Skip to content

A study by researchers showing troubling effects from certain pesticides (especially a class of fungicides) raises all sorts of questions: What is the long-term effect of chronic low doses of these fungicides in the foods we eat? How much of these chemicals are we getting exposed to? The Univ. of North Carolina researchers studied the effect of 294 chemicals (all common food-use pesticides or other environmental chemicals) on "mouse cortical neurons" (mouse brain cells). They found that one group of chemicals, which they referred to as "cluster 2", "mimics brain disorders" such as autism, advanced age, Alzheimer's, Parkinson's disease, and other neurodegenerative disorders. The chemicals (all pesticides, and mainly fungicides) causing these effects are: fenamidone, pyraclostrobin, famoxadone, trifloxystrobin, fenpyroximate, azoxystrobin, fluoxastrobin pyridaben and rotenone. Even though this study was done on mouse cortical neurons (in vitro), it is meaningful because of the similarities with human brain cells.

Very little is known about human exposure to these chemicals (how much is our exposure?) and their effects on humans, but the data suggest effects similar to that in neurological disorders. The researchers point out that many of the chemical residues in this cluster were found on conventionally raised foods, especially leafy green vegetables, and were detected at relatively high levels, especially pyraclostrobin. Most of these fungicides only came into use after 2000 and usage of these fungicides has been increasing in the U.S, with the exception of pyridaben (decreasing use) and rotenone (very low use). "These data suggest significant human exposure potential to many of the chemicals in cluster 2".

They point out that these fungicide residues have not been detected on organically produced foods (EPA and USDA data), which suggests a way to minimize exposure. None of these chemicals can be used by organic farmers in the U.S. Possible exposure is also from gardens and lawns (if used), contaminated water, and for farm workers in conventional agriculture. From Science Daily:

Could new class of fungicides play a role in autism, neurodegenerative diseases?

Scientists at the UNC School of Medicine have found a class of commonly used fungicides that produce gene expression changes similar to those in people with autism and neurodegenerative conditions, including Alzheimer's disease and Huntington's disease.

Mark Zylka, PhD, senior author of the study and associate professor of cell biology and physiology at UNC, and his team exposed mouse neurons to approximately 300 different chemicals.... "Based on RNA sequencing, we describe six groups of chemicals," Zylka said. "We found that chemicals within each group altered expression in a common manner. One of these groups of chemicals altered the levels of many of the same genes that are altered in the brains of people with autism or Alzheimer's disease." Chemicals in this group included the pesticides rotenone, pyridaben, and fenpyroximate, and a new class of fungicides that includes pyraclostrobin, trifloxystrobin, fenamidone, and famoxadone. Azoxystrobin, fluoxastrobin, and kresoxim-methyl are also in this fungicide class.

"We cannot say that these chemicals cause these conditions in people," Zylka cautioned. "Many additional studies will be needed to determine if any of these chemicals represent real risks to the human brain." Zylka, a member of the UNC Neuroscience Center, and his group found that these chemicals reduced the expression of genes involved in synaptic transmission -- the connections important for communication between neurons. If these genes are not expressed properly, then our brains cannot function normally. Also, these chemicals caused an elevated expression of genes associated with inflammation in the nervous system. This so-called neuroinflammation is commonly seen in autism and neurodegenerative conditions.

The researchers also found that these chemicals stimulated the production of free radicals -- particles that can damage the basic building blocks of cells and that have been implicated in a number of brain diseases. The chemicals also disrupted neuron microtubules. "Disrupting microtubules affects the function of synapses in mature neurons and can impair the movement of cells as the brain develops," Zylka said. "We know that deficits in neuron migration can lead to neurodevelopmental abnormalities. We have not yet evaluated whether these chemicals impair brain development in animal models or people."

Jeannie T. Lee, MD, PhD, professor of genetics at Harvard Medical School and Massachusetts General Hospital, who was not involved in this research, said, "This is a very important study that should serve as a wake-up call to regulatory agencies and the general medical community. The work is timely and has wide-ranging implications not only for diseases like autism, Parkinson's, and cancer, but also for the health of future generations. I suspect that a number of these chemicals will turn out to have effects on transgenerational inheritance."

