Tag Archives: Western diet

Image result for gout in toe Gout is something that is not discussed that much, but it has been increasing in recent years and now afflicts about  3.9% of adults in the US. Gout is a form of inflammatory arthritis, characterized by recurrent attacks of pain, tenderness, and swelling of a joint, frequently the joint of the big toe. It is caused by elevated levels of uric acid in the blood (known as hyperuricaemia).

Gout occurs more commonly in men ages 40 and older, who eat a lot of meat and seafood, drink a lot of alcohol (especially beer) or sweetened drinks, have high blood pressure, metabolic syndrome, or are overweight.  Gout used to be known as "the disease of kings" or "rich man's disease". [On the other hand, past research has shown that consumption of coffee, cherries, vitamin C foods, and dairy products, losing weight and physical fitness seems to decrease the risk.]

Recent research showed that the DASH diet reduces blood pressure and reduces uric acid in the blood, which is why a research team (study in The BMJ) now looked at  whether it lowers the risk of gout. The Dietary Approaches to Stop Hypertension or DASH diet is high in fruit, vegetables, whole grains, legumes, nuts, and low-fat dairy, and low in red and processed meats, salt, and sugary drinks. On the other hand, the typical Western diet has higher intakes of red and processed meats, sweetened beverages, sweets, desserts, French fries, and refined grains. The researchers analysed data on a total of 44,444 male health professionals, who had no history of gout at the start of the study. During the 26 years of the observational study, they documented 1731 cases of gout.

The researchers found that eating a more DASH type diet - a diet rich in fruits, vegetables, legumes, nuts, whole grains, and low in salt, sugary drinks, and red and processed meats, is associated with a lower risk of gout. On the other hand, a more 'Western' diet is associated with a higher risk of gout. They found that the effects are dose dependent - the more DASH-type diet, the lower the risk of gout. Bottom line: Once again, eating lots of fruits, vegetables, nuts, legumes, and whole grains is linked to health benefits. From Science Daily:

Diet rich in fruit, vegetables and whole grains may lower risk of gout

A diet rich in fruit and vegetables, nuts and whole grains and low in salt, sugary drinks, and red and processed meats, is associated with a lower risk of gout, whereas a typical 'Western' diet is associated with a higher risk of gout, finds a study published by The BMJ.

Gout is a joint disease which causes extreme pain and swelling. It is most common in men aged 40 and older and is caused by excess uric acid in the blood (known as hyperuricaemia) which leads to uric acid crystals collecting around the joints. The Dietary Approaches to Stop Hypertension (DASH) diet reduces blood pressure and is recommended to prevent heart disease. It has also been found to lower uric acid levels in the blood. Therefore, the DASH diet may lower the risk of gout.

To investigate this further, a team of US and Canada based researchers examined the relationship between the DASH and Western dietary patterns and the risk of gout. They analysed data on over 44,000 men aged 40 to 75 years with no history of gout who completed detailed food questionnaires in 1986 that was updated every four years through to 2012.

Each participant was assigned a DASH score (reflecting high intake of fruits, vegetables, nuts and legumes, such as peas, beans and lentils, low-fat dairy products and whole grains, and low intake of salt, sweetened beverages, and red and processed meats) and a Western pattern score (reflecting higher intake of red and processed meats, French fries, refined grains, sweets and desserts). During 26 years of follow-up, a higher DASH score was associated with a lower risk for gout, while a higher Western pattern was associated with an increased risk for gout.

Image result for gout NHS Credit: Both photos of gout on this page are from NHS.UK

 Interesting idea - that perhaps our community of gut microbes being out of whack (dysbiosis) leads to hypertension. This study was done in both humans and mice - with an analysis of bacteria in both hypertensive individuals and pre-hypertensives, and also healthy individuals (the controls). Then the microbes from 2 hypertensive individuals were transplanted into mice (fecal microbiota transplants). And lo and behold - the mice became hypertensive with an alteration of their gut microbes. This is amazing!

