Category: Nutrition

Low GI Diet Has Noticeable Benefit against Diabetes

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Following a low glycaemic diet confers small but important benefits in blood glucose levels, cholesterol, weight and other risk factors, according to a study published by The BMJ.

The improvements were over and above existing drug and insulin therapy, suggesting this diet may help complement treatment, said the researchers.

Research has shown that foods with a low glycaemic index (GI), which is a measure of how quickly a food affects blood glucose levels relative to white bread, can help keep blood sugar levels steady and reduce the risk of heart disease in people with diabetes. These include foods such as vegetables, most fruits, pulses and wholegrains.

Due to this, clinical guidelines across the world recommend a low GI or GL (glycaemic load) diet for people with diabetes. However, the last European Association for the Study of Diabetes (EASD) guidelines were released over 15 years ago and since that time a number of trials have been published.
So researchers set out to summarise the effect of low GI/GL dietary patterns on blood sugar control and other known risk factors in diabetes to help inform the update of the EASD guidelines for nutrition treatment.

Their results are based on 27 randomised controlled trials published up to May 2021 investigating the effect of diets with low GI/GL in diabetes for three or more weeks.

The trial recruited a total of 1617 participants with type 1 or 2 diabetes, who were predominantly middle aged, overweight or obese with moderately controlled type 2 diabetes treated with drugs or insulin.

Though the trials varied quality, the researchers could assess the certainty of evidence using the recognised GRADE system.

The results show that low-GI/GL dietary patterns were linked to small but clinically meaningful reductions in blood sugar levels (HbA1c) compared with higher-GI/GL control diets.

Some other risk factors saw changes, such as fasting glucose (blood sugar levels after a period of fasting), LDL cholesterol, body weight, and C-reactive protein (a chemical associated with inflammation), but not blood insulin levels, HDL cholesterol, waist circumference, or blood pressure. The certainty of evidence was high for reduction in blood sugar levels and moderate for most other outcomes.

Limitations that included imprecision in the evidence for the effect of low GI/GL dietary patterns on LDL cholesterol and waist circumference, and the small number of available trial comparisons for blood pressure and inflammatory markers.

However, they say their findings show that low GI/GL dietary patterns “are considered an acceptable and safe dietary strategy that can produce small meaningful reductions in the primary target for glycaemic control in diabetes, HbA1c, fasting glucose, and other established cardiometabolic risk factors.”

“Our synthesis supports existing recommendations for the use of low GI/GL dietary patterns in the management of diabetes,” they concluded.

Source: MedicalXpress

Could Nutritional Supplements Play a Role in Fighting COVID?

Photo by Diana Polekhina on Unsplash
Photo by Diana Polekhina on Unsplash

Researchers suggest that nutritional supplements such as Vitamin C do play a role in reinforcing the immune system against SARS-CoV-2.

An article in Advances in Experimental Medicine and Biology lays out the scientific rationale and possible benefits — as well as possible drawbacks — of several dietary supplements currently in clinical trials related to COVID-19 treatment. The article was written by Johns Hopkins Medicine gastroenterologist Gerard Mullin, MD, and colleagues.

Dr Mullin, associate professor of medicine at the Johns Hopkins University School of Medicine, and his colleagues shine a light on melatonin, vitamin C, vitamin D, zinc and several plant-based compounds, such as green tea and curcumin. For instance, the authors explained that vitamin C (ascorbic acid), “contributes to immune defense by supporting cell functions of both the innate and adaptive immune systems.”

The authors discuss in the journal article the mechanism of action of each of the supplements works, how each could benefit a patient with COVID.

Zinc is well tolerated, and well known for its antioxidant, anti-inflammatory, immunomodulatory, and antiviral activities, the latter possibly mediated by its ability to inhibit RNA virus replication, thereby protecting cells from viral infection, oxidative damage, and dysfunction. It has been shown “to inhibit coronavirus RNA replication.” They also noted that, when administered at symptom onset, zinc “can reduce the duration of symptoms from illness attributed to more innocuous coronavirus infections, such as the common cold.”

Finally, Dr Mullin and colleagues gave short summaries of the clinical trials underway to test each supplement’s effectiveness in fighting COVID.

