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Category: nutrition

Published on Leave a comment on Walnuts Feed Beneficial Gut Bacteria and Other Health Benefits

Once again, a study finds that consumption of nuts is beneficial to health - this time by impacting the gut microbiome (community of microbes) in a beneficial way. This was a nicely done study -18 healthy adults randomly assigned first to either eating about a handful of walnuts daily (42 g) or zero nuts daily for 3 weeks, and then assigned to the other group for 3 weeks, with a "washout period" of 1 week in-between. Walnut consumption resulted in higher amounts of beneficial gut bacteria (Faecalibacterium, Clostridium, Dialister, and Roseburia) which are butyrate producing (beneficial!), and lowering of proinflammatory secondary bile acids and LDL cholesterol (both beneficial).

As seen in this walnut study from the University of Illinois, adding walnuts to the diet has quick effects on the gut microbiome. Other studies find that diets rich in nuts (which are a source of dietary fiber and unsaturated fatty acids) are associated with a reduced risk of death from cancer and heart disease. Bottom line: eating some nuts daily feeds beneficial bacteria in the gut, and so has beneficial health effects. This walnut study had everyone eating about a handful of walnut halves a day (42 g, which is a little less than 1/2 cup walnut halves).

From Science Daily: Walnuts impact gut microbiome and improve health

Diets rich in nuts, such as walnuts, have been shown to play a role in heart health and in reducing colorectal cancer. According to a new study from the University of Illinois, the way walnuts impact the gut microbiome -- the collection of trillions of microbes or bacteria in the gastrointestinal tract -- may be behind some of those health benefits.  ...continue reading "Walnuts Feed Beneficial Gut Bacteria and Other Health Benefits"

Published on Leave a comment on Eating Dark Chocolate Benefits Vision?

A wacky study in some ways, but the results give another great reason to eat dark chocolate ("It's for my vision") if the results hold up with more research. Unfortunately the milk chocolate used did not have the same beneficial effects for vision (it just had no effect). But still to be determined is how long does the small increase in vision acuity and contrast sensitivity last after eating dark chocolate, and does it really mean anything in the real world? The beneficial results in vision were found about 2 hours after eating the dark chocolate, so it is unknown how long the beneficial effect lasted.

The good news is that in the study 30 healthy adults were randomly assigned to different groups, it was "double blind" (no one knew who got what to eliminate bias), it was rigorously done, they used real chocolate available to everyone (72% Cacao Dark Chocolate bar vs Crispy Rice Milk Chocolate bar - both from Trader Joe's), and the researchers had no ties to industry. The researchers concluded eating a "dark chocolate bar improves the ability to see low- and high-contrast targets, possibly owing to increased blood flow", but they don't know what this means for real life.

As the researchers point out -  there were 8 times more flavanols in the dark (316.3 mg) vs milk chocolate bar (40 mg). Their thinking was clear in the study's introduction: "Several studies suggest that dark chocolate from favanol-rich cacao beans may enhance blood flow to central and peripheral nervous systems, improve cardiovascular function, and retard memory loss and other signs and symptoms of degenerative diseases, including Alzheimer and Parkinson diseases. The cacao flavanols in dark chocolate have antioxidant effects that retard and partially reverse degenerative changes in various diseases. Dark chocolate consumption also has been associated with enhanced mood and cognition."  Wow.

The big question: How much dark chocolate did they eat to get these beneficial effects?  Answer: 47 grams (or 1 serving, 280 calories) of the 72% cacao dark chocolate. From Medical Xpress:

A bit of dark chocolate might sweeten your vision

It may not replace prescription glasses, but a few bites of dark chocolate might offer a slight and temporary bump up in vision quality, new research suggests. Heart-healthy compounds in chocolate called flavanols appeared to sharpen eyesight for a group of 30 healthy young adults in the new study. The observed change in vision was small, but significant. However, the study authors stressed that it's too early for ophthalmologists to recommend chocolate as medicine for the eyes. 

...continue reading "Eating Dark Chocolate Benefits Vision?"

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Published on 1 Comment on Five Studies Looking at Vitamin D and Health

The last post was about several reviews of vitamin D studies, and how when people are put randomly into different groups and then followed for a while - that the studies generally are not finding the same wonderful effects of higher levels of vitamin D in the blood that observational studies are finding - instead finding no effect or mixed results. Some issues with observational studies: the groups are self-selected, some are a one time snapshot of a person (thus one can't tell what happens over time); and can't prove cause and effect (can only say there is an association or link). [See all posts about vitamin D.]

