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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"

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"

Uh-oh, it looks like some (many?) new or fairly new kitchen cabinets are outgassing several types of PCBs from the wood sealants used on the cabinets. PCBs (polychlorinated biphenyls) were banned in the 1970s due to health risks - for example, they are known carcinogens, and some are neurotoxic (also here).

Researchers from the University of Iowa monitored air inside and outside 16 Iowa homes and found 3  types of PCBs (PCB-47, PCB-51, and PCB-68) wafting off the finished kitchen cabinets. They suggest that the PCBs becoming airborne are "unintentional impurities", that is, inadvertent byproducts of polymer sealants (from the common ingredient 2,4-dichlorobenzoyl peroxide) used in modern kitchen cabinetry. They found that unfinished cabinets had no PCB emissions. The concentrations seemed to be dependent on the year the house was built - with higher levels in houses built in the past 5 years (one house had just been completed),  and also in a recently remodeled kitchen (new cabinets!). The cabinets were made by different manufacturers.

So now we have a new source of indoor air pollution to think about. The big questions are: 1) What, if anything, does this mean for human health? 2) How long does this outgassing from sealants go on for? 3) Are there alternative sealers that don't have this problem? By the way, the researchers discuss that household paints emit PCBs (such as PCB 11) as byproducts of paint pigment manufacturing, and yes, they were found both inside and outside houses. We love our plastics, use them in so many products, but there are consequences. From Env. Health News:

Finished kitchen cabinets are emitting toxic PCBs

Researchers tested indoor air at 16 homes and found three types of PCBs are widespread, and finished cabinets are the source of the toxics, according to a study released today. They suspect the PCBs [polychlorinated biphenyls] are byproducts of sealants used on the cabinets. The study, from the University of Iowa, is the first to suggest wood finishing products are a significant source of PCBs to indoor air and finds that, despite federal bans on PCBs, the chemicals are still being released into the environment, including our homes.  ...continue reading "Kitchen Cabinet Sealants Can Be A Source of Indoor Air Pollution"

Nice to hear that a new study found that across the lifespan, human brains are capable of producing new neurons (neurogenesis). Neurons are nerve cells, what we popularly call brain cells, and are the basic working unit of the nervous system. The human brain contains about 100 billion neurons.

The researchers did find some age differences (e.g. with age there was less neuroplasticity or the brain's ability to reorganize itself by forming new neural connections, and a decline in angiogenesis - the development of new blood vessels). But still... the findings are reassuring. Interesting how the researchers did the study. They examined 28 brains (specifically, newly formed neurons and the state of blood vessels within the hippocampus) right after death from previously healthy people (aged 14 to 79), who died suddenly.

While they found age differences, they did not find gender differences. The researchers summarized that healthy older subjects without cognitive impairment (meaning they were mentally healthy), neuropsychiatric disease, or treatment (e.g. depression drugs or psychotropic drugs) display preserved neurogenesis (produce new neurons) throughout life. From Science Daily:

Older adults grow just as many new brain cells as young people

Researchers show for the first time that healthy older men and women can generate just as many new brain cells as younger people.

There has been controversy over whether adult humans grow new neurons, and some research has previously suggested that the adult brain was hard-wired and that adults did not grow new neurons. This study, to appear in the journal Cell Stem Cell on April 5, counters that notion. Lead author Maura Boldrini, associate professor of neurobiology at Columbia University, says the findings may suggest that many senior citizens remain more cognitively and emotionally intact than commonly believed. ...continue reading "Some Good News About The Aging Brain"

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"

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"

New research published in The Lancet estimates that lead exposure results in about 400,000 deaths every year in the USA - which includes about 250,000 deaths from cardiovascular disease. The study looked at "historical exposure" to lead, which means they looked at a person's lead exposure years ago (which could have been from many sources, such as breathing lead contaminated dust, drinking water from leaded pipes, from lead paint, leaded gas, or eating from cans that have been soldered with lead). What was noteworthy in this study following over 14,000 adults was that there were increased death rates even from low lead blood levels (concentrations of lead in blood lower than 5 μg/dL).

Lead exposure has been declining since the 1970s after lead was eliminated (banned) from paint and gasoline, but this study looked at adults born in the years when lead exposure was higher during childhood and adulthood. Baseline data (blood lead levels) was collected between 1988 and 1994 and then individuals were followed for the next 2 decades. The researchers found that there was a dose response curve - the higher the blood lead level, the higher the death rate from any cause (all-cause mortality), from cardiovascular disease, and from ischaemic heart disease in the next two decades.

