Eating leafy greens could help prevent macular degeneration
Westmead Institute for Medical Research (Australia), October 13, 2021
A new study has shown that eating vegetable nitrates, found mainly in green leafy vegetables and beetroot, could help reduce your risk of developing early-stage age-related macular degeneration (AMD).
Researchers at the Westmead Institute for Medical Research interviewed more than 2,000 Australian adults aged over 49 and followed them over a...
Eating leafy greens could help prevent macular degeneration
Westmead Institute for Medical Research (Australia), October 13, 2021
A new study has shown that eating vegetable nitrates, found mainly in green leafy vegetables and beetroot, could help reduce your risk of developing early-stage age-related macular degeneration (AMD).
Researchers at the Westmead Institute for Medical Research interviewed more than 2,000 Australian adults aged over 49 and followed them over a 15-year period.
The research showed that people who ate between 100 to 142 mgs of vegetable nitrates each day had a 35% lower risk of developing early AMD than people who ate less than 69mgs of vegetable nitrates each day.
Lead Researcher Associate Professor Bamini Gopinath from the Westmead Institute and the University of Sydney said the link between vegetable nitrates and macular degeneration could have important implications.
"This is the first time the effects of dietary nitrates on macular degeneration risk has been measured.
"Essentially we found that people who ate 100 to 142 mgs of vegetable nitrates every day had a reduced risk of developing early signs of macular degeneration compared with people who ate fewer nitrates.
"If our findings are confirmed, incorporating a range of foods rich in dietary nitrates - like green leafy vegetables and beetroot - could be a simple strategy to reduce the risk of early macular degeneration," Associate Professor Gopinath said.
Spinach has approximately 20mg of nitrate per 100g, while beetroot has nearly 15mg of nitrate per 100g.
The research did not show any additional benefits for people who exceeded 142mgs of dietary nitrate each day. It also did not show any significant connections between vegetable nitrates and late stage AMD, or between non-vegetable nitrates and AMD risk.
One in seven Australians over 50 have some signs of macular degeneration.
Age is the strongest known risk factor and the disease is more likely to occur after the age of 50.
There is currently no cure for the disease.
The research compiled data from the Blue Mountains Eye Study, a benchmark population-based study that started in 1992.
It is one of the world's largest epidemiology studies, measuring diet and lifestyle factors against health outcomes and a range of chronic diseases.
"Our research aims to understand why eye diseases occur, as well as the genetic and environmental conditions that may threaten vision," Associate Professor Gopinath concluded.
Research review shows intermittent fasting works for weight loss, health changes
University of Illinois Chicago, October 13, 2021
Intermittent fasting can produce clinically significant weight loss as well as improve metabolic health in individuals with obesity, according to a new study review led by University of Illinois Chicago researchers.
"We noted that intermittent fasting is not better than regular dieting; both produce the same amount of weight loss and similar changes in blood pressure, cholesterol and inflammation," said Krista Varady, professor of nutrition at the UIC College of Applied Health Sciences and author of "Cardiometabolic Benefits of Intermittent Fasting."
According to the analysis published in the Annual Review of Nutrition, all forms of fasting reviewed produced mild to moderate weight loss, 1 percent to 8 percent from baseline weight, which represents results that are similar to that of more traditional, calorie-restrictive diets. Intermittent fasting regimens may also benefit health by decreasing blood pressure and insulin resistance, and in some cases, cholesterol and triglyceride levels are also lowered. Other health benefits, such as improved appetite regulation and positive changes in the gut microbiome, have also been demonstrated.
The review looked at over 25 research studies involving three types of intermittent fasting:
- Alternate day fasting, which typically involves a feast day alternated with a fast day where 500 calories are consumed in one meal.
- 5:2 diet, a modified version of alternate day fasting that involves five feast days and two fast days per week.
- Time-restricted eating, which confines eating to a specified number of hours per day, usually four to 10 hours, with no calorie restrictions during the eating period.
Various studies of time-restricted eating show participants with obesity losing an average of 3 percent of their body weight, regardless of the time of the eating window.
Studies showed alternate day fasting resulted in weight loss of 3 percent to 8 percent of body weight over three to eight weeks, with results peaking at 12 weeks. Individuals on alternate day fasting typically do not overeat or binge on feast days, which results in mild to moderate weight loss, according to the review.
