Mini Mikkipedia - Hypertension
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Bye!
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Hey everyone, it's Mikki here. You're listening to another mini Mikkipedia on a Monday. And this Monday, I want to chat about hypertension or high blood pressure. I get several messages each month with people worried about their sodium intake and blood pressure. Not that they have high blood pressure, but the prevailing public health message is that we need to be concerned with sodium. Now,
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On today's episode, I want to chat a little bit about the controversy with sodium, with other dietary factors that do increase blood pressure and why that's a risk. And then also what we can do from a diet perspective to reduce blood pressure. It's a little bit of a laundry list of things that we can do, but hopefully some of this stuff will be helpful for anyone who has questions, concerns, queries, or is
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particularly concerned about their blood pressure. And if you do have hypertension, then what I will say upfront is that you actually should be concerned. Hypertension is defined as a sustained elevation of systemic arterial blood pressure. And what this means when you get a blood pressure reading is that your systolic blood pressure is 130 millimeters of mercury or higher.
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and or your diastolic blood pressure is 80 mmHg or higher. And these values are based on guidelines set by the American Heart Association, American College of Cardiology, many New Zealand, obviously the Heart Foundation, organizations, all of the same ilk. And there are also several stages and classifications for hypertension as well. So what is considered a normal blood pressure?
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would be less than 120 millimetres of mercury and less than 80 millimetres of mercury for your systolic and diastolic blood pressure. It's a bit of a mouthful isn't it so I'm just going to continue on with the numbers. Elevated is between 120 to 129 systolic and stage one hypertension is between 130 to 139 for your systolic and between 80 and 89 for your diastolic.
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Stage 2 hypertension is greater than 140 over greater than 90. And these classifications help guide treatment decisions and interventions. So if somebody is suspected of having hypertension, then it is essential to confirm the diagnosis with repeated measurements. And it's worthwhile doing this if this is you actually having a blood pressure measurement kit yourself to be able to do it at home. And with the end goal really with
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Hypertension is to reduce the risk of that cardiovascular disease including heart attack, stroke and heart failure as well as other complications like kidney disease. Blood pressure is or high blood pressure is a serious thing to consider and there are two different types of hypertension. There's primary or essential hypertension and secondary and it's really important to know the difference.
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Because with primary, which is the most common type of hypertension, it's when the high blood pressure doesn't have an identifiable cause, and it's believed to be a result from a combination of genetic, environmental, and possibly hormonal factors, and around 90-95% of all hypertension cases are primary. With secondary hypertension, this is high blood pressure that has an identifiable cause, usually from another underlying health condition or medication, and it can result from conditions such as kidney disease,
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hormonal disorders, certain medications or substances, and potentially the result of endocrine disorders such as Cushing's syndrome and primary aldosterinism, which are pretty rare. And in fact, secondary hypertension is only 5-10% of all hypertension cases. And therefore, in the case of secondary hypertension, the end goal is to treat that underlying cause, which will then significantly resolve, or at least improve, that high blood pressure
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The reason why we should be interested in blood pressure and hypertension is because it is an independent risk factor for cardiovascular disease and that is the leading cause of early mortality in many Western nations including New Zealand. And it's often labelled a silent killer because it frequently presents without any other symptoms, especially in those early stages. Which does mean that regular blood pressure screenings are pretty important.
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However, in some cases, especially when blood pressure is severely elevated or has been high for an extended period of time, there are some symptoms that someone can experience. These include headaches, especially in the back of the head and upon waking up, dizziness or lightheadedness, blurred or double vision, shortness of breath, nosebleeds, chest pain or discomfort, blood spots in the eyes, palpitations or irregular heartbeats.
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Tinnitus which is buzzing or ringing in the ears, nausea or vomiting, confusion or altered mental state, fatigue or a flushed face or feeling excessively hot. Now I don't probably need to tell you that a lot of these symptoms are actually quite nonspecific, which means they can be caused by a variety of conditions. So if you are experiencing any of these symptoms, particularly in combination or if they come on suddenly, you really should sort of seek the advice of your doctor.
