Plant-based and/or fish diets may help lessen severity of COVID-19 infection
Johns Hopkins University, June 8, 2021
Plant-based and/or fish (pescatarian) diets may help lower the odds of developing moderate to severe COVID-19 infection, suggest the findings of a six-country study, published in the online journal BMJ Nutrition Prevention & Health.
They were associated with 73% and 59% lower odds, respectively, of severe disease, the findings indicate.
Several studies have suggested that dietmight have an important role in symptom severity and illness duration of COVID-19 infection. But, as yet, there’s little evidence to confirm or refute this theory.
To explore this further, the researchers drew on the survey responses of 2884 frontline doctors and nurses with extensive exposure to SARS-CO-v2, the virus responsible for COVID-19 infection, working in France, Germany, Italy, Spain, the UK and the US.
The participants were all part of a global network of healthcare professionals registered with the Survey Healthcare Globus network for healthcare market research. The researchers used this network to identify clinicians at high risk of COVID-19 infection as a result of their jobs.
The online survey, which ran between July and September 2020, was designed to elicit detailed information about respondents’ dietary patterns, based on a 47-item food frequency questionnaire, over the previous year, and the severity of any COVID-19 infections they had had, using objective criteria.
The survey also gathered information on personal background, medical history, medication use, and lifestyle.
The various diets were combined into plant-based (higher in vegetables, legumes, and nuts, and lower in poultry and red and processed meats); pescatarian/plant-based (as above, but with added fish/seafood); and low carb-high protein diets.
Some 568 respondents (cases) said they had had symptoms consistent with COVID-19 infection or no symptoms but a positive swab test for the infection; 2316 said they hadn’t had any symptoms/tested positive (comparison group).
Among the 568 cases, 138 clinicians said they had had moderate to severe COVID-19 infection; the remaining 430 said they had had very mild to mild COVID-19 infection.
After factoring in several potentially influential variables, including age, ethnicity, medical specialty, and lifestyle (smoking, physical activity), respondents who said they ate plant-based diets’ or plant-based/pescatarian diets had, respectively, 73% and 59% lower odds of moderate to severe COVID-19 infection, compared with those who didn’t have these dietary patterns.
And compared with those who said they ate a plant-based diet, those who said they ate a low carb-high protein diet had nearly 4 times the odds of moderate to severe COVID-19 infection.
These associations held true when weight (BMI) and co-existing medical conditions were also factored in.
But no association was observed between any type of diet and the risk of contracting COVID-19 infection or length of the subsequent illness.
This is an observational study, and so can’t establish cause, only correlation. It also relied on individual recall rather than on objective assessments, and the definition of certain dietary patterns may vary by country, point out the researchers.
Men outnumbered women in the study, so the findings may not be applicable to women, they add.
But plant-based diets are rich in nutrients, especially phytochemicals (polyphenols, carotenoids), vitamins and minerals, all of which are important for a healthy immune system, say the researchers.
And fish is an important source of vitamin D and omega-3 fatty acids, both of which have anti-inflammatory properties, they add.
“Our results suggest that a healthy diet rich in nutrient dense foods may be considered for protection against severe COVID-19,” they conclude.
“The trends in this study are limited by study size (small numbers with a confirmed positive test) and design (self-reporting on diet and symptoms) so caution is needed in the interpretation of the findings,” comments Deputy Chair of the NNEdPro Nutrition and COVID-19 Taskforce, Shane McAuliffe.
“However, a high quality diet is important for mounting an adequate immune response, which in turn can influence susceptibility to infection and its severity.”
He adds:”This study highlights the need for better designed prospective studies on the association between diet, nutritional status and COVID-19 outcomes.”
Greater magnesium intake associated with reduced hostility among young adults
Columbia University, June 4, 2021
According to news originating from New York City, New York, research stated, “Hostility is a complex personality trait associated with many cardiovascular risk factor phenotypes. Although magnesium intake has been related to mood and cardio-metabolic disease, its relation with hostility remains unclear.”
Our news journalists obtained a quote from the research from Columbia University, “We hypothesize that high total magnesium intake is associated with lower levels of hostility because of its putative antidepressant mechanisms. To test the hypothesis, we prospectively analyzed data in 4,716 young adults aged 18-30 years at baseline (1985-1986) from four U.S.cities over five years of follow-up using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Magnesium intake was estimated from a dietary history questionnaire plus supplements at baseline. Levels of hostility were assessed using the Cook-Medley scale at baseline and year 5 (1990-1991). Generalized estimating equations were applied to estimate the association of magnesium intake with hostility as repeated measures at the two time-points (baseline and year 5). General linear model was used to determine the association between magnesium intake and change in hostility over 5 years. After adjustment for socio-demographic and major lifestyle factors, a significant inverse association was observed between magnesium intake and hostility level over 5 years of follow-up. Beta coefficients (95% CI) across higher quintiles of magnesium intake were 0 (reference),-1.28 (-1.92,-0.65),-1.45 (-2.09,-0.81),-1.41 (-2.08,-0.75) and-2.16 (-2.85,-1.47), respectively (Plinear-trend < .01).”
