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Flaxseed, a Functional Food—Constituents and Their Health Benefits
Published in Robert Fried, Richard M. Carlton, Flaxseed, 2023
Robert Fried, Richard M. Carlton
Serotonin is a substance mainly found in the brain, the bowels and blood platelets. It transmits messages between nerve cells throughout the body and in the brain. Sometimes called the “happy chemical” because it contributes to our feeling of well-being and happiness, it is the precursor for melatonin that helps the body’s sleep-wake cycles and the internal clock. It also plays a role in appetite, emotions and motor, cognitive and autonomic functions.
Sleep Science
Published in Gia Merlo, Kathy Berra, Lifestyle Nursing, 2023
Glenn S. Brassington, Glenn T. Brassington
It is now believed that our sleep–wake circadian rhythm is 10–15 minutes longer than 24 hours, requiring us to reset our internal clock each day. The daily pattern of action of the circadian alerting rhythm is to begin to alert the organism at about 9 a.m. and to increase alertness slowly until 9 p.m. with the greatest alerting effect occurring between 6 a.m. and 9 p.m. The circadian alerting rhythm decreases its action slowly and almost completely withdrawn between 3 a.m. and 6 a.m. Figure 4.2 depicts this process, known as the Opponent Process Model (Edgar, 1993). The “afternoon dip” (i.e., between 1 and 3 p.m.) in energy is associated with the withdrawal of circadian alerting and increasing sleep drive.
Dementia
Published in Henry J. Woodford, Essential Geriatrics, 2022
Sleep: changes in diurnal variation – loss of internal clock. Repeated phone calls in the early hours or wandering outdoors at night. Early morning waking is associated with depression, which may co-exist with or mimic dementia (see Chapter 8). REM sleep disorder (vivid dreams, jerking or thrashing movements during sleep) is associated with DLB (see page 185).
What can we learn from senescent platelets, their transcriptomes and proteomes?
Published in Platelets, 2023
Harriet E. Allan, Ami Vadgama, Paul C. Armstrong, Timothy D. Warner
Platelet senescence has been described in a number of studies and is in general terms a physical state that platelets adopt before their clearance by the reticuloendothelial system.15–18 The mechanisms governing platelet senescence are still being investigated, with two proposed processes: a “multi-hits” process and intrinsic internal timer process.16 The first of these suggests that platelets accumulate various damages as they circulate until they reach a threshold for their clearance.17 More recent research, however, has implied that platelets are released from the precursor megakaryocyte with a predefined internal molecular clock influenced by the anti- and pro-apoptotic proteins, BCL-XL and Bak.16 While there is compelling evidence for this latter process to be more important, the ultimate trigger or triggers regulating the timing of the internal clock need to be investigated further. Further, under certain pathological conditions, the presence of exhausted platelets has been demonstrated, which may contribute to overall platelet dysfunction. Indeed, in such circumstances exhausted platelets may arise from chronic stimulation, potentially accelerating the rate of aging and thereby taking on “senescent” phenotype.19–21
The relationship between chronotype and obesity: A systematic review
Published in Chronobiology International, 2023
Evening chronotypes have shown significantly higher body weight and BMI values than the morning chronotypes (Ruiz-Lozano et al. 2016). A large-scale epidemiological study has reported that social jetlag is associated with increased BMI (Roenneberg et al. 2012). Social jetlag has been associated with obesity and adverse metabolic symptoms commonly found in obese individuals (Parsons et al. 2015). Moreover, social jetlag has been shown to be associated with an unhealthy diet and late meal timing (Mota et al. 2019). Furthermore, high levels of social jetlag have been associated with obesity (Li et al. 2022). It has been reported that living against one’s internal clock may be a factor that contributes to the obesity “epidemic” (Parsons et al. 2015). In the literature, sleep deficiency, evening chronotype and social jetlag have been shown to be associated with obesity (Ali et al. 2020; Krueger et al. 2023; Martínez-Lozano et al. 2020; Zhang et al. 2022). Social jetlag leads patients to have frequent nocturnal eating behaviors (Ali et al. 2020). It has been reported that eating late hours is associated with lower weight loss (Cossec et al. 2021).
Environmental light exposure and mealtime regularity: Implications for human health
Published in Chronobiology International, 2022
The significance of meal timing is tied to the body’s internal clock and its profound role on metabolism. Mealtime is regarded as one key area to explain the obesity and metabolic syndrome incidence among individuals with reduced energy intake (Oda 2015). Food and the associated nutrient intake at various points of the day are considered as one of the main synchronizers of the master clock and organ clocks (Escobar et al. 2009; Oda 2015). For instance, an animal study demonstrated that glucose intake and amino acid synchronized the SCN and liver clock, respectively (Iwanaga et al. 2005). Furthermore, the rhythms and processes of the digestive system are affected when meal timing is reversed (Oda 2015). Another animal study demonstrated that irregular eating style leads to abnormalities in the liver clock and greater cholesterol levels, even when the amount of food intake is similar (Yamajuku et al. 2009). The author concluded that regular daily meals normalize the liver clock genes, improving cholesterol homeostasis and lipid profile.