Inflammation and elevated levels of the hormones insulin and estrogen can lead to an increased risk of breast cancer. Meal timing can impact these risk parameters. The thinking is that humans have evolved to eat during the day, when the body is more insulin sensitive, and to fast at night. Eating late at night – particularly large meals – can be detrimental and, along with DNA damage, provides fertile ground for cancer to develop. In this clip, Dr. Ruth Patterson discusses how eating in accordance with the body's natural circadian rhythm may reduce the risk of breast cancer.
Rhonda: Right. So these three factors that are known, the fasting, high-fasting insulin, the high free estrogen...
Rhonda: ...and the high inflammatory markers.
Rhonda: So as measured by certain biomarkers like C-reactive protein.
Rhonda: So these are all associated with, in some, cases even two to threefold increased risk.
Ruth: Yeah, I say definitely twofold and maybe a little bit more. I think that's generally what we...what the metric we use, each one of them increases the risk individually by twofold. Combination wise we don't know, it's probably not quite additive, but they still would have a combined effect too that's, you know, reason to look at all these different pathways. But those are definitely the three major metabolic pathways that we think feed into. Having kind of fertile soil so that when these DNA changes happen, they're in a place where they're kind of like fertile soil and more likely to go to an invasive tumor type.
Rhonda: Okay. And what's so interesting about this is that, your work, so your work and the work of others is showing that these three different biomarkers, let's say, they can be modified by changing your lifestyle pattern.
Ruth: Right. Much of my research lately has focused on timing of meals, which I think is a little bit of a newer hypothesis. We all, you know, evolved to eat during the day when we're out getting our food and then fast at night when we're in a rest state. But now with, you know, modern lighting and with modern lifestyles and short...longer and longer work weeks, you know, our meal patterns less and less resemble the way we evolved to eat. And we believe that it's very metabolically detrimental to eat a lot of energy and then right away lay down. You know, what are you doing? You're laying down, you don't need to have all the energy on board and all that metabolism going on, when actually you should be in a fasting catabolic state.
Rhonda: And most people probably actually eat one of their largest meals in the evening.
Ruth: Right. Which is just so counter...and just even in a common sense way, why do you need all that energy right before you're about to become completely comatose? It makes no sense, right? You really need the energy during the day, you know, when you're busy up walking.
Rhonda: That's a very good point. And I think you also mentioned another important point and that is eating during the day when we're supposed to eat, and timing it with our circadian rhythm.
Rhonda: Which is the biological clock inside of our...every cell we've got a master regulator and different, you know, tissues which we can talk about in a minute. But that master clock, what's interesting is that it does...it...you know, between 10% to 15% of the human genome is regulated by these clocks. And about 50% of those genes are involved in metabolism.
Rhonda: And humans are the most insulin sensitive upon waking, you know, first thing in the morning. And then as the day goes, insulin sensitivity goes down. And so, you know, eating your biggest meal in the evening when you're the most insulin insensitive would increase one of those biomarkers you're talking about.
Ruth: Absolutely, right. Or just metabolically dysregulate you which is what we're trying to have regulated metabolism, and that definitely dysregulates it. And the whole circadian rhythm concept is the idea that, as you mentioned, the master clock is entrained to light, you know, it responds to light. So the master clock's getting the signal, let's say, in the evening, you're done. But if you're eating, the peripheral clocks like in your liver are going, "No, we're waking up, we're getting energy." And we believe that when those two clocks are out of sync that that itself leads to some type of metabolic dysregulation. And we don't have fully metabolic, you know, or molecular understanding of exactly how this works. But it's a pretty solid theory, at least what we've seen in animal research.
A measurable substance in an organism that is indicative of some phenomenon such as disease, infection, or environmental exposure.
Referring to the set of metabolic pathways that break down molecules (such as polysaccharides, lipids, nucleic acids, and proteins) into smaller units to be oxidized to release energy or used in other anabolic reactions.
The body’s 24-hour cycles of biological, hormonal, and behavioral patterns. Circadian rhythms modulate a wide array of physiological processes, including the body’s production of hormones that regulate sleep, hunger, metabolism, and others, ultimately influencing body weight, performance, and susceptibility to disease. As much as 80 percent of gene expression in mammals is under circadian control, including genes in the brain, liver, and muscle. Consequently, circadian rhythmicity may have profound implications for human healthspan.
In a state of deep unconsciousness for a prolonged or indefinite period, especially as a result of severe injury or illness.
A ring-shaped protein found in blood plasma. CRP levels rise in response to inflammation and infection or following a heart attack, surgery, or trauma. CRP is one of several proteins often referred to as acute phase reactants. Binding to phosphocholine expressed on the surface of dead or dying cells and some bacteria, CRP activates the complement system and promotes phagocytosis by macrophages, resulting in the clearance of apoptotic cells and bacteria. The high-sensitivity CRP test (hsCRP) measures very precise levels in the blood to identify low levels of inflammation associated with the risk of developing cardiovascular disease.
Endogenous female sex hormones. Estrogens include estrone, estradiol, and estriol. They promote the development and maintenance of secondary sex characteristics in females. Estrogens regulate the menstrual cycle and play key roles in fertility and reproduction. They influence other aspects of health, too, including cognitive function, bone health, and risk of developing cardiovascular disease and cancer.
A critical element of the body’s immune response. Inflammation occurs when the body is exposed to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a protective response that involves immune cells, cell-signaling proteins, and pro-inflammatory factors. Acute inflammation occurs after minor injuries or infections and is characterized by local redness, swelling, or fever. Chronic inflammation occurs on the cellular level in response to toxins or other stressors and is often “invisible.” It plays a key role in the development of many chronic diseases, including cancer, cardiovascular disease, and diabetes.
A peptide hormone secreted by the beta cells of the pancreatic islets cells. Insulin maintains normal blood glucose levels by facilitating the uptake of glucose into cells; regulating carbohydrate, lipid, and protein metabolism; and promoting cell division and growth. Insulin resistance, a characteristic of type 2 diabetes, is a condition in which normal insulin levels do not produce a biological response, which can lead to high blood glucose levels.
The thousands of biochemical processes that run all of the various cellular processes that produce energy. Since energy generation is so fundamental to all other processes, in some cases the word metabolism may refer more broadly to the sum of all chemical reactions in the cell.
Restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window that begins with the first food or non-water drink) without an overt attempt to reduce caloric intake. TRE is a type of intermittent fasting. It may trigger some beneficial health effects, such as reduced fat mass, increased lean muscle mass, reduced inflammation, improved heart function with age, increased mitochondrial volume, ketone body production, improved repair processes, and aerobic endurance improvements. Some of these effects still need to be replicated in human trials.
Learn more about the advantages of a premium membership by clicking below.
The FoundMyFitness Q&A happens monthly for premium members. Attend live or listen in our exclusive member-only podcast The Aliquot.