Regarding Vitamin D, which has received a lot of attention with regard to COVID outcomes, Dr Mullin said that, “to date, there are abundant data associating low vitamin D status to higher vulnerability to COVID-19 and poor clinical outcomes.”

The authors however struck a note of caution in that “any benefit of dietary supplements against COVID-19 depends on results of randomised controlled trials” and peer-reviewed literature.

Source: John Hopkins Medicine

Meat Substitutes Don’t Offer the Same Nutrition as Meat

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A study comparing meat and plant-based burger patties has found significant differences in nutritional content.  

As plant-based foods have improved in quality and availability, some have achieved a taste and texture remarkably similar to real beef, and they may even seem nutritionally equivalent in terms of items such as vitamins, fats and protein, based on their nutritional information labels.

But a Duke University research team’s deeper examination of the nutritional content of plant-based meat alternatives, using an analysis known as ‘metabolomics,’ shows they’re still quite different.  

Manufacturers of meat substitutes have gone to great trouble to make their plant-based products as meaty as possible, such as adding leghemoglobin, a plant-derived iron-carrying molecule to simulate bloodiness. Indigestible fibres like methyl cellulose thicken the texture of the meat substitutes. And to bring the plant-based meat alternatives up to the protein levels of meat, they use isolated plant proteins. Some meat-substitutes also add vitamin B12 and zinc to further replicate meat’s nutrition.

However, many other components of nutrition do not appear on the labels, and that’s where the products differ widely from meat, according to the study, which appears this week in Scientific Reports.

The metabolites that the scientists measured are building blocks of the body’s biochemistry, crucial to the conversion of energy, signaling between cells, building structures and tearing them down, and a host of other functions. There are expected to be more than 100 000 of these molecules in biology and about half of the metabolites circulating in human blood are estimated to be derived from our diets.

“To consumers reading nutritional labels, they may appear nutritionally interchangeable,” said Stephan van Vliet, a postdoctoral researcher at the Duke Molecular Physiology Institute who led the research. “But if you peek behind the curtain using metabolomics and look at expanded nutritional profiles, we found that there are large differences between meat and a plant-based meat alternative.”

The researchers compared 18 samples of a popular plant-based meat alternative to 18 grass-fed ground beef samples from a ranch in Idaho. The analysis of 36 carefully cooked patties found that 171 out of the 190 metabolites they measured varied between beef and the plant-based meat substitute.

The beef contained 22 metabolites that the plant substitute did not, while the plant-based substitute contained 31 metabolites that meat did not. The greatest distinctions occurred in amino acids, dipeptides, vitamins, phenols, and types of saturated and unsaturated fatty acids found in these products.

A number of important metabolites were found only in beef, or in greater quantities, including creatine, spermine, anserine, cysteamine, glucosamine, squalene, and the omega-3 fatty acid DHA. “These nutrients have potentially important physiological, anti-inflammatory, and or immunomodulatory roles,” the authors wrote in the paper.

“These nutrients are important for our brain and other organs including our muscles” van Vliet said. “But some people on vegan diets (no animal products), can live healthy lives – that’s very clear.” Besides, the plant-based meat alternative contained several beneficial metabolites not found in beef such as phytosterols and phenols.

“It is important for consumers to understand that these products should not be viewed as nutritionally interchangeable, but that’s not to say that one is better than the other,” said van Vliet, who eats a plant-heavy diet which still includes meat. “Plant and animal foods can be complementary, because they provide different nutrients.”

More research is needed, he said, to determine whether the presence or absence of particular metabolites in meat and plant-based meat alternatives have any short- or long-term effects.

No funding was received to perform this work.

Source:  Duke University School of Nursing

Sense of Smell Loss Uneven in Elderly

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Contrary to previously held scientific belief, the declining sense of smell in older people is not uniform, and their liking of many smells remains the same. Researchers at the University of Copenhagen reached this conclusion after examining a large group of older Danes’ and their intensity perception of common food odours.

The decline in smell has been demonstrated scientifically. Sense of smell gradually begins to decline from about the age of 55, and 75% of those over 80 show major olfactory impairment. While it was previously believed that one’s sense of smell broadly declined with increasing age, a study from the University of Copenhagen reports that certain food odours are significantly more affected than others.