Zylka's group also analyzed information from the U.S. Geological Survey, which monitors countywide pesticide usage, as well as the Food and Drug Administration and the U.S. Department of Agriculture, which test foodstuffs yearly for pesticide residues. Of the chemicals Zylka's team studied, only the usage of pyridaben has decreased since 2000. Rotenone use has remained the same since 2000. However, the use of all the fungicides in this group has increased dramatically over the past decade.

Indeed, a study from the Environmental Protection Agency found that pyraclostrobin is found on foods at levels that could potentially affect human biology, and another study linked pyraclostrobin usage to honeybee colony collapse disorder. The pesticide rotenone was previously implicated in Parkinson's disease through replicated animal experiments and through human epidemiological studies.....Previous work has also shown that a single dose of the fungicide trifloxystrobin reduced motor activity for several hours in female rats and for days in male rats. Disrupted motor function is a common symptom of Parkinson's disease and other neurological disorders. The related fungicide picoxystrobin impaired motor activity in rats at the lowest dose tested.

Zylka added, "The real tough question is: if you eat fruits, vegetables or cereals that contain these chemicals, do they get into your blood stream and at what concentration? That information doesn't exist." Also, given their presence on a variety of foodstuffs, might long term exposure to these chemicals -- even at low doses -- have a cumulative effect on the brain?

Zylka noted that conventionally grown leafy green vegetables such as lettuce, spinach, and kale have the highest levels of these fungicides. But due to each chemical's effectiveness at reducing fungal blights and rust, crop yields have increased and farmers are expanding their use of these chemicals to include many additional types of food crops.

Zylka's team hopes their research will encourage other scientists and regulatory agencies to take a closer look at these fungicides and follow up with epidemiological studies. "Virtually nothing is known about how these chemicals impact the developing or adult brain," Zylka said. "Yet these chemicals are being used at increasing levels on many of the foods we eat."

Applying fungicide to apple orchard. Credit: Univ. of Kentucky Agriculture Extension

Another study that found benefits to dog ownership. The study authors concluded that: "Our study provides evidence that dog owners are at a lower risk for ischemic stroke, hemorrhagic stroke and heart failure." This could be to daily exercise, or that dog ownership results in less stress or better psychosocial health, or even some other reason (perhaps dog owners are healthier to start with).   Note: myocardial infarction (MI) is commonly known as a heart attack. From Medscape:

Canine Companions Appear to Help Heart Health: Swedish Study

Middle-aged and older dog owners were less likely to die from cardiovascular heart disease (CVD) or all causes, and those who lived alone were less likely to have an MI (myocardial infarction) or stroke, during a decade of follow-up in a large study based on Swedish national registry data[1]. The findings suggest that "especially for those who live alone, dog ownership makes a significant difference . . . in health status," Dr Mwenya Mubanga (Uppsala University, Sweden) told Heartwire from Medscape.....

Dog owners get daily exercise from walking their dogs, and canine companions can reduce stress, which might explain these findings, the researchers speculate....Similarly, Dr Gang Hu (Pennington Biomedical Research, Baton Rouge, LA).....pointed out that the dog owners do more exercise (by walking their dogs), which may contribute to having a lower body weight, lower blood pressure, and possibly good lipid levels and a lower risk of diabetes—which may all act to lower mortality. Having a dog may also reduce the chances of having depression, which might partly explain the more striking findings in the people who lived alone, he added.

Since 2001, dog owners in Sweden have been required by law to register their dogs, and an estimated 83% of dogs were registered that year with the Swedish Board of Agriculture and/or the Swedish Kennel Club dog registries, Mubanga and colleagues explain. They examined the Swedish national registry data to see how dog ownership was related to new CVD events or mortality.....This included 162,091 dog owners (4.8% of the population) and 3,195,153 people who were not dog owners.

Dog owners who lived alone or with at least one child or adult were less likely to die of CVD or all causes during follow-up compared with those who did not own a dog, but the relationships were stronger for solitary dwellers. Among dog owners, solitary dwellers (but not others) were also significantly less likely to have an MI or stroke than people who did not have a dog.