Studies for the 5:2 diet showed similar results to alternate day fasting, which surprised the study's reviewers. The subjects who participate in the 5:2 diet fast much less frequently than alternate-day fasting participants do, but the weight loss results are similar.
Weight loss with alternate day and 5:2 fasting are comparable to more traditional daily calorie-restrictive diets. And, both fasting diets showed individuals were able to maintain an average of 7 percent weight loss for a year.
"You're fooling your body into eating a little bit less and that's why people are losing weight," Varady said.
Varady added the review set out to debunk some myths regarding intermittent fasting. Intermittent fasting does not negatively affect metabolism, nor does it cause disordered eating, according to the studies reviewed.
"Fasting people are worried about feeling lethargic and not being able to concentrate. Even though you are not eating, it won't affect your energy," Varady said. "A lot of people experience a boost of energy on fasting days. Don't worry, you won't feel crappy. You may even feel better."
The study review includes a summary of practical considerations for those who may want to try intermittent fasting. Among the considerations are:
- Adjustment time—Side effects such as headaches, dizziness and constipation subside after one to two weeks of fasting. Increased water intake can help alleviate headaches caused by dehydration during this time.
- Exercise—Moderate to high-intensity endurance or resistance training during food abstention can be done, and some study participants reported having more energy on fast days. However, studies recommend those following alternate day fasting eat their fasting day meal after exercise.
- Diet during fasting—There are no specific recommendations for food consumption during intermittent fasting, but eating fruits, vegetables and whole grains can help boost fiber intake and help relieve constipation that sometimes accompanies fasting.
- Alcohol and caffeine—For those using an alternate day or 5:2 fasting plan, alcohol is not recommended on fast days as the limited calories should be used on healthy foods that provide nutrition.
There are several groups who should not intermittent fast, according to the studies. Those individuals include:
- Those who are pregnant or lactating.
- Children under 12.
- Those with a history of disordered eating.
- Those with a body mass index, or BMI, less than 18.5.
- Shift workers. Studies have shown they may struggle with fasting regimens because of shifting work schedules.
- Those who need to take medication with food at regimented times.
"People love intermittent fasting because it's easy. People need to find diets that they can stick to long term. It's definitely effective for weight loss and it's gained popularity because there are no special foods or apps necessary. You can also combine it with other diets, like Keto," Varady said.
Varady has recently been awarded a National Institutes of Health grant to study time-restricted eating for 12 months to see if it works long term.
Antioxidants to prevent Alzheimer's disease
A balanced intake of antioxidants could prevent the development of Alzheimer's disease.
Institut National de la Recherche Scientifique (France), October 13, 2021
Research conducted by the Ph.D student Mohamed Raâfet Ben Khedher and the postdoctoral researcher Mohamed Haddad of the Institut national de la recherche scientifique (INRS) has shown that an oxidation-antioxidant imbalance in the blood is an early indicator of Alzheimer's disease, rather than a consequence. This breakthrough made by researchers under the supervision of the Professor Charles Ramassamy provides an avenue for preventive intervention: the antioxidants intake.
The research team showed that oxidative markers, known to be involved in Alzheimer's disease, show an increase up to five years before the onset of the disease. The results of this study, published in the Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring (DADM) journal, suggest that oxidation may be an early marker of this disease that affects more than 500,000 Canadians.
“Given that there is an increase in oxidative stress in people who develop the disease, we may regulate the antioxidant systems. For example, we could modulate the antioxidant systems, such as apolipoproteins J and D, which transport lipids and cholesterol in the blood and play an important role in brain function and Alzheimer's disease. Another avenue would be to increase the intake of antioxidants through nutrition”, says Professor Ramassamy.
Accessible biomarkers
Unlike the current set of invasive and expensive tests used to diagnose Alzheimer's disease, the oxidative markers discovered by Professor Ramassamy's research team can be detected by a blood test. These markers are found in plasma extracellular vesicles, which are pockets released by all cells in the body, including those in the brain.
The research team focused specifically on the "sporadic" Alzheimer's disease, the most common form of the disease which results primarily from the presence of the APOE4 susceptibility gene. This same form of the disease had been studied by the team for other early markers.
