Category: Diet and Nutrition

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Higher Dietary Soy and Legume Intake Linked to Lower Hypertension Risk

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Optimal daily amount may be about 170g of legumes and 60-80g of soy, evidence suggests

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A higher dietary intake of soy and legumes is linked to a lower risk of high blood pressure, finds a pooled data analysis of the available evidence, published in the open access journal BMJ Nutrition Prevention & Health.

And the optimal daily amount may be around 170g of legumes, which include peas, lentils, chickpeas and beans, and 60 to 80g of soy foods, examples of which include tofu, soy milk, edamame, tempeh, and miso, the findings indicate.

Legumes and soy foods have been associated with an overall lower risk of cardiovascular disease, but the evidence on their potential for lowering high blood pressure is mixed and needs to be systematically quantified, explain the researchers.

To explore this further, the researchers scoured databases for relevant studies published up to June 2025, and found 10 publications that included data from 12 prospective observational studies.

Five studies were from the USA, 5 from Asia (China, Iran, South Korea and Japan), and 2  were from Europe (France and the UK). Nine studies included both men and women, 2 included only women, and 1 included only men.

The number of study participants ranged from 1152 to 88 475 and the number of cases of high blood pressure ranged from 144 to 35 375.

Pooled data analysis of the study findings showed that higher daily intake of legumes and soy foods was associated with a lower risk of developing high blood pressure.

Compared with those with a low intake of legumes, those with a high intake were 16% less likely to develop high blood pressure. Similarly, those with a high intake of soy foods were 19% less likely to develop the condition than those with a low intake.

When assessing the association between quantity and lower risk, a linear reduction (30%) emerged for legumes up to around 170 g/day, while most of the reduction in risk (28-29%) for soy foods was observed at between 60 and 80 g/day, with no further reduction in risk at higher intake.

One hundred grams of legumes/soy is equivalent to a serving size of about one cup or 5–6 tablespoons of cooked beans, peas, chickpeas, lentils, soybeans or a palm-size serving of tofu, explain the researchers.

Using World Cancer Research Fund evidence grading criteria for evaluating the likelihood of causality, the researchers consider the overall evidence to indicate a probable causal relationship between both legume and soy intake and a reduced risk of high blood pressure.

There are plausible explanations for the findings, they say. Legumes and soy are high in potassium, magnesium, and dietary fibre, all of which are known for their blood pressure lowering properties.

And recent research has suggested that the fermentation of soluble fibre from legumes and soy produces short-chain fatty acids that influence blood vessel dilation, while the isoflavone content of soy also seems to help lower blood pressure, they explain.

The researchers acknowledge various limitations to their findings, including the variability of the studies in the pooled data analysis. This included differences in legume types, levels of intake, preparation methods, dietary contexts, and the definition of high blood pressure.

“Despite these limitations, the findings of this meta-analysis have major public health implications, given the alarming global increase in hypertension prevalence,” they point out.

“Current legume consumption across Europe and the UK remains below dietary recommendations, with average intakes of only 8–15g/day, far below the recommendations of 65 to 100g/day recommended for overall cardiovascular health,” they add.

“Although further large-scale cohorts are needed for confirmation, these findings provide further evidence in support of dietary recommendations to the public to prioritise and integrate legumes and soy foods as healthy protein sources in the diet,” they conclude.

“This research strengthens the evidence base for the cardioprotective benefits of plant-based diets. The authors have significantly added to the case for using legumes and soy as primary dietary strategies to mitigate the global burden of hypertension,” comments Professor Sumantra Ray, chief scientist and executive director of NNEdPro Global Institute for Food, Nutrition and Health, which co-owns BMJ Nutrition Prevention & Health.

“The strengths of the study lie in its rigorous dose-response analyses, which offer practical dietary targets for use in public health guidelines and clinical practice. But we can’t entirely rule out the influence of unmeasured influential factors. And the plateauing of benefits for soy at 60–80g/day warrants further investigation, as it remains unclear if this reflects a true biological limit or is a byproduct of the smaller number of studies available for analysis.”