Eva Honnens de Lichtenberg Broge and her fellow researchers tested the ability of older Danes to perceive everyday food odours. The researchers measured how intensely older adults perceived different food odours — as well as how much they liked the odours.

“Our study shows that the declining sense of smell among older adults is more complex than once believed. While their ability to smell fried meat, onions and mushrooms is markedly weaker, they smell orange, raspberry and vanilla just as well as younger adults. Thus, a declining sense of smell in older adults seems rather odor specific. What is really interesting is that how much you like an odour is not necessarily dependent on theintensity perception,” observed Eva Honnens de Lichtenberg Broge.

For example, liking seemed to be largely unaffected for fried meat, onions and mushrooms, despite the largest decline in intensity perception was seen for these specific odors. The ability to smell coffee declined, among other things, though they didn’t like the aroma of coffee to the same degree as younger adults.

The test subjects included 251 Danes between the ages of 60 and 98 and a younger group consisting of 92 people between the ages of 20 and 39.

Everyday food odours

Instead of using odours of chemical origin, which is commonly the procedure when testing the sense of smell, Eva Honnens de Lichtenberg Broge developed a test kit including 14 natural food odours familiar from everyday life, including bacon, onions, toast, asparagus, coffee, cinnamon, orange and vanilla. The odours, mainly made from essential oils, were presented to participants by sniffing sticks.

The food odours were chosen based upon commonly consumed foods and dishes that older people often eat and enjoy most according to meal plans and surveys from a Danish catering company that provides food for the elderly.

What’s the story?

The researchers can only speculate as to why the declining sense of smell in older adults seems to be odours specific, especially for savoury food smells and why, in some cases, liking is largely unaffected. 

“This may be due to the fact that these are common food odours in which saltiness or umami is a dominant taste element. It is widely recognised that salty is the basic taste most affected by aging. Since taste and smell are strongly associated when it comes to food, our perception of aroma may be disturbed if one’s taste perception of saltiness is impaired to begin with,” Eva Honnens de Lichtenberg Broge suggested.

Nutriton and quality of life

The researchers hope that their findings will help improve nutrition for the elderly. While the sense of smell is important for stimulating appetite and our serotonin levels as well, according to Eva Honnens de Lichtenberg Broge, their study demonstrates that the sensitivity of one’s sense of smell need not be decisive — participants’ liking of certain foods remained unchanged.

“Our results show that as long as a food odour is recognisable, its intensity will not determine whether or not you like it. So, if one wants to improve food experiences of older adults, it is more relevant to pay attention to what they enjoy eating than it is to wonder about which aromas seem weaker to them,” concluded Eva Honnens de Lichtenberg Broge.

Source: University of Copenhagen – Faculty of Science

Journal information: de Lichtenberg Broge, E.H., et al. (2021) Changes in perception and liking for everyday food odors among older adults. Food Quality and Preference. doi.org/10.1016/j.foodqual.2021.104254.

Artificial Sweeteners Can Turn Gut Bacteria Bad

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Scientists have found that common artificial sweeteners can turn previously healthy gut bacteria pathogenic, invading the gut wall and potentially leading to serious health issues.

This study is the first to show the pathogenic effects of some of the most widely used artificial sweeteners (saccharin, sucralose, and aspartame) on two types of gut bacteria, Escherichia coli and Enterococcus faecalisE. faecalis is capable of crossing the intestinal wall to enter the bloodstream and congregate in the lymph nodes, liver, and spleen, causing a number of infections including septicaemia. To top it off, this commensal bacteria has emerged as a multi-drug resistant pathogen.

Previous studies have shown that artificial sweeteners can affect the composition of gut bacteria, but this new molecular research, led by academics from Anglia Ruskin University (ARU), has shown that sweeteners can also induce pathogenic features in certain bacteria. It found that these pathogenic bacteria can latch onto, invade and kill epithelial Caco-2 cells lining the intestinal wall.

This new study discovered that at a concentration equivalent to two cans of diet soft drink, all three artificial sweeteners significantly increased the adhesion of both E. coli and E. faecalis to intestinal Caco-2 cells, and differentially increased biofilm formation. Bacteria growing in biofilms are less sensitive to antimicrobial resistance treatment and are more likely to secrete toxins and express disease-causing virulence factors.

