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Category: nutrition

Published on Leave a comment on All Vitamin D Supplements Are Not The Same

For years it has been generally accepted that vitamin D3 is superior to vitamin D2 when taken as a supplement. Another recent study confirms that they are not equivalent in their effects in the human body, and that vitamin D3 is far superior.

Vitamin D2 (ergocalciferol) is plant and fungus-derived, and vitamin D3 (cholecalciferol) is animal-derived. Vitamin D3 is also naturally produced in the skin when exposed to sunlight, which is why it is frequently called the "sunshine vitamin".

From Science Daily: Study questions the role of vitamin D2 in human health but its sibling, vitamin D3, could be important for fighting infections

New research has found significant differences between the two types of vitamin D, with vitamin D2 having a questionable impact on human health. However, the study found that vitamin D3 could balance people's immune systems and help strengthen defences against viral infections such as Covid-19.

In a collaborative study by the Universities of Surrey and Brighton, researchers investigated the impact of vitamin D supplements -- D2 and D3 -- taken daily over a 12-week period on the activity of genes in people's blood. ...continue reading "All Vitamin D Supplements Are Not The Same"

Published on Leave a comment on Eating Meat Less Frequently Associated With a Lower Risk of Cancer

The evidence keeps growing that cutting back on how frequently a person eats meat may have health benefits such as lowering cancer risk  A recent study found that eating a low-meat diet (5 or less times a week), or just eating fish and not meat, or a no meat diet (vegetarian or vegan) all are associated with a lower risk of cancer - when compared to those who eat meat more than 5 times per week.

Just keep in mind that they only asked people about their diets one time (at the study start) in an eleven year time period - thus it doesn't account for dietary changes over time. Also, other studies also find that there are health benefits (including lower risks of cancer) to eating less meat and more fruits, vegetables, whole grains, legumes, seeds, nuts  - think along the lines of a Mediterranean diet.

From Science Daily: Low-meat and meat-free diets associated with lower overall cancer risk

Eating meat five times or less per week is associated with a lower overall cancer risk, according to a study published in the open access journal BMC Medicine. ...continue reading "Eating Meat Less Frequently Associated With a Lower Risk of Cancer"

Published on Leave a comment on Vitamin D Supplements and Autoimmune Disease

Yesterday's post was about how several well-done large studies did not find the health benefits from vitamin D supplements that the researchers had hoped for. In one of the studies (the VITAL trial) discussed yesterday, Vitamin D supplements did not prevent cancer or cardiovascular events (e.g., stroke, heart attack), which was the focus of the study.

But... one positive finding (in a separate analysis of the study results) did come out of the study: vitamin D supplements reduced the incidence of autoimmune disease by 22% over the 5+ years of the VITAL trial. This included rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, and psoriasis.

The more than 25,000 participants (all older than 50 years) took vitamin D 2000 IUs daily or 1 g marine omega-3 fatty acids (fish oil) daily,  or both, or none for more than 5 years. Only the vitamin D supplementation (whether taken alone or with fish oil) had a statistically significant health effect.

From Medical Xpress: Study finds vitamin D supplements with or without Omega-3s decreased risk of autoimmune diseases

Autoimmune diseases (AD) such as rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease and psoriasis, are a leading cause of morbidity and mortality as people age. Few effective treatments are available for AD, but some preclinical studies have hinted that supplements, including vitamin D and omega-3 (or n-3) fatty acids, may have beneficial effects. In a new study published in BMJ, investigators from Brigham and Women's Hospital evaluated whether taking vitamin D and/or omega fatty acid supplements could affect rates of AD.  ...continue reading "Vitamin D Supplements and Autoimmune Disease"

Published on Leave a comment on Some Large Studies Find No Benefit From Vitamin D Supplements

Several recent articles on Medscape (a site for medical professionals) highlight the debate over vitamin D. The question: Does daily vitamin D supplementation have positive health benefits or not? Everyone agrees that if there is an actual deficiency, then it has positive health effects. But how about the average person with levels above the deficiency level?

Numerous observational studies find that low levels of vitamin D are associated with all sorts of health problems (e.g., cancer, heart disease), but randomly controlled trials (RCT) where people are randomly assigned to different groups with no one knowing what they are getting - just aren't finding health benefits. The strongest evidence so far has been for vitamin D supplementation resulting in lower incidence of upper respiratory illnesses.

