(Press-News.org) Exposure to natural light could help treat and prevent type 2 diabetes, new research being presented at the annual meeting of the European Association for the Study of Diabetes (EASD) in Hamburg, Germany (2-6 Oct), suggests.
“The misalignment of our internal circadian clock with the demands of a 24/7 society is associated with an increased incidence of metabolic diseases, including type 2 diabetes,” says Ivo Habets, of Maastricht University, Maastricht, the Netherlands, who co-led the research. “Natural daylight is the strongest zeitgeber, or environmental cue, of the circadian clock but most people are indoors during the day and so under constant artificial lighting.
“We were interested in whether increasing daytime exposure to natural light would improve blood sugar control in individuals with T2D.
“We also wanted to know if it would affect their substrate metabolism or nutrient use. This usually follows a 24-hour rhythm, with the body switching from using carbohydrates as its source of energy during the day, to fat at night. We'd previously shown that people at higher risk of type 2 diabetes are less able to make this switch and we wanted to find out if exposure to natural light would make the switch over easier in people who already have diabetes.”
To explore this, Mr Habets and colleagues in the Netherlands and Switzerland carried out a range of metabolic tests on a group of people with T2D when they were exposed to natural light and when they were exposed to artificial light and compared the results. The 13 participants (average age:70 years, BMI: 30.1kg/m2, HbA1c: 6.1, fasting plasma glucose: 8.1mmol/L) stayed in research facilities, which allowed their light exposure, meal and activity patterns to be tightly controlled.
They were exposed to two lighting conditions during office hours (8am to 5pm) in a randomised cross-over fashion: natural daylight from windows and artificial LED lighting. There was a gap of at least four weeks between the two interventions, each of which lasted 4.5 days.
During the natural daylight intervention, the light intensity was usually highest at 12:30pm, with an average reading of 2453 lux. The artificial light was a constant 300 lux.
Evenings were spent in dim light (less than 5 lux) and the sleeping period (11pm to 7am) in darkness. The participants were provided with standardised meals, meaning they ate the same food in both interventions. Blood sugar levels were continuously recorded by monitors worn on the upper arm and a range of other tests were performed on the final day and a half of each intervention.
On day 4, 24h substrate metabolism, resting energy expenditure and respiratory exchange ratio (this provides an indication of whether fat or carbohydrates are being used as the source of energy), were measured every five hours and blood was taken assess circulating metabolites. Core body temperature was measured for 24h. Substrate metabolism, resting energy expenditure, respiratory exchange ratio and core body temperature all follow a 24-hour rhythm and the researchers wanted to see if this differed in the two conditions.
On day 5 (the final half day), a fasted muscle biopsy was taken to assess clock gene expression – the activity of genes known to be involved in the circadian clock. A mixed meal test (MMT), a measure of insulin production, was then carried out.
Blood glucose levels were within the normal range (4.4-7.8 mmol/L) for longer during the natural daylight intervention than in the artificial light intervention (59% of the 4.5 days vs 51%).
The respiratory exchange ratio was lower during the daylight intervention than during the artificial light intervention, indicating that the participants found it easier to switch from using carbohydrate to fat as an energy source when exposed to natural light.
Per1 and Cry1, genes that help control circadian rhythms, were more active in natural light than in artificial light.
Resting energy expenditure and core body temperature followed similar 24-hour patterns in both light conditions. Serum insulin levels, measured during the MMT, were similar in both light conditions but the pattern of serum glucose and plasma free acids was significantly different between conditions.
The results, particularly the better blood sugar control, during the natural light invention, suggest that exposure to natural daylight is beneficial to the metabolism and so could help with the treatment and prevention of type 2 diabetes and other metabolic conditions, such as obesity, says Mr Habets.
He adds: “Our research shows that the type of light you are exposed to matters for your metabolism. If you work in an office in almost no exposure to natural light, it will have an impact on your metabolism and your risk or control of type 2 diabetes, so try to get as much daylight as possible, and ideally, get outdoors when you can.
“Further research is still needed to determine the extent to which artificial light affects metabolism and the amount of time that needs be spent in natural light or outdoors to compensate for this.”
Notes to editors:
718 at the annual meeting of the European Association for the Study of Diabetes (EASD). Note the authors have provided updated data and have thus updated the abstract below. The material has been peer reviewed by the congress selection committee. There is no full paper at this stage, but the authors are happy to answer your questions. The slide presentation to go with the abstract will not be ready until the congress.
Exposure to daylight rather than artificial light improves blood sugar control and nutrient use in individuals with type 2 diabetes, small Dutch study finds
ELSE PRESS RELEASES FROM THIS DATE:
Shorter course of radiation therapy is safe for patients with early-stage breast cancer who have undergone mastectomy and reconstruction
Boston – Researchers at Dana-Farber Brigham Cancer Center have found that a shorter course of radiation therapy after mastectomy and breast reconstruction surgery provides the same protection against breast cancer recurrence and equivalent physical side-effects but substantially reduces life disruption and financial burden for patients. The results of the multicenter randomized clinical trial – the FABREC Study (Hypofractionated versus Conventionally Fractionated Postmastectomy Radiation Therapy After Implant-Based Reconstruction) – were presented ...