According to the news editors, the research concluded: “The inverse association was inde-pendent of socio-demographic and major lifestyle factors, supplement use, and depression status at year 5. This prospective study provides evidence that in young adults, high magne-sium intake was inversely associated with hostility level independent of socio-demographic and major lifestyle factors.”
Study compares heart benefits of low-fat and plant-centered diets
New findings suggest that a plant-centered diet could help lower heart disease risk
University of Minnesota, June 7, 2021
There has been a long-standing debate as to whether a low-fat or a plant-centered diet is better at lowering the risk of cardiovascular disease. A new study that followed more than 4,700 people over 30 years, found that a plant-centered diet was associated with a lower long-term risk for cardiovascular disease. However, both diets were linked with lower LDL, or bad cholesterol, levels.
“Since 1980, dietary guidelines in the United States and in Europe have recommended eating low amounts of saturated fat because of the high rates of heart disease in these regions,” said research team leader David Jacobs, PhD, from the University of Minnesota. “This is not necessarily wrong, but our study shows that plant-centered diets can also lower bad cholesterol and may be even better at addressing heart disease risk.”
The plant-centered diet emphasizes fruit, vegetables, legumes, whole grains, nuts and seeds, low-fat dairy, and fish. It also limits high-fat red and processed meats, salty snacks, sweets, and sugar-sweetened soft drinks. The low-fat diet is based on the Keys Score, a good formulation of the “low saturated fat” message, driven by saturated fat, but also including polyunsaturated fat and dietary cholesterol.
Yuni Choi, PhD, a postdoctoral fellow in Jacobs’ lab will present the research as part of NUTRITION 2021 LIVE ONLINE, a virtual conference hosted by the American Society for Nutrition (ASN).
“Our findings show that it is important to view diet quality from a holistic perspective,” said Choi. “Targeting just single nutrients such as total or saturated fat doesn’t take into account the fats that are also found in healthy plant-based foods such as avocado, extra virgin olive oil, walnuts and dark chocolate — foods that also have cardioprotective properties and complex nutrient profiles.”
The new research is based on participants in the four U.S. clinics of the Coronary Artery Risk Development in Young Adults study (CARDIA), which enrolled 5115 Black and white men and women in 1985-1986. During more than 30 years of follow up, there were 280 cases of cardiovascular disease, 135 cases of coronary heart disease, and 92 cases of stroke among the study participants.
To assess eating patterns, the researchers conducted three detailed diet history interviews over the follow-up period. These diet history questionnaires determined what participants ate and then asked them to list everything consumed in that category. For example, participants who reported eating meat in the past 30 days would be asked what meat items and how much they consumed. This was repeated for around 100 areas of the diet. Based on this information, the researchers calculated scores for all participants based on both the Keys Score of the A Priori Diet Quality Score (APDQS), which captures the plant-centered diet.
After accounting for various factors including socioeconomic status, educational level, energy intake, history of cardiovascular disease, smoking and body mass index, the researchers found that having a more plant-centered diet (higher APDQS Scores) and consuming less saturated fat (lower Keys Scores) were both associated with lower LDL levels. However, lower LDL levels did not necessarily correlate with lower future risk of stroke. Higher APDQS scores, but not lower Keys Scores, were strongly associated with a lower risk for coronary heart disease and stroke.
“Based on our study, we suggest that people incorporate more nutritionally-rich plant foods into their diets,” said Choi. “One way to do this is to fill 70 percent of your grocery bag with foods that include vegetables, fruits, whole grains, nuts, legumes, coffee and tea.”
The researchers are carrying out a variety of studies looking at how the APDQS diet score relates to various health outcomes. They are also interested in studying how different diets affect gut bacteria, which is known to influence many aspects of health and disease.
High caffeine consumption may be associated with increased risk of blinding eye disease
Mount Sinai School of Medicine, June 7, 2021
Consuming large amounts of daily caffeine may increase the risk of glaucoma more than three-fold for those with a genetic predisposition to higher eye pressure according to an international, multi-center study. The research led by the Icahn School of Medicine at Mount Sinai is the first to demonstrate a dietary – genetic interaction in glaucoma. The study results published in the June print issue of Ophthalmology may suggest patients with a strong family history of glaucoma should cut down on caffeine intake.