Source: The BMJ Group

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Cutting Calories to Slow Ageing – Without Compromising Health

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Restricting calorie intake in species such as mice, rhesus monkeys, and fruit flies has been shown to extend their lifespans. In some cases, these animals not only live longer, but are also free of disease. But when pushed too far, calorie restriction can have negative impacts. Mice that undergo 40% reduction in calorie intake, for example, are more susceptible to infections, less likely to reproduce, and experience stunted growth.

Scientists have wondered whether there is a way to reap the longevity benefits of calorie restriction in humans without its negative repercussions. And in a new study, published April 13 in Nature Aging, they found a potential answer in an immune-related protein called complement component 3 (C3).

Yale researchers have previously shown that people who undergo moderate calorie restriction – a 14% reduction in calorie intake – for two years developed better immune defence without any growth or reproductive trade-offs.

“This concept demonstrates that ageing is actually malleable and a process that can be targeted,” says senior author Vishwa Deep Dixit, PhD, Waldemar Von Zedtwitz Professor of Pathology, professor of immunobiology and of comparative medicine, and director of the Yale Center for Research on Aging (Y-Age) at Yale School of Medicine.

Calorie restriction reduces inflammation-related protein

In the new study, Dixit and his colleagues at YSM analysed the plasma samples of 42 individuals who took part in a National Institutes of Health-funded two-year trial called the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy or CALERIE.

“It’s the only trial of its kind that has been done with such rigor and control and demonstrates relevance to human physiology,” Dixit says. During the trial, participants were able to reduce their calorie intake by 11 to 14% without feeling deprived.

In their analysis, the researchers detected more than 7000 proteins in the longitudinal plasma samples. Among them was an immune-related protein called complement component 3 (C3) that was significantly reduced following calorie restriction. C3 was of particular interest to the scientists as prior studies have suggested that activation of the complement system – a network of proteins involved in the defence against pathogens – could drive chronic inflammation, a major hallmark of ageing and age-associated diseases.

“But the causal effects of C3 in ageing and chronic inflammation have not been identified. So, we were very excited to find that in our study,” says Hee-Hoon Kim, PhD, a postdoctoral associate in the Dixit lab and a co-first author of the paper.

A target to slow ageing

When comparing the protein levels before and after two years of calorie restriction, the researchers identified white adipose tissue – the main type of fat tissue in mammals – as the primary site affected by calorie restriction.

The researchers confirmed their findings in animals. As with the human plasma, they found that C3 expression increased with age in mice. Further biochemical analyses showed that visceral white adipose tissue was responsible for an increase in C3 during ageing.

“We were not expecting that because these proteins are mainly synthesised in the liver,” says Manish Mishra, PhD, a postdoctoral associate in the Dixit lab and a co-first author of the study.

Single-cell RNA sequencing further revealed that the protein is produced by age-associated macrophages within the adipose tissues.

“This whole process was unknown in the beginning,” Mishra says. “Just to narrow it down to the subtypes of macrophages responsible for this complement protein production was very challenging.”

The body’s first line of immune defence, macrophages are mostly known for their role in engulfing pathogens. These immune cells also help maintain the balance of tissue functions, Dixit adds.

The question is whether the benefits gained from a reduction in C3 can be achieved without weight loss.

The researchers initially suspected that the shedding of adipose tissue or body fat due to weight loss may have stalled C3 production and slowed down the ageing process. After all, most of the study participants lost about 8.2kg after two years of moderate calorie restriction. However, when the researchers analysed the body mass index of the study participants, they did not observe any correlation between weight loss and a decrease in complement proteins.

“This suggests that calorie restriction has a beneficial effect that is unique to adipose tissues and is likely independent of weight loss,” Kim says.

Further, when the researchers inhibited C3 activation using a drug to mimic the effect of calorie restriction, the mice experienced less age-related inflammation.

The finding demonstrates that what is beneficial early on in life can be detrimental later on, Dixit says. This theory, known as antagonistic pleiotropy, was first proposed by biologist Peter Medawar in 1952 to describe the ageing process. A prime example of this theory is growth hormone production, which is essential in early development but could also drive cancer later in life.

