Tag: Mediterranean diet

Each Gram of Sugar Dropped from a Diet Slows Biological Aging

Photo by Sharon Mccutcheon on Unsplash

Researchers at UC San Francisco have found a link between following a diet that is rich in vitamins and minerals, especially one without much added sugar, and having a younger biological age at the cellular level.

They looked at how three different measures of healthy eating affected an “epigenetic clock” – a biochemical test that can approximate both health and lifespan – and found that the better people ate, the younger their cells looked. Even when people ate healthy diets, each gram of added sugar they consumed was associated with an increase in their epigenetic age.

“The diets we examined align with existing recommendations for preventing disease and promoting health, and they highlight the potency of antioxidant and anti-inflammatory nutrients in particular,” said Dorothy Chiu, PhD, a postdoctoral scholar at the UCSF Osher Center for Integrative Health and first author of the study, appearing in JAMA Network Open. “From a lifestyle medicine standpoint, it is empowering to see how heeding these recommendations may promote a younger cellular age relative to chronological age.”

The study is one of the first to show a link between added sugar and epigenetic aging, and the first to examine this link in a heterogenous group of women – both Black and white – in midlife. Most studies on the topic have involved older white participants.

The study helps deepen our understanding of why sugar is so detrimental to health, said study co-senior author Elissa Epel, PhD, a UCSF professor in the Department of Psychiatry and Behavioral Sciences.

“We knew that high levels of added sugars are linked to worsened metabolic health and early disease, possibly more than any other dietary factor,” Epel said. “Now we know that accelerated epigenetic aging is underlying this relationship, and this is likely one of many ways that excessive sugar intake limits healthy longevity.”

Women in the study reported consuming an average of 61.5 grams of added sugar per day, though the range was large: from 2.7 to 316 grams of added sugar daily. A bar of milk chocolate has about 25 grams of added sugar, while a can of cola has about 39 grams. The US Food and Drug Administration recommends adults consume no more than 50 grams of added sugar per day.

A nutrient-based approach

For the cross-sectional study, researchers analysed food records from 342 Black and white women with a mean age of 39 years from Northern California. Then, they compared their diets with epigenetic clock measures, which were derived from saliva samples.

Researchers scored the women’s diets to see how they compared to a Mediterranean-style diet rich in anti-inflammatory and antioxidant foods and then to a diet linked to lower risk for chronic disease.

Finally, they scored the women’s diets against a measure they created called the “Epigenetic Nutrient Index (ENI),” which is based on nutrients (not foods) that have been linked to anti-oxidative or anti-inflammatory processes and DNA maintenance and repair. These include Vitamins A, C, B12 and E, folate, selenium, magnesium, dietary fibre and isoflavones.

Adherence to any of the diets was significantly associated with lower epigenetic age, with the Mediterranean diet having the strongest association.

The researchers examined sugar intake separately and found that consuming foods with added sugar was associated with accelerated biological aging, even in the presence of an otherwise healthy diet.

“Given that epigenetic patterns appear to be reversible, it may be that eliminating 10 grams of added sugar per day is akin to turning back the biological clock by 2.4 months, if sustained over time,” said co-senior author Barbara Laraia, PhD, RD, a UC Berkeley professor in the Food, Nutrition and Population Health program. “Focusing on foods that are high in key nutrients and low in added sugars may be a new way to help motivate people to eat well for longevity.”

Source: University of California San Francisco

Mediterranean Lifestyle Linked to Lower Risk of All-cause and Cancer Mortality

in Mayo Clinic Proceedings.

People who adhere to a Mediterranean lifestyle, which involves a plant-rich diet, adequate rest, physical activity and socialisation, have a lower risk of all-cause and cancer mortality, according to a new study in Mayo Clinic Proceedings. People who adhered to the lifestyle’s emphasis on rest, exercise, and socialising with friends had a lower risk of cardiovascular disease mortality.

While many studies have established the health benefits of a Mediterranean diet and lifestyle, there are few studies on the diet outside of its region of origin. “This study suggests that it’s possible for non-Mediterranean populations to adopt the Mediterranean diet using locally available products and to adopt the overall Mediterranean lifestyle within their own cultural contexts,” said lead author Mercedes Sotos Prieto, Ramon y Cajal research fellow at La Universidad Autónoma de Madrid and adjunct assistant professor of environmental health at Harvard Chan School. “We’re seeing the transferability of the lifestyle and its positive effects on health.”