Nice summary article about the known benefits of nuts and seeds, and the nutrients they contain. Bottom line: all nuts and seeds are beneficial to health. It's best to eat a variety of nuts, and eat some nuts daily or at least a few times a week. A typical serving is 1/4 cup or small handful of nuts. Go to the article for the complete nut and seed list and a nut and seed nutrient chart. From Today's Dietician:

The Wonders of Nuts and Seeds

Nuts and seeds have been part of the human diet since Paleolithic times. A few nuts, such as almonds and walnuts, and seeds, namely flax and chia, get most of the glory, but the fact is each nut and seed brings something beneficial to the table. While exact nutrient compositions vary, nuts and seeds are rich sources of heart-healthy fats, fiber, plant protein, essential vitamins and minerals, and other bioactive compounds, including an array of phytochemicals that appear to have antioxidant and anti-inflammatory properties.

A wealth of data from prospective observational studies and clinical trials suggest that tree nut consumption reduces the risk of several chronic diseases, including cardiovascular disease (CVD), type 2 diabetes, and some forms of cancer. Moreover, there may be benefits for cognitive health. Adding support to these findings is research suggesting that incorporating tree nuts in the diet lowers the risk of conditions that contribute to disease, such as hypertension, high cholesterol, insulin resistance, abdominal obesity, endothelial dysfunction, oxidative stress, and inflammation. Various components of nuts, such as heart-healthy monounsaturated and polyunsaturated fats, plant-based protein, fiber, vitamins, minerals, and phytochemicals may work together to offer protection against oxidation, inflammation, cancer, and CVD.

Recent findings from the PREDIMED trial suggest that a Mediterranean diet that includes one serving of nuts per day protects against heart attack, stroke, or death from other cardiovascular causes in people at high risk due to type 2 diabetes or metabolic syndrome. PREDIMED data also suggest that eating more than three servings of nuts per week reduces risk of death from all causes, especially if also following a Mediterranean diet. Subjects who frequently consumed both total nuts and walnuts had a lower rate of death from cancer....While the number of nuts per serving varies by type, a typical serving is 1 oz or about 1/4 cup or a small handful (palm of the hand only)....

Almonds are high in monounsaturated fats, which may explain their association with lower LDL cholesterol levels and reduced heart disease risk. The antioxidant function of the vitamin E (37% DV in 1 oz) in almonds along with their magnesium and potassium also may play a role in cardiovascular health. One study found that almonds may reduce LDL as much as statins.

Brazil and cashew nuts: Technically a seed, 1 oz of Brazil nuts contains a whopping 767% DV for selenium. That's over the Tolerable Upper Intake Level of 400 mcg. But eating two Brazil nuts per day has been shown to be an effective way to increase blood levels of this antioxidant mineral healthfully. Cashews are lower in fat than most nuts and contain anacardic acid, which may improve insulin sensitivity and help prevent chronic inflammation.

Pecans contain multiple forms of vitamin E and are especially rich in gamma-tocopherol, which has been shown to inhibit oxidation of LDL cholesterol. Oxidized LDL contributes to inflammation in the arteries and is a risk factor for CVD. Pecans also have the highest polyphenol and flavonoid content of the tree nuts.

Pistachios: Two studies have shown that eating in-shell pistachios enhances feelings of fullness and satisfaction while reducing caloric intake. When eating in-shell pistachios, study subjects consumed about 40% fewer calories compared with pistachio kernels. Pistachios have the second highest polyphenol and flavonoid content of the tree nuts. 

Walnuts are another excellent source of plant-based omega-3 fatty acids. Walnuts also boast the highest antioxidant content of the tree nuts, followed by pecans and cashew nuts. This makes walnuts one of the best nuts for anti-inflammatory benefits. Like pecans, walnuts are unusually rich in the gamma-tocopherol form of vitamin E. ... Walnut consumption among NHANES subjects is positively associated with cognitive function in both younger and older adults. They're a natural source of melatonin, which is critical in the regulation of sleep, circadian (daily) rhythms, and may play a role in walnuts' anticancer benefits.

A recent study in the Journal of Internal Medicine had interesting results regarding sun exposure - more was beneficial for health.

In the study, women were followed for 20 years, and any  deaths were put into one of 3 groups: as being from: heart disease, cancer, or other (non-heart disease and non-cancer). Swedish women followed for 20 years found that the more sunlight exposure they had, the longer the life expectancy, the less death from heart disease (cardiovascular disease) and causes other than heart disease or cancer (non-heart disease and non-cancer group), but the more skin cancer (basal cell carcinoma, squamous cell carcinoma and melanoma) they developed. 