Proteins like C3 are evolutionarily designed to protect us from infections, but as humans live much longer than their ancestors, these molecules can come back to harm us. Lowering the level of C3 proteins may be the key to enhancing health span, Dixit says.

The researchers are now investigating whether they could hold back C3 production to slow down ageing in humans using FDA-approved inhibitor drugs. “The idea is not to remove complement systems that are required for us to fight infections,” Dixit says. “Instead, the goal is to restore the balance.”

By Kristel Tjandra

Source: Yale University

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Increasing Fruit, Fibre, Dairy and Caffeine Linked to Lower Risk of Tinnitus

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But quality of evidence low and further studies needed to verify the relationship, say researchers

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Increased consumption of fruit, dietary fibre, dairy products and caffeine may be associated with a reduced risk of tinnitus (ringing in the ears), suggests an analysis of the available evidence, published in the open access journal BMJ Open.

The researchers stress that their findings can’t establish a direct (causal) relationship and should be interpreted with care because of the low quality of the evidence. But they say possible reasons may involve the protective effects of these diets on blood vessels and nerves, as well as their anti-inflammatory and antioxidant properties.

Tinnitus is the perception of sound (ringing, buzzing or clicking) when there’s no external source. Data suggests it affects around 14% of adults worldwide and is associated with depression, anxiety, stress, and in severe cases, suicide.

There is no cure, but treatments such as counselling, behavioral therapy, medications, and hearing aids can help to reduce symptoms.

Diet can also have a significant impact on tinnitus. It’s thought that eating high-quality nutrients can have a positive effect on hearing by improving blood flow to the inner ear and reducing oxidative damage and inflammation. But previous studies show conflicting results and it’s still uncertain which specific foods worsen or relieve symptoms.

To explore this further, the researchers trawled research databases looking for studies linking tinnitus and diet in adults published up to May 2024.

They found eight observational studies involving 301,533 people that assessed 15 dietary factors using validated questionnaires that were of suitable quality to include in their analysis.

The dietary factors included carbohydrates, caffeine, eggs, fruits, fibres, fat, meat, protein, sugar, fish, vegetables and dairy.

The combined findings revealed that increased consumption of fruit, dietary fibre, dairy products and caffeine was associated with a reduced occurrence of tinnitus. These reductions were 35% for fruit intake, 9% for dietary fibre, 17% for dairy products, and 10% for caffeine intake.

No associations were found between other dietary factors and tinnitus and results were consistent after further analyses, although the authors note that the association between caffeine intake and tinnitus remains contentious.

The authors acknowledge that due to the observational design of included studies, causality cannot be established, and the relatively small number of included studies may have led to certain conventionally accepted beneficial dietary factors (such as vegetables and eggs) not demonstrating significant differences.

However, they suggest that “the primary underlying mechanisms may involve the protective effects of these diets on blood vessels and nerves, as well as their anti-inflammatory and antioxidant properties” and say further large-scale studies are needed “to complement and verify the relationship between dietary intake and tinnitus.”

Source: BMJ Group

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New Report Highlights Fructose as a Key Driver of Metabolic Disease

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Researchers emphasise fructose’s unique role in obesity, metabolic syndrome and other chronic diseases

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A new report, published in Nature Metabolism, is shedding light on the distinct and underappreciated role of fructose in driving disease, separate from its role as a simple source of calories.

Researchers examine how common dietary sweeteners, including table sugar (sucrose) and high-fructose corn syrup, impact human health. While both contain glucose and fructose, fructose has unique metabolic effects that may more directly contribute to obesity and related conditions.

“Fructose is not just another calorie,” said Richard Johnson, MD, professor at the University of Colorado Anschutz and study lead author. “It acts as a metabolic signal that promotes fat production and storage in ways that differ fundamentally from glucose.”

