[ad_1]
How did these individuals become vitamin D deficient in the first place? According to Bredesen, it’s a combination of lifestyle habits and nutritional choices: “They’re living indoors, they’re not getting out enough, they’re not taking vitamin D, or they’re not absorbing the vitamin D they are taking.”
[ad_2]
[ad_1]
Ranked as the ninth leading cause of mortality globally and contributing to more than 1 million annual deaths, it’s no wonder that the prevention and management of Type 2 diabetes, blood glucose spikes, and insulin resistance is a high priority in public health.
[ad_2]
[ad_1]
These sun-confounding factors include time of day, time of year, location, skin tone, wearing SPF, air pollution, and even age. Combined with the reality of our lives—which are mostly spent indoors, these factors make getting enough D from the sun unrealistic.
[ad_2]
[ad_1]
In one case report published in Annals of Dermatology, a 7-year-old boy with reduced vitamin D receptor (VDR) expression in alopecia areata had new hair growth after six weeks2
[ad_2]
[ad_1]
Keeping inflammatory pathways in check, instead of “burning” unchecked, is pivotal for overall health. And since 25(OH)D levels (i.e., the blood biomarker measure of vitamin D sufficiency) have been observed to influence CRP status, ongoing research that investigates exactly how vitamin D plays a part in regulating a healthy inflammatory response is important to gain an understanding of how the essential vitamin helps support cardiovascular, neurological, musculoskeletal, gastrointestinal, and immune health.*
[ad_2]
[ad_1]
While most known for its role in bone and immune health, vitamin D touches pretty much every system in your body. And studies consistently show that poor vitamin D status is linked to type 2 diabetes1
[ad_2]
[ad_1]
Considering clinical vitamin D insufficiency persists in almost half of the U.S., population (41 percent1
[ad_2]
[ad_1]
mbg’s vitamin D3 potency+ provides 5,000 IU of organic vitamin D3 derived from sustainable, vegan algal oil, plus a trio of organic oils (avocado, flax, and olive, to be exact) to optimize bioavailability and absorption.* (All in one gelcap, mind you.)
[ad_2]
[ad_1]
Staying consistent with fitness isn’t always easy. Maybe you’ve had a busy few weeks where family, work, or travel took priority over your workouts (we’ve all been there). Or perhaps you’ve been going strong in your routine but still feel like your muscles could use an extra edge.
[ad_2]
[ad_1]
Most plant-based milks are not fortified with iodine.
“Adequate dietary iodine is required for normal thyroid function.” In fact, the two thyroid hormones are named after how many iodine atoms they contain: T3 and T4. “Given that iodine is extensively stored in the thyroid gland itself, it can safely be consumed intermittently,” so we don’t need to consume it every day. However, our overall diet does need a good source of it. Unfortunately, the common sources aren’t particularly health-promoting: iodized salt and dairy foods. (Iodine-based cleansers like betadine are used on cows “to sanitize the udders, resulting in leaching of iodine in the milk.”) Iodine may also be added to cattle feed, and some commercially produced breads contain food additives with iodine.
If you put people on a paleo-type diet and cut out their dairy and table salt, they can develop an iodine deficiency, even though they double their intake of seafood, which can also be a source of iodine. What about those switching to diets centered around whole plant foods? They also cut down on ice cream and Wonder Bread, and if they aren’t eating anything from the sea, like seaweed or other sea vegetables, they can run into the same problem.
A three-year-old’s parents reported striving to feed her only the healthiest foods, and her diet included only plant-based, unsalted, and unseasoned foods. She got no unprocessed foods, but she also got no vitamin supplementation, which could be deadly. Without vitamin B12, those on strictly plant-based diets can develop irreversible nerve damage, but in this case, a goiter arose first, due to inadequate iodine intake.
In another case of “veganism as a cause of iodine-deficient hypothyroidism,” a toddler became ill after weaning. Before weaning, he was fine because his mother kept taking her prenatal vitamins, which fortunately contained iodine.