“By identifying oxidative markers in the blood of individuals at risk five years before the onset of the disease, we could make recommendations to slow the onset of the disease and limit the risks”, scientists noted.
This breakthrough brings new hope to Alzheimer's research. Once the disease is symptomatic, it is difficult, if not impossible, to reverse it.
Meditation training reduces long-term stress, according to hair analysis
Max Planck Institute for Human Cognitive and Brain Sciences (Germany), October 11, 2021
Mental training that promotes skills such as mindfulness, gratitude or compassion reduces the concentration of the stress hormone cortisol in hair. This is what scientists from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig and the Social Neuroscience Research Group of the Max Planck Society in Berlin have found out. The amount of cortisol in hair provides information about how much a person is burdened by persistent stress. Earlier positive training effects had been shown in acutely stressful situations or on individual days—or were based on study participants' self-reports.
According to a study by the Techniker Krankenkasse, 23 percent of people in Germany frequently suffer from stress. This condition not only puts a strain on the well-being of those affected, but it is also linked to a number of physiological diseases, including diabetes, cardiovascular diseases and psychological disorders such as depression, one of the world's leading causes of disease burden (Global Burden of Disease Study, 2017).
Therefore, effective methods are being sought to reduce everyday stress in the long term. One promising option is mindfulness training, in which participants train their cognitive and social skills, including attention, gratitude and compassion, through various meditation and behavioral exercises. Various studies have already shown that even healthy people feel less stressed after a typical eight-week training program. Until now, however, it has been unclear how much the training actually contributes to reducing the constant burden of everyday stress. The problem with many previous studies on chronic stress is that the study participants were usually asked to self-assess their stress levels after the training. However, this self-reporting by means of questionnaires could have distorted the effects and made the results appear more positive than they actually were.
The reason for such a bias: The participants knew they were training their mindfulness, and a reduction in stress levels was a desired effect of this training. This awareness alone has an impact on subsequent information. "If you are asked whether you are stressed after a training session that is declared as stress-reducing, even addressing this question can distort the statements," explains Lara Puhlmann, doctoral student at the Max Planck Institute for Human Cognitive and Brain Sciences and first author of the underlying publication, which has now appeared in the journal Psychosomatic Medicine. Factors such as social desirability and placebo effects played a role here. Unlike pharmacological studies, for example, in which the study participants do not know whether they have actually received the active substance or not, so-called blinded studies are not possible in mental training. "The participants know that they are ingesting the 'antidote,'" says Puhlmann. "In mindfulness research, we are therefore increasingly using more objective, i.e. physiological, methods to measure the stress-reducing effect more precisely."
The concentration of cortisol in hair is considered a suitable measure of exposure to prolonged stress. Cortisol is a hormone that is released when we are confronted with an overwhelming challenge, for example. In that particular situation, it helps put our body on alert and mobilize energy to overcome the challenge. The longer the stress lasts, the longer an increased concentration of cortisol circulates around our body—and the more it accumulates in our hair. On average, hair grows one centimeter per month. To measure the study participants' stress levels during the 9-month training, the researchers, in cooperation with the working group of Clemens Kirschbaum at the University of Dresden, analyzed the amount of cortisol every three months in the first three centimeters of hair, starting at the scalp.
The mental training itself was developed as part of a large-scale longitudinal study on the effects of mental training, the ReSource project, led by Tania Singer, scientific director of the Social Neuroscience Research Group. This 9-month mental training program consisted of three 3-month sessions, each designed to train a specific skill area using Western and Far Eastern mental exercises. The focus was either on the factors of attention and mindfulness, on socio-affective skills such as compassion and gratitude, or on so-called socio-cognitive skills, in particular the ability to take perspective on one's own and others' thoughts. Three groups of about 80 participants each completed the training modules in different order. The training lasted up to nine months, 30 minutes a day, six days a week.
Less stress, less cortisol
And it really showed: After six months of training, the amount of cortisol in the subjects' hair had decreased significantly, on average by 25 percent. In the first three months, slight effects were seen at first, which increased over the following three months. In the last third, the concentration remained at a low level. The researchers therefore assume that only sufficiently long training leads to the desired stress-reducing effects. The effect did not seem to depend on the content of the training. It is therefore possible that several of the mental approaches studied are similarly effective in improving the way people deal with chronic everyday stress.
