Being a morning person can reduce the risk of breast cancer, research suggests.
A study found that people who prefer to grow up bright and early are less likely to get the disease than & # 39; night owls & # 39 ;.
This is believed to be due to early light exposure, which cuts off the supply of the hormone melatonin, which regulates sleep.
Several studies have shown that melatonin has the ability to protect against cancers, especially breast cancer.
The new study found for every 100 women, one less developed the disease when she gets up and goes to bed early.
The results also found that participants who slept for more than seven to eight hours were more likely to get breast cancer.
Critics have pointed out that this is a & # 39; small effect & # 39; is, when we say that when we go to bed a & # 39; very little affects our risk of breast cancer & # 39 ;.
Being a morning person can reduce your risk of breast cancer, research suggests (stock)
One in eight UK and US women will get breast cancer at some point in their lives, statistics show.
Working late shifts have been repeatedly associated with the disease in recent years, the researchers wrote in the British Medical Journal.
This is probably caused by the way the shift disturbs our body clock and exposes us to the light at night.
The World Health Organization has even classified shifts that disrupt the body clock as & # 39; probably carcinogenic to humans & # 39; in 2007.
However, less is known about how insomnia, disturbed sleep and a & # 39; morning or evening person & # 39; affect our health.
University of Bristol experts, led by professor Caroline Relton, investigated whether closed eyes influence the risk of breast cancer.
They searched for genetic & # 39; traits & # 39; that & # 39; robustly associated & # 39; are with insomnia, sleep duration and our preference for mornings or evenings.
These properties were screened in 180,216 women who participated in the UK Biobank study and 228,951 women with breast cancer.
All participants also completed a questionnaire about their sleeping habits.
The results showed that women who reported that they preferred evenings in the morning were less likely to develop breast cancer.
The researchers wrote their findings & # 39; provide strong evidence for a causal effect of chronotype on breast cancer risk & # 39 ;.
Chronotype refers to the & # 39; time & # 39; who prefers our body clock & # 39; with some people who are morning lions and others night owls.
Dr John O & # 39; Neill, research group leader at the Laboratory of Molecular Biology of the Medical Research Council, said: & # 39; A difference of less than one percent is a small effect size.
EXPLANED: HOW THE CIRCADIAN Rhythm WORKS
In a healthy person, the cortisol levels peaked around 8 o'clock, which in theory shakes us up and goes down at 3 o'clock the next day, before returning to its peak five hours later.
Ideally, this 8 peak is triggered by exposure to sunlight, if not an alarm. If this is the case, the adrenal glands and brain will produce adrenaline.
Cortisol levels begin to fall in the middle of the morning, while adrenaline (for energy) and serotonin (a mood stabilizer) continue to pump.
& # 39; The metabolic rate and the body's core temperature rise in the afternoon, making us hungry and ready to eat.
The cortisol levels start to decrease after midday. Metabolism slows down and fatigue comes in. The serotonin gradually changes to melatonin, causing drowsiness. Our blood sugars decrease and at 3 o'clock at night, when we are in the middle of our sleep, the cortisol levels have reached a low of 24 hours.
& # 39; I would be inclined to give the opposite interpretation to their press release, that having an evening chronotype has very little influence on the risk of breast cancer. & # 39;
Dr. Neill also pointed out that the findings show only a correlation and do not prove that our sleep time drives our risk of cancer.
Dr. Chris Bunce, professor of translational cancer biology at the University of Birmingham, agreed. & # 39; The observed associations are very small correlative, & # 39; he said.
& # 39; It is dangerous to suggest, even unintentionally, to women that changing their sleep patterns will significantly change their risk of breast cancer. & # 39;
Professor Relton and colleagues couldn't explain why the risk was greater for women who slept longer each night.
And the researchers emphasize that their study assumed that the participants themselves report their sleeping habits.
The women were also all of European descent and therefore other results may apply to other ethnicities, they add.
More research is also needed to discover exactly how different sleep patterns can lead to breast cancer.
Despite the critics' criticism, the researchers said the findings & # 39; have potential consequences for influencing (the) sleeping behavior of the general population to improve health & # 39 ;.