Most vegetarians and vegans are apparently unaware of the importance of iodine intake during pregnancy, “for the neurodevelopment of the unborn child, similar to their omnivorous counterparts.” The American Thyroid Association and the American Academy of Pediatrics have recommended that women, even just planning on getting pregnant, should take a daily supplement containing 150 micrograms (mcg) of iodine, yet only 60 percent of prenatal vitamins marketed in the United States contain this essential mineral. So, despite the recommendations, about 40 percent of prenatal vitamins don’t contain it. “Therefore, it is extremely important that women, especially when pregnant, breastfeeding, or planning a pregnancy, read the labels of their multivitamin supplements to ensure that they are receiving an adequate amount of iodine.”
Women of reproductive age have an average iodine level of 110 mcg/liter, which is fine for nonpregnant individuals, but we’d really like women to get at least 150 mcg/liter during pregnancy. (It’s basically a 24-hour urine test, in which iodine sufficiency is defined as 100 mcg/liter of urine in nonpregnant adults; the average vegan failed to reach this in the largest study done to date, one out of Boston.)
The recommended average daily intake is 150 mcg per day for most people, which we can get in about a cup and a half of cow’s milk. Regrettably, plant-based milks aren’t typically fortified with iodine and average only about 3 mcg per cup. Although many plant-based milks are fortified with calcium, researchers found in the largest systematic study to date that only 3 out of 47 were fortified with iodine. Those that were fortified had as much as cow’s milk, but those that weren’t fell short, as you can see at 3:30 in my video Are Vegans at Risk for Iodine Deficiency?.
Plant-based milk companies brag about enriching their milks with calcium and often vitamins B12, D, and A, but only rarely are attempts made to match iodine content. The only reason cow’s milk has so much is that producers enrich the animals’ feed or it comes dripping off their udders. So, why don’t plant-milk companies add iodine, too? I was told by a food scientist at Silk that my carrageenan video played a role in the company switching to another thickener. Hopefully, Silk will see this video, too, and consider adding iodine, or maybe another company will snatch the opportunity for a market advantage.
The researchers conclude that individuals who consume plant-based milks not fortified with iodine may be at risk for iodine deficiency, unless they consume alternative dietary iodine sources, the healthiest of which are sea vegetables, which we’ll cover next.
Doctor’s Note:
This is the first in a four-video series on thyroid function. The next three are:
For more on iodine, see the related posts below.
[ad_2]
Michael Greger M.D. FACLM
Source link
[ad_1]
For perhaps 99.99 percent of our time as a species on Earth, we lived outdoors in the natural environment. Might there be a health benefit to returning now and again, and surrounding ourselves with nature? That’s a question that urban planners have asked. “Are people living in greener areas healthier than people living in less green areas?” Should we put it in a park or another car park?
“In a greener environment, people report fewer symptoms of illness and have better perceived general health. Also, people’s mental health appears to be better”—and by a considerable amount. Indeed, “assuming a causal relation between greenspace and health, 10% more greenspace in the living environment leads to a decrease in the number of symptoms that is comparable with a decrease in age by 5 years.” That is a big assumption, though.
Still, you could imagine some potential mechanisms of why it could be. It could mean less air pollution, and air pollution is no joke. It is the fifth leading cause of death on our planet, killing about five million people a year. Though, of course, our number one risk factor is our diet, which kills twice as many individuals, as you can see below and at 1:18 in my video Are There Health Benefits of Spending Time in Nature?.
So, it could be an antipollution effect, or maybe there’s something special about experiencing greenspaces beyond them just offering more opportunities to exercise. The simplest explanation is probably that a natural setting “simply promotes health-enhancing behavior rather than having specific and direct benefits for health.” It’s harder to go jogging in the park when there is no park. Ironically, it seems that even when people have access to nature, they don’t necessarily take advantage of it. And, even if there were a link, “a question remains about the possibility of a ‘self-selection’ phenomenon: do natural environments elicit increased physical activity and well-being, or do physically active individuals choose to live in areas with more opportunities for physical activity?” What I wanted to know is, “apart from the promotion of physical activity,” are there “added benefits to health of exposure to natural environments”?