But anyway, today's post is about some more vitamin D studies, all published in 2018. All of them find health benefits from higher blood levels of vitamin D. What is an ideal level of vitamin D varies from study to study, and some are observational - thus can only say "find an association with" in the findings. The fifth study finds beneficial effects from higher doses of vitamin D, and the participants were randomly assigned to the groups (good!). Click on links to read details. All excerpts are from Science Daily:

Vitamin D deficiency linked to greater risk of diabetes

An epidemiological study conducted by researchers at University of California San Diego School of Medicine and Seoul National University suggests that persons deficient in vitamin D may be at much greater risk of developing diabetes. The findings are reported in the April 19, 2018 online issue of PLOS One.  ...continue reading "Five Studies Looking at Vitamin D and Health"

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Published on 2 Comments on Mixed Findings In Vitamin D Supplement Studies

The controversy over whether people should be supplementing with vitamin D or not, and whether there are health benefits or harms from vitamin D supplementation is heating up. While observational studies have found health benefits with higher vitamin D blood levels, the beneficial results have generally not held up (or mixed findings) when people were randomly assigned to groups (randomized clinical trials). Most agree that blood levels of under 20 ng per mL is too low, but an issue is what is a desirable blood level? Should healthy people routinely supplement?

Having higher blood levels of vitamin D from sunshine appears to be good (it's the sunshine vitamin, after all). It's the taking of a vitamin D supplement that is now controversial and being debated. By the way, if one decides to take a vitamin D supplement, then the D3 form is desirable (rather than D2).

It was pointed out that a number of negative health effects can occur in those taking more than 4000 IU daily of vitamin D. For example, it may cause toxic effects such as renal impairment, hypercalcemia, or vascular calcification. In  2014, 3% of all U.S. adults and 6.6% of adults older than 60 years reported taking a vitamin D supplement of 4,000 or more IU per day. [See all vitamin D posts - most discuss observational studies finding benefits.]

The following are articles from Medscape (the medical site) and American Family Physician discussing recent research that is not finding health benefits with vitamin D supplementation, or mixed findings (e.g. one review found it may be protective in lowering death from any reason or from cancer; also reduce the number of upper respiratory infections). Therefore, some medical groups suggest that vitamin D screening is an unnecessary test, a waste of money,  and shouldn't be routinely done in healthy individuals. Note that many, many trials are going on right now to try to settle the vitamin D supplement issue (whether there are health benefits or not). ...continue reading "Mixed Findings In Vitamin D Supplement Studies"

Published on Leave a comment on Perhaps The Type Of Iron Supplement Matters

Does the type of iron in supplements and additives matter for your health? OK, this was a preliminary study and done in a lab using human cells, which means much more research needs to be done, but... It may be that different forms of iron in supplements and additives have slightly different effects in the human body, specifically the intestines. Ferrous sulphate so far looks good (had no effect on the cancer cells studied), while 2 other forms of iron - ferric citrate and ferric EDTA - may actually promote the formation of colon cancer. That is, they may be considered carcinogenic.

Ferric EDTA and ferric citrate have been observed to promote colon cancer in studies using mice. Bottom line: When buying supplements and foods, check labels to make sure the iron is in the form of ferrous sulphate, and not ferric citrate or ferric EDTA. From Science Daily:

Certain iron supplements may influence the development of colon cancer ...continue reading "Perhaps The Type Of Iron Supplement Matters"

Published on Leave a comment on Fruits, Vegetables, and Pesticide Residues

Wondering which fruits and vegetables have the most pesticide residues? The annual Dirty Dozen List of produce with the most pesticide residues has once again been published by the Environmental Working Group (EWG). They suggest that these fruits and vegetables are good candidates for buying organic.

Why organic? Because while almost 70 % of the produce sampled by the Federal Government had pesticide residues, some have more than others. For example: about one-third of the strawberries sampled contained 10 or more pesticides. Yikes! The following article also discusses some recent reproductive research and  pesticides on food, as well as EWG's "Clean Fifteen" list of fruits and vegetables with the least pesticide residues. (See more PESTICIDE posts.) From Environmental Health News:

Report calls out worst produce for pesticides—strawberries, spinach top list

Just when you thought it couldn't get any harder to eat healthy. Turns out those nutrient packed foods we're all told to eat—such as strawberries and spinach— are also consistently tainted with potentially harmful pesticides. Both foods top the "Dirty Dozen" list released today by the Environmental Working Group (EWG), which analyzed federal data on pesticides in produce.