Additionally, all three sweeteners caused the pathogenic gut bacteria to invade Caco-2 cells found in the wall of the intestine, save for saccharin, which had no significant effect on E. coli invasion.

Senior author Dr Havovi Chichger, Senior Lecturer in Biomedical Science at ARU, said: “There is a lot of concern about the consumption of artificial sweeteners, with some studies showing that sweeteners can affect the layer of bacteria which support the gut, known as the gut microbiota.

“Our study is the first to show that some of the sweeteners most commonly found in food and drink—saccharin, sucralose and aspartame—can make normal and ‘healthy’ gut bacteria become pathogenic. These pathogenic changes include greater formation of biofilms and increased adhesion and invasion of bacteria into human gut cells.

“These changes could lead to our own gut bacteria invading and causing damage to our intestine, which can be linked to infection, sepsis and multiple-organ failure.

“We know that overconsumption of sugar is a major factor in the development of conditions such as obesity and diabetes. Therefore, it is important that we increase our knowledge of sweeteners versus sugars in the diet to better understand the impact on our health.”
Source: EurekAlert!

Journal reference: Shil, A & Chichger, H (2021) Artificial Sweeteners Negatively Regulate Pathogenic Characteristics of Two Model Gut Bacteria, E. coli and E. faecalis. International Journal of Molecular Sciences. doi.org/10.3390/ijms22105228.

Scientists Search for Ways to Make Plant-based Protein Tastier and Healthier

As the demand for meat continues to increase around the world, a paper in the new Nature journal, Science of Food, that explores the topic of ways to create healthier, better-tasting and more sustainable plant-based protein products that mimic animal-based foods. 

It’s no simple task, said lead author of the article, renowned food scientist David Julian McClements, University of Massachusetts Amherst Distinguished Professor.

“With Beyond Meat and Impossible Foods and other products coming on the market, there’s a huge interest in plant-based foods for improved sustainability, health and ethical reasons,” said  McClements, a leading expert in food design and nanotechnology, and author of Future Foods: How Modern Science Is Transforming the Way We Eat.

It’s a growing industry: in 2019, the US plant-based food market was valued at nearly $5 billion, with 40.5% of sales in the milk category and 18.9% in plant-based meat products. That reflects a growth in market value of 29% from 2017.

“A lot of academics are starting to work in this area and are not familiar with the complexity of animal products and the physicochemical principles you need in order to assemble plant-based ingredients into these products, each with their own physical, functional, nutritional and sensory attributes,” McClements said.

With funding from the USDA’s National Institute of Food and Agriculture and the Good Food Institute, McClements is leading a multidisciplinary team at UMass Amherst that is discovering how to design better plant-based protein. Co-author Lutz Grossmann, who recently joined the UMass Amherst food science team as an assistant professor, has expertise in alternative protein sources, McClements noted.

“Our research has pivoted toward this topic,” McClements said. “There’s a huge amount of innovation and investment in this area, and I get contacted frequently by different startup companies who are trying to make plant-based fish or eggs or cheese, but who often don’t have a background in the science of foods.”

While the plant-based food sector is growing to meet consumer demand, Prof McClements noted in the paper that “a plant-based diet is not necessarily better than an omnivore diet from a nutritional perspective.”

In order to provide the micronutrients that are naturally present in animal meat, milk and eggs, plant-based products have to be fortified with vitamin D, calcium, zinc and others. Adequate amounts of micronutrients are needed for, among other things, the proper functioning of the immune system. Meat-free diets presently increase risks for fractures and other conditions, although they have other considerable health benefits.

Plant-based foods also need to be digestible and provide the full complement of essential amino acids.

McClements said that many of the current generation of highly processed, plant-based meat products are unhealthy because they contain large amounts of of saturated fat, salt and sugar. But, he added, ultra-processed foods do not necessarily have to be unhealthy.

“We’re trying to make processed food healthier,” McClements explained. “We aim to design them to have all the vitamins and minerals you need and have health-promoting components like dietary fiber and phytochemicals so that they taste good and they’re convenient and they’re cheap and you can easily incorporate them into your life. That’s the goal in the future, but we’re not there yet for most products.”