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And the problem with hypertension is that it can exist without symptoms for many years, but continue to cause internal damage to organs like the heart, the kidneys, the eyes, and blood vessels. So it is crucial for someone to understand their risk factors for hypertension and to get their blood pressure checked regularly. And if they do have high blood pressure, then work on strategies to lower blood pressure. That is one of the single most important things.
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that someone can do. And it isn't just as simple as reducing salt on food at all. And in fact, there is a little bit of controversy around salt actually. So the relationship between dietary salt, sodium chloride and hypertension has been a topic of scientific investigation for decades. And some may argue that there is substantial evidence that high salt intake can raise blood pressure in many people.
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However, the magnitude of this effect and its implications for health, as well as the ideal level of salt intake, are pretty grey actually. There are some people who are salt sensitive, but as I understand it, that is a small minority of the population, maybe 3% of the population. And that just means that their blood pressure is more affected by salt intake than others. On the other hand, there are some people who can consume
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amounts of sodium and salt without experiencing a significant rise in blood pressure or continue to have their normal sort of blood pressure. And this variability is influenced by genetics, age, race, and of course the presence of certain medical conditions. Sodium is super important in the body so it plays crucial roles in maintaining the body's fluid balance, nerve function, and muscle contraction. However, where
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blood pressure and salt sort of intervene, if you like, is that excessive sodium may lead to increased blood volume, which can place an added strain on the heart and blood vessels, potentially leading to hypertension. And this is where some of that recommendation for reducing sodium comes in. So many health organizations, such as the World Health Organization, American Heart Association, New Zealand Heart Foundation, recommend reducing sodium intake.
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to lower the risk of hypertension and cardiovascular diseases. These recommendations often suggest an intake of less than 2,300 milligrams of sodium per day with an ideal limit of 1,500 milligrams for certain populations. Now that equates to about a teaspoon of salt per day. Sodium is about 60% of table salt and table salt sodium chloride, so that would sort of provide you about that 2,300 milligrams of sodium.
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The thing is, though, is that there are several studies showing a U-shaped relationship between sodium intake and health, suggesting that both very high and very low sodium intakes might be associated with increased health risks, and that the focus on sodium could distract from other dietary factors which are important for things like hypertension and endothelial dysfunction, such as overall diet quality, potassium intake, and the ability
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carbohydrate and sugar intake, and of course the balance of sodium to potassium. And there's also debate over how universally applicable the salt guidelines are given the variability in individual responses to salt intake. And interestingly, when you look at meta-analyses and reviews on salt and hypertension, guidelines largely base their recommendations for population-wide sodium restriction on blood pressure but fail
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that reducing sodium has on other surrogate markers of cardiovascular disease risk, such as heart rate, noradrenaline, insulin resistance, cholesterol, triglycerides, aldosterone, and renin, which can all be worsened by sodium restriction. Prospective studies show that sodium restriction in the range recommended by dietary guidelines might actually increase the risk of cardiovascular events and death.
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at the Cochrane systematic reviews of the literature. The last one I believe was done in 2020 and it revealed that you get a minor reduction in blood pressure when you restrict your salt, but you do get an increase in some of these other markers like insulin and triglycerides, both of which increase cardiovascular disease risk.