The report outlines how fructose metabolism bypasses key regulatory steps in the body’s energy-processing pathways. This can lead to increased fat synthesis, depletion of cellular energy (ATP) and the production of compounds linked to metabolic dysfunction. Over time, these effects may contribute to metabolic syndrome, a cluster of conditions that includes obesity, insulin resistance and cardiovascular risk.

Importantly, the authors emphasise that fructose’s impact extends beyond dietary intake alone. The body can also produce fructose internally from glucose, suggesting that its role in disease may be broader than previously recognised.

The findings come amid ongoing concern about rising rates of obesity and diabetes worldwide. Although some countries have seen declines in sugary beverage consumption, overall intake of “free sugars” remains above recommended levels in many regions and continues to increase in others.

While fructose may have once served an evolutionary purpose, helping the body store energy that can aid survival during times of food scarcity, the researchers argue that in today’s environment of constant food availability, these same mechanisms now contribute to chronic disease.

“This review highlights fructose as a central player in metabolic health,” said Johnson. “Understanding its unique biological effects is critical for developing more effective strategies to prevent and treat metabolic disease.”

By Kelsea Pieters

Source: Colorado University Anschutz

Categories : Diet and Nutrition Metabolic DisordersTags :

Ultra-processed Foods Linked with Greater Risk of Overweight or Obesity in Adolescents

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The conclusion comes from a systematic review and meta-analysis of 23 studies and 155 000 adolescents across multiple countries and regions.

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Adolescents who consume more ultra-processed foods (UPFs) have significantly higher odds of being overweight or obese, according to a new systematic review and meta-analysis published in the open-access journal PLOS One by Mekuriaw Nibret Aweke of the University of Gondar, Ethiopia, and colleagues. In the most recent of the analysed studies, higher UPF consumption was linked with more than twice the odds of overweight or obesity compared to lower UPF consumption.

Being overweight or obese during adolescence raises a person’s likelihood of developing type 2 diabetes, high cholesterol, hypertension, and metabolic syndrome. The increasing consumption of UPFs – defined as industrial products made largely from extracted, modified, or synthetic ingredients, and typically high in added sugars, salt, unhealthy fats, and chemical additives – represents one of the fastest-growing unhealthy eating patterns among young people worldwide.

In the new study, researchers systematically searched multiple databases for observational studies reporting on UPF consumption and weight outcomes in adolescents aged 10 through 19. They identified 23 eligible studies involving a total of 155 000 adolescents, conducted across 16 countries between 2008 and 2025.

In a meta-analysis of all 23 studies, the researchers found that adolescents with higher UPF consumption had 63% greater odds of overweight or obesity compared with those with lower intake (OR = 1.63; 95% CI: 1.36–1.95). The positive association was consistent across all geographic regions studied, including Africa, Asia, Europe, North America, and South America. Subgroup analysis by year of publication showed that the most recent studies, published in 2024 and 2025, reported the highest odds ratio (OR = 2.09), suggesting the association may be growing stronger as UPF consumption rises globally.

Among other aspects, the study is limited by its reliance on observational designs, which cannot establish causation, and by variation across studies in how UPF consumption and obesity were measured.

The authors conclude that public health strategies should prioritize reducing UPF consumption among adolescents through education, policy interventions, and promotion of minimally processed, nutrient-dense foods.

The authors add: “Higher consumption of ultra-processed foods is linked to a substantially increased risk of overweight and obesity among adolescents, emphasising the need for early dietary interventions.”

“Improving adolescent nutrition today is essential to protecting long-term population health and reducing healthcare costs associated with obesity-related conditions.”

Provided by PLOS

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People Who Consume Ultra-Processed Foods Have Worse Muscle Health

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Thigh muscle fat identified as a potential modifiable risk factor for knee osteoarthritis

Representative axial T1-weighted spin-echo thigh MRI scans in (A) a 61-year-old female participant and (B) a 62-year-old female participant. Both participants were of similar age and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared). Both had Physical Activity Scale for the Elderly scores above the mean score in the study. According to the World Health Organization definition, the participant in B qualified as having abdominal obesity (abdominal circumference ≥ 88 cm). Abdominal circumference is a measure of central obesity that captures fat distribution and serves as an indicator of cardiometabolic health. Compared with the participant in A, the participant in B had a higher proportion of ultra-processed food (UPF) in their diet (87.1% vs 29.5%) and exhibited fattier thigh muscles bilaterally, with Goutallier grade (GG) for all thigh muscles summing to 25 for the participant in A and 38 for the participant in B.