Now certainly, just being exposed to sunlight can treat things like seasonal affective disorder and provide vitamin D, the sunshine vitamin, but are there any other inherent benefits? You don’t know until you put it to the test. Some of the studies are just silly, though. Consider “Relationships Between Vegetation in Student Environments and Academic Achievement Across the Continental U.S.” At first, I thought the study was about academic achievement and vegetarianism, but no—it’s about vegetation. Researchers found a “positive relationship between non-forest vegetation and graduation rates for schools.” Maybe the Ivy League’s edge is from the ivy?
The study entitled “View Through a Window May Influence Recovery from Surgery” starts to make things more interesting. As you can see below and at 3:04 in my video, some patient rooms at a suburban hospital looked out at trees, while others to a brick wall. “Twenty-three surgical patients assigned to rooms with windows looking out on a natural scene had shorter postoperative hospital stays…and took fewer potent analgesics [painkillers] than 23 matched patients in similar rooms with windows facing a brick building wall.” You can’t chalk that up to a vitamin D effect.
What could it be about just looking at trees? Maybe it is the “vitamin G”—just the color of green. We know how healthy it is to eat our greens. What about just looking at them? Researchers had people exercise while watching a video simulating going through a natural, green-colored setting, the same video in black and white, or everything tinted red, and no differences were noted (with the exception that red made people feel angry), as you can see below and at 3:46 in my video.
The most interesting mechanism that has been suggested that I’ve run across is fractals. Have you ever noticed that “for example, in a tree, all the branches—from big to small—are scaled-down versions of the entire tree”? Each branch has a shape similar to the whole tree itself. Fractal patterns are found throughout nature, where you see “a cascade of self-similar patterns over a range of magnification scales, building visual stimuli that are inherently complex.” And, as you can see when you’re hooked up to an EEG, our brain seems to like them, too.
Regardless of the mechanism, if you compile all the controlled studies on using nature as a health promotion intervention, you tend to see mostly psychological benefits, whereas the findings related to physical outcomes were less consistent. “The most common type of study outcome was self-reported measures of different emotions.” For instance, what makes you feel better: staring at a kiwifruit orchard or a building? (See below and 4:41 in my video.) Awkwardly described, thanks presumably to the language barrier, as a comparison of “synthetic versus organic stimulation.”
As you can see below and at 5:00 in my video, natural settings may make people more attentive and less sad, but when it comes to some objective measures like blood pressure, no significant effect was found. People who exercise outdoors often say they feel great, “suggesting that green exercise activities can increase…various psychological subscales,” such as “mood, focus, and energy”—within just five or so minutes of being out in the woods.
Yet these studies tended not to be randomized trials. Researchers just asked people who already sought out nature what they thought about nature, so it’s no wonder they like it—otherwise, they wouldn’t be out there. But nature-based interventions are low-cost, often free, in fact, and non-invasive (unless you count the mosquitoes). So, if you want “a natural high,” I say go for it, whatever makes you happy. (Not all green exercisers like trees. Golfers just viewed them as obstacles.)
For more on air pollution, see my videos Best Food to Counter the Effects of Air Pollution and The Role of Pesticides and Pollution in Autism.
Of course, there are benefits to any kind of exercise indoors or out. Check out the related posts below.
[ad_2]
Michael Greger M.D. FACLM
Source link
[ad_1]
The sun “gives” people vitamin D by converting cholesterol in the skin into vitamin D3,…
[ad_2]
[ad_1]
Does eating fish or taking fish oil supplements reduce stroke risk?
In my last video, we started to explore what might explain the higher stroke risk in vegetarians found in the EPIC-Oxford study. As you can see below and at 0:25 in my video Vegetarians and Stroke Risk Factors: Omega-3s?, vegetarians have a lower risk of heart disease and cardiovascular disease overall, but a higher risk of stroke. We looked into vitamin D levels as a potential mechanism, but that didn’t seem to be the reason. What about long-chain omega-3s, the fish fats like EPA and DHA?
Not surprisingly, their levels are found to be “markedly lower in vegetarians and particularly in vegans than in meat-eaters.” They’re about 30 percent lower in vegetarians and more than half as low in vegans, as you can see below and at 0:45 in my video.
