Lets take a trip back in time a few years to 2015 and discuss a research article published in the journal PLoS One titled "Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk."
In this article the authors were exploring a relationship between how often we eat, how many night-time calories we eat and the likelihood of cancer (which in this study was breast cancer). At first glance one might say... how can that possibly be related. Well let us dive into the research presented in this article and gain a better understanding!
Relationship Between Timing Of Eating and Cancer?
Cancer, often times we think of this as one monolithic disease, however it's actually a blanket term for a variety of different but related disorders that all center around uncontrolled cellular division and growth. How could this set of diseases be related to when we eat? Well the answer to that question potentially lies in inflammation. Inflammation is, if you really boil it down, just our body turning up our immune system functioning. It can occur for a variety of reasons (like a virus, or bacterial infection, or an allergen).
There is a growing body of literature which has been linking cancer, in part, to low levels of inflammation in the body. [3] Inflammation is a common symptom of a variety of other disorders which ARE linked to cancer (Diabetes for example). [4] Where the authors of today's article site previous lab work showing that tumors generally form in cells of a tissue that are inflamed. [5]. Further more, still other studies have shown a relationship between a protein called a c-reactive protein, which is a marker for inflammation, and breast cancer. [6]
Most of you are likely aware that inflammation is influenced by the things we eat, but that is not the topic of discussion for today. Today we are taking a look at the effect WHEN we eat has on our bodies. It may surprise some of you but there is precedent in the literature from animal studies that show differing levels of inflammation relating to how many of times an animal ate throughout the day.[8] The researchers found that by placing the animals on a feeding-fasting regimen (IE only eating for an 8 hour window during the day, and fasting the remainder of the time). It was also shown that mice seemed most effective when synchronized with the animals sleep wake cycle (having the 8 hour window for eating when the animal was typically awake, rather than during a period when they would normally be sleeping). [9] Unfortunately the authors report that human studies do not seem to be able to replicate the information observed in the animal models. [11] (though perhaps newer research has changed this finding?)
What Were The Authors of Today's Study Looking At?
Data from a 2009-2010 nutrition survey done by the US National Center for Health Statistics. This study considered data from 2650 women who both extensively recorded their diets, as well as had a physical workup performed by a physician.
Using this data the authors looked at how the way those women ate influenced the bio-markers that were analyzed (fasting blood glucose, C-Reacive Protein levels). This allowed the authors to look for associations between diet (and WHEN/HOW OFTEN the women ate) and the aforementioned indicators for diabetes (blood glucose) and inflammation (C-Reactive Protein).
What Did They Observe?
On Average The Women:
- Were 46.8 years old
- Fasted for 12.4 hours per night
- Ate 4.7 times per day
The authors reported some tests from their statistical analysis of the data and found that eating more times per day correlated to an increase in the amount of calories consumed in the evening (p< 0.001), and they found that increase in the night time fasting duration was inversely correlated (meaning if it went up then the other statistic went down) with night time calorie consumption (p< 0.001).
This all makes logical sense. (People who eat more times are more likely to eat in the evening, and fast for a shorter period of time)
They identified some interesting statistical relationships from the data as well:
- Eating frequency was inversely correlated with C-Reactive Protein levels (one additional meal resulted in 8% Less C-Reactive Protein, p=0.03)
- Eating 10% more calories at night resulted in a 3% increase in C-Reactive Protein levels (p = 0.02).
- Women who ate fewer than 30% of their calories in the evening had LOWER C-Reactive Protein levels then those who ate more calories in the evening. (Each additional hour of fasting = 8% lower concentration of C-Reactive Protein)
-None of the fasting information correlated with insulin resistance (in relation to blood glucose concentrations and diabetes).
What Conclusions Do They Draw From This/What Does This Indicate?
Evening calorie intake is associated with increased levels of inflammation (based on the relationship with the C-Reactive Protein, a bio-marker for inflammation). Interestingly the C-Reactive Protein is also a bio-marker for an increased risk of developing breast cancer.
The authors reported that the association between the C-Reactive Protein was independent of other lifestyle choices.
The authors suggest that this data is indicative that meal timing may result in the increased inflammation. They postulate that eating at the wrong time in the sleep wake cycle (later in the evening) could disrupt the sleep wake cycle and this may lead to increased inflammation.
Indeed, they report, there is some evidence in the literature that genes associated with inflammation are expressed more if the sleep wake cycle gets disturbed. [8].
They conclude that:
[The] results of this study suggest that reducing evening energy intake, eating more frequently, and fasting for longer nightly intervals (when fasting is initiated early in the evening) may reduce systemic inflammation in the body which could subsequently reduce breast cancer and chronic disease risk.
However they are careful not to make any BOLD claims and state that these associations require further study (randomized clinical trials) to truly show that changing meal frequency significantly influences inflammation. However if their data is eventually confirmed it would be strong evidence that it is a smart idea to limit the amount of calories we consume in the evening.
It's quite fascinating to me that there is such a relationship! What do you think about this? Are you surprised that eating in the evening could very well lead to greater inflammation and possible health issues?
Answering Our Title Image Question
Does eating more times per day reduce your chance of getting cancer? Possibly (there data shows a slight reduction in inflammation levels with increased number of meals). However eating more, later in the day may very well increase your chance. It seems that as is often the case with biology and our bodies. There is just a lot more to this, then one might initially expect.
Sources
Text Sources
- http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136240
- https://en.wikipedia.org/wiki/Inflammation
- http://www.nature.com/nature/journal/v420/n6917/full/nature01322.html
- http://www.jci.org/articles/view/JCI29069
- https://www.ncbi.nlm.nih.gov/pubmed/11866137
- http://cancerpreventionresearch.aacrjournals.org/content/6/3/188
- https://www.drweil.com/health-wellness/body-mind-spirit/heart/elevated-c-reactive-protein-crp/
- http://www.cell.com/cell-metabolism/fulltext/S1550-4131(12)00189-1
- https://academic.oup.com/nutritionreviews/article-abstract/72/5/308/1933482/Time-restricted-feeding-and-risk-of-metabolic
- https://sleepfoundation.org/sites/default/files/SleepWakeCycle.pdf
- http://jandonline.org/article/S2212-2672(15)00205-1/fulltext
Image Sources
All Non Cited Images Are From Pixabay.com, Flickr.com, Pexels.com, or Wikipedia.com And Are Available For Reuse Under Creative Commons Licenses
Any Gifs Are From Giphy.com and Are Also Available for Use Under Creative Commons Licences
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