The study showed that transplanting microbes from hypertensives to non-hypertensives caused an elevation in blood pressure in the formerly healthy group. This shows the direct influence of gut microbes on blood pressure. The bacteria found in both the pre-hypertensives and hypertensives (especially an overgrowth of Prevotella and Klebsiella bacteria) are those linked to inflammation. And what kind of diet is linked to that bacteria? A high fat diet. Yes, the Western diet with lots of fat and highly processed foods.

The researchers talked about other research also showing Prevotella being associated not only with hypertension, but also other diseases (e.g., periodontal diseases and rheumatoid arthritis). On the other hand, Faecalibacterium, Oscillibacter, Roseburia, Bifidobacterium, Coprococcus, and Butyrivibrio, which were "enriched" in healthy controls, were lower in pre-hypertensive and hypertensive persons. In the past I have posted about a "special" bacteria that is even called  a "keystone" gut bacteria - Faecalibacterium prausnitziithat is linked to health and is low or absent in the gut in a number of diseases ((here and here). It is not available in a supplement at this time (because it dies within a few minutes upon exposure to oxygen), but diet influences it. A high animal meat, high animal fat, high sugar, highly processed foods, and low fiber diet (the typical Western diet) lowers F. prausnitzii numbers, while a high-fiber, low meat diet increases F. prausnitzii numbers.

What you can do: Feed the beneficial gut microbes by increasing the amount of fruits, vegetables, whole grains, seeds, nuts that you eat. And cut back on the greasy, high fat processed and fast foods.

The following excerpt is misleading - for example, it ignores the first part of the actual study which looked at the gut bacteria of pre-hypertensives, hypertensive, and healthy people. Then gut bacteria from hypertensive people were transplanted into healthy mice, and gut bacteria from healthy people were transplanted into hypertensive mice. Also, it wasn't rats, but mice used in the study. It goes to show why it's important to look at original studies - not just believe articles out there blindly. [See original study.] From Science Daily: Unhealthy gut microbes a cause of hypertension, researchers find

Researchers have found that the microorganisms residing in the intestines (microbiota) play a role in the development of high blood pressure in rats mice....Scientists studied two sets of rats mice, one group with high blood pressure ("hypertensive") and one with normal blood pressure ("normal").... All animals were then given antibiotics for 10 days to reduce their natural microbiota. After the course of antibiotics, the researchers transplanted hypertensive microbiota to normal blood pressure rats mice and normal microbiota to the hypertensive group. 

The researchers found that the group treated with hypertensive microbiota developed elevated blood pressure. A more surprising result is that the rats mice treated with normal microbiota did not have a significant drop in blood pressure, although readings did decrease slightly. This finding is "further evidence for the continued study of the microbiota in the development of hypertension in humans and supports a potential role for probiotics as treatment for hypertension," wrote the researchers. "Studies showing that supplementing the diet with probiotics (beneficial microorganisms found in the gut) can have modest effects on blood pressure, especially in hypertensive models."

NOTE that the actual study said in its CONCLUSIONS:  "Taken together, we have described clearly the disordered profiles of gut microbiota and microbial products in human patients with pre-hypertension and hypertension, established the relationship between gut dysbiosis and hypertension, and provided important evidence for the novel role of gut microbiota dysbiosis as a key factor for blood pressure changes. Our findings point towards a new strategy aimed at preventing the development of hypertension and reducing cardiovascular risks through restoring the homeostasis of gut microbiota, by improving diet and lifestyle or early intervening with drugs or probiotics."

 Another article commenting that increasing the amount of dietary fiber eaten by people eating a typical Western diet (which is low in fiber) will improve their gut microbiome (community of microbes). Research is finding that the added dietary fiber is food (nutrition) for microbes in the gut, and eating additional fiber daily will help restore or increase bacterial diversity, which then should lead to health benefits. Note: Easy ways to increase dietary fiber are increasing intake of whole grains, legumes, nuts, seeds, fruits, and vegetables. Think of food writer Michael Pollan's advice: "Eat food. Not too much. Mostly plants."