https://doi.org/10.1148/radiol.251129 ©RSNA 2026

Researchers found that a diet high in ultra-processed foods is associated with higher amounts of fat stored inside thigh muscles, regardless of calorie or fat intake, physical activity or sociodemographic factors in a population at risk for knee osteoarthritis. Results of the study were published in Radiology.

Ultra-processed foods usually have longer shelf lives and can be highly appealing and convenient. They contain a combination of sugar, fat, salt and carbohydrates which affect the brain’s reward system, making it hard to stop eating.

“Over the past decades, in parallel to the rising prevalences of obesity and knee osteoarthritis, the use of natural ingredients in our diets has steadily diminished and been replaced by industrially-processed, artificially flavored, colored and chemically altered food and beverages, which are classified as ultra-processed foods,” said the study’s lead author, Zehra Akkaya, MD, researcher and consultant for the Clinical & Translational Musculoskeletal Imaging group at University of California, San Francisco, Department of Radiology and Biomedical Imaging.

Dr. Akkaya and the research team set out to assess the relationship of ultra-processed food intake and intramuscular fat in the thigh.

For the study, researchers analyzed data from 615 individuals who participated in the Osteoarthritis Initiative who were not yet affected by osteoarthritis, based on imaging. The Osteoarthritis Initiative is a nationwide research study, sponsored by the National Institutes of Health, that helps researchers better understand how to prevent and treat knee osteoarthritis.

“Osteoarthritis is an increasingly prevalent and costly global health issue,” Dr. Akkaya said. “It constitutes one of the largest non-cancer-related health care costs in the United States and around the world. It is highly linked to obesity and unhealthy lifestyle choice.”

Of the 615 individuals, (275 men, 340 women) the average age was 60 years. On average, participants were overweight with a body mass index (BMI) of 27. Approximately 41% of the foods they consumed over the prior year were ultra-processed.

The researchers found that the more ultra-processed foods people consumed, the more intramuscular fat they had in their thigh muscles, regardless of caloric intake.

“In addition to investigating the quality of our modern diet in relationship to thigh muscle composition, in this study, we used widely available, non-enhanced MRI, making our approach accessible and practical for routine clinical use and future studies,” Dr. Akkaya said. “These MRIs do not require advanced or costly technology, which means they can be easily incorporated into standard diagnostic practices.”

Source: Radiological Society of North America

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Sugary Drink Taxes May Not Be Effective in Fast-food Settings

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Analysis of nearly 7 billion Taco Bell transactions finds sugary drink taxes not linked to lower beverage calorie purchases

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Taxes on sugary drinks had no effect on beverage calorie purchases from fast-food chain restaurants in the U.S., according to a new study by Brian Elbel and Pasquale Rummo from NYU Grossman School of Medicine and colleagues publishing April 2nd in the open-access journal PLOS Medicine.

Sugary drink taxes have been adopted in several U.S. jurisdictions as a public health strategy to curb sugar consumption and improve dietary behaviors. Research on the impact of these taxes on grocery stores purchases attribute sugary drink taxes to an estimated 15% decrease in sales. However, whether this translates to an impact in restaurant sales has not been well studied.

Researchers analyzed six years of sales data (2015–2020) from more than 7,300 Taco Bell locations nationwide, focusing on drive‑through purchases. The study compared beverage calories per transaction at 60 restaurants across five jurisdictions with sugary drink taxes—Albany, California; Cook County, Illinois; Oakland, California; Philadelphia, Pennsylvania; and Seattle, Washington—with a matched group of similar restaurants in areas without such taxes.

Overall, the analysis found no significant association between sugary drink taxes and beverage calories per transaction, suggesting that sugary drink taxes of this size or alone may not substantially reduce beverage calorie consumption in fast food restaurant settings.