To tackle these challenges, McClements said, the UMass Amherst team of scientists is taking a holistic, multidisciplinary approach.

Source: University of Massachusetts Amherst

Journal information: McClements, D. J & Grossmann, L., (2021) A brief review of the science behind the design of healthy and sustainable plant-based foods. npj Science of Food. doi.org/10.1038/s41538-021-00099-y

Milk Consumption Does Not Raise Cholesterol Levels

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Regular consumption of milk is not associated with increased levels of cholesterol, according to new research.

A study published in the International Journal of Obesity analysed three large population studies and found that people who regularly drank high amounts of milk had lower levels of both ‘good’ and ‘bad’ cholesterol, although their BMI levels were higher than non-milk drinkers. Analysis of other large studies also suggests that regular milk drinkers had a 14% lower risk of coronary heart disease.

The team of researchers took a genetic approach to milk consumption by looking at a variation in the lactase gene associated with digestion of lactose. The study found that this gene variation for digesting lactose was a good identifier for people who consumed higher levels of milk.

“We found that among participants with a genetic variation that we associated with higher milk intake, they had higher BMI, body fat, but importantly had lower levels of good and bad cholesterol,” said Vimal Karani, Professor of Nutrigenetics and Nutrigenomics at the University of Reading said. “We also found that those with the genetic variation had a significantly lower risk of coronary heart disease. All of this suggests that reducing the intake of milk might not be necessary for preventing cardiovascular diseases.”

Contradictory research on the effect of high dairy intake and obesity and metabolic disorders was the motivation for the study. To exclude the effects of differences in sampling size, ethnicity and other factors, the team conducted a meta-analysis of data in up to 1.9 million people, including the UK Biobank and used the genetic approach to avoid confounding.

Even though the UK Biobank data showed that those with the lactase gene had an 11% reduced risk of type 2 diabetes, the study did not find a link between higher milk intake and increased likelihood of diabetes or related traits, such as glucose and inflammatory biomarkers.

“The study certainly shows that milk consumption is not a significant issue for cardiovascular disease risk even though there was a small rise in BMI and body fat among milk drinkers. What we do note in the study is that it remains unclear whether it is the fat content in dairy products that is contributing to the lower cholesterol levels or it is due to an unknown ‘milk factor’,” said Professor Karani.

Source: EurekaAlert

Journal information: Karani Santhanakrishnan Vimaleswaran et al, Evidence for a causal association between milk intake and cardiometabolic disease outcomes using a two-sample Mendelian Randomization analysis in up to 1,904,220 individuals, International Journal of Obesity (2021). DOI: 10.1038/s41366-021-00841-2

Bulimia Experience as a Teen Shaped Man’s Healthy Recipe Project

A UK man who started a project coming up with gut-healthy-recipes said that it was “shaped” by his having had bulimia in his teenage years.

Clinician and scientist Dr Sunni Patel, 35, said as a teen he thought he was “chubby” and experienced the eating disorder when he was aged 15 to 18.

Binge eating was his “solace” he said, and he used religious fasting “as a cover”.

Dr Patel started a website sharing recipes, and he urged people not to underestimate how gut health affects mental health.

“I’d find comfort and my escapism via food.”
Dr Sunni Patel

He said he would fast for four days a week, eating fruit at the end of the day.

Being from a traditional Asian background, the way “one looks and acts tends to be judged a lot more”, he said.

“Because I’d got bulimia as a get out, I’d binge eat. I might eat six or seven crisp packets at one sitting. I’d find comfort and my escapism via food.”

Suffering bullying at school, Dr Patel said that there was “pressure as a teenager to look cool”. He said that “the thinner I got, the more attractive I felt”. Bulimia became the “solution”, he added.

As he lost weight, he began receiving compliments which would “feed the beast”.

At least 1.5 million people in the UK have an eating disorder, experts estimate, with 25% being male. Bulimia nervosa is a condition that occurs most commonly in adolescent females, though it can appear in just about any patient. It is characterised by indulgence in binge-eating, and inappropriate compensatory behaviours to prevent weight gain.