Researchers feel that fiber intake needs to be increased to more than current dietary guidelines, and that beneficial effects to the microbiome starts to occur rapidly (within 2 weeks) of changing to a higher fiber diet. This post from January 21, 2016 discussed the Sonnenburg research on gut microbe depletion (from a low fiber diet), and this April 28, 2015 post discussed the O'Keefe research (changing the diet has big effect on colon cancer risk) - both studies are mentioned below. See the page Feeding Your Gut Microbes for more information. From Science Daily:

Can more fiber restore microbiome diversity?

Scientists are pushing to restore human health in Western countries by changing our diet to restore the microbial species lost over the evolution of Western diet. Researchers advocate for strategically increasing dietary fiber intake as one path forward in regaining microbial biodiversity.

Insufficient nutrients for our gut microbes have been linked to a loss of certain beneficial bacterial species in industrialized societies and are likely impacting our immunological and metabolic health, although more data is needed. For example, most Westerners consume half of the amount of dietary fiber recommended by dietary guidelines, which nutritionists refer to as the "fiber gap," which is a problem because dietary fiber is the primary source of nutrition (e.g., carbohydrates) accessible to gut bacteria in humans.

"The idea to boost fiber levels is not new," says Jens Walter of the University of Alberta, Canada. "However, depletion of the microbiome adds a new perspective to this low-fiber Western diet that we are currently eating." Earlier this year, Stanford University's Justin Sonnenburg found that mice fed a typical Western diet (high in fat and carbohydrates and low in fiber) transferred a lower diversity of beneficial microbial species to future generations. The re-introduction of the microbes' preferred fiber at that stage did not result in a return of some (good) species, indicating that extinctions had occurred in only a few generations.

Walter and co-author Edward Deehan, his PhD student, are concerned that a dramatic shift away from a diet similar to the one under which the human-microbiome symbiosis evolved is a key factor in the rise of non-communicable disorders like obesity. "There is a lot of epidemiological evidence that fiber is beneficial, and food products containing dietary fiber have FDA-approved health claims for both colon cancer and coronary heart disease. There is also quite a bit of clinical evidence (although it is less consistent)," Walter says. "The most pressing issue at the moment that neither consumption of fiber in society nor the doses used in clinical research are high enough."

Walter has noticed that often researchers evaluating fiber doses in diets and health outcomes do so with "doses of fiber that [he] would consider physiologically irrelevant. Most of these studies use 5-15 grams of fiber; I would not think that these amounts would be actually beneficial," he says.

People living in non-industrialized societies have an average intake of fiber that is much higher than the low norms of Western societies. The authors note the recent work from the Stephen J.D. O'Keefe lab in Nature Communications in which modern African-Americans were given a traditional South-African diet that contained 55 grams of daily dietary fiber and had improved markers for colon cancer within two weeks.

 A recent study using mice, and following them for 4 generations, has implications for Americans who typically eat a low-fiber diet (average of 15 grams daily). Note that current dietary guidelines recommend that women should eat around 25 grams and men 38 grams daily of fiber.The researchers found that low-fiber diets not only deplete the complex microbial ecosystems residing in the gut, but can cause an irreversible loss of diversity within those ecosystems in as few as three or four generations.

This is because fiber feeds the millions of microbes in the gut - and so a fiber-rich diet can nourish a wide variety of gut microbes, but a low-fiber diet can only sustain a narrower community. As the generations went by, the rodents’ guts became progressively less diverse, as more and more species were extinguished. If the fourth-generation mice switched to high-fiber meals, some of the missing microbes rebounded, but most did not. It took a fecal transplant (mice style) to get back the missing microbes. From Science Daily:

Low-fiber diet may cause irreversible depletion of gut bacteria over generations

A study by Stanford University School of Medicine investigators raises concerns that the lower-fiber diets typical in industrialized societies may produce internal deficiencies that get passed along to future generations. The study, conducted in mice, indicates that low-fiber diets not only deplete the complex microbial ecosystems residing in every mammalian gut, but can cause an irreversible loss of diversity within those ecosystems in as few as three or four generations.

Once an entire population has experienced the extinction of key bacterial species, simply "eating right" may no longer be enough to restore these lost species to the guts of individuals in that population, the study suggests. Those of us who live in advanced industrial societies may already be heading down that path.