In an earlier study from the ReSource project with the same sample, the researchers had investigated the effects of training on dealing with acute stressful situations. In this study, the participants were placed in a stressful job interview and had to solve difficult maths problems under observation. The results showed that people who had undergone socio-cognitive or socio-affective training released up to 51 percent less cortisol under stress than those who had not been trained. In this case, they did not measure the amount of cortisol in the subjects' hair, but instead acute cortisolsurges in their saliva. Overall, the researchers conclude that training can improve the handling of acute particularly stressful social situations as well as chronic everyday stress. "We assume that different training aspects are particularly helpful for these different forms of stress," says Veronika Engert, head of the research group "Social Stress and Family Health" at the Max Planck Institute for Human Cognitive and Brain Sciences.
"There are many diseases worldwide, including depression, that are directly or indirectly related to long-term stress," explains Puhlmann. "We need to work on counteracting the effects of chronic stress in a preventive way. Our study uses physiological measurements to prove that meditation-based training interventions can alleviate general stress levels even in healthy individuals."
Study: Moderate carbohydrate intake is a cardiovascular benefit for women
Monash University (Australia), October 13, 2021
Women's heart health has been the focus of a recent study by Monash University, with researchers finding that proportional carbohydrate intake and not saturated fat was significantly associated with cardiovascular disease benefit in Australian women.
Cardiovascular disease (CVD) is the leading cause of death in women. Poor diet is recognized as both an independent CVD risk factor and a contributor to other CVD risk factors, such as obesity, diabetes mellitus (DM), hypertension, and dyslipidaemia.
The research found that in middle-aged Australian women, increasing the percentage of carbohydrate intake was significantly associated with reduced odds of CVD, hypertension, diabetes mellitus, and obesity.
Furthermore, a moderate carbohydrate intake between 41.0 percent—44.3 percent of total energy intake was associated with the lowest risk of CVD compared to women who consumed less than 37 percent energy as carbohydrates. No significant relationship was demonstrated between proportional carbohydrate intake and all-cause mortality.
In addition, increasing proportional saturated fat intake was not associated with cardiovascular disease or mortality in women; rather, increasing saturated fat intakecorrelated with lower odds of developing diabetes mellitus, hypertension, and obesity.
The findings are now published in the British Medical Journal.
The results contradict much of the historical epidemiological research that supported a link between saturated fat and CVD. Instead, the results mirror contemporary meta-analysis of prospective cohort studies where saturated fat was found to have no significant relationship with total mortality or CVD.
While the cause of this inconsistency in the literature is unclear, it has been suggested that historical studies neglected to adjust for fiber, which is known to help prevent plaque from forming in the arteries.
"Controversy still exists surrounding the best diet to prevent CVD," said Sarah Zaman, a former Monash University professor who is now an associate professor at the University of Sydney.
"A low-fat diet has historically been the mainstay of primary prevention guidelines, but the major issue within our dietary guidelines is that many dietary trials have predominately involved male participants or lacked sex-specific analyses."
She adds: "Further research is needed to tailor our dietary guidelines according to sex."
The study's first author Sarah Gribbin, a Doctor of Medicine and BMedSc (Hons) student, says: "As an observational study, our findings only show association and not causation. Our research is purely hypothesis-generating. We are hoping that our findings will spark future research into sex-specific dietary research."
The Heart Foundation, which is one of the study's funders, welcomed the focus on women and CVD, which has historically been under-researched.
Heart Foundation manager, food and nutrition, Eithne Cahill, cautioned that "not all carbohydrates are created equal."
"We know that quality carbohydrate foods such as vegetables and whole grains—including whole grain bread, cereals, and pasta—are beneficial for heart health, whereas poor quality carbohydrates such as white bread, biscuits, cakes, and pastries can increase risk," she said.
"Similarly, different fats have different effects on heart health. That is why the Heart Foundation focuses on healthy eating patterns—that is, a combination of foods, chosen regularly over time—rather than a single nutrient or food. Include plenty of vegetables, fruit, and whole grains, and heart-healthy fat choices such as nuts, seeds, avocados, olives and their oils for cooking and a variety of healthy proteins especially seafood, beans and lentils, eggs and dairy."