Thus the main finding is of a dose-dependent relationship between sun exposure and life expectancy.

One surprising result was that nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group. Those who avoided sun exposure had an increased risk of death mainly due to heart disease and "other causes" (non-cancer/non-heart disease).

I wondered about other cancers in this study, and this is all they had to say in the journal article:  "Thus, women with NMSC (nonmalignant skin cancer) had a 37% higher prevalence of other internal cancers than those without NMSC and a fourfold increased prevalence of MM (malignant melanoma). The incidence of other internal cancer was not increased subsequently on NMSC diagnosis."  I now have another question:  How do the women with cancer in the high and low sun exposure group do after another 10 or 20 years?  I would have liked for this study to continue longer.

The researchers felt that sunshine and vitamin D had a role in these results, and suggested that we need to rethink the "avoid sunshine" advice now given to people. In other words, some sunshine is good for health. From Science Daily:

Why do sunbathers live longer than those who avoid the sun?

New research looks into the paradox that women who sunbathe are likely to live longer than those who avoid the sun, even though sunbathers are at an increased risk of developing skin cancer. An analysis of information on 29,518 Swedish women who were followed for 20 years revealed that longer life expectancy among women with active sun exposure habits was related to a decrease in heart disease and noncancer/non-heart disease deaths, causing the relative contribution of death due to cancer to increase.

Whether the positive effect of sun exposure demonstrated in this observational study is mediated by vitamin D, another mechanism related to UV radiation, or by unmeasured bias cannot be determined. Therefore, additional research is warranted. 

"We found smokers in the highest sun exposure group were at a similar risk as non-smokers avoiding sun exposure, indicating avoidance of sun exposure to be a risk factor of the same magnitude as smoking," said Dr. Pelle Lindqvist, lead author of the Journal of Internal Medicine study. "Guidelines being too restrictive regarding sun exposure may do more harm than good for health."

A cataract is a clouding of the lens in the eye leading to a decrease in vision. It can affect one or both eyes, it is more common with age, and can even lead to blindness. About 20 million people globally are blind due to cataracts. Vitamin supplements have failed to find an effect in numerous studies.

But in this study, eating foods rich in vitamin C and to a smaller degree manganese had the beneficial effect of slowing cataract progression over the course of 9 1/2 years. Manganese is a micronutrient that is necessary in small amounts, but it is rare to be deficient in manganese. However manganese has numerous negative effects if too much is ingested or if there is too much exposure. Bottom line: increased intake of fruit and vegetables (for vitamin C) could help prevent the development or progression of cataracts.  From Medical Xpress:

Increased vitamin C in the diet could help protect against cataracts

Higher dietary intake of vitamin C has been found to have a potentially preventative effect on cataract progression in the first twin study of cataracts to examine to what degree genetic and environmental factors influence their progression with age. Cataract is a common condition in which the lens of the eye becomes cloudy as a result of oxidation over time. Whilst this is a natural part of ageing for many, for others it is more severe and causes blurred vision, glare and dazzle that cannot be corrected by glasses or contact lenses.

The study, led by King's College London and published in the journal Ophthalmology, looked at the progression of cataracts in the eyes of 324 pairs of female twins .... They found that those participants who had a higher intake of vitamin C were associated with a 33 per cent risk reduction of cataract progression and had 'clearer' lenses after the 10 years than those who had consumed less vitamin C as part of their diet.

The study, funded by the Wellcome Trust and Guide Dogs for the Blind, also found that environmental factors (including diet) influenced cataract more than genetic factors, which only explained a third of the change in lens opacity. The fluid in the eye that bathes the lens is high in vitamin C, which helps to stop the lens from oxidising and protects it from becoming cloudy. It is thought that increased intake of vitamin C has a protective effect on cataract progression by increasing the vitamin C available in the eye fluid.

Kate Yonova-Doing, the study's first author said: 'The human body cannot manufacture vitamin C, so we depend on vitamins in the food we eat. We did not find a significantly reduced risk in people who took vitamin tablets, so it seems that a healthy diet is better than supplements.'

