for breakfast) and a ‘control’ group, who do not change anything. These groups are monitored and tested before, after and usually numerous times throughout the experiment to compare and contrast results.

References

Mozaffarian D, Rosenberg I, Uauy R. History of modern nutrition science—implications for current research, dietary guidelines, and food policy BMJ 2018; 361 :k2392 doi:10.1136/bmj.k2392