Monday, November 30, 2015

Meat, Veganism and Science

Today’s post isn’t going to be a “pro-veganism” rant or anything like that. I’m aiming to provide a balanced overview on meat-eating. This post is going to be looking at meats, their pro’s and con’s and the recent research spreading around them and also veganism and I’ll leave the decision to which option could potentially be the best for your health, to you, the reader.



Pros.


Meat is a good source of protein, vitamins and minerals, including iron, zinc and B vitamins. It is also one of the main sources of vitamin B12. It’s recommended that we try to eat lean cuts of meat and skinless poultry whenever possible to cut down on fat and also always cook meat thoroughly.

Proteins are complex substances, made up of chains of amino acids. Amino acids are building blocks that combine in different formations to make up the proteins in your body. There are 20 amino acids in total – your body can create some of these itself, but there are nine essential amino acids that you can only get from protein that you eat. After you eat protein, it’s broken down in the body into amino acids.  They are then transported in the bloodstream, where they’re rearranged into new proteins that are required for the healthy growth of all of our body tissues, such as your muscles (including your heart), internal organs (such as your lungs and liver) and skin.  Also, proteins are a great source of energy.

Cons.


Saturated fats, found in meat, can block the absorption of essential fats which are important for maintaining cell structure. An increase in saturated fats in the body can cause cells to become more rigid and affect the flow of nutrients in and out of the cells.

Furthermore, if you eat a lot of red and processed meat, it is recommended that you cut down as there is likely to be a link between red and processed meat and bowel cancer. This has been proven in research published in the recent years and has been making news headlines as of late.

The Research...

The first piece of research has found that diets high in meat may lead to an increased risk of developing renal cell carcinoma (RCC) through the intake of carcinogenic compounds created by specific cooking techniques, such as barbecuing and pan-frying. The kidney is a biochemically active organ which is responsible for filtering many harmful toxins from the body, s it was essential to investigate the effects of dietary intake, including carcinogens, on kidney cancer risk.



A potential theory for the cause could be ingestion of meat-cooking mutagens, harmful compounds created when the meat is cooked in a certain way. Cooking meat at high temperatures or over an open flame, such as when barbecuing or pan-frying, is known to result in the formation of carcinogens, including 2-amino-1-methyl-6-phenyl-imidazo(4,5-b) pyridine (PhIP) and amino-3,8-dimethylimidazo(4,5-f) quinoxaline (MeIQx).



However, the researchers don’t suggest that people should remove meats entirely from their diets, but rather consume it in moderation, as part of a well-balanced diet, complete with fruits and vegetables. They also advised that: when grilling or pan-frying meat, to try to avoid charring it as much as possible.

Studies on cancer risks of  different types of meat

The International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, has evaluated the carcinogenicity of the consumption of red meat and processed meat.

Red meat.

The IARC classified the consumption of red meat as probably carcinogenic to humans (Group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect. This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer.

Processed meats.

Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer. The experts concluded that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18%.



Overall effects of meat consumption.

The IARC working group considered more than 800 studies that investigated associations of more than a dozen types of cancer with the consumption of red meat or processed meat in many countries and populations with diverse diets. The most prominent evidence came from big prospective cohort studies conducted over the past 20 years.

"These findings further support current public health recommendations to limit intake of meat," says Dr. Christopher Wild, director of IARC. "At the same time, red meat has nutritional value. Therefore, these results are important in enabling governments and international regulatory agencies to conduct risk assessments, in order to balance the risks and benefits of eating red meat and processed meat and to provide the best possible dietary recommendations."



On how meat-eaters defend their eating habits...

Researchers have found that meat eaters who justify their eating habits feel less guilty and are more tolerant of social inequality say, researchers. They found that the vast majority of omnivores defend consuming animals by rationalizing their behaviour using one of four rationalizations, which they call the 4Ns.

Typical comments used to justify eating meat include these 4Ns:

  1. Natural "Humans are natural carnivores"
  2. Necessary "Meat provides essential nutrients"
  3. Normal "I was raised eating meat"
  4. Nice "It's delicious"


Since veganism and vegetarianism are perceived to be the  healthiest lifestyle to live. More and more people are cutting out meats and animal produce in order to have a plant based diet.

In addition to weight loss, a vegan low-carbohydrate diet may also reduce the risk of heart disease by 10 percent over 10 years, researchers have demonstrated for the first time. The diet is a low-carbohydrate vegan diet. A lot of low-carbohydrate diets have been able to improve weight loss, but most highlight eating animal proteins and fats, which can raise body cholesterol levels. A diet that is high in vegetable proteins and oils may reduce the risk of heart disease by lowering "bad cholesterol" levels in the body.

Finally, although some meats can cause cancer it's also beneficial to not completely cut out meat and other animal produce from the body because they do have some beneficial nutrients that are essential to the body. Even if some of the nutrients can be sought via other means, vitamin B12 is an essential one which can be found in  meat, eggs and milk. This brings us back to the saying "everything in moderation is good".



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References:
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[1] http://www.nhs.uk/Livewell/Goodfood/Pages/Healthyeating.aspx
[2] http://www.nhs.uk/Livewell/Goodfood/Pages/meat.aspx
[3] Stephanie C. Melkonian, Carrie R. Daniel, Yuanqing Ye, Nizar M. Tannir, Jose A. Karam, Surena F. Matin, Christopher G. Wood, Xifeng Wu.Gene-environment interaction of genome-wide association study-identified susceptibility loci and meat-cooking mutagens in the etiology of renal cell carcinoma. Cancer, 2015; DOI:10.1002/cncr.29543

University of Texas M. D. Anderson Cancer Center. "Increased meat consumption, especially when cooked at high temperatures, linked to elevated kidney cancer risk: Individuals with certain genetic variations more vulnerable to dietary risk." ScienceDaily. ScienceDaily, 9 November 2015. <www.sciencedaily.com/releases/2015/11/151109083413.htm>.