The study is important because glaucoma is the leading cause of blindness in the United States. It looks at the impact of caffeine intake on glaucoma, and intraocular pressure (IOP) which is pressure inside the eye. Elevated IOP is an integral risk factor for glaucoma, although other factors do contribute to this condition. With glaucoma, patients typically experience few or no symptoms until the disease progresses and they have vision loss.
“We previously published work suggesting that high caffeine intake increased the risk of the high-tension open angle glaucoma among people with a family history of disease. In this study we show that an adverse relation between high caffeine intake and glaucoma was evident only among those with the highest genetic risk score for elevated eye pressure,” says lead/corresponding author Louis R. Pasquale, MD, FARVO, Deputy Chair for Ophthalmology Research for the Mount Sinai Health System.
A team of researchers used the UK Biobank, a large-scale population-based biomedical database supported by various health and governmental agencies. They analyzed records of more than 120,000 participants between 2006 and 2010. Participants were between 39 and 73 years old and provided their health records along with DNA samples, collected to generate data. They answered repeated dietary questionnaires focusing on how many caffeinated beverages they drink daily, how much caffeine-containing food they eat, the specific types, and portion size. They also answered questions about their vision, including specifics on if they have glaucoma or a family history of glaucoma. Three years into the study later they had their IOP checked and eye measurements.
Researchers first looked at the relationship looked between caffeine intake, IOP and self-reported glaucoma by running multivariable analyses. Then they assessed if accounting for genetic data modified these relationships. They assigned each subject an IOP genetic risk score and performed interaction analyses.
The investigators found high caffeine intake was not associated with increased risk for higher IOP or glaucoma overall; however, among participants with the strongest genetic predisposition to elevated IOP – in the top 25 percentile – greater caffeine consumption was associated with higher IOP and higher glaucoma prevalence. More specifically, those who consumed the highest amount of daily caffeine- more than 480 milligrams which is roughly four cups of coffee – had a 0.35 mmHg higher IOP. Additionally, those in the highest genetic risk score category who consumed more than 321 milligrams of daily caffeine – roughly three cups of coffee – had a 3.9-fold higher glaucoma prevalence when compared to those who drink no or minimal caffeine and in lowest genetic risk score group.
“Glaucoma patients often ask if they can help to protect their sight through lifestyle changes, however this has been a relatively understudied area until now. This study suggested that those with the highest genetic risk for glaucoma may benefit from moderating their caffeine intake. It should be noted that the link between caffeine and glaucoma risk was only seen with a large amount of caffeine and in those with the highest genetic risk,” says co-author Anthony Khawaja, MD, PhD, Associate Professor of Ophthalmology University College London (UCL) Institute of Ophthalmology and ophthalmic surgeon at Moorfields Eye Hospital. “The UK Biobank study is helping us to learn more than ever before about how our genes affect our glaucoma risk and the role that our behaviors and environment could play. We look forward to continuing to expand our knowledge in this area.”
Red onions pack a cancer-fighting punch, study reveals
University of Guelph (Ontario), June 7, 2021
The next time you walk down the produce aisle of your grocery store, you may want to reach for red onions if you are looking to fight off cancer.
In the first study to examine how effective Ontario-grown onions are at killing cancer cells, U of G researchers have found that not all onions are created equal.
Engineering professor Suresh Neethirajan and PhD student Abdulmonem Murayyan tested five onion types grown in Ontario and discovered the Ruby Ring onion variety came out on top.
Onions as a superfood are still not well known. But they contain one of the highest concentrations of quercetin, a type of flavonoid, and Ontario onions boasts particularly high levels of the compound compared to some parts of the world.
The Guelph study revealed that the red onion not only has high levels of quercetin, but also high amounts of anthocyanin, which enriches the scavenging properties of quercetin molecules, said Murayyan, study’s lead author.
“Anthocyanin is instrumental in providing colour to fruits and vegetables so it makes sense that the red onions, which are darkest in colour, would have the most cancer-fighting power.”
Published recently in Food Research International, the study involved placing colon cancer cells in direct contact with quercetin extracted from the five different onion varieties.
“We found onions are excellent at killing cancer cells,” said Murayyan. “Onions activate pathways that encourage cancer cells to undergo cell death. They promote an unfavourable environment for cancer cells and they disrupt communication between cancer cells, which inhibits growth.”
The researchers have also recently determined onions are effective at killing breast cancer cells.
“The next step will be to test the vegetable’s cancer-fighting powers in human trials,” said Murayyan.
These findings follow a recent study by the researchers on new extraction technique that eliminates the use of chemicals, making the quercetin found in onions more suitable for consumption.
Other extraction methods use solvents that can leave a toxic residue which is then ingested in food, said Neethirajan.