The proliferation of nearly fiber-free, processed convenience foods since the mid-20th century has resulted in average per capita fiber consumption in industrialized societies of about 15 grams per day. That's as little as one-tenth of the intake among the world's dwindling hunter-gatherer and rural agrarian populations, whose living conditions and dietary intake presumably most closely resemble those of our common human ancestors, said Justin Sonnenburg, PhD, associate professor of microbiology and immunology and senior author of the study, to be published Jan. 13 in Nature.

Virtually all health experts agree that low-fiber diets are suboptimal. Probably the chief reason for this is that fiber, which can't be digested by human enzymes, is the main food source for the commensal bacteria that colonize our colons, Sonnenburg said. Thousands of distinct bacterial species inhabit every healthy individual's large intestine. "We would have difficulty living without them," he said. "They fend off pathogens, train our immune systems and even guide the development of our tissues."

Surveys of humans' gut-dwelling microbes have shown that the diversity of bacterial species inhabiting the intestines of individual members of hunter-gatherer and rural agrarian populations greatly exceeds that of individuals living in modern industrialized societies, Sonnenburg said. In fact, these studies indicate the complete absence, throughout industrialized populations, of numerous bacterial species that are shared among many of the hunter-gatherer and rural agrarian populations surveyed, despite those groups' being dispersed across vast geographic expanses ranging from Africa to South America to Papua New Guinea.

The Stanford researchers employed young laboratory mice that had been specially bred and raised in aseptic environments so that, unlike ordinary mice (and ordinary humans), their intestines were devoid of any microbial inhabitants. After populating the mice's guts with microbes from a human donor, the scientists divided them into two groups. One group was fed a diet rich in plant-derived fiber. The other group's diet, equivalent to the first with respect to protein, fat and calories, was practically devoid of fiber content.

During the experimentation that followed, the researchers analyzed fecal samples from the animals. The two groups' gut-bacteria profiles were initially indistinguishable but soon diverged. "Within a couple of weeks, we saw a massive change," said Justin Sonnenburg. "The low-fiber-intake mice harbored fewer bacterial species in their gut." More than half of these bacterial species' numbers had dwindled by over 75 percent, and many species seemed to have disappeared altogether.

After seven weeks, the mice that had consumed a low-fiber diet were switched back to a high-fiber diet for four weeks. The mice's gut-bacteria profiles partly recovered -- probably due to an uptick in abundance of some bacteria whose ranks had declined to undetectable levels during the low-fiber-intake period. Still, this restoration was only partial: One-third of the original species never fully recovered despite their return to a high-fiber diet. No such changes were seen in the control mice consistently fed a high-fiber diet.

The real surprise came after mice had been bred and maintained on low-fiber diets for a few generations. In their experimental confines, these mice were exposed to microbes only through contact with their parents. Each successive generation's gut-bacterial ecosystem declined in diversity. By generation four, the depletion had reached a point where nearly three-quarters of the bacterial species resident in their great-grandparents' guts appeared absent in their own. Even after these mice were put back on a high-fiber diet, more than two-thirds of the bacterial species identified in the guts of their first-generation ancestors proved irretrievable, indicating extinction of those species by the fourth generation of fiber deprivation.

On the other hand, a somewhat more aggressive measure -- fecal transplantation -- did result in these lost species' retrieval, the study found. Introducing fecal contents of fourth-generation high-fiber-diet mice into the intestines of fourth-generation low-fiber mice, together with putting them on the high-fiber diet for two weeks, fully restored their bacterial profiles. Within 10 days of the procedure, the composition and diversity of the bacteria in the intestines of this group were indistinguishable from those of control mice.

  Over and over studies find that a person's diet is linked to health and diseases, and now a study finds that an unhealthy diet is linked to shrinkage of the brain, specifically the volume of the left hippocampus. The biggest effects on the hippocampus are found with both greater consumption of an unhealthy diet and lower consumption of a healthy diet.  The hippocampus is a brain structure associated with both learning and memory, as well as mood regulation, and is specifically implicated in depression. In dementia and Alzheimer's disease, the hippocampus is one of the first regions of the brain to suffer damage.