EWG, which examined tests done over the past few years by the U.S. Department of Agriculture, reports almost 70 percent of the produce sampled by the feds had pesticide residues. Some were worse than others: "More than 98 percent of samples of strawberries, spinach, peaches, nectarines, cherries and apples tested positive for residue of at least one pesticide," according to the report.  ...continue reading "Fruits, Vegetables, and Pesticide Residues"

Published on Leave a comment on Ultra-Processed Foods and Alzheimer’s?

The last post dealt with the link between highly processed food and increased risk of cancer. Now an interesting article written by Dr. Lisa Mosconi (Associate Director of the Alzheimer’s Prevention Clinic at Weill Cornell Medical College/New York -Presbyterian Hospital) refers to that study when discussing research about lifestyles (and especially diet) and later Alzheimer's disease.

It'll be interesting to see how this research plays out - is her approach stressing diet (and avoiding ultra-processed food and trans fats) and lifestyle correct or not? Much of what she says definitely makes sense and is supported by research, such as the negative health effects of chronic inflammation, and how eating actual, real foods has beneficial health effects. On the other hand, vitamin, mineral, and fish oil supplements generally don't show those health benefits (as she discusses here).

Currently there are a number of theories about causes of Alzheimer's disease (including the role of microbes), as well as a number of drug treatments that so far have gone nowhere. If Dr. Mosconi's research interests you, then read the interview she did in 2017. [In the interview she talks about the importance of exercise, intellectual stimulation, social networks, and the benefits of eating real foods rather than supplements. She recommends: drink water, eat fish, eat vegetables and fruit, eat glucose rich foods, and don't eat highly processed and fast foods.]  From Quartz:

The road to Alzheimer’s disease is lined with processed foods

Dementia haunts the United States. There’s no one without a personal story about how dementia has touched someone they care for. But beyond personal stories, the broader narrative is staggering: By 2050, we are on track to have almost 15 million Alzheimer’s patients in the US alone. ... It’s an epidemic that’s already underway—but we don’t recognize it as such. The popular conception of Alzheimer’s is as an inevitable outcome of aging, bad genes, or both.  ...continue reading "Ultra-Processed Foods and Alzheimer’s?"

Published on Leave a comment on Ultra-Processed Food and Risk of Cancer

A recent study published in BMJ (British Medical Journal) found a link between high consumption of ultra-processed food and higher rates overall of cancer, but also a higher risk of breast cancer. Specifically, a 10% increase in the proportion of ultra-processed foods in the diet was associated with a greater than 10% increase of overall cancer and 11% increase of breast cancer during the 6+ years of the study.

Alarmingly (because of the health implications), several surveys (in Europe, the US, Canada, New Zealand, and Brazil) have suggested that ultra-processed food products are now between 25 to 50% of calories eaten every day.

Ultra-processed food is food that is highly processed. It is food that is mass produced and packaged, as well as foods that have manufactured substances in them - such as hydrogenated oils (also contains trans fats), protein isolates, additives, preservatives, artificial or natural flavors, colors, nitrites (in processed meat), titanium dioxide (nanoparticles), etc.

The food packaging can leach chemicals such as pthalates (endocrine disruptors). The list goes on and on and on. All of these things in ultra-processed foods may be involved in causing health problems, including cancer.

They are typically also poorer nutritionally and higher in salt than unprocessed or minimally processed foods. These ultra-processed foods that are so popular are all around us - in fast food, in mass produced desserts and breads, packaged snacks, soups, cold cuts, margarine, frozen or shelf stable ready to eat meals, instant foods, sodas and drinks, etc.

On the other hand, unprocessed or minimally processed foods are fresh, dried, ground, chilled, frozen, pasteurised, or fermented foods such as fruits, vegetables, legumes (beans), rice, pasta, eggs, meat, fish, or milk. There are also “processed culinary ingredients”  which are salt, vegetable oils, butter, sugar, and other substances extracted from foods and used in kitchens to transform unprocessed or minimally processed foods into "culinary preparations" (meals).