“This new method that we tested to be effective only uses super-heated water in a pressurized container,” he said. “Developing a chemical-free extraction method is important because it means we can use onion’s cancer-fighting properties in nutraceuticals and in pill form.”
While we can currently include this superfood in salads and on burgers as a preventative measure, the researchers expect onion extract will eventually be added to food products such as juice or baked goods and be sold in pill form as a type of natural cancer treatment.
Exercise likely to be best treatment for depression in coronary heart disease
RCSI University of Medicine and Health Sciences (Ireland), June 8, 2021
A study by RCSI indicates that exercise is probably the most effective short-term treatment for depression in people with coronary heart disease, when compared to antidepressants and psychotherapy or more complex care.
The study, led by researchers at RCSI University of Medicine and Health Sciences, is published in the June edition of Psychosomatic Medicine.
This is the first systematic review to compare treatments for depression in those with coronary disease and the findings provides valuable clinical information to help doctors determine the best treatment plan for patients.
The researchers reviewed treatment trials which investigated antidepressants, psychotherapy, exercise, combined psychotherapy and antidepressants, and collaborative care (i.e. treatments devised by a multidisciplinary team of clinicians with input from the patient).
To measure effectiveness, the researchers looked at factors including patient adherence to the treatment (dropout rate) and change in depressive symptoms eight weeks after commencing treatment.
The strongest treatment effects were found to be exercise and combination treatments (antidepressants and psychotherapy). However, as the combination study results have a high risk of bias, the findings of the review suggest that exercise is probably the most effective treatment. Antidepressants had the most research support, while psychotherapy and collaborative care did not perform very well.
“Depression is common in patients with coronary artery disease. Having both conditions can have a significant impact on the quality of life for patients so it is vital that they access to the most effective treatments,” commented Dr Frank Doyle, Senior Lecturer Division of Population Health Sciences, RCSI and the study’s first author.
“Our study indicates that exercise is likely to be the best treatment for depression following coronary artery disease. Our findings further highlight the clinical importance of exercise as a treatment as we see that it improves not only depression, but also other important aspects of heart disease, such as lowering blood pressure and cholesterol, in these patients.”
“We continue to see emerging evidence of the importance of lifestyle to treat disease – in comparison to other treatments – but further high-quality research is needed. People with coronary heart disease who have symptoms of depression should talk to their doctor about treatments that are most suitable for their personal needs, and clinicians can be confident of recommending exercise to their patients.”
Dr Frank Doyle and the study’s senior authors, Prof. Jan Sorensen (Health Outcomes Research Centre, RCSI) and Prof. Martin Dempster (School of Psychology, Queen’s University Belfast), conducted the study in collaboration with researchers in the USA, The Netherlands, the UK and Denmark.
This study was also the first of its kind to establish a new method to conduct systematic reviews known as a hybrid review, which is a combination of umbrella reviews and systematic reviews.
Study examines link between obesity, food container chemical substitutes
University of Iowa, June 9, 2021
A new study from the University of Iowa shows that a pair of common chemicals that manufacturers use to make plastic food containers, water bottles, and other consumer products do not contribute to obesity to the extent of the chemical it’s replacing.
The chemicals — bisphenol F and bisphenol S (known as BPF and BPS) — are being used increasingly by food packaging manufacturers as substitutes for bisphenol A (BPA), which studies have found disrupts endocrine systems and causes numerous health problems. BPA is used in many kinds of packaging for snacks and drinks, canned foods, and water bottles. The chemical is absorbed into the body mainly through the food or water it contacts in the container.
But concern was raised several years ago when numerous studies found BPA increases the risk of various health issues, in particular obesity, diabetes, and cardiovascular disease. A consumer backlash erupted after the studies received media attention so manufacturers started reducing the use of BPA in some consumer products or even eliminating it in so-called “BPA-free” products by replacing it with such alternatives as BPF and BPS.
However, little is known on the potential impact of BPF and BPS exposure in humans. The new University of Iowa College of Public Health study is the first to determine the health impacts of BPF and BPS exposure on obesity in humans. Using data from a nationwide population-based study conducted by the U.S. Centers for Disease Control (CDC), the researchers confirm that BPA is associated with increased obesity in humans. But the study found no links between obesity and either BPF or BPS at the current exposure levels.
However, the researchers warn that fewer products currently use BPF and BPS–BPA still has more than half the global market share for the chemicals, and the average concentration of BPF and BPS is about one-fourth that of BPA in the US population. Whether BPF and BPS pose an increased risk of obesity at the same population exposure levels as BPA remains unknown. Future studies will be needed to confirm the results, as BPF and BPS are likely to replace BPA in more consumer products.