Professor Eva Schernhammer, chair of the epidemiology department at the University of Vienna, said the results identify a need for future research, investigate how stress on our biological clock can be reduced & # 39 ;.
In a linked editorial, she added that the study could help women take care of their health in old age and avoid illnesses associated with a & # 39; deranged & # 39; body clock.
& # 39; People with the greatest mismatch between internal physiological timing and external societal demands run the risk of circadian misalignment, & she said.
& # 39; Night shift is one of the heaviest external stresses on the circadian clock.
& # 39; (It) requires radical changes in the timing of behaviors such as eating and sleeping, resulting in circadian disruption or misalignment.
& # 39; Night work changes the primary output of the circadian clock – melatonin rhythms – most seriously when the working hours do not match the preferred sleep timing: morning people working in night shifts or & # 39; in the evening people who work in the morning.
& # 39; Chronic exposure to circadian disease disruption has a long-term adverse effect on health, increasing the risk of death from major causes, including cancer, especially breast cancer.
WHAT IS BREAST CANCER, HOW MANY PEOPLE DO IT AND WHAT ARE THE SYMPTOMS?
Breast cancer is one of the most common forms of cancer in the world. Every year in the UK there are more than 55,000 new cases and the disease claims the lives of 11,500 women. In the US, it kills 266,000 people every year and kills 40,000. But what causes it and how can it be treated?
What is breast cancer?
Breast cancer develops from a cancer cell that develops in the lining of a canal or lobulus in one of the breasts.
When breast cancer has spread into the surrounding breast tissue, it becomes an & # 39; invasive & # 39; called breast cancer. Some people are diagnosed with & # 39; carcinoma in situ & # 39; where no cancer cells have grown beyond the canal or lobule.
Most cases develop in women older than 50, but younger women are sometimes affected. Breast cancer can occur in men, although this is rare.
The cancer cells are classified from the first phase, which means slow growth, to phase four, which is the most aggressive.
What causes breast cancer?
A cancerous tumor starts with an abnormal cell. The precise reason why a cell becomes cancerous is unclear. It is thought that something damages or changes certain genes in the cell. This makes the cell abnormal and multiplies & # 39; out of control & # 39 ;.
Although breast cancer can occur for no apparent reason, there are some risk factors that can increase the chance of developing breast cancer, such as genetics.
What are the symptoms of breast cancer?
The usual first symptom is a painless lump in the breast, although most breast nodules are not cancerous and are fluid-filled cysts that are benign.
The first place that breast cancer usually spreads to is the lymph nodes in the armpit. If this happens, you will develop a swelling or lump in an armpit.
How is breast cancer diagnosed?
- First assessment: a doctor examines the breasts and armpits. They can perform tests such as a mammography, a special x-ray of the breast tissue that may indicate the possibility of tumors.
- Biopsy: A biopsy is when a small piece of tissue is removed from a part of the body. The sample is then examined for abnormal cells under the microscope. The sample can confirm or exclude cancer.
If it is confirmed that you have breast cancer, further tests may be needed to assess if it has spread. For example a blood test, an ultrasound scan of the liver or a chest x-ray.
How is breast cancer treated?
Treatment options that can be considered include surgery, chemotherapy, radiotherapy and hormone treatment. A combination of two or more of these treatments is often used.
- Surgery: breast-conserving surgery or removal of the affected breast depending on the size of the tumor.
- Radiotherapy: a treatment that uses high-energy rays aimed at cancerous tissue. This kills cancer cells, or prevents cancer cells from multiplying. It is mainly used in addition to surgery.
- Chemotherapy: a treatment for cancer through the use of anti-cancer drugs that kill cancer cells, or to prevent them from multiplying
- Hormone treatments: Some types of breast cancer are influenced by the & # 39; female & # 39; hormone estrogen, which can stimulate cancer cells to divide and multiply. Treatments that lower the levels of these hormones, or make them not work, are often used in people with breast cancer.
How successful is the treatment?
The outlook is best for those who are diagnosed when the cancer is still small and has not spread. Surgical removal of a tumor at an early stage can then give a good chance of a cure.
The routine mammography offered to women between the ages of 50 and 70 means that more breast cancers are diagnosed and treated at an early stage.
For more information, visit breastcancercare.org.uk or www.cancerhelp.org.uk
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