Anti-cancer effects found in natural compound derived from onions
Kumamoto University (Japan), October 18, 2021
Research from Kumamoto University, Japan has found that a natural compound isolated from onions, onionin A (ONA), has several anti-ovarian cancer properties. This discovery is a result of research on the effects of ONA on a preclinical model of epithelial ovarian cancer (EOC) both in vivo and in vitro. This research comes from the same group that found ONA suppressed pro-tumor activation of host myeloid cells.
According to a 2014 review of cancer medicines from the World Health Organization, EOC is the most common type of ovarian cancer and has a 5-year survival rate of approximately 40%. It has a relatively low lifetime risk that is less than 1%, but that can increase up to 40% if there is a family history of the disease. A majority of patients (80%) experience a relapse after their initial treatment with chemotherapy, therefore a more effective line of treatment is needed.
Kumamoto University researchers found that ONA has several effects on EOC. The group's in vitro experiments showed that EOCs, which usually proliferate in the presence of pro-tumor M2 macrophages, showed inhibited growth after introduction of ONA. This was thought to be due to ONAs influence on STAT3, a transcription factor known to be involved in both M2 polarization and cancer cell proliferation. Furthermore, the team found that ONA inhibited the pro-tumor functions of myeloid derived suppressor cells (MDSC), which are closely associated with the suppression of the anti-tumor immune response of host lymphocytes, by using preclinical sarcoma model. ONA was also found to enhance the effects of anti-cancer drugs by strengthening their anti-proliferation capabilities. Moreover, experiments on an ovarian cancer murine model that investigated the effects of orally administered ONA resulted in longer lifespans and inhibited ovarian cancer tumor development. This was considered to be a result of ONA's suppression of M2 polarized macrophages.
The research shows that ONA reduces the progression of malignant ovarian cancer tumors by interfering with the pro-tumor function of myeloid cells. ONA appears to activate anti-tumor immune responses by nullifying the immunosuppressive function of myeloid cells. ONA has the potential to enhance existing anti-cancer drugs while also having little to no cytotoxic effects on normal cells. Additionally, side effects in animals have not been seen. With a little more testing, an oral ONA supplement should greatly benefit cancer patients.
Risk of chronic diseases caused by exogenous chemical residues
Dalian Institute of Chemical Physics (China), October 13, 2021
Chronic diseases are main killers affecting the health of human. The morbidities of major chronic diseases such as obesity, hypertension, diabetes, hyperuricemia and dyslipidemia are as high as 10% to 30%, showing a gradually upward trend as well.
More and more studies have shown that environmental pollution is a major health risk factor that cannot be ignored. However, the evidence for their relationship is equivocal and the underlying mechanisms is unclear.
Recently, a research group led by Prof. Xu Guowang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) discovered the risk of chronic diseases caused by exogenous chemical residues through metabolome-wide association study.
Their findings were published in Environment International on Oct. 8. Researchers from National Institute for Nutrition and Health of the Chinese Center for Disease Control and Prevention, and Tongji Medical College of Huazhong University of Science and Technology were also involved in this study.
The researchers discovered positive associations of serum perfluoroalkyl substances (PFASs) with hyperuricemia, and revealed the mechanism of the relationship between the exogenous chemical residues in the serum and the risk of chronic diseases at the metabolic level.
The researchers investigated the relationship between 106 exogenous chemical residues and five chronic diseases in 496 serum samples. They revealed the metabolic perturbations related to exogenous chemical residues and chronic diseases by the metabolome-wide association study combined with meeting-in-the-middle approach and mediation analysis, and investigated the further potential underlying mechanism at the metabolic level.
"PFASs were the risk factor for hyperuricemia," said Prof. Xu. Lipid species including glycerophospholipids and glycerides presented the strongest correlation with exposure and disease, which were not only positively related to PFASs exposure but also the risk factor for hyperuricemia. "We also found that key mediation metabolites mediated 25% to 68% of the exposure-disease risk relationship," Prof. Xu added.
This study provides in-depth etiological understanding for the occurrence and development of diseases, which may be helpful for the early detection of the disease and the identification of early warning markers.
