We are often told that being overweight increases our risk of cancer. In fact, in the UK, obesity is the biggest preventable cause of cancer after smoking, according to Cancer Research UK. But why does being overweight increase a person’s likelihood of developing cancer? A group of scientists say they now know. The team from Trinity College Dublin say the reason overweight people are at greater risk of developing cancer is because a certain cell in the body that’s used to destroy cancer gets clogged with fat and stops working as a result. Publishing their findings in the Nature Immunology journal, the team said they were able to show that the body’s natural cancer-fighting cells get clogged by fat. They are hopeful that new drug treatments can be developed that will reverse the effects and restore the cancer-killing ability of said cells. Until then, though, the best advice remains to stay a healthy weight, stop smoking and cut down on alcohol. Speaking about the findings of the research, Dr Leo Carlin, from the Cancer Research UK Beatson Institute, said: “Although we know that obesity increases the risk of 13 different types of cancer, we still don't fully understand the mechanisms underlying the link. “This study reveals how fat molecules prevent immune cells from properly positioning their tumour-killing machinery, and provides new avenues to investigate treatments.” [Related reading: Major study finds eating processed meat raises risk of breast cancer]
Women who are larks, otherwise known as “morning people”, have a lower risk of developing breast cancer, a study has revealed. While the exact reason why remains unknown, the team of researchers from the University of Bristol in the UK say their findings are important and add to the growing understanding of how sleep affects our health. A person’s body clock (also known as their circadian rhythm) regulates when a person feels sleepy or awake over a 24-hour period. So-called morning people wake up earlier, peak earlier in the day and feel sleepy earlier in the evening. In contrast, “evening people” (night owls) get up later, peak later in the day and go to sleep later in the evening. Using a data analysis technique called Mendelian randomisation, the researchers looked at DNA snippets of more than 400,000 women. They discovered that women who were larks were less likely to have breast cancer than their night owl peers. Speaking about the findings of the research, Dr Rebecca Richmond, a researcher from the University of Bristol, told the BBC: “The findings are potentially very important because sleep is ubiquitous and easily modified. “Previous research has looked at the impact of shift work, but this is showing there may be a risk factor for all women.” Nevertheless, many questions still remain. For example, more research now needs to be conducted to see whether the body clock itself is directly impacting a person’s risk of developing cancer, or if factors like night owls breaking their natural circadian rhythm to accommodate jobs is having an impact. [Related reading: Major study finds eating processed meat raises risk of breast cancer]
A major study has found that eating processed meat, like bacon and sausages, may raise the risk of breast cancer in women. According to the review of studies involving more than one million women, eating higher levels of processed meat could result in a 9% greater risk of developing breast cancer. The research by a team from Harvard University’s T H Chan School of Public Health reviewed 15 related studies. It supports previous findings by the World Health Organisation (WHO) which suggest processed meats cause cancer. However, while the study has identified a potential link between processed meat and breast cancer, there is no clear evidence to show these types of foods are actually the cause. Furthermore, as outlined by the study authors in the International Journal of Cancer, their findings only relate to processed meat, not red meat. Bacon, sausages, salami, ham, hot dogs and corned beef are all examples of processed meat. And while it is not fully known why these foods are associated with a greater risk of cancer, it is thought that preservatives, like salt, may react with protein in the meat turning it carcinogenic. But rather than eliminating processed meat from your diet completely, the advice is simply to cut down. At present, current NHS guidelines recommend eating no more than 70g of red and processed meat a day. If you’re eating more than that on a regular basis, maybe it’s time to make some dietary changes.
As part of a new obesity drive, Public Health England is telling people in the UK to “get on a diet” and wants to cut portion sizes of some of the nation’s most popular foods. Pizzas, ready meals, takeaways and processed meat will all be targeted as part of the initiative to cut calorie consumption by 20% by 2024. In addition, the government agency has called on the food industry to start using healthier ingredients and encourage people to choose lower calorie foods. The drive to eat healthier will not only improve the health of the nation, but also reduce the burden on the NHS associated with obesity-related illnesses. Public Health England says the cost per year of obesity to the NHS is £6 billion. Combined with the sugar reduction programme that came into effect last year and the sugary drinks levy which comes into force next month, this new initiative will also help reduce the number of calories consumed by children in the UK. Talking about the new steps, Public Heath England chief executive Duncan Selbie said: "Britain needs to go on a diet. Children and adults routinely eat too many calories, and it's why so many are overweight or obese." Food manufacturers, supermarkets, takeaways and fast-food outlets have all been told they need to reduce the calories in the foods such as crisps and savoury snacks, cooking sauces and dressings, ready meals and takeaways, and food-to-go like sandwiches. If these companies do not listen to PHE, the agency said it would be willing to ask the government to legislate. Guidelines suggest that women eat no more than 2,000 calories a day, while men should limit themselves to 2,500.
It is something many people will be considering in the New Year, but the plethora of diet advice available out there can be confusing and contradictory. That's why the Mayo Clinic in Arizona set out to see which of the so-called 'low-carb' diets in the weight loss market is the most effective and, more importantly, how safe they all are. They published the results of their study in The Journal of the American Osteopathic Association. Their analysis of some 41 trials that evaluated the weight loss effects of low-carb diets found that individuals lost between 2.5-9 more pounds than individuals who followed a low-fat diet. Dr. Heather Fields, an internal medicine physician at Mayo Clinic and lead researcher on the study, said that adhering to low-carb diets in the short-term appears to be safe and promotes weight reduction. "However, that weight loss is small and of questionable clinical significance in comparison to low-fat diets. We encourage patients to eat real food and avoid highly processed foods, especially processed meats, such as bacon, sausage, deli meats, hot dogs, and ham when following any particular diet," she added. This is the biggest warning to come out of the research and it's because when people are following low-carb diets they tend to eat more meat, and this could increase their risk of death from all causes, including cancer - especially if they consume a lot of processed meat. Nevertheless, the studies showed that compared with many other diets, low-carb ones were effective for weight loss without adverse effects on blood pressure, glucose, and cholesterol.
People have talked about the possible negative effects of processed meat for a long time and numerous studies linking high consumption of red and processed meats with higher risk of colorectal cancer have even influenced public health recommendations in some countries. But now a report compiled on behalf of the World Health Organisation by a working group of 22 experts from 10 countries around the world has concluded that there is an association with eating processed meats and colorectal cancer risks. The findings, published recently in The Lancet Oncology, said that 50g of processed meat a day, which is equivalent to less than two slices of bacon, increased a person’s chances of developing colorectal cancer by 18%. Furthermore, the study said that red meats were “probably carcinogenic, but there was limited evidence to comment further. However, despite these findings, the WHO also emphasised that there are still health benefits associated with eating meat. Cancer Research UK’s advice is that people should cut down on their consumption of red and processed meats, rather than give them up completely. In fact, the organisation said that the occasional bacon sandwich would do little harm. Processed meat is meat that has had its shelf life extended or its taste changed by means of smoking, curing, or adding preservatives or salt. Bacon, sausages, hotdogs, corned beef, salami, ham, beef jerky and other canned meats are all considered “processed”. Chemicals used during the processing of the meats are thought to be carcinogenic catalysts, as is high-temperature cooking such as on a barbecue. Dr Kurt Straif from the WHO said: “For an individual, the risk of developing colorectal (bowel) cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed.”