What is going on? Some suggest that low vitamin D levels are a marker for ill health (the illness reduces the vitamin D levels), and that vitamin D levels go down when there is chronic inflammation. It could also be a proxy for sun exposure (the more sunlight, the higher the vitamin D levels). Note that sunlight may have additional benefits compared to just vitamin D supplementation (e.g, blue light is immune boosting).

John M. Mandrola, MD writes for Medscape, and his articles tend to be thought-provoking. Some excerpts of a Commentary by Dr. John Mandrola from Medscape: Why Is Vitamin D Hype So Impervious to Evidence?

The vitamin D story exudes teaching points: it offers a master class in critical appraisal, connecting the concepts of biologic plausibility, flawed surrogate markers, confounded observational studies, and slews of randomized controlled trials (RCTs) showing no benefits on health outcomes.

Yet despite the utter lack of benefit seen in trials, the hype continues....

My questions are simple: Why doesn't the evidence persuade people? How many nonsignificant trials do we need before researchers stop studying vitamin D, doctors stop (routinely) measuring levels, and patients stop wasting money on the unhelpful supplement? What are the implications for this lack of persuasion?  ...continue reading "Some Large Studies Find No Benefit From Vitamin D Supplements"

Published on Leave a comment on Commonly Used Pesticide Is Found In Many People
Weed and feed product (with 2,4-D)

The results of a recently published large study are depressing, but not surprising. The pesticide 2,4-D, which was originally used in Agent Orange, is still around decades later and found everywhere you look - including in us.

In the past decade there has been a tremendous increase in the amount of both agricultural and residential use of 2,4-D in the US. The herbicide (a type of pesticide) is used to kill unwanted vegetation, including weeds. In 2020 alone, 33.3 million pounds of 2,4-D were used for agricultural purposes in the US! This number is projected to rise more each year, especially because it's used on genetically modified crops.

The study (with 14,395 participants) found that in 2011-2012, 40% of persons had 2,4-D in their urine. This was a massive increase from the start of the study in 2001 (17.1%). It is expected to have increased since then. Other studies find that current levels of pesticide residues (including additional pesticides) are in over 90% of all Americans, including pregnant women.

Children (aged 6 to 11 years) had the highest 2,4-D concentrations, and below that women of childbearing age. Interestingly, one difference they found was that non-Hispanic white persons had higher levels of 2,4-D in the blood than black persons.

The researchers thought that this might be because so much is used on lawns and green spaces in white suburban areas (think of those "perfect manicured lawns"). High-income persons had higher levels (manicured lawns!) than lower income persons. Agricultural workers also had higher levels of 2,4-D.

Health effects from 2,4-D: They include an increase in the risk of non-Hodgkin lymphoma, pediatric leukemia, birth defects (e.g., hypospadias in boys), allergic wheeze, hypothyroidism, chloracne, abnormal sperm, reduced fertility, soft tissue sarcoma, and olfactory deficits. It is an endocrine disruptor.

How do we get exposed to 2,4-D? Food and water frequently have 2,4-D residues. It can be in dust, in the air (from drift when applied nearby), rain, and even on our pets (when they go on treated lawns). We can inhale it, ingest it (from food and water), and absorb it through our skin and eyes. It is in most household carpet dust samples (it gets tracked inside).

What to do? Some simple steps:

  1. Avoid using any pesticides, including weed and feed products on lawns! Lawns do NOT need pesticides to be healthy!
  2. Stay off pesticide treated lawns, especially in the first 3 days and before a rainfall.
  3. Take shoes off at the door to avoid tracking in 2,4-D (and other pesticides, heavy metals).
  4. Eat organic food, as much as possible. [2,4-D is not allowed to be used in organic farms.]
2,4-D product near refrigerated foods

2,4-D (2,4-Dichlorophenoxyacetic acid) is commonly added to weed and feed products, and used by both ordinary consumers and lawn care services. Incredibly, big box stores such as Costco sell big bags of these 2,4-D products - even next to food! This makes consumers think it's safe. But it's not.