[4] VĂ©ronique Bouvard, Dana Loomis, Kathryn Z Guyton, Yann Grosse, Fatiha El Ghissassi, Lamia Benbrahim-Tallaa, Neela Guha, Heidi Mattock, Kurt Straif, International Agency for Research on Cancer Monograph Working Group. Carcinogenicity of consumption of red and processed meat. The Lancet Oncology, 2015 (in press) DOI: 10.1016/S1470-2045(15)00444-1

World Health Organization. "Processed meat can cause cancer." ScienceDaily. ScienceDaily, 27 October 2015. <www.sciencedaily.com/releases/2015/10/151027135116.htm>.

[5] Jared Piazza, Matthew B. Ruby, Steve Loughnan, Mischel Luong, Juliana Kulik, Hanne M. Watkins, Mirra Seigerman. Rationalizing meat consumption. The 4Ns. Appetite, 2015; 91: 114 DOI: 10.1016/j.appet.2015.04.011
Lancaster University. "How people defend eating meat." ScienceDaily. ScienceDaily, 18 May 2015. <www.sciencedaily.com/releases/2015/05/150518121442.htm>.

[6] St. Michael's Hospital. "Low-carb vegan diet may reduce heart disease risk, weight." ScienceDaily. ScienceDaily, 22 May 2014. <www.sciencedaily.com/releases/2014/05/140522105136.htm>.

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Thursday, November 19, 2015

One Paragraph on Sweets, the Brain and Eating Habits | One Paragraph Science



Eating sweet foods causes the brain to form a memory of a meal, according to researchers at Georgia State University, Georgia Regents University and Charlie Norwood VA Medical Centre. The research published in the journal Hippocampus found that neurons in the dorsal hippocampus, which is the part of the brain that is critical for episodic memory (the memory of autobiographical events experienced at a particular time and place), are activated by consuming sweets. The experiment consisted of feeding a meal including a sweetened solution, either sucrose or saccharin to rats. They found that this significantly increased the expression of the synaptic plasticity marker called activity-regulated cytoskeleton-associated protein (Arc) in their dorsal hippocampal neurons. Synaptic plasticity is a process that is necessary for making memories. Forming memories are essential for a healthy diet. Researchers have found that people with amnesia will repeatedly eat if presented with food, even if they've already eaten because they have no memory of the meal.  This new research can be used to figure out the causes of obesity, especially considering how the brain controls meal onset and frequency.  Research shows that increased snacking is correlated positively with obesity, and obese individuals snack more frequently than people who aren't obese. Studies also show that over the past thirty years, children and adults are eating more snacks per day and gaining more of their daily calories from snacks, mostly in the form of desserts and sweetened beverages. The researchers hope to use this research in the future to determine if nutritionally balanced liquid or solid diets that typically contain protein, fat and carbohydrates have a similar effect on Arc expression in dorsal hippocampal neurons and whether increases in Arc expression are necessary for the memory of sweet foods.



References [1]

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Monday, November 09, 2015

One Paragraph on Eye drops for Cataracts | One Paragraph Science


Cataracts are primarily a disease of ageing. Instead of an operating to remove them, researchers are trying to make a cataract-dissolving-eye drops which can break down cataracts and restore transparency of the lens and vision.  Cataracts can be successfully removed with surgery, but this method is costly, and most individuals blinded by severe cataracts in developing countries go untreated. A characteristic of the condition is the mis-folding and clumping together of crucial proteins known as crystallins. So that our lenses are able to function well, crystallins (which we are born and live our whole lives with) must maintain both the transparency of fibre cells and their flexibility as the eyes' muscles constantly stretch and relax the lens to allow us to focus on objects at different distances.  Scientists at the University of California San Francisco exploited a key difference between correctly folded crystallins and their amyloid forms; finding that amyloids are much harder to dissolve. After researching over 2450 compounds and reducing them down to 12 they finally came to find, what they named, Compound 29. Compound 29 is both dissolvable in solution (so can be given in eye drops) and has the ability to dissolve amyloids that had already been formed. Results were observed when Compound 29 eye drops were applied in mice that naturally developed age-related cataracts, and also when the compound was applied to human lens tissue affected by cataracts that had been removed during surgery. This technique will also be a great benefit to dogs that are also prone to developing cataracts as they grow old. Besides Compound 29's potential for cataract treatment, the insights gained through the research could have broader applications, especially in neurodegenerative disorders. 

References: [1]


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Tuesday, November 03, 2015

One Paragraph on Male and Female Brain Differences | One Paragraph Science



There’s actually no difference between the male and female minds. 
A new research study, published in the journal Neuroimage, is disproving the myth that states that the hippocampus (a crucial part of the brain that consolidates new memories and helps connect emotions to the senses) is larger in females than in males. Leading a team of students at the Rosalind Franklin Medical School, Lise Elliot, Ph.D., conducted a meta-analysis of structural MRI volumes that found no significant difference in hippocampal size between men and women. A meta-analysis is a statistical technique that allows researchers to combine the findings from many independent studies into a comprehensive review. The team examined findings from 76 published papers, involving more than 6,000 healthy individuals. Hippocampi are located on both sides of the brain, under the cerebral cortex. The team's findings test the familiar argument that a disproportionately larger hippocampus explains females' tendency toward greater emotional expressiveness, stronger interpersonal skills, and better verbal memory. Through their research, they found that there is no difference in the size of the corpus callosum (which is the white matter that allows the two sides of the brain to communicate) nor do men and women differ in the way their left and right hemispheres process language. 

Rferences: {1}



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