The study did NOT find any association with unprocessed, minimally processed, or processed culinary ingredients with cancer. Only with the ultra-processed food. Instead, the study found that higher consumption of “minimally/unprocessed foods” (and lower ultra-processed food) was associated with lower risks of overall cancer and breast cancer.

So an apple is unprocessed, and plain apple sauce made with just apples is minimally processed, while a packaged apple dessert with additives added is ultra-processed. Think of it as "transformed food". Also keep in mind that your beneficial gut microbes like unprocessed or minimally processed food - especially those high in fiber. You know - a diet rich in fruits, vegetables, whole grains, seeds, nuts, legumes (beans).  ...continue reading "Ultra-Processed Food and Risk of Cancer"

Published on Leave a comment on DASH Diet Linked To Lower Rate of Depression

A number of recent studies and articles have discussed the effectiveness of diet in treating or preventing depression with the main conclusion that yes, it helps. Now an observational study (that will be presented in April) found that elderly people following the DASH diet most closely were 11% less likely to become depressed over time than those that did not.

Researchers studying 964 elderly participants over six and a half years found that those who followed the DASH diet, which emphasizes whole grains, fruits, and vegetables, had lower rates of depression, while those who ate a traditional Western diet were more prone to depression. The DASH (Dietary Approaches to Stop Hypertension) diet also emphasizes low sodium (salt) to lower blood pressure, as well as foods rich in nutrients (such as potassium, calcium, and magnesium) that are thought to lower blood pressure.

The study's lead author L. J. Cherian (at Rush Medical Center in Chicago) said that "we need to view food as medicine”. Yes. Eating more fruits and vegetables, whole grains, legumes, seeds, nuts have many health benefits (such as cardiovascular benefits, improving the gut microbes) -  a win-win. From Science Daily:

Diet shown to reduce stroke risk may also reduce risk of depression

People who eat vegetables, fruit and whole grains may have lower rates of depression over time, according to a preliminary study that will be presented at the American Academy of Neurology's 70th Annual Meeting in Los Angeles, April 21 to 27, 2018. The study found that people whose diets adhered more closely to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. In addition to fruit and vegetables, the DASH diet recommends fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar. Studies have shown health benefits such as lowering high blood pressure and bad cholesterol (LDL), along with lowering body weight.  ...continue reading "DASH Diet Linked To Lower Rate of Depression"

Published on Leave a comment on Popular Weedkiller Found In Pregnant Women

A recent study of pregnant women found new health problems with the pesticide glyphosate, which is the active ingredient in the weedkiller Roundup (made by Monsanto).

The researchers found that women  with higher levels of glyphosate are more likely to have shorter pregnancies. Another major finding was that almost all the pregnant women (93%) in this study had detectable levels of glyphosate in their urine. I posted about this study earlier, but now it has been published in the journal Environmental Health.

All the pregnant women were living in central Indiana (in the cornbelt) in a mix of areas (suburban, urban, and rural), and whether they had well or public drinking water. In case you don't know, it is not good for a baby to be born early, and there can be lifelong health consequences - so every extra week (till full term) is good during pregnancy.

The researchers found higher levels of glyphosate in women living in rural areas (farm areas) and those drinking greater than 24 ounces a day of caffeinated beverages. The researchers thought that diet (food) and inhalation of contaminated dust were the major ways that the glyphosate got into the pregnant women.

Glyphosate is the most heavily used herbicide (a type of pesticide) in the world. Nearly 300 million pounds were applied in the U.S. in 2015, with much of the application in the Midwest. Scroll down to see a USGS map of glyphosate (Roundup) use in 2015 in the US. You can see that incredibly huge amounts of glyphosate are used in the midwest on farmland - greater than 88.6 pounds per square mile! (it's the dark brown areas on the map). Top crops it's used on are corn, soybeans, and canola, especially genetically modified Roundup Ready crops.

It is also used as a dessicant right before harvest ("preharvest") on many crops. This is why crops have glyphosate residues on them, and why so many streams and lakes are contaminated (due to agricultural runoff). About 90% of corn and soybean crops grown in the United States are Roundup Ready, and then these grains are used in most processed foods. Note: glyphosate (Roundup) can not be used on organic crops.

The herbicide has been linked to a number of health problems, including cancer, birth defects, endocrine disruption, and reproductive problems. (Posts on glyphosate.)  There are currently hundreds of lawsuits from farmers and others claiming that Roundup gave them cancer.

...continue reading "Popular Weedkiller Found In Pregnant Women"