Led by La Universidad Autónoma de Madrid and Harvard T.H. Chan School of Public Health, the study analysed the habits of 110,799 members of the UK Biobank cohort, a population-based study across England, Wales, and Scotland using the Mediterranean Lifestyle (MEDLIFE) index, which is derived from a lifestyle questionnaire and diet assessments. Participants, who were between the ages of 40 and 75, provided information about their lifestyle according to the three categories the index measures: “Mediterranean food consumption” (intake of foods part of the Mediterranean diet such as fruits and whole grains); “Mediterranean dietary habits” (adherence to habits and practices around meals, including limiting salt and drinking healthy beverages); and “physical activity, rest, and social habits and conviviality” (adherence to lifestyle habits including taking regular naps, exercising, and spending time with friends). Each item within the three categories was then scored, with higher total scores indicating higher adherence to the Mediterranean lifestyle.

The researchers followed up nine years later to examine participants’ health outcomes. Among the study population, 4247 died from all causes; 2401 from cancer; and 731 from cardiovascular disease. Analysing these results alongside MEDLIFE scores, the researchers observed an inverse association between adherence to the Mediterranean lifestyle and risk of mortality. Participants with higher MEDLIFE scores were found to have a 29% lower risk of all-cause mortality and a 28% lower risk of cancer mortality compared to those with lower MEDLIFE scores. Adherence to each MEDLIFE category independently was associated with lower all-cause and cancer mortality risk. The “physical activity, rest, and social habits and conviviality” category was most strongly associated with these lowered risks, and additionally was associated with a lower risk of cardiovascular disease mortality.

Source: Harvard T.H. Chan School of Public Health

‘Green’ Mediterranean Diet Reduces Aortic Stiffness

Photo by Charlotte Karlsen on Unsplash

Among a variety of diets a low-calorie ‘green’ Mediterranean diet caused the biggest reduction in aortic stiffness among overweight or dyslipidaemic individuals in a post hoc analysis of a randomised trial. The findings were discussed in Journal of the American College of Cardiology.

As its name suggests, the green Mediterranean diet is rich in plant polyphenols and lower in red or processed meat and simple carbohydrates than a typical low-calorie Mediterranean diet.

Controlling for other variables, the green Mediterranean diet reduced proximal aortic stenosis (PAS) by 15%, better than a typical hypocaloric Mediterranean diet (7.3% reduction) or following standard healthy diet guidelines (4.8% reduction).

The study used the unique environment of a remote Israeli nuclear research facility, where the makeup of the staff meals could be closely controlled and monitored. This also created the limitation of having a predominantly male population for the study group.

More than simple weight loss, the green Mediterranean diet may have greater influence on PAS, which as a measure of “the aortic stiffness from the ascending to the proximal descending thoracic aorta, is a distinct marker of vascular aging and a sensitive early predictor of cardiovascular morbidity and mortality risk,” the researchers noted. “Beyond aging, and similarly to atherosclerosis, PAS is sensitive to obesity-related metabolic conditions, specifically metabolic syndrome.”

Source: MedPage Today

Study Finds Healthy Diet is Independently Linked to Fitness

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A healthy diet is associated with greater physical fitness in middle-aged adults, according to research published in the European Journal of Preventive Cardiology.

“This study provides some of the strongest and most rigorous data thus far to support the connection that better diets may lead to higher fitness,” said study author Dr Michael Mi of Beth Israel Deaconess Medical Center. “The improvement in fitness we observed in participants with better diets was similar to the effect of taking 4000 more steps each day.”

Cardiorespiratory fitness reflects the body’s ability to provide and use oxygen for exercise, and it integrates the health of multiple organ systems, such as the heart, lungs, blood vessels and muscles. It is one of the most powerful predictors of longevity and health. While exercise increases cardiorespiratory fitness, it is also the case that among people who exercise the same amount, there are differences in fitness, suggesting that additional factors contribute. A nutritious diet is associated with numerous health benefits, but it has been unclear whether it is also related to fitness.

This study examined whether a healthy diet is associated with physical fitness in community-dwelling adults. The study included 2380 individuals in the Framingham Heart Study. The average age was 54 years and 54% were women. Participants underwent a maximum effort cardiopulmonary exercise test on a cycle ergometer to measure peak VO2. This is the gold standard assessment of fitness and indicates the amount of oxygen used during the highest possible intensity exercise.