The authors note that consumer behaviour in restaurants—such as choosing combo meals or prioritising convenience—may limit the effectiveness of these policies.

Elbel adds, “Using millions of transactions from six years of sales data, we found that sugary beverage taxes did not influence beverage calories when implemented in five cities in the U.S.”

Rummo notes, “These results suggest that sugary drink taxes may not be effective in reducing beverage calorie consumption in fast food restaurants, as compared to supermarkets. This could be because the sizes of sugary drink taxes in the U.S. are too small for consumers or that they just aren’t responsive to price changes in these settings, among other reasons.”

Provided by PLOS

Categories : Diet and Nutrition Obstetrics & GynaecologyTags :

Study: Intermittent Fasting Positively Affects Female Hormones in PCOS 

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Polycystic ovary syndrome, or PCOS, affects as many as 18% of all childbearing-age women. The condition occurs when a woman’s body produces too androgens, chiefly testosterone. Menstrual irregularity, obesity and even infertility can result.

The first line of treatment is typically hormonal birth control, said UIC professor of nutrition Krista Varady. But there can be negative side effects to mood, libido and metabolism, plus an increased stroke risk in some people, Varady said.

“We’re looking for other ways of lowering testosterone levels in these women,” she said. “One way is through weight loss. If someone loses around 5% of their body weight, they can actually help lower testosterone levels and sidestep any kind of drug intervention.”

A new study led by Varady tested how one weight-loss method — intermittent fasting — affects hormones and symptoms in patients with PCOS. Published in Nature Medicine, the research shows that restricting eating to a six-hour daily window decreased testosterone without negatively affecting female hormones. The study also showed that weight loss through calorie counting decreased testosterone. 

However, some critics of intermittent fasting have posited that the diet disrupts female hormones, Varady said.

“There’s a particular sentiment that intermittent fasting is really bad for women.” This is untrue, she said. “This study and several other studies published by our lab and others show that intermittent fasting can actually improve female hormone levels, particularly in women with PCOS.” 

Varady and her colleagues studied a type of intermittent fasting called time-restricted eating. In this method, you eat only during a set six- or eight-hour period each day. During the remaining 18 or 16 hours, you fast with calorie-free beverages and water until the next day. 

Simply put, the strategy helps people eat less, Varady said. So does counting calories, a method Varady and her colleagues tested alongside intermittent fasting in the study. But intermittent fasting had some additional benefits.

“It’s a way of reducing energy intake without having to do really complicated calorie counting,” she said about intermittent fasting. Varady and others have shown in previous work that eating only during an eight-hour window can cut around 300 to 500 calories a day.

In addition to obesity and insulin resistance, which raise risks of diabetes and heart disease, PCOS can cause ovarian cysts, acne and facial hair growth.

In a group of 76 pre-menopausal women with PCOS, the researchers tested how outcomes differed after six months between time-restricted eating between 1 and 7 p.m. daily and calorie counting. Both diet schemes ended up cutting participants’ intake by about 200 calories per day, the team found, leading to average weight loss of about 10 pounds over the six months.

Both groups also experienced a decrease in testosterone concentrations. But only time-restricted eating reduced free androgen index, the ratio between testosterone and the protein that transports it through the blood, which is a marker of how much active testosterone is reaching a body’s tissues. It also improved A1C levels, a risk marker for diabetes, Varady said.

Though intermittent fasting did not lessen other PCOS symptoms, like menstrual period irregularity, Varady suggested those symptoms might improve with longer time on the diet and greater weight loss.

About 80% of the participants in the time-restricted eating group said they were going to continue the diet, Varady said.

Story by Tess Joosse

Source: EurekAlert!

Categories : Diet and Nutrition GastrointestinalTags :

Trace Levels of Food Pathogen Aren’t Always a Health Risk, Study Finds

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Ultra-sensitive food safety tests may drive food waste and unavailability with limited public health benefit, according to a Frontiers in Science study.

These food safety measures and ultra-sensitive tests may drive edible food being thrown away, excessive packaging, and extra costs for consumers.