Dr Patel said after he went to university he stopped, “I wasn’t able to find the safe space to have the… episodes, I didn’t want the truth to come out.”

From around the age of 24, he received cognitive behavioural therapy and in recent years has had psychotherapy.

“I was diagnosed with gut issues in 2014 and that’s when I started exploring the link between gut health and depression. As my diet became healthier so did my mind.”

A business director as well as a clinician, he now comes up with gut-healthy-recipes that are shared on his Dish Dash Deets website, set up during the COVID pandemic, where he also keeps a blog.

Included in his recipes are his top foods to combat depression and low mood, such as bananas, berries, beans and lentils.

He said to anyone that is in a similar position to his, “find a safe person to talk to”, who would not judge, adding: “Don’t feel any shame. You’re human.”

“The more that you rely on it, you use it as your way of escaping, the more it becomes your norm,” he said.

He also currently does live cook-alongs on Instagram with invited celebrities and chefs.

“Food is still my escapism. Now I enjoy being in the kitchen and making things that will serve my needs, not make things worse.”

Source: BBC News

A Mediterranean Diet Keeps Dementia at Bay

A dish full of vegetables which could be in a Mediterranean diet.

Researchers have reported that a Mediterranean diet may reduce the risk of developing dementia and cognitive loss, helping preserve memory functions as people age.

Specifically, the diet appears to lower the level of amyloid and tau proteins that are linked with dementia. People following the Mediterranean diet, already noted for its numerous health benefits, scored better on memory tests than those who were not following the diet.

The first of these proteins, amyloid protein, forms plaques in the brain, whereas the second, tau protein, forms tangles. Both are present in the brains of people with Alzheimer’s, though they are not uncommon in the brains of healthy older people, too.

“These results add to the body of evidence that shows what you eat may influence your memory skills later on,” said study author Tommaso Ballarini, PhD, of the German Center for Neurodegenerative Diseases in Bonn, Germany. He adds:

Studies have linked good health with the foods that people living in Greece, Spain, and Italy ate before the 1960s. This diet consists primarily of vegetables and fruits, nuts and seeds, legumes, potatoes, whole grain foods, seafood, extra virgin olive oil, and wine in moderation. Poultry, eggs and dairy products are present to a limited extent, while red meat, added sugar, refined grains and oils, and processed foods are typically lacking in a Mediterranean diet.

Kristin Kirkpatrick, a dietitian at Cleveland Clinic told Medical News Today that the contents of a Mediterranean diet offers beneficial “omega-3 fatty acids, polyphenols, specific minerals, fiber, and protein” that “may support the brain’s health and protection throughout the years.”

However, Kirkpatrick cautioned that, “A diet, even one with strong clinical data on its benefit, is only as healthy as the individuals who choose its structure.”

Sensible portion sizes are important, she noted and warned against the “consumption of processed foods that are marketed as heart-healthy or contain the components seen in a traditional Mediterranean approach.”

The investigators recruited 512 individuals from the German Centre for Neurodegenerative Diseases’ Longitudinal Cognitive Impairment and Dementia StudyTrusted Source. Participant  assessments showed that 343 were at a higher risk of developing Alzheimer’s disease while the other 169 people were “cognitively normal.”

Participants filled in questionnaires regarding the food they ate the previous month and the investigators asked them to record their intake of 148 specific food items. Participants were scored on their diet’s similarity to a Mediterranean diet, the most similar receiving a 9 and the least similar a 1. Since this was a self-reported study on eating habits, errors or misrepresentations are possible.

Individuals also took cognitive tests designed to detect the progression of Alzheimer’s disease. The tests assessed five areas: memory, working memory, language, executive functions, and visuospatial abilities. MRI brain scans determined each individual’s brain volume.

Finally, the researchers analyzed spinal fluid from a subsample of 226 participants who gave their consent, assessing the presence and amounts of the two biomarker proteins: amyloid and tau.

After adjusting for sex, age, and education, the scientists identified several clear links between better cognitive health and a Mediterranean diet.

The investigators  reported that:

  • Every dietary score point lower than 9 was linked to almost 1 year of the brain ageing that occurs in Alzheimer’s disease progression.
  • Participants who most closely followed the Mediterranean diet had fewer amyloid and tau protein biomarkers in their spinal fluid than those who had lower dietary scores.
  • People on the Mediterranean diet scored better on memory tests than people who were not.