According to “the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date,” combining 28 randomized controlled trials, stroke has no benefit. There is evidence that taking fish oil “does not reduce heart disease, stroke or death,” or overall mortality, either. This may be because, on the one hand, the omega-3s may be helping, but the mercury in fish may be making things worse. “Balancing the benefits with the contaminant risks of fish consumption has represented a challenge for regulatory agencies and public health professionals.”
For example, dietary exposure to polychlorinated biphenyls (PCBs) may be associated with an increased risk of stroke. In one study, for instance, “neither fish nor intake of PCBs was related to stroke risk. However, with adjustment for fish intake,” that is, at the same fish intake, “dietary PCBs were associated with an increased risk of total stroke,” so the PCB pollutants may be masking the fish benefit. If we had a time machine and could go back before the Industrial Revolution and find fish in an unpolluted state, we might find that it is protective against stroke. Still, looking at the EPIC-Oxford study data, if fish were protective, then we might expect that the pescatarians (those who eat fish but no other meat) would have lower numbers of strokes since they would have the fish benefit without the risk from other meat. But, no. That isn’t the reality. So, it doesn’t seem to be the omega-3s either.
Let’s take a closer look at what the vegetarians are eating.
When it comes to plant-based diets for cardiovascular disease prevention, all plant foods are not created equal. There are two types of vegetarians—those who do it for their health, and those who do it for ethical reasons, like global warming or animals—and the latter tend to eat different diets. Health vegans tend to eat more fruits and fewer sweets, for instance, and you don’t tend to see them chomping down on vegan donuts, as shown below and at 2:41 in my video.
“Concerns about health and costs were primary motivations for [meat] reduction” in the United States. A middle-class American family is four times more likely to reduce meat for health reasons compared to environmental or animal welfare concerns, as you can see in the graph below and at 2:55 in my video.
But in the United Kingdom, where the EPIC-Oxford stroke study was done, ethics was the number one reason given for becoming vegetarian or vegan, as you can see in below and at 3:05 in my video.
We know that “plant-based diets, diets that emphasize higher intakes of plant foods and lower intakes of animal foods, are associated with a lower risk of incident cardiovascular disease, cardiovascular disease mortality, and all-cause mortality”—a lower risk of dying from all causes put together—“in a general US adult population.” But, that’s only for healthy plant foods. Eating a lot of Wonder Bread, soda, and apple pie isn’t going to do you any favors. “For all types of plant-based diets, however, it is crucial that the choice of plant foods is given careful consideration.” We should choose whole fruits and whole grains over refined grains and avoid trans fats and added sugars. Could it be that the veggie Brits were just eating more chips? We’ll find out next.
Another strikeout trying to explain the increased risk. Could it be that the vegetarians were eating particularly unhealthy diets? Labels like vegetarian or vegan just tell me what is not being eaten. You can be vegetarian and consume a lot of unhealthy fare, like french fries, potato chips, and soda. That’s why, as a physician, I prefer the term whole food, plant-based nutrition. That tells me what you do eat. You eat vegetables and follow a diet centered around the healthiest foods out there.
If you missed the first four videos in this series, see:
Surprised about the fishy oil findings? Learn more: Is Fish Oil Just Snake Oil? and Omega-3s and the Eskimo Fish Tale.
[ad_2]
Michael Greger M.D. FACLM
Source link
[ad_1]
Could the apparent increased stroke risk in vegetarians be reverse causation? And what about vegetarians versus vegans?
In the “Risks of Ischaemic Heart Disease and Stroke in Meat Eaters, Fish Eaters, and Vegetarians Over 18 Years of Follow-Up” EPIC-Oxford study, not surprisingly, vegetarian diets were associated with less heart disease—10 fewer cases per 1,000 people per decade compared to meat eaters—but vegetarian diets were associated with three more cases of stroke. So, eating vegetarian appears to lower the risk of cardiovascular disease by 7 overall, but why the extra stroke risk? Could it just be reverse causation?
