Updated: Jun 14, 2019
As you may have noticed, there is a ton of information on nutrition out there. Finding reliable, applicable, maintainable ways to improve or maintain our health can be overwhelming. In today's blog, we are going to try to explain our thought process when we go through research, and give you some take-home points from a major study that was recently published.
(If you don't like reading skip down to this heading: So what can we really take away from this study?)
A study conducted on 195 countries (lots of subjects!) from 1990 – 2017 (long term!) assessed suboptimal diet as a risk factor for disease onset and early death. This study was published in The Lancet, a prestigious, peer-reviewed medical journal (this means that other scientists need to review the research to determine if it is reliable before it gets published...which journal a study gets published in matters).
Published in April of this year, researchers studied adults 25 years of age and older. Using findings from previous studies, 15 dietary risk factors (DRF) were identified. Adults were assessed for their intake of each DRF, and then the effect of each DRF on disease, and the level of intake associated with the lowest risk of mortality (death) was calculated.
We will focus on findings most relevant to our readers (Canadians). For information on how countries around the world performed, you can see the results of the study here.
· Researchers can say with a level of confidence at 95% that in 2017, 11 million deaths and 255 million disease diagnoses across the 195 counties were attributable to DRF (i.e. to diet)
· Cardiovascular disease was the leading contributor to diet related deaths
· Following cardiovascular disease, cancers and type II diabetes were leading contributors of diet related deaths
· More than 5 million diet related deaths and 177 million diet related disease diagnoses occurred in adults younger than 70 years
· The DRFs most connected to early death or the burden of disease are: - high sodium intake - low whole-grain intake - low fruit intake
(remember that this is a global assessment)
· Other DRFS notably associated with death or disease are: - low vegetable intake - low nut/seed intake - low omega-3 fatty acid intake
· High income areas in North America had the highest daily intake of the following unhealthy foods: - processed meat - trans fats
· Globally, these common dietary risk factors were noted: - suboptimal daily intake of healthy foods - higher than optimal daily intake of unhealthy foods, specifically: sugar sweetened beverages (highest in young adults), processed meat sodium red meat - men have higher intake of both healthy and unhealthy foods than women - intake of healthy and unhealthy foods highest in middle aged (50-69 years) adults, and lowest in young (25 -49 years) adults
· It is estimated that improvement of diet could prevent 1 in 5 deaths globally
· It is estimated that improvement of diet could prevent 1 in 5 deaths globally (just thought that was worth repeating)
· Suboptimal diet contributes to more deaths than any other risks, including smoking
· High-middle and middle-income countries had the greatest risk of death and disease from high sodium intake
· High and low-middle income countries had the greatest risk of death and disease from low whole-grain intake
· In low income countries, low intake of fruit was the leading dietary risk factor for death &
· Dietary risk factors affect everybody, regardless of age, sex and sociodemographics
· Non optimal intake of whole grains, fruits, and sodiums contributed to than 50% of deaths and 66% of diseases
LIMITATIONS OF THE STUDY
The limitations of this study include the fact that authors did not look at the effect of other forms of malnutrition, like obesity or undernutrition. Additionally, the evidence supporting a causal relationship between the DRFs and disease was based on observational studies, which is generally a weaker strength of evidence. Due to the large size of the study, and the complexities of gathering nutrition information from a global population, assumptions on various data were made using statistical analysis.
It is important to note that diet is a tough lifestyle factor to assess, because death, disease and our overall health are subject to many other confounding factors.
Note that this was a global study, which means the findings are quite general. Questions must be asked before applying the findings to a specific population. For instance, low fruit intake is cited as a top contributing factor to early death or disease onset; however, can we assume that low fruit intake is likely not a problem in middle class North America?
- Once the DRFs are broken down by sociodemographic, we see that low fruit intake is not as big of a concern for higher income or middle-income regions. So what factors should we be focusing on?
- This study cites high sodium intake and low whole grain intake as the primary DRFs for high-income and low-middle income regions. But this still leads to some questions.
- Does high sodium intake negatively impact everyone, or just those with cardiovascular disease risk factors? Does the source of the sodium play a role (ex. high sodium intake due to fast food consumption vs. high sodium intake due to the addition of salt to whole foods)?
At the end of the day, it is very difficult to point to one dietary factor as the definitive cause of early death or disease. That being said, the authors suggest that it might be more effective to encourage populations to add in the good, rather than omit the “bad” (much like our post from earlier this week suggested). They suggest this because the riskier DRFs identified by this study are lack of certain healthier items, not an over consumption of less healthy items (with the exception of high sodium intake).
So what can we really take away from this study?
Firstly, based on this study and many before it, we are going to take away this idea: stop demonizing fruit. The sugar content of fruit does not have the same impact on your body as the sugar content of, for example, candy (more will be posted on his later). Fruit contains fibre, vitamins, minerals and phytonutrients. Let’s worry less about our fruit intake, and more about the intake of non-whole foods. Unless your health care provider has advised against the intake of fruit or certain fruits, do not fear the fruit! The second idea we are going to take away: whole grains are not your enemy. Carbohydrates have been given a bad rep over the years, and while this idea has its validity it does not necessarily apply to all carbohydrate types. Whole grain carbohydrates are not going to contribute the decline of your health, whereas the overconsumption of carbohydrates, particularly refined/processed ones, may. Whole grains contain vitamins, minerals and fibre, all of which contribute to a healthy body. When eaten in proper proportions and when chosen correctly, carbohydrates from whole grains can positively contribute to your health. Just remember that a serving of whole grains should be about the size of your palm, not the entirety of your plate.
A note on fibre: on average, Canadians are consuming half of the recommended daily fibre intake. Fibre can help regulate blood glucose levels, lower bad cholesterol, and of course, keep you regular. Current research has also shown that fibre can lower your risk of cardiovascular disease and some cancers, such as colon cancer. Remember, fibre comes from vegetables, fruits, and whole grains.
And of course, be mindful of your sodium intake and note that fast food contains excessive amounts of sodium. In summation, nutrition is complex, but eating a diet of whole foods and a variety of plants will contribute to a healthy body. Keep this in mind when choosing a way of eating for weight loss. Our overall health needs to be taken into consideration when choosing a diet or way of eating because weight loss does not necessarily mean better health. In fact, current research has shown that it is possible to be overweight and healthy, with limited impact (if any) on mortality (more will be posted on this later).
While we can lose weight by omitting groups of food, we have to give more consideration to our overall long-term health. Weight loss does not always equal better health. Plant based foods (that includes whole grains) provide a wide range of vitamins, minerals and phytonutrients. Decreasing levels of healthy foods (vegetables, fruits, whole grains, nuts/seeds, omega-3 sources), while increasing levels of unhealthy foods (red meats, processed meats, sodium), appears to have a long-term negative impact on your health.
CFB TAKE HOME POINT
Diet is directly connected to millions of deaths and diseases globally, but that means there’s a silver lining...Diet is within our control. In other words, our health is largely within our control. What you eat matters. And you are in control of what you eat.
Trendy diets may help you lose weight, but weight loss does not always equate to better long-term health. This study suggests there are risks to not eating a well-rounded diet.
In line with the CFB June nutrition challenge, continue to strive for meals that contain: ½ a plate of vegetables palm size serving of carbohydrates (whole grains!) palm size serving of protein (less red and processed meat, more fish and plant- based proteins) thumb-size serving of fat
Remember, we are largely in control of our health (not totally, but largely)! What we do, what we eat…it matters. We hope the review of this long-term global study inspires you to think critically about information you encounter, and to make healthy choices for the rest of your life.