Dr Ballarani concluded that, “More research is needed to show the mechanism by which a Mediterranean diet protects the brain from protein buildup and loss of brain function, but findings suggest that people may reduce their risk for developing Alzheimer’s by incorporating more elements of the Mediterranean diet into their daily diets.”

Source: Medical News Today

Could Cutting Sugary Drinks Reduce Cancer Risk in Women?

A higher intake of sugar-sweetened beverages (SSBs) in adulthood and adolescence was linked to an increased risk of early-onset colorectal cancer (CRC) in women, according to data from a large prospective study.

The Nurses’ Health Study II followed over 95 000 registered nurses from 1991 to 2015. Those consuming at least two SSB servings a day in adulthood had more than double the early-onset CRC risk of those consuming less than one serving a week. This rose by 16% with each extra serving per day.

In the adolescent years of ages 13 to 18, each serving-per-day increment was associated with a 32% higher risk of early-onset CRC. Meanwhile, replacing each SSB serving per day for adults with a serving of a non-SSB drink was associated with a 17-36% lower risk.

“Considering the well-established, adverse health consequences of SSBs and the highest consumption being characterized in adolescents and young adults under age 50 years, our findings reinforce the public health importance of limiting SSB intake for better health outcomes,” Yin Cao, ScD, MPH, of Washington University in St. Louis, and co-researchers wrote.

Although CRC has been on the decline, the age of early onset — that is, diagnosed before age 50 — has been increasing the past two decades. In comparison to adults born around 1950, those born around 1990 had twice the colon cancer risk and four times the rectal cancer risk.

An estimated 12% of the US population currently consume more than three SSB servings per day, as shown by National Health and Nutrition Examination Survey data. SSBs in the US are often include high fructose corn syrup as an ingredient, as opposed to South Africa which uses cane sugar.

In this study, the population consisted overwhelmingly of white females, ages 25 to 42, with an average age of approximately 42 at enrollment. Over up to 24-plus years of follow-up, 109 cases of early-onset CRC were recorded.

The researchers found that those with higher SSB intakes in adulthood tended to be less physically active and more likely to have a lower endoscopy history, to use non-steroidal anti-inflammatory drugs, and consume red and processed meats. They were also less likely to take multivitamins and to have a reduced intake of alcohol, fibre, folate, and calcium, and to have a poorer diet overall.

No association was found between intake of artificially sweetened beverages or fruit juice in adulthood and risk of early-onset CRC, mirroring past research.

The investigators listed a number of possible pathways for the effect of SSBs on early-onset CRC. 

For example, compared with isocaloric solid foods, energy-containing beverages do not create a feeling of satiation, leading to weight gain. SSBs also initiate rapid blood glucose response and insulin secretion, possibly leading to insulin resistance, inflammation, obesity, and type 2 diabetes — metabolic conditions which are linked to heightened CRC risk.

Other possibilities include intestinal dysbiosis and endotoxemia caused by high fructose levels , the principal sweetener in SSBs in the US and certain other countries, which can impair gut barrier function, increasing gut permeability, and possibly promote cancer formation. A recent experimental study suggested that the high-fructose corn syrup in SSBs from the US enhanced the growth of aggressive tumours in mice, regardless of weight and metabolic syndrome.

High-fructose corn syrup has also been linked to metabolic dysregulation, regardless of obesity.

Fortunately, overall SSB intake has been trending downward in recent years, and Dr Cao and co-authors concluded that further limiting consumption may be “an actionable strategy to curb the rising incidence of [early-onset] CRC.”

Study limitations, the researchers said, included possible unknown confounding variables, the few early-onset CRC cases prevented pinpointing the window of exposure, and there weren’t enough diabetic participants to stratify by a personal history of diabetes. Since the participants were mostly white women, the results were not readily generalisable to other ethnic groups or to men.

Source: MedPage Today

Source Reference: Hur J, et al “Sugar-sweetened beverage intake in adulthood and adolescence and risk of early-onset colorectal cancer among women” Gut 2021; DOI: 10.1136/gutjnl-2020-323450.