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There is no definitive proof that sodium restriction reduces cardiovascular events or mortality, but there is good evidence that it can reduce quality of life and may increase the risk of cardiovascular morbidity and mortality. Reducing sodium almost is the opposite of what you would expect it to do. Some observational studies that have looked at this U-shaped or J-shaped relationship have
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negative health outcomes comes when your sodium intakes are around 3000 to 5000 milligrams per day. So it's quite a lot, sort of more than that 1500 milligram recommendation or that 2300 milligram cap. And in the PURE study, Prospective Urban Rural Epidemiology, it's quite a large study found that sodium intakes between 3000 to 6000 milligrams were associated with a more favorable risk profile for
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than either super low or super high intakes. And look, the real challenge is actually estimating sodium intake. I mean, who sits there and measures every grain of salt that they put in their food? And in part, we don't even know where sodium is in a lot of our food choices. And it certainly doesn't exist in isolation. People who consume a lot of sodium might in fact have a lot of processed food in their diet, which is where
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the majority of sodium is found in the typical western diet. So this is just something to be mindful of if you're concerned about salt intake. Now as a clinician I am still conservative. If I have someone who has hypertension I'm not going to ignore the fact that sodium can play a role in this because they may well be salt sensitive. A genetic test would determine it as would reducing sodium intake and
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measuring the effects that this might have on their blood pressure. However, reducing sodium might not be the primary place I go to, and it might not be the focus of that discussion. It will come into it, but there are some other heavy hitters which I think are important, not just me, other people as well, when it comes to hypertension. And unsurprisingly, sugar plays a major role in this, particularly fructose.
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which is found in nature, in fruit, which I'm less concerned about unless someone is eating a ton of like dried fruit or something like that, but it's more from things like sucrose, which is half fructose, half glucose, and that's table sugar, and of course high fructose corn syrup if you are in North America. Now we don't have a lot of high fructose corn syrup here in New Zealand, that's where a lot of the research has been done looking at the impact of fructose
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But it is worth mentioning that high fructose corn syrup, which gets a really bad rap for good reason, has about 55% of its carbohydrate coming from fructose and 45 from glucose, which isn't actually that different from sucrose, which is what we have here in New Zealand, which is a 50-50 split. So some studies show that high intake of added sugars, especially fructose, can lead to an increase in blood pressure through things like
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endothelial dysfunction. So excessive sugar consumption might impair the endothelium, which is the inner lining of our blood vessels, making them less flexible. And a less elastic vessel could contribute to higher blood pressure. High fructose consumption might increase sodium absorption in the gut and decrease its excretion by the kidneys. So it can contribute to fluid retention and increase blood pressure. And it may also increase sympathetic nervous system
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which in turn can elevate blood pressure. And of course, if you have a high intake of added sugars and excess calories which cause you to gain body fat, you then of course run the risk of carrying excess body fat which places you at increased risk. And obesity is a well-known risk factor for hypertension. It can lead to increased blood volume and cardiac output, placing additional stress on artery walls. High intake of sugars has been linked to the development of insulin resistance.
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obviously, and metabolic syndrome, which does include increased blood pressure, but a host of other things such as high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels. Insulin resistance can result in higher levels of insulin in the blood, which may lead to blood vessel constriction and kidney sodium retention, both of which can also raise blood pressure. You've got inflammation, which can damage
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hardening of the arteries which increases blood pressure. You've got uric acid and this is one which I spoke at length to Dr. Richard Johnson about on a previous podcast. And uric acid is a compound that the body produces as it breaks down purines, which are nitrogen containing compounds found in certain foods. But also it's related to fructose metabolism because when the body metabolizes fructose one of these byproducts is uric acid.
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So ingesting large amounts of fructose, as might be found in sugar sweetened beverages or foods containing a lot of sugar, can lead to increased production of uric acid. And there have been several studies to show this direct association between the consumption of fructose rich beverages and elevated uric acid levels. This would include people who just have straight high sugar in their diet as well, because sugar,
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is essentially fructose and glucose together as I said. Now elevated uric acid levels have also been associated with increased risk of hypertension because it might impede nitric oxide production. Nitric oxide helps relax and dilate blood vessels. When you get this reduced nitric oxide availability, it can cause the blood vessels to constrict leading to elevated blood pressure.
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You can also have activation of the renin-angiotensin system, which is a hormonal system that plays a significant role in regulating blood pressure and fluid balance. Its activation can lead to an increase in blood pressure. And uric acid might also induce inflammation and endothelial dysfunction, as I mentioned earlier. Inflammation can damage blood vessels and contribute to hypertension.