The international team of researchers make it clear that food safety is an important concern, as foodborne pathogens account for approximately 420 000 deaths and 600 million cases of illness each year. However, the authors argue that food systems will be more sustainable, while continuing to protect public health, if “zero-detection” expectations are replaced with evidence-based targets for “sufficiently safe” food.

Their new article sets out how regulators might find trade-offs with other important factors, such as food supply security, sustainability, and nutritional health.

“Although the public expects food to be completely safe, there will always be some risk of foodborne illness. Zero risk doesn’t exist, and we shouldn’t be aiming for that either. Just as we don’t limit highway speeds to 10 miles per hour to minimize road deaths, we need to take a balanced approach that considers possible negative consequences of extreme food safety measures,” said lead author Prof Martin Wiedmann from Cornell University.

Read and download the article

Impact of aiming for zero risk

The study’s authors highlight several situations where excessive caution can cause harm.

Many rules and purchasing standards rely heavily on detecting a pathogen, sometimes treating any detection as unacceptable without fully considering dose, exposure, the food’s ability to support microbial growth, or who is most at risk.

For example, a food product might be considered contaminated if it tests positive for the bacterium Listeria monocytogenes, regardless of levels.

These alarms can result from ultra-sensitive tests detecting small amounts of microbes unlikely to cause disease in humans. In some cases, the concerns may come from bacteria that are not harmful themselves, but are an indirect indicator of contamination.

Throwing away such food reduces the available food supply and wastes resources. Similarly, recalling food products from consumers can damage consumer trust, pushing people away from otherwise healthy products.

Other protective measures, such as storage temperatures, packaging, and heat treatment, can waste energy, increase costs, and reduce nutritional content. While these are all important safety measures, they should only be applied if needed and associated trade-offs should be considered.

“A tremendous amount of food is wasted that would have been sufficiently safe to eat. Too often, trade-offs such as environmental or economic costs are only considered after a traditional microbial risk assessment. We cannot afford to carry on like this at a time when we desperately need to reduce our impact on the planet and assure not only food safety but food security,” said co-author Prof Sophia Johler at Ludwig Maximilian University of Munich, Germany.

Focus on risk rather than hazard

The current situation is driven by an emphasis on hazard-based assessments, according to the authors, where regulations focus on detecting pathogens, regardless of the threat to consumers. The researchers argue that the food system should move towards more flexible risk-based approaches, which assess the probabilities of harms and adjust the safety measures accordingly.

Regulations that overemphasize stringent corrective actions (such as recalls) when swab samples from a food-processing facility test positive for an indicator, for example, could lead to undue corrective actions in areas that are unlikely to contaminate the food. The authors explain that this could be an opportunity cost that diverts resources away from more effective interventions and control strategies in high-risk areas.

“There’s well-established evidence that focusing on end-product testing is generally ineffective to ensure safety. Overemphasis on end-product testing may distract from other food safety measures (e.g., applying validated and verified process controls), which can provide greater public health benefits,” said co-author Dr Sriya Sunil at Cornell University.

Better tools to assess priorities

Computational tools that incorporate vast amounts of information across the food production system could help with establishing acceptable risks.

One challenge is how to prioritize different hazards. For example, in the US, norovirus causes thousands of times more cases than Listeria monocytogenes, yet Listeria monocytogenes causes more deaths per year.

While there are trade advantages to having consistent international food safety standards, the balance between competing interests may vary between regions. This can become even more complex when factoring in the health and environmental implications of greenhouse gas emissions.

“Specialists across social sciences, economics, and life sciences must work together to establish values that align with consumers’ priorities. Together with advanced models that build on geographic information, AI, and genomics, we can assess, manage, and communicate risks far more accurately,” said Wiedmann.

Source: Frontiers

Categories : Diet and Nutrition Neurodegenerative DiseasesTags :

High Meat Intake Linked to Lower Dementia Risk in APOE4

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Older people with a genetic risk of Alzheimer’s disease did not experience the expected increase in cognitive decline and dementia risk if they consumed relatively large amounts of meat. This is shown in a new study from Karolinska Institutet published in JAMA Network Open. The results may contribute to the development of more individually tailored dietary advice.