From Science Daily: One out of three people exposed to potentially harmful pesticide

One out of three people in a large survey showed signs of exposure to a pesticide called 2,4-D, according to a study published today by researchers at the George Washington University. This novel research found that human exposure to this chemical has been rising as agricultural use of the chemical has increased, a finding that raises worries about possible health implications.  ...continue reading "Commonly Used Pesticide Is Found In Many People"

Published on Leave a comment on Dining Early Is Healthier Than Close to Bedtime

An easy-peasy way to lower your risk for type 2 diabetes may be to not eat late dinners. Research conducted in Spain found that eating a meal an hour before bedtime decreases insulin secretion, impairs and decreases glucose tolerance, and so increases type 2 diabetes risk.

Lead author Marta Garaulet, PhD said: "We found that late eating disturbed blood sugar control in the whole group." The study had 845 participants, none with diabetes, all living in Spain. Melatonin levels (which rise naturally in the 2 hours before bedtime) were involved - so researchers say don't eat a meal then. Those with a certain gene variant had more disturbed blood sugar control than those without the gene.

Bottom line: Don't eat a meal in the 2 hours before bedtime. 

From Medscape: Eating Dinner Late Ups Diabetes Risk; Melatonin Involved

Eating dinner close to bedtime when endogenous melatonin levels are high is associated with decreased insulin secretion and decreased glucose tolerance, which increase the risk of type 2 diabetes. ...continue reading "Dining Early Is Healthier Than Close to Bedtime"

Published on Leave a comment on Adding Prunes to the Diet Has Health Benefits
Prunes

A study has given further support to the view that eating prunes (dried plums) has health benefits. Penn State University researchers reviewed studies and found that eating prunes may help protect against bone loss in postmenopausal women, as well as having anti-inflammatory and antioxidative effects. All good!

A good amount to eat (according to the studies reviewed) is about 100 grams or 10 prunes (dried plums) each day.

But... don't just focus on eating prunes (dried plums) as a healthy food. Eating several servings of a variety of fruits every day (whether fresh, frozen, or dried) has numerous health  benefits and should be part of your regular diet. Fruit is anti-inflammatory, great for the gut microbes, high in fiber, and contains minerals and nutrients. Enjoy!

From Science Daily: Eating prunes may help protect against bone loss in older women

It's already well known that prunes are good for your gut, but new Penn State research suggests they may be good for bone health, too. ...continue reading "Adding Prunes to the Diet Has Health Benefits"

Published on Leave a comment on Most Americans Are Not Eating Enough Fruits and Vegetables

Recently the CDC (Centers for Disease Control and Prevention) released the  depressing news that very few Americans are eating recommended amounts of fruits and vegetables. Many studies show that eating several servings each day of fruits and vegetables has all sorts of health benefits (e.g., live longer, lower inflammation, lower risk of diabetes and some cancers).

The CDC reported in the Jan. 7, 2022 CDC weekly report that surveys of 294,566 adults in 2019 found that only 12.3% of American adults met fruit intake recommendations, and 10.0% of adults met vegetable intake recommendations.

What are the daily recommendations for fruits and vegetables? According to the CDC, current Dietary Guidelines for Americans advise eating more fruits and vegetables as part of a healthy dietary pattern. This means adults should consume 1.5 to 2 cups of fruit and 2 to 3 cups vegetables daily. (Note: A serving is usually about 1/2 cup of fruits or vegetables.)

Why should you follow these guidelines? The CDC states: "A healthy diet supports healthy immune function and helps to prevent obesity, type 2 diabetes, cardiovascular diseases, and some cancers." Also, having "some of these conditions can predispose persons to more severe illness and death from COVID-19."

Another reason, and one that they don't mention is research finding that eating more fruits and vegetables daily (as part of a healthy diet such as the Mediterranean diet) also improves the gut microbiome. What you eat feeds gut microbes - so you want to feed beneficial microbes associated with health, and not those microbes associated with chronic inflammation and some chronic diseases (e.g. heart disease, diabetes, some cancers).

CDC weekly report, Jan. 7, 2022: Adults Meeting Fruit and Vegetable Intake Recommendations — United States, 2019

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Published on 1 Comment on Some Emulsifiers Harm the Gut Microbiome

Emulsifiers are in many of the processed foods we buy. They are added to the foods to enhance texture and extend shelf life. Animal and human studies find that some emulsifiers (e.g., soy lecithin, carrageenan, polysorbate-80) can promote gut inflammation and alter the gut microbiome in a negative or harmful way. Recent research adds to this list the common emulsifier carboxymethylcellulose (CMC), also known as cellulose gum.