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impact on hypertension but it isn't just sugar either obviously. There's a really big role for lowering your carb intake to lower blood pressure. The number of reasons I've already mentioned but very briefly weight loss. So if you reduce your body weight you reduce that cardiac output, you reduce that plasma volume, you reduce the pressure on arterial walls, you get a reduction in insulin levels and when you reduce insulin levels
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There's a promotion of sodium and water excretion, which can decrease blood volume and blood pressure, which is one of the side effects, if you like, of a low carb diet. You immediately drop your blood pressure. A low carb diet might improve vascular function, which can influence blood pressure. You can get that reduction in inflammation. You can get a shift in electrolytes, which reduces fluid retention and decreases blood pressure, as I mentioned. And it can reduce
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activity in the sympathetic nervous system, the phytoflite system, and overactivity of the sympathetic nervous system can raise blood pressure, so a reduction can contribute to lower blood pressure, which is one of the reasons why a highly strung out and stressed individual often presents with high blood pressure, which is probably a podcast for another day. So definitely lowering your carbs in a low carb diet for anyone with high blood pressure is an absolute given to my mind.
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What are some other dietary things that you can do though? There's quite a lot of research to show that taking a magnesium supplement of about 300 milligrams to 400 milligrams a day of a well-absorbed magnesium, such as magnesium glycinate, magnesium chelate with amino acids, magnesium malate, magnesium threonate, magnesium citrate even, can help lower blood pressure.
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And there are certainly a lot of studies to show that people who do have hypertension are magnesium depleted in the blood. So there is that relationship there. And interestingly, when you look at the research around this, there are significant drops in both systolic and diastolic blood pressure when people are given magnesium at that rate of about 350 milligrams or maybe even 400 milligrams of magnesium a day over several weeks.
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Magnesium activates a sodium potassium pump, which plays a role in the flexibility of our endothelial cells and of our vascular cells. So it can definitely help to vasodilate and help reduce that sort of vasoconstriction in the cell membranes. Magnesium is a super easy one to take. And I mentioned the types of magnesium that I would suggest and in amounts that might be a little bit more than what
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is suggested on the back of your magnesium supplement. Not just magnesium though. So you've also got Coenzyme Q10. Now this may work better in addition to other supplements which I'll mention rather than just by itself, but it is hypothesized that CoQ10 might improve endothelial function, reduce oxidative stress, and enhance the availability of nitric oxide which is a vasodilator, which is really important for blood pressure.
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mentioned earlier. So the types of amounts you'd be looking at would be 100 to 300 milligrams a day, noting that a product like MitoQ is a lot more potent so I would suspect that MitoQ would be more in the realm of 20 of 10 to 20 milligrams per day. While we don't have a ton of large well designed trials to show that this is beneficial over the long term there is
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some research to show in the short term it can reduce blood pressure and it's very safe and it has been proven in other areas for cardiovascular benefits so I have no concerns at all about recommending CoQ10. And quercetin is another supplement to consider. It's a naturally occurring flavonoid found in many fruits, vegetables and
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It is believed to exert its sort of anti-hypertensive effects by promoting relaxation of the blood vessels, vasodilation, reducing oxidative stress, it inhibits that angiotensin converting enzyme and improves endothelial function. So it can result in a modest reduction in blood pressure, but of course trials are mixed in this response. It's very safe though.
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The doses used in studies that have observed positive effects typically range from about 500 to 1000 milligrams a day. And we just need more trials to assess what its impact is for people more broadly at that population level, what it looks like for hypertension. But certainly if you've got issues with hypertension, you've got no issues at all with trying it. Garlic is another one actually that's been used for its medicinal properties for centuries.
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One of the health benefits that has garnered attention is also related to its potential antihypertensive effects and it works a lot like the other supplements. So it contains allicin, which is one of the most well-known sulfate containing compounds that promotes vasodilation. It inhibits that angiotensin II, which is an enzyme that can constrict blood vessels and exhibits these antioxidant properties.
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It has a multiple of other sort of cardiovascular benefits as well. Generally speaking, the dosage in studies might range from about 600 to 1500 milligrams of aged garlic extract divided into daily sort of doses. And consuming about one to two cloves of fresh garlic daily is another approach mentioned in some studies. But what I would recommend doing is actually chopping up the garlic and leaving it to sort of oxidize a little bit. Because potentially you get more.