Makes sense that not driving to work in a car, but using mass transit (public transport), cycling, or walking to work results in lower body mass index (BMI) and body fat. They're moving more! From Science Daily:

Public transport, walking and cycling to work are all associated with reductions in body fat for adults in mid-life

Adults who commute to work via cycling or walking have lower body fat percentage and body mass index (BMI) measures in mid-life compared to adults who commute via car, according to a new study incThe Lancet Diabetes & Endocrinology journal. Even people who commute via public transport also showed reductions in BMI and percentage body fat compared with those who commuted only by car. This suggests that even the incidental physical activity involved in public transport journeys may be important.

The study looked at data from over 150000 individuals from the UK Biobank data set, a large, observational study of 500000 individuals aged between 40 and 69 in the UK. The study is the largest to date to analyse the health benefits of active transport.

The strongest associations were seen for adults who commuted via bicycle, compared to those who commute via car. For the average man in the sample (age 53 years; height 176.7cm; weight 85.9kg), cycling to work rather than driving was associated with a weight difference of 5kg or 11lbs (BMI difference 1.71 kg/m2). For the average woman in the sample (age 52 years; height 163.6cm; weight 70.6kg), the weight difference was 4.4kg or 9.7lbs (BMI difference 1.65 kg/m2). After cycling, walking to work was associated with the greatest reduction in BMI and percentage body fat, compared to car-users (BMI difference 0.98 kg/m2 for men; 0.80 kg/m2 for women). For both cycling and walking, greater travelling distances were associated with greater reductions in BMI and percentage body fat.

Commuters who only used public transport also had lower BMI compared to car-users (BMI difference of 0.70kg/m2 for men), as did commuters who combined public transport with other active methods (BMI difference 1.00 kg/m2 for men; 0.67 kg/m2 for women). The effect of public transport on BMI was slightly greater than for commuters who combined car use with other active methods (BMI difference 0.56 kg/m2 for men). The link between active commuting and BMI was independent of other factors such as income, area deprivation, urban or rural residence, education, alcohol intake, smoking, general physical activity and overall health and disability.

A thought-provoking article by Heiman and Greenway was just published in the journal Molecular Metabolism making the case that changes in farming practices over the last 50 years have resulted in decreased agricultural diversity which, in turn, has resulted in decreased dietary diversity, and that the reduction in dietary diversity has changed and decreased the richness of the human gut microbiota (microbes living in the gut). And meanwhile, during the past 50 years, the rates of obesity, type 2 diabetes, and inflammatory bowel diseases sharply increased - and in each of these conditions there is a reduction of the gut microbial diversity. Similar views have also been stated by others in the field of microbiology.

The thinking is that the more diverse the diet, the more diverse the gut microbiome (and healthier), and the more it can adapt to disturbances. Heiman and Greenway state: "Unfortunately, dietary diversity has been lost during the past 50 years because of economic pressures for greater food production to support a growing world population.... Of the 250,000 to 300,000 known edible plant species, humans use only 150 to 200...Today, 75 percent of the world's food is generated from only 12 plants and five animal species."

Also, agricultural practices of using antibiotics as growth promoters for poultry, swine, and cattle further harm the human gut microbiome when the meat is ingested by humans, and pesticide residues on crops ingested by humans may have gut microbiome effects. Even emulsifiers, used in processed foods, reduce microbial richness. Every time a person goes on a certain diet (vegan, Paleo, etc) or makes dietary choices in which some foods are eliminated, it makes it easier for some microbial species, and gives them a competitive advantage over other gut microbes. From Science Daily:

Reduction in dietary diversity impacts richness of human gut microbiota

Changes in farming practices over the last 50 years have resulted in decreased agro-diversity which, in turn, has resulted in decreased dietary diversity. The significant impact of this change in dietary richness on human health is an emerging topic for discussion

Heiman and Greenway describe how the reduction in dietary diversity has changed the richness of human gut microbiota, the community of microorganisms living in the gut. The researchers point out that healthy individuals have diverse gut microbiota and many of the common pathologies of the 21st century, including type 2 diabetes, obesity and inflammatory bowel disease, are associated with reduced microbiotic richness.

Gut microbiota function as an endocrine organ, metabolizing specific nutrients from the diet and producing specific substances that act as metabolic signals in the host. It follows then that highly specialized diets will change the landscape of the gut microbiome over time. In fact, it takes only a few days of changing diet to alter the microbiotic makeup of the human gut. And if the dietary change involves elimination of one or more macronutrients (think Atkins or Paleo or vegan), humans are essentially selecting for some microbiotic species over others.