A small study randomly assigned 16 healthy adults to either an emulsifier-free diet or an identical diet with added 15 g per day of CMC for 11 days. No one knew what diet they were eating, and for those 11 days the participants were inpatient - thus no chance for cheating or altering the diet. Extensive testing (even biopsies on day 1 and 11!) was done before, during, and after the study. The Univ. of Pennsylvania researchers found that CMC resulted in several harmful changes, including a negative effect on the gut microbiome (microbial community of bacteria, viruses, fungi).

Results: The researchers found that CMC increased abdominal discomfort after meals, disturbed the gut microbial community and reduced its diversity (not good!). It resulted in reductions of short-chain fatty acids and free amino acids (thus impacted how nutrients are absorbed). One of the beneficial microbes associated with good health, and that was reduced in number was Faecalibacterium prausnitzii.

Two of the subjects who had CMC in their foods had increased microbial "encroachment into the normally sterile inner mucus layer" of the gut, which is a central feature of chronic inflammation diseases (e.g., IBD, type 2 diabetes). They also had large "alterations in microbiota composition". This means that there is variation in how people respond to the emulsifier CMC, with some people more sensitive than others.

The scary part is that the intestinal changes happened after just 11 days with a daily intake of 15 g of CMC - a dose that is approximately the total emulsifier consumption for a person whose diet is largely highly processed food. Yes, that is many of us eating a Western style diet (e.g., highly processed foods, and low in fiber, fresh fruits, vegetables, and whole grains). The scientists believe that long-term consumption of emulsifiers, because they result in gut microbial disruption and inflammation, are contributing to chronic diseases.

Bottom line: Read the ingredients list on food labels. Try to avoid foods that have ingredients listed that you wouldn't normally have in your kitchen. That means soy lecithin, CMC, cellulose gum, carrageenan, artificial colors. Even "natural flavors" (which are laboratory concoctions) should be avoided as much as possible.

From Medical Xpress: Ubiquitous food additive alters human microbiota and intestinal environment

New clinical research indicates that a widely used food additive, carboxymethylcellulose, alters the intestinal environment of healthy persons, perturbing levels of beneficial bacteria and nutrients. These findings, published in Gastroenterology, demonstrate the need for further study of the long-term impacts of this food additive on health.  ...continue reading "Some Emulsifiers Harm the Gut Microbiome"

Published on Leave a comment on Goji Berries Benefit Eye Health
Eye. Credit: Wikipedia

Eating a handful of dried goji berries appears to have health benefits for the eyes - they may prevent or slow down age related macular degeneration (AMD). Goji berries contain high levels of lutein and zeaxanthin. These carotenoids are essential components for eye health, and are associated with a reduced risk of cataract development and AMD.

University of California researchers found that 14 healthy middle-aged adults  eating a handful (28 grams or 1 ounce) of dried goji berries 5 days a week for 90 days increased the density of protective pigments in their eyes (macular pigment optical density or MPOD). This is an optical biomarker for AMD. Their skin carotene scores also increased.

However, the 13 persons taking lutein and zeaxanthin in the form of dietary supplements (6 mg lutein and 4 mg zeaxanthin) did not have these beneficial changes in the eye. Their skin carotene scores also did not increase. These results are similar to many studies finding the same thing - eating actual foods has many health benefits, but not dietary supplements.

Dried goji berries. Wikipedia

Bottom line: Eat more servings of foods rich in lutein and zeaxanthin.

Foods with high levels of both lutein and zeaxanthin include: dried goji berries, parsley, spinach, kale, collard greens, turnip greens, mustard greens, corn, basil, leeks, egg yolks, pistachios, peas, broccoli. Slightly lower levels are in: lettuce, green and red peppers, carrots, kiwi, grapes, squash, pumpkin, corn tortillas, corn chips, Einkorn wheat, and durum wheat.

Most fruits (tangerines, raspberries, papayas, peaches, oranges, cherries, blueberries) also contain lutein and zeaxanthin, but in smaller amounts.

From Science Daily: Dried goji berries may provide protection against age-related vision loss

Regularly eating a small serving of dried goji berries may help prevent or delay the development of age-related macular degeneration, or AMD, in healthy middle-aged people, according to a small, randomized trial conducted at the University of California, Davis.  ...continue reading "Goji Berries Benefit Eye Health"