Participants also completed the Harvard semi-quantitative food frequency questionnaire to assess intake of 126 dietary items during the last year ranging from never or less than once per month to six or more servings per day. The information was used to rate diet quality using the Alternative Healthy Eating Index (AHEI; 0 to 110) and Mediterranean-style Diet Score (MDS; 0 to 25), which are both associated with heart health. Higher scores indicated a better quality diet emphasising vegetables, fruits, whole grains, nuts, legumes, fish and healthy fats and limiting red meat and alcohol.

The researchers evaluated the association between diet quality and fitness after controlling for other factors that could influence the relationship, including age, sex, total daily energy intake, body mass index, smoking status, cholesterol levels, blood pressure, diabetes and routine physical activity level. The average AHEI and MDS were 66.7 and 12.4, respectively. Compared with the average score, an increase of 13 points on the AHEI and 4.7 on the MDS was associated with a 5.2% and 4.5% greater peak VO2, respectively.

Dr Mi said: “In middle-aged adults, healthy dietary patterns were strongly and favourably associated with fitness even after taking habitual activity levels into account. The relationship was similar in women and men, and more pronounced in those under 54 years of age compared to older adults.”

To discover the potential mechanism linking diet and fitness, the researchers performed further analyses. They examined the relationship between diet quality, fitness and metabolites, which are substances produced during digestion and released into the blood during exercise. Researchers measured 201 metabolites (eg amino acids) in blood samples collected in a subset of 1154 study participants. Some 24 metabolites were associated with either poor diet and fitness, or with favourable diet and fitness, after adjusting for the same factors considered in the previous analyses. Dr Mi said: “Our metabolite data suggest that eating healthily is associated with better metabolic health, which could be one possible way that it leads to improved fitness and ability to exercise.”

“This was an observational study and we cannot conclude that eating well causes better fitness, or exclude the possibility of a reverse relationship, i.e. that fit individuals choose to eat healthily.”

Dr Mi concluded: “There are already many compelling health reasons to consume a high-quality diet, and we provide yet another one with its association with fitness. A Mediterranean-style diet with fresh, whole foods and minimal processed foods, red meat and alcohol is a great place to start.”

Source: European Society of Cardiology

Western Diet Increases Prostate Cancer Risk

A study published in BJU International found that while adherence to healthy diets seems to have no effect on prostate cancer risk, following an unhealthy ‘Western’ diet may increase the risk of developing aggressive prostate cancer.

The study assessed the diets of 15 296 men recruited in Spain in from 1992–1996. Among these men, 609 prostate cancer cases were identified during a median follow-up of 17 years. Diets were categorised as Western, Prudent, or Mediterranean. The Western dietary pattern consisted of a high intake of high-fat dairy products, processed meat, refined grains, sweets, caloric drinks, convenience food, and sauces, and a low intake of low-fat dairy products and whole grains. The Prudent dietary pattern was characterised by a high intake of low-fat dairy products, vegetables, fruits, whole grains, and juices. The Mediterranean dietary pattern represented a high intake of fish, vegetables, legumes, boiled potatoes, fruits, olives, and vegetable oil, and a low intake of juices.

No effect over prostate cancer risk was detected for the Prudent and Mediterranean dietary patterns, but detrimental effect was observed with the Western dietary pattern. This effect was only observed for aggressive tumors.

“Our results indicate that avoiding unhealthy dietary habits could be the best nutritional strategy to prevent aggressive prostate cancer,” said lead author Adela Castelló-Pastor, PhD, of the Carlos III Institute of Health and CIBERESP, in Spain. “Substituting the intake of Western-type diet products by products characteristic of the Mediterranean diet could also decrease the risk of other chronic diseases,” added co–senior author Marina Pollán, PhD, of the Carlos III Institute of Health and CIBERESP, in Spain.

“The information provided by the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition – or EPIC – has contributed to improving scientific knowledge of the relationship between diet and cancer and other chronic diseases,” added co–senior author Maria-José Sánchez, MD, PhD, lecturer at the Andalusian School of Public Health, scientific director at ibs.GRANADA and researcher at CIBERESP, in Spain.

Source: Wiley

A Mediterranean Diet Doesn’t Keep Dementia at Bay

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It has been suggested in a number of studies that eating a healthy diet may reduce a person’s risk of dementia. A new study published in the journal Neurology has found, however, that both the conventionally recommended diet and the Mediterranean diet are not linked to a reduced risk of dementia.