When studies have shown higher mortality among those who quit smoking compared to people who continue to smoke, for example, we suspect “reverse causality.” When we see a link between quitting smoking and dying, instead of quitting smoking leading to people dying, it’s more likely that being “affected by some life-threatening condition” led people to quit smoking. It’s the same reason why non-drinkers can appear to have more liver cirrhosis; their failing liver led them to stop drinking. This is the “sick-quitter effect,” and you can see it when people quit meat, too.
As you can see below and at 1:16 in my video Vegetarians and Stroke Risk Factors: Vitamin D?
, new vegetarians can appear to have more heart disease than non-vegetarians. Why might an older person all of a sudden start eating vegetarian? Well, they may have just been diagnosed with heart disease, so that may be why there appear to be higher rates for new vegetarians—an example of the sick-quitter effect. To control for that, you can throw out the first five years of data to make sure the diet has a chance to start working. And, indeed, when you do that, the true effect is clear: a significant drop in heart disease risk.
So, does that explain the apparent increased stroke risk, too? No, because researchers still found higher stroke risk even after the first five years of data were skipped. What’s going on? Let’s dive deeper into the data to look for clues.
What happens when you break down the results by type of stroke and type of vegetarian (vegetarian versus vegan)? As you can see below and at 2:09 in my video, there are two main types of strokes—ischemic and hemorrhagic. Most common are ischemic, clotting strokes where an artery in the brain gets clogged off, as opposed to hemorrhagic, or bleeding strokes, where a blood vessel in the brain ruptures. In the United States, for example, it is about 90:10, with nine out of ten strokes the clotting (ischemic) type and one out of ten bleeding (hemorrhagic), the latter being the kind of stroke vegetarians appeared to have significantly more of. Now, statistically, the vegans didn’t have a significantly higher risk of any kind of stroke, but that’s terrible news for vegans. Do vegans have the same stroke risk as meat eaters? What is elevating their stroke risk so much that it’s offsetting all their natural advantages? The same could be said for vegetarians, too.
Even though this was the first study of vegetarian stroke incidence, there have been about half a dozen studies on stroke mortality. The various meta-analyses have consistently found significantly lower heart disease risk for vegetarians, but the lower stroke mortality was not statistically significant. Now, there is a new study that can give vegetarians some comfort in the fact that they at least don’t have a higher risk of dying from stroke, but that’s terrible news for vegetarians. Statistically, vegetarians have the same stroke death rate as meat eaters. Again, what’s going on? What is elevating their stroke risk so much that it’s offsetting all their natural advantages?
Let’s run through a couple of possibilities. As you can see in the graph below and at 3:48 in my video, if you look at the vitamin D levels of vegetarians and vegans, they tend to run consistently lower than meat eaters, and lower vitamin D status is associated with an increased risk of stroke. But who has higher levels of the sunshine vitamin? Those who are running around outside and exercising, so maybe that’s why their stroke risk is better. What we need are randomized studies.
When you look at people who have been effectively randomized at birth to genetically have lifelong, lower vitamin D levels, you do not see a clear indicator of increased stroke risk, so the link between vitamin D and stroke is probably not cause-and-effect.
We’ll explore some other possibilities, next.
So far in this series, we’ve looked at what to eat and what not to eat for stroke prevention, and whether vegetarians do have a higher stroke risk.
It may be worth reiterating that vegetarians do not have a higher risk of dying from a stroke, but they do appear to be at higher risk of having a stroke. How is that possible? Meat is a risk factor for stroke, so how could cutting out meat lead to more strokes? There must be something about eating plant-based that so increases stroke risk that it counterbalances the meat-free benefit. Might it be because plant-based eaters don’t eat fish? We turn to omega-3s next. For other videos in this series, see related posts below.
There certainly are benefits to vitamin D, though. Here is a sampling of videos where I explore the evidence.
[ad_2]
Michael Greger M.D. FACLM
Source link
[ad_1]
And based on the findings, it would appear vitamin D is just as essential as ever. Namely, the number of major cardiovascular events was 9% lower in the participants supplementing vitamin D compared to the placebo group, with the rate of heart attacks specifically being 19% lower, and an 11% lower chance of coronary revascularization, compared to the placebo.
[ad_2]