So....you want to protect your hippocampus from shrinkage. The researchers themselves  suggest that the effects may be reversible, and suggest "dietary interventions to promote hippocampal health". Once again, a healthy diet means lots of plant-based foods (for example, a Mediterranean based diet with lots of fruits, vegetables, legumes, nuts, berries, seeds), and decreasing a Western-style diet with highly processed foods, low fiber, lots of meat, fat,  and refined sugars. From Medscape:

Unhealthy Diet May Shrink the Brain

Consumption of an unhealthy Western diet characterized by meat, hamburgers, chips, and soft drinks, may reduce the volume of the left hippocampus, whereas a healthy diet of fresh vegetables and fish may increase hippocampal volume. In a study of more than 250 individuals, investigators found that during a period of 4 years, there was a difference of more than 200 cubic millimeters in hippocampal volume between individuals who ate a healthy diet and those who consumed an unhealthy diet.

"These findings suggest the potential for dietary interventions to promote hippocampal health, decrease age-related atrophy, and prevent negative health outcomes associated with hippocampal atrophy," they add. Previous studies have shown that quality of diet is associated with depression and cognitive health. Animal research indicates that this may be mediated by changes in the hippocampus. Specifically, a high-fat diet reduces brain-derived neurotrophic factor levels, which impairs neuronal plasticity, learning, and behavior.

For the current study, the researchers examined data from the Personality and Total Health Through Life Study on 255 individuals aged 60 to 64 years at baseline....Participants were classified as consuming either a "prudent/healthy diet," consisting of fresh vegetables, salad, fruit, and grilled fish, or a "Western/unhealthy diet," consisting of roast meat, sausages, hamburgers, steak, chips, crisps, and soft drinks. A 1-point difference on an 11-point scale of consumption of each type of diet corresponded to 1 standard deviation difference....

The investigators found that for each standard deviation increase in consumption of the "prudent diet," there was a 45.7 cubic millimeter increase in left hippocampal volume. In contrast, each standard deviation increase in consumption of the Western diet was independently associated with a 52.6 cubic millimeter decrease in the volume of the left hippocampusThe impact of diet on hippocampal volume was independent of age, sex, education, labor-force status, depressive symptoms, use of medication, physical activity, smoking, hypertension, and diabetes.

 

The difference in left hippocampal volume between those with a healthy diet and those with an unhealthy diet was 203 cubic millimeters, which accounted for 62% of the average decline in left hippocampal volume during the 4-year study period. Interestingly, there were no significant associations between right hippocampal volume and dietary patterns, although there was a nonsignificant relationship.

In an interview with Medscape Medical News, Dr Jacka pointed out the the research was observational in nature, and therefore it cannot be stated for certain that the Western diet is causing the hippocampus to shrink. "However, there have been many studies in animals that show that a diet high in saturated fats and refined sugars has a very potent negative impact on the brain proteins (neurotrophins) that both protect neurons from oxidative stress and promote the growth of new neurons in the hippocampus," she said.

"Similarly, there are many studies that show that food components high in antioxidants or protective lipids, such as omega-3 fatty acids, increase levels of these proteins. There are also many studies showing that the animal equivalent of 'junk food' diets impair hippocampal-dependent learning and memory." Crucially, Dr Jacka believes that switching from a Western to a "prudent" diet would lead to increases in hippocampal volume."From what we know so far, it seems that neurotrophin levels and hippocampal volume and function are relatively labile and readily influenced by environmental exposures, including both diet and physical activity," she said. "So there is every reason to believe that the noxious impact of unhealthy diets can be reversed by dietary improvement and vice versa."

This is of particular importance given that the latest Global Burden of Diseases data from The Lancet indicate that unhealthy diets are the leading cause of early mortality worldwide and that mental disorders are the leading cause of global disability. With a growing body of evidence showing that unhealthy diets are linked to mental, neurodegenerative, and neurodevelopmental disorders, Dr Jacka said the findings have "enormous implications for public health."