Lead is a naturally occurring heavy metal, but it's also a poisonous substance for humans, and accumulates in teeth and bones. Lead can pass through the blood-brain barrier in children and fetuses and kill brain cells (and cause neurological damage). Lead can enter blood vessels and harm the endothelial cells that line the blood vessels. This process hardens arteries and causes plaque to form in blood vessels, increasing blood pressure, and the risk of heart disease and stroke. Lead can damage the kidneys, which play an important role in regulating blood pressure, and so increase a person’s risk of heart disease and stroke.

The Centers for Disease Control and Prevention (CDC) have stated that there are no safe blood levels of lead for children (zero is best), and the researchers of this study believe the same is true for adults. From Science Daily:

Historical lead exposure may be linked to 256,000 premature deaths from cardiovascular disease in adults in United States each year

New estimates suggest that 256,000 premature deaths from cardiovascular disease -- including 185,000 deaths from ischemic heart disease -- in the USA may be linked to historical lead exposure in middle-aged and older adults (people currently aged 44 years or over), according to an observational study following 14,300 people for almost 20 years, published in The Lancet Public Health journal.  ...continue reading "Even Low Level Lead Exposure Is Linked to Later Health Problems"

This recent study adds to the body of knowledge of what negative major life events (resulting in lots of stress, anxiety, worry) does to a middle-aged person's health. Negative life events could be an interpersonal conflict (e.g. divorce), a death in the family, financial hardship, and serious medical emergencies. Using MRIs, the researchers found that each fateful life event (FLE), especially those that involve interpersonal relationships, accelerates brain aging about .37 years (about a third of a year). And the more negative life events, the bigger the effect. From Science Daily:

Negative fateful life events and the brains of middle-aged men

Conflict, a death in the family, financial hardship and serious medical crises are all associated with accelerated physical aging. In a new study, researchers at the University of California San Diego School of Medicine found that such negative fateful life events -- or FLEs -- appear to also specifically accelerate aging in the brain

Writing in the journal Neurobiology of Aging, a research team, led by senior author William S. Kremen, PhD, professor of psychiatry and co-director of the Center for Behavior Genetics of Aging at UC San Diego School of Medicine, found that major adverse events in life, such as divorce, separation, miscarriage or death of a family member or friend, can measurably accelerate aging in the brains of older men, even when controlling for such factors as cardiovascular risk, alcohol consumption, ethnicity and socioeconomic status, which are all associated with aging risk. 

Specifically, they found that on average, one FLE was associated with an increase in predicted brain age difference (PBAD) of 0.37 years. In other words, a single adverse event caused the brain to appear physiologically older by approximately one-third of a year than the person's chronological age, based upon magnetic resonance imaging (MRI). 

The researchers studied 359 men, ages 57 to 66 years old, participating in the Vietnam Era Twin Study of Aging (VETSA). Researchers asked participants to tally a list of life-changing events over the past two years .... All participants underwent MRI exams and further physical and psychological assessments within one month of completing the most recent self-reports. The MRIs assessed physiological aspects of the brain, such as volume and cortical thickness -- a measure of the cerebral cortex or outer layer of the brain linked to consciousness, memory, attention, thought and other key elements of cognition.

Hatton said exposure to chronic stress has long been associated with biological weathering and premature aging, linked, for example, to oxidative and mitochondrial damage in cells, impaired immune system response and genomic changes. The study's authors said their findings provide a possible link between molecular aging and brain structure changes in response to major stressful life events. They do note that the study was a snapshot of a narrow demographic: older, predominantly white, males. It is not known whether females or other ethnicities would show similar findings.

Of course! The results of this study made perfect sense to me - that losing your wealth or savings in late middle-age is such a mental shock ("negative wealth shock") that it increases the risk of death for any reason ("all cause mortality") tremendously over the next 20 years. About 50% increased risk of death. For example, if you have to live off your savings after you get laid off or can't work due to illness, and perhaps even lose your house to foreclosure, is STRESSFUL beyond belief. Almost incomprehensible to anyone who has not personally gone through it.

On top of that, a person may then not be able to afford to go to the doctor, even if there is a problem, once they're financially stressed. And of course they may never financially recover because the "negative wealth shock" happened at an older age (the people were 51 to 61 at the start of the study).

Other research conducted at time of the Great Recession showed significant associations between negative wealth shocks and short-term health changes - including increased risk of depression, anxiety, suicide, impaired cardiovascular function, and substance abuse. And now we know that long-term there is an increased risk of death. From Science Daily:

Losing your nest egg can kill you

A sudden loss of net worth in middle or older age is associated with a significantly higher risk of death, reports a new Northwestern Medicine and University of Michigan studyWhen people lose 75 percent or more of their total wealth during a two-year period, they are 50 percent more likely to die in the next 20 years, the study found.  ...continue reading "Losing Your Wealth In Late Middle-Age and Increased Risk of Death"

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?"