The importance of microbiota diversity cannot be overstated. They produce an abundance of important molecules for the host and with increased variation comes increased adaptability and an increased range of physiological responses. "The greater the repertoire of signals, the more likely is the ability to maintain homeostasis when dietary intake is perturbed," explain Heiman and Greenway. "Furthermore, because each particular macronutrient has the potential to be metabolized by microbiota into unique metabolic signals, the greater the variety in signals, the greater the variety of responses possible."

Another study showing that higher physical activity (from a variety of activities) is "related to larger gray matter volume in the elderly, regardless of cognitive status", specifically in gray matter areas of the brain responsible for memory, learning, and cognition. In other words, higher levels of physical activity reduce brain atrophy that occurs with aging and improves cognitive function in elderly individuals.  There is also discussion of higher activity levels improving cerebral (brain) blood flow. Bottom line: get off your butt and move more for better brain health. From Medical Xpress:

Burning more calories linked with greater gray matter volume, reduced Alzheimer's risk

Whether they jog, swim, garden or dance, physically active older persons have larger gray matter volume in key brain areas responsible for memory and cognition, according to a new study by researchers at the University of Pittsburgh School of Medicine and UCLA.The findings, published today in the Journal of Alzheimer's Disease, showed also that people who had Alzheimer's disease or mild cognitive impairment experienced less gray matter volume reduction over time if their exercise-associated calorie burn was high.

A growing number of studies indicate physical activity can help protect the brain from cognitive decline, said investigator James T. Becker, Ph.D., professor of psychiatry, Pitt School of Medicine..... "Our study is one of the largest to examine the relationship between physical activity and cognitive decline, and the results strongly support the notion that staying active maintains brain health."

Led by Cyrus Raji, M.D., Ph.D., formerly a student at Pitt School of Medicine and now a senior radiology resident at UCLA, the team examined data obtained over five years from nearly 876 people 65 or older participating in the multicenter Cardiovascular Health Study. All participants had brain scans and periodic cognitive assessments. They also were surveyed about how frequently they engaged in physical activities, such as walking, tennis, dancing and golfing, to assess their calorie expenditure or energy output per week.

Using mathematical modeling, the researchers found that the individuals who burned the most calories had larger gray matter volumes in the frontal, temporal and parietal lobes of the brain, areas that are associated with memory, learning and performing complex cognitive tasks. In a subset of more than 300 participants at the Pitt site, those with the highest energy expenditure had larger gray matter volumes in key areas on initial brain scans and were half as likely to have developed Alzheimer's disease five years later.

"Gray matter houses all of the neurons in your brain, so its volume can reflect neuronal health," Dr. Raji explained. "We also noted that these volumes increased if people became more active over five years leading up to their brain MRI."

Not good news. More than half of Americans’ calories come from “ultra-processed foods,” according to a new study published in BMJ OpenUltra-processed foods were defined as "formulations of several ingredients which, besides salt, sugar, oils and fats, include food substances not used in culinary preparations, in particular, flavours, colours, sweeteners, emulsifiers and other additives used to imitate sensorial qualities of unprocessed or minimally processed foods and their culinary preparations or to disguise undesirable qualities of the final product". Whew....

In other words, they're not real foods, but fake or pseudo foods with lots of added stuff that doesn't occur naturally. Examples are instant soups, sodas, many frozen meals, cake mixes, packaged snacks, energy drinks, syrups (excluding maple syrup). Ultra-processed foods account for about 90% or almost all of the added sugars Americans eat.

Food can be classified 4 ways: unprocessed or minimally processed foods (such as fresh, dry or frozen fruits or vegetables, grains, legumes, meat, fish and milk); processed culinary ingredients (including table sugar, oils, fats, salt, and other substances extracted from foods or from nature, and used in kitchens to make culinary preparations); processed foods (foods manufactured with the addition of salt or sugar or other substances of culinary use to unprocessed or minimally processed foods, such as canned food and simple breads and cheese) and ultra-processed foods (see above for definition).

It's time for Americans to cut back on ultra-processed foods and take Michael Pollan's advice on how to improve our health: "Eat real food. Not too much. Mostly plants." From Medical Xpress:

'Ultra-processed' foods make up more than half of all calories in US diet

'Ultra-processed' foods make up more than half of all calories consumed in the US diet, and contribute nearly 90% of all added sugar intake, finds research published in the online journal BMJ Open. Ultra-processed foods are formulations of several ingredients. Besides salt, sugar, oils and fats, they include substances not generally used in cooking, such as flavourings, emulsifiers, and other additives designed to mimic the qualities of 'real foods'.