Short-course radiation as effective as standard treatment for patients who opt for breast reconstruction after mastectomy
SAN DIEGO, October 1, 2023 — In a first-of-its-kind study, people with breast cancer who underwent implant-based breast reconstruction immediately following a mastectomy reported that getting fewer, higher doses of radiation was just as effective as standard radiation, did not increase side effects and saved them time and money. There also was a small improvement in quality of life for women under 45 who received the shortened treatment regimen. The FABREC study is the first prospective randomized study comparing quality-of-life and clinical outcomes following accelerated versus conventional radiation therapy specifically for patients with ...
Sexual activity and vaginal dilation associated with fewer side effects after cervical cancer treatment
SAN DIEGO, October 1, 2023 — People who engage in sexual activity or vaginal dilation after chemoradiation treatment for cervical cancer are at lower risk for long-term side effects, according to a new study from researchers in Austria. Findings of the EMBRACE study will be presented today at the American Society for Radiation Oncology (ASTRO) Annual Meeting. “Curing cancer is always our first priority,” said lead study author Kathrin Kirchheiner, MSc, PhD, a clinical psychologist in the department of radiation oncology at the Medical University of Vienna. “But with a growing number of relatively young cervical cancer survivors, ...
High-dose radiation offers new treatment option for older patients with inoperable kidney tumors
SAN DIEGO, October 1, 2023 — Older adults diagnosed with kidney tumors that are not suitable for surgery may benefit from targeted, high-dose radiation, a new study from Australian and Dutch researchers suggests. A multi-institutional phase II study – TransTasman Radiation Oncology Group (TROG) FASTRACK II – found 100% local control and cancer-specific survival for longer than three years among patients who were treated non-invasively for inoperable kidney cancer with stereotactic ablative body radiotherapy (SABR). Findings will be presented today at the American Society for Radiation Oncology (ASTRO) ...
Liquid biopsies can rapidly detect residual disease following cervical chemoradiation, study finds
SAN DIEGO, October 1, 2023 — Two liquid biopsy tests that look for the presence of human papillomavirus (HPV) in the blood accurately identified patients with a high risk of cervical cancer recurrence after the completion of chemoradiation, a new study confirms. Findings will be presented today at the American Society for Radiation Oncology (ASTRO) Annual Meeting. The study compared two novel tests – a digital polymerase chain reaction (dPCR) test and a sequencing test for genetic material from HPV, the main cause of cervical cancer – and found they were equally effective at identifying residual disease in the blood of patients who ...
Metaphors for human fertilization are evolving, study shows
New Haven, Conn. — In a common metaphor used to describe human fertilization, sperm cells are competitors racing to penetrate a passive egg. But as critics have noted, the description is also a “fairy tale,” rooted in cultural beliefs about masculinity and femininity. A new study by Yale sociologist Rene Almeling provides evidence that this metaphor remains widely used despite the profound shift in recent decades in social and scientific views about gender, sex, and sexuality. But her findings, based ...
Study suggests threshold for type 2 diabetes diagnosis in women under 50 years should be lowered
New research to be presented at this year’s Annual Meeting of the European Association for the Study of Diabetes (EASD) in Hamburg, Germany (2-6 October) and published in the journal Diabetes Therapy suggests that the diagnosis threshold for type 2 diabetes (T2D) should be lowered in women aged under 50 years, since natural blood loss through menstruation could be affecting their blood sugar management. The study is by Dr Adrian Heald, Salford Royal Hospital, UK, and colleagues. Analysis of the national diabetes ...
Synergistic work of cations in anion exchange membranes for OH- transport in fuel cells
Anion exchange membrane fuel cells (AEMFCs) have gained attention in the process of fuel cell development because they operate in alkaline environments, the redox reaction rate at the electrodes is faster, and non-precious metal catalysts such as Ni, Co, and Ag can be used, which reduces the cost of fuel cells. However, the mobility of OH- is only 56.97% of that of H+ under the same conditions, and its stability is poor, so improving the ionic conductivity and mechanical properties of anion exchange membranes (AEM) is the key to the commercialization ...
Hairy polymer balls help get genetic blueprints inside T-cells for blood cancer therapy
Tokyo, Japan – Scientists from Tokyo Metropolitan University have realized a new polymer that can effectively transport plasmid DNA into T-cells during chimeric antigen receptor (CAR) T-cell therapy, a key treatment for blood cancer. Importantly, it can get genes into floating T-cells, not only ones fixed to surfaces. It is stable, non-toxic, and doesn’t use viruses. It outperforms polyion compounds considered a gold standard in the field, paving the way for new therapies. T-cells, or lymphocytes, are a type of white blood cell that helps our immune system fight germs and protect us from disease. Recently, technology has become available that helps reprogram T-cells to fight cancer. ...
Reducing fishing gear could save whales with low impacts to California’s crab fishermen
(Santa Barbara, Calif.) — Sometimes simple solutions are better. It all depends on the nature of the problem. For humpback whales, the problem is the rope connecting a crab trap on the seafloor to the buoy on the surface. And for fishermen, it’s fishery closures caused by whale entanglements. Managing this issue is currently a major item on California’s agenda, and it appears less fishing gear may be the optimal solution. So says a team of researchers led by Christopher Free, at UC Santa Barbara, after modeling the benefits and impacts that several management strategies would have on whales and fishermen. ...