The Mediterranean diet features a high intake of vegetables, legumes, fruits, fish and healthy fats such as olive oil, and a low intake of dairy products, meats and saturated fatty acids. “Previous studies on the effects of diet on dementia risk have had mixed results,” said study author Isabelle Glans, MD, of Lund University. “While our study does not rule out a possible association between diet and dementia, we did not find a link in our study, which had a long follow-up period, included younger participants than some other studies and did not require people to remember what foods they had eaten regularly years before.”

For the study, researchers identified 28 000 people from Sweden. Participants had an average age of 58 and did not have dementia at the start of the study. They were followed over a 20-year period. During the study, participants filled out a seven-day food diary, a detailed food frequency questionnaire and completed an interview. By the end of the study, 1943 people, or 6.9%, were diagnosed with dementia, including Alzheimer’s disease and vascular dementia.

Researchers examined how closely participants’ diets aligned with conventional dietary recommendations and the Mediterranean diet. After adjusting for age, gender, and education, researchers did not find a link between following either a conventional diet or the Mediterranean diet and a reduced risk of dementia. Dr Glans noted that further research is needed to confirm the findings.

Nils Peters, MD, of the University of Basel in Switzerland, who wrote an editorial accompanying the study, said, “Diet on its own may not have a strong enough effect on memory and thinking, but is likely one factor among others that influence the course of cognitive function. Dietary strategies will still potentially be needed along with other measures to control risk factors.” A limitation of the study was the risk of participants misreporting their own dietary and lifestyle habits.

Source: American Academy of Neurology

GPs Should Aim for Diabetes Remission Through Weight Loss

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A large-scale review of clinical evidence concluded that achieving ‘remission’ for people with type 2 diabetes through dietary approaches and weight loss should be the primary treatment goal of GPs and healthcare practitioners.

Corresponding author Dr Duane Mellor at Aston University said: “Accounting for all the evidence, our review suggests remission should be discussed as a primary treatment goal with people living with type 2 diabetes. There are multiple dietary approaches that have been shown to bring about T2DM remission though at present meal replacements offer the best quality evidence. Low carbohydrate diets have been shown to be highly effective and should also be considered as a dietary approach for remission.”

Lead author, Dr Adrian Brown, UCL Division of Medicine said: “Traditionally T2DM has focussed on managing a person’s blood glucose with medication, however the approach doesn’t address the underlying causes of T2DM. There is now a growing body of research that shows losing significant weight, 10-15kg, either through weight loss surgery or dietary approaches, can bring about type 2 diabetes remission (non-diabetic blood sugar levels).”

Expert reviewers analysed over 90 research papers covering international clinical trials and clinical practice data of dietary methods used to treat T2DM. Their findings were published in the Journal of Human Nutrition & Dietetics.

The study found that meal-replacement diets helped 36% people successfully achieve remission, while low carbohydrate diets were able to help 17.6 % of people achieve and maintain remission for at least two years. People who lost the most weight and kept the weight off using both of these dietary approaches were able to stay in remission.

Calorie restricted and Mediterranean diets were somewhat less effective, with only about 5% of people on calorie restricted diets and 15% of people on a Mediterranean diet staying in remission after one year.

There were multiple definitions of ‘remission’: one is a return to non-diabetic blood sugar levels (glycated haemoglobin less than 48mmol/mol), without diabetes drugs. Other definitions however say weight (especially fat around the midsection) must be lost to achieve remission, and others allow medication to be used.

Some reports also suggested low-carbohydrate diets can normalise blood sugar levels even without weight loss, since carbohydrates cause blood sugar levels to rise. A low-carbohydrate diet means reduced blood sugar, leading to improved blood sugar control. However, if weight is lost without blood glucose being non-diabetic, the authors are suggesting this should instead be called mitigation, as the underlying mechanisms of T2DM are not being addressed.

Dr Brown said: “The evidence is clear that the main driver of remission remains the degree of weight loss a person achieved. Therefore, for those not achieving weight loss but achieving a non-diabetic blood glucose we are suggesting this isn’t remission per se, but rather ‘mitigation’ of their diabetes.”

The review concluded that while weight loss seems to best predict remission success, it assumes fat loss from the pancreas and liver. Future studies should compare how these diets work for different ethnic groups, as T2DM can occur at different body weights in different ethnic groups.

Dr Mellor added: “Not everyone will be able to achieve remission, but people who are younger (less than 50), male, have had type 2 diabetes for less than six years and lose more weight are more likely to be successful.”

Source: Ashton University

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