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potent sort of allicin release then. But of course, a garlic supplement, you're going to be much more certain of the impact or the amount of allicin that you have available in it. Be mindful though, that if you are on any sort of anticoagulant or antiplatelet medications, do exercise caution because garlic can be a, or is considered a blood thinner, which is super helpful unless you're already on something that thins your blood. Now, beet.
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Supplements of course are well known for their vasodilation effect in helping sort of boosting nitric oxide. Clearly this is going to be useful for lowering your blood pressure. The dosage varies across studies but many have used beetroot juice ranging from 70mls to 500mls providing that 300 to 600mg of nitrates. I would go more for a capsule or a powder that is lower
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and use a reputable brand when you are considering taking a beet supplement. So they definitely show promise as a natural approach to managing blood pressure. Of course people with kidney problems or prone to kidney stones need to be cautious because beetroot is a source of oxalate so don't go crazy. And just be mindful that beetroot can sort of upset the gut so if that is you then this is not the supplement for you.
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The last supplement which I think I'll mention here is cocoa because we all love chocolate and it's been studied for its cardiovascular benefits because of its rich content of flavonoids which also stimulate production of nitric oxide in the endothelium and it can reduce blood pressure for this reason. Additionally of course flavonoids possess antioxidant and anti-inflammatory properties. So there have been clinical studies showing a modest reduction in blood pressure
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in doses that amount to about 500 milligrams to a thousand milligrams of flavanols a day, which can be found in a range of cocoa-based food and supplements. But of course, not all cocoa products of are created equal. Dark chocolate generally contains more flavanols and processed, really processed products like that Dutch processed cocoa powder is more processed so actually that's lower in flavanol sort of content. And don't forget the sugar
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A hundred gram bar of dark chocolate contains around 500 to a thousand milligrams of flavonols. You don't want to be eating a hundred grams of chocolate a day. Go instead for sort of cocoa powder and natural unsweetened cocoa powder can contain anywhere from 30 to 120 milligrams of flavonols per gram. So a tablespoon of cocoa powder, which is about five grams, could provide you between 150 to 600 flavonols. But
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As I said, Dutch processed cocoa powder will have a lot less. Do be mindful of the calorie content when it comes to cocoa based products is I guess what I'm saying. So in summary then, if you have high blood pressure, should you lower your salt intake? I wouldn't go crazy on salt, but it wouldn't be my primary intervention point looking at the population wide sort of reductions in blood pressure that come from actually reducing sodium content.
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absolutely do it and assess the impact it has for you particularly. But I think your major overall strategies where appropriate would be to lose weight, to adopt a low carbohydrate approach, particularly a low sugar approach, to investigate supplements that move the needle like magnesium, potentially CoQ10 and cursitin together, a beet supplement. You could look at cocoa as well,
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Having a look at an overall diet quality, getting a lot of fresh fruit and vegetables, which will all come in as part of that low carb approach. I mentioned fresh fruit, I don't mean six to eight pieces a day, but incorporating one to two pieces is no big deal to my mind. And certainly exercise. One of the biggest doll movers with blood pressure is absolutely exercise. Aerobic exercise, strength training, the whole gamut. And of course, finally, look at your stress response.
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Anything you're doing that makes you this highly strung out individual needs to be looked at if you are experiencing high blood pressure. So there probably needs to be a shift in that lifestyle behavior as well. I didn't talk about coffee. I won't go into the details. If it gives you anxiety, you probably want to steer clear of it. All right, team. So bit of a brief overview on hypertension. Quite a big topic, actually. Bigger than I anticipated it to be. Hopefully you'll find something helpful and useful there.
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Until next week you can catch me over on Facebook @mikkiwillidennutrition, Instagram and Twitter and threads occasionally @mikkiwilliden in head to my website mikkiwilliden.com where you can sign up for my Christmas seminar. That's right peeps. We are taking care of you over the Christmas season. When I say we, I mean me anyway. Have a great week.