APOE is a gene that affects the risk of Alzheimer’s disease. In Sweden, approximately 30 per cent of the population are carriers of the gene combinations APOE 3/4 or APOE 4/4. Among people with Alzheimer’s disease, those with these genotypes account for nearly 70 per cent.

When the Swedish Food Agency presented an overview of research on the link between diet and dementia last year, more research was requested to assess a possible link between meat consumption and the development of dementia.

‘This study tested the hypothesis that people with APOE 3/4 and 4/4 would have a reduced risk of cognitive decline and dementia with higher meat intake, based on the fact that APOE4 is the evolutionarily oldest variant of the APOE gene and may have arisen during a period when our evolutionary ancestors ate a more animal-based diet,’ says first author Jakob Norgren, researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet.

The study followed more than 2100 participants in the Swedish National Study on Aging and Care, Kungsholmen (SNAC-K) for up to 15 years. All were aged 60 or older and had no diagnosis of dementia at the start of the study. The association between self-reported diet and cognitive health measures was analysed, adjusting for age, sex, education and lifestyle factors.

Twice the risk of dementia

At lower meat intake, the group with APOE 3/4 and 4/4 had more than twice the risk of dementia than people without these gene variants. However, the increased risk of cognitive decline and dementia in the risk groups was not seen in the fifth of participants who consumed the most meat. Their median consumption is estimated at approximately 870 grams of meat per week, standardised to a daily energy intake of 2,000 calories.

‘Those who ate more meat overall had significantly slower cognitive decline and a lower risk of dementia, but only if they had the APOE 3/4 or 4/4 gene variants,’ says Jakob Norgren. He continues: 

‘There is a lack of dietary research into brain health, and our findings suggest that conventional dietary advice may be unfavourable to a genetically defined subgroup of the population. For those who are aware that they belong to this genetic risk group, the findings offer hope; the risk may be modifiable through lifestyle changes. ‘

The study also shows that the type of meat is important.

‘A lower proportion of processed meat in total meat consumption was associated with a lower risk of dementia regardless of APOE genotype,’ says Sara Garcia-Ptacek, assistant professor at the same department, who together with senior lecturer Erika J Laukka is the study’s last author.

The findings also extend beyond brain health. In a follow-up analysis, the researchers observed a significant reduction in all-cause-mortality in carriers of APOE 3/4 and 4/4 with higher consumption of unprocessed meat.

However, the study is observational and needs to be followed up with intervention studies that can better demonstrate causal relationships.

‘Clinical trials are now needed to develop dietary recommendations tailored to APOE genotype,’ says Jakob Norgren. He continues:

‘Since the prevalence of APOE4 is about twice as high in the Nordic countries as in the Mediterranean countries, we are particularly well suited to conduct research on tailored dietary recommendations for this risk group.’

The research was funded by, among others, the Swedish Alzheimer’s Foundation, the Swedish Dementia Foundation, the Emil and Wera Cornell Foundation, the Leif Lundblad family and other philanthropists, the Swedish Research Council and FORTE. The researchers state that they have no related conflicts of interest.

APOE Gene Facts:

Apolipoprotein E plays a central role in the transport of cholesterol and fats in the brain and blood. The protein is encoded by the APOE gene, which exists in three main variants: epsilon 2, 3 and 4. These variants affect the risk of developing Alzheimer’s disease and cardiovascular disease. Each person inherits two APOE genes, one from each parent, giving six possible combinations (genotypes): 2/2, 2/3, 2/4, 3/3, 3/4 and 4/4.

Compared to the most common genotype 3/3, one 4 variant increases the risk of Alzheimer’s disease by about three to four times and two 4 variants by about ten to fifteen times, while the 2 variant is associated with a lower risk. However, the increase in risk varies between different ethnic groups.

Source: Belloy et al., JAMA Neurology, 2023

Source: Karolinska Institutet