"It's the first time that a dietary pattern has been linked to specific changes in the brain. We've known for a long time that there's a correlation between dietary pattern and the risk of a number of brain illnesses, like depression and dementia, and the mechanism behind this, we believe, involves neuroplastic processes of how food affects brain growth. This is the first study that's really shown that quite conclusively," he said.    BMC Med. Published online September 8, 2015. Full text

 The blue structure in the brain is the hippocampus. Credit: BrainHQ

Image result for plant foods Prostate cancer diagnosis is scary enough, but knowing that dietary changes can increase favorable odds is good. Once again a Mediterranean style diet  or "healthy diet"(whole grains, fruits, vegetables, seeds, nuts, legumes, olive oil, and fish) is beneficial, while a Western diet (highly processed foods, red meat, processed meat, and dairy) is linked to higher rates of death. This study was from the Harvard School of Public Health and followed male physicians for an average of 14 years after prostate cancer diagnosis. From Science Daily:

Western diet may increase risk of death after prostate cancer diagnosis

After a prostate cancer diagnosis, eating a diet higher in red and processed meat, high-fat dairy foods, and refined grains--known as a Western diet--may lead to a significantly higher risk of both prostate cancer-related mortality and overall mortality compared with eating a diet rich in vegetables, fruits, fish, whole grains, legumes, and healthy oils, according to a new study from Harvard T.H. Chan School of Public Health.

The study, which appears online June 1, 2015 in the journal Cancer Prevention Research, offers insight on how diet may help improve survivorship for the nearly three million men living with prostate cancer in the U.S."There is currently very little evidence to counsel men living with prostate cancer on how they can modify their lifestyle to improve survival. Our results suggest that a heart-healthy diet may benefit these men by specifically reducing their chances of dying of prostate cancer," said Jorge Chavarro, assistant professor of nutrition and epidemiology at the Harvard Chan School and senior author of the study.

Researchers examined health and diet data from 926 men participating in the Physicians' Health Study I and II who were diagnosed with prostate cancer. They followed the men for an average of 14 years after their diagnosis, grouping them into quartiles according to whether they followed a Western dietary pattern or a "prudent" (higher consumption of vegetables, fruits, fish, legumes, and whole grains) dietary pattern.

They found that men who ate mostly a Western diet (those in the highest quartile of the Western dietary pattern) had two-and-a-half times higher risk of prostate cancer-related death--and a 67% increased risk of death from any cause--than those in the lowest quartile. Men who ate mostly a "prudent" diet had a 36% lower risk of death from all causes.

Once again, research finds that eating highly processed foods is not the best, this time for cognitive performance of 17 year olds. From Medical Xpress:

Western diet leads to poorer performance

Higher intake of a western diet by 14-year-olds has been linked with diminished cognitive performance at age 17.

Researchers found that participants with a western dietary pattern—characterised by high intakes of takeaway food, red and processed meat, soft drink, fried and refined food—scored lower in cognitive tasks, particularly those involving reaction time/psychomotor function, visual attention, learning and memory.

Chips and crisps came in for a particular drubbing: their high consumption was significantly associated with longer reaction times on detection tasks. In contrast to their peers, study participants with a high intake of fruits and leafy vegetables had better cognitive performance, which lead researcher Dr Anett Nyaradi says could be due to increased micronutrient content. This includes folate from leafy green vegetables, which previous research has linked to enhanced cognitive development.

Led by UWA and the Telethon Kids Institute, the study involved 602 members of the Western Australian Pregnancy Cohort (Raine) Study....Dr Nyaradi says several factors may be at play in this diet-related decline in cognitive skills, including the level of omega-6 fatty acids in fried foods and red meat.

Metabolic pathways function best with a balanced 1:1 ratio of omega-3 and omega-6 fatty acids, but the western diet can shift this to a 1:20 or 1:25 ratio.High intake of saturated fat and simple carbohydrates has been linked to impairment in the functioning of the hippocampus, a brain structure centrally involved in learning and memory that increases its volume during adolescence, Dr Nyaradi says.

"Adolescence represents a critical time period for brain development. It is possible that poor diet is a significant risk factor during this period…indeed, our findings support this proposition."