Ultra-processed foods include mass produced soft drinks; sweet or savoury packaged snacks; confectionery and desserts; packaged baked goods; chicken/fish nuggets and other reconstituted meat products; instant noodles and soups.

To assess the contribution of ultra-processed foods to the intake of added sugars in the US diet, the researchers drew on dietary data involving more than 9000 people from the 2009-10 National Health and Nutrition Examination Survey (NHANES), an ongoing nationally representative cross sectional survey of US civilians. They looked at the average dietary content of added sugars and the proportion of people who consumed more than 10% of their total energy intake—the maximum recommended limit—from this source. 

Ultra-processed foods made up over half of total calorie intake (just under 60%) and contributed almost 90% of energy intake from added sugarsAdded sugars represented 1 in every 5 calories in the average ultra-processed food product—far higher than the calorie content of added sugars in processed foods and in unprocessed or minimally processed foods and processed culinary ingredients, including table sugar, combined. A strong linear association emerged between the dietary content of ultra-processed foods and the overall dietary intake of added sugars. Furthermore, the proportion of people exceeding the recommended upper limit of 10% of energy from added sugars was far higher when ultra-processed food consumption was high, rising to more than 80% among those who ate the most ultra-processed foods.

Notably, only those Americans whose ultra-processed food consumption was within the lowest 20% had an average daily added sugar intake that fell below the maximum recommended limit. Several leading health bodies, including the World Health Organization, the Canadian Heart and Stroke Foundation, the American Heart Association, and the US Dietary Guidelines Advisory Committee have concluded that excess added sugar intake increases the risk not only of weight gain, but also of obesity and diabetes, which are associated with a heightened risk of cardiovascular disease, and tooth decay. Cutting back on the consumption of ultra-processed foods could be an effective way of curbing excessive added sugar intake in the US, conclude the researchers.

Brain aging can be viewed as having 2 parts: chronological age (normally  the brain grey matter volume slowly shrinks with advancing age) and a lifetime of exposures - which can be negative from unhealthy lifestyle and injuries, and positive from a healthy lifestyle and enriched environments. That's why after a lifetime there can be wide variation in the physiological age of our brains. These differences in the  brain (in the grey matter) can be measured with magnetic resonance imaging (MRIs).

The researchers in this study used the concept of physiological age - the difference between the chronological age and predicted age, as a marker of brain health. They looked at adults of varying ages,and found that the more flights of stairs a person climbs daily, and the more years of school a person had completed, the "younger" their brain physically appears.  This study was a cross-sectional study and so shows an association rather than a definite cause, but interestingly other forms of exercise did not show this link (walking/hiking, jogging, running, bicycling, aerobic exercise, lap swimming, tennis.squash/racquetball, low intensity exercise). From Science Daily:

Want a younger brain? Stay in school -- and take the stairs

Taking the stairs is normally associated with keeping your body strong and healthy. But new research shows that it improves your brain's health too -- and that education also has a positive effect. In a study recently published in the journal Neurobiology of Aging, researchers led by Jason Steffener, a scientist at Concordia University's Montreal-based PERFORM Centre, show that the more flights of stairs a person climbs, and the more years of school a person completes, the "younger" their brain physically appears.

The researchers found that brain age decreases by 0.95 years for each year of education, and by 0.58 years for every daily flight of stairs climbed -- i.e., the stairs between two consecutive floors in a building.

For the study, Steffener and his co-authors used magnetic resonance imaging (MRI) to non-invasively examine the brains of 331 healthy adults who ranged in age from 19 to 79. They measured the volume of grey matter found in participants' brains because its decline, caused by neural shrinkage and neuronal loss, is a very visible part of the chronological aging process. Then, they compared brain volume to the participants' reported number of flights of stairs climbed, and years of schooling completed. 

Results were clear: the more flights of stairs climbed, and the more years of schooling completed, the younger the brain. "This study shows that education and physical activity affect the difference between a physiological prediction of age and chronological age, and that people can actively do something to help their brains stay young," he says.