Does Vitamin D Reduce Cholesterol In Children?

Written by Dr. Steve Chaney on . Posted in Vitamin D, Vitamin D and Heart Disease

Is Vitamin D Associated With Heart Disease Risk?

Author: Dr. Stephen Chaney

 

vitamin-d-reduce-cholesterol-childrenNot too many years ago, we thought of vitamin D as affecting bone density and little else. Then we discovered that almost every cell in our body has vitamin D receptors. This has lead to research suggesting that vitamin D affects our health in many ways that were unimaginable only a couple of decades ago.

For example, low vitamin D levels are associated with increased risk of heart disease. The linkage between vitamin D and heart disease has not been proven. Nor do we know the mechanism. However, this has lead to ongoing research asking if there is any relationship between vitamin D and cholesterol metabolism.

The answer appears to be yes. Several studies have suggested a correlation between low vitamin D levels and elevated total cholesterol, LDL cholesterol, and triglycerides – all risk factors for heart disease.

The next question is how early in life is this correlation found. Again, some studies have suggested that the same correlation between low vitamin D and high levels of unhealthy lipids are found in teens. But, what about pre-teens, children who haven’t gone through puberty yet? That’s what this study was designed to determine.

 

How Was The Study Done?

vitamin-d-reduce-cholesterol-children studyThe current study  was based on data collected from 419 children, ages 6-8, in the Physical Activity and Nutrition in Children (PANIC) Study in Eastern Finland. This was a lifestyle study that collected information on body weight, diet, and activity levels.

Fasting blood samples were also collected and analyzed for blood lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) and for 25-hydroxyvitamin D (25(OH)D), which is considered the most accurate measure of vitamin D status. The National Institutes of Health considers:

  • <30 nmol/L of 25(OH)D an indicator of vitamin D deficiency.
  • 30 to <50 nmol/L 25(OH)D an indicator of vitamin D insufficiency.
  • ≥50 nmol/L 25(OH)D an indicator of adequate vitamin D status.

To put this study in perspective, vitamin D status is a major concern in Finland because of its proximity to the Arctic Circle. There is little sunlight in the winter, and, although the days are long in the summer, the sun is weak. The major sources of vitamin D in the Finnish diet are fish, vitamin D-fortified fluid milk products, vitamin D-fortified fat spreads, and vitamin D supplementation. Vitamin D fortification was introduced in Finland in 2003. Vitamin D supplementation has also become increasing popular. The number of people using vitamin D supplements has increased from 11% in 2000 to 41% in 2011.

A recent study  looking a vitamin D status between 2000 and 2011 found that the combination of food fortification and vitamin D supplementation has been successful at improving vitamin D status in the Finnish population, increasing average 25(OH)D levels from 48 nmol/L to 65 nmol/L.

 

Does Vitamin D Reduce Cholesterol In Children?

vitamin dIn this study the mean serum 25(OH)D in the children was 68.1 nmol/L. 20% of the children had serum 25(OH)D below 50 nmol/L, and only 4 children (1%) had serum 25(OH)D below 30 nmol/L. When 25(OH)D levels were compared with blood lipid levels:

  • Higher serum 25(OH)D levels were associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
  • The association between higher 25(OH)D levels and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.

What Does This Mean For You?

I don’t want to overinterpret the study. Not all studies show an inverse association between 25(OH)D and cholesterol levels. Most of the previous studies have also indicated that higher 25(OH)D levels were associated increased HDL levels, while this study found higher 25(OH)D levels associated with decreased HDL levels. Much more research needs to be done.

However, this study is yet another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.

My recommendations are to:

  • Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
  • Get your serum 25(OH)D level determined and take vitamin D supplements if it is low.

 

The Bottom Line

 

A recent study of vitamin D status in Finnish children ages 6-8 found:

  • Higher vitamin D status was associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
  • The association between better vitamin D status and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.

This study is another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.

My recommendations are to:

  • Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
  • Get your serum 25-hydroxyvitamin D level determined and take vitamin D supplements if it is low.
  • Make sure your children are getting enough vitamin D in their diet and have optimal serum 25-hydroxyvitamin D.

For more details, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Do Omega-3s Lower Blood Pressure in Young, Healthy Adults?

Posted August 14, 2018 by Dr. Steve Chaney

What Is The Omega-3 Index And Why Is It Important?

Author: Dr. Stephen Chaney

 

Do omega-3s lower blood pressure in healthy adults?

omega-3s lower blood pressure young adultsThe literature on the potential health benefits of omega-3s is very confusing. That’s because a lot of bad studies have been published. Many of them never determined the omega-3 status of their subjects prior to omega-3 supplementation. Others relied on dietary recalls of fish consumption, which can be inaccurate.

Fortunately, a much more accurate measure of omega-3 status has been developed and validated in recent years. It’s called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA compared to 26 other fatty acids found in cellular membranes. Using modern technology, it can be determined from a single finger prick blood sample. It is a very accurate reflection of omega-3 intake relative to other fats in the diet over the past few months. More importantly, it is a measure of the omega-3 content of your cell membranes, which is a direct measure of your omega-3 nutritional status.

A recent extension of the Framingham Heart Study reported that participants with an Omega-3 Index >6.8% had a 39% lower risk of cardiovascular disease than those with an Omega-3 Index <4.2% (WS Harris et al, Journal of Clinical Lipidology, 12: 718-724, 2018 ). Although more work needs to be done, an Omega-3 Index of 4% or less is generally considered indicative of high cardiovascular risk, while 8% or better is considered indicative of low cardiovascular risk. For reference, the average American has an Omega-3 Index in the 4-5% range. In Japan, where fish consumption is much higher and cardiovascular risk much lower, the Omega-3 Index is in the 9-11% range.

Previous studies have suggested that omega-3 fatty acids lower blood pressure to a modest extent. Thus, it is not surprising that more recent studies have shown an inverse correlation between Omega-3 Index and blood pressure. However, those studies have been done with older populations, many of whom had already developed high blood pressure.

From a public health point of view, it is much more interesting to investigate whether it might be possible to prevent high blood pressure in older adults by optimizing omega-3 intake in a young, healthy population, most of whom had not yet developed high blood pressure. Unfortunately, there were no studies looking at that population. The current study was designed to fill that gap.

 

How Was The Study Done?

omega-3s lower blood pressure young healthy adultsThe current study (M.G. Filipovic et al, Journal of Hypertension, 36: 1548-1554, 2018 ) was based on data collected from 2036 healthy adults, aged 25-41, from Liechtenstein. They were participants in the GAPP (Genetic and Phenotypic Determinants of Blood Pressure) study. Participants were excluded from the study if they had been diagnosed with high blood pressure and were taking medication to lower their blood pressure. They were also excluded if they had heart disease, chronic kidney disease, other severe illnesses, obesity, sleep apnea, or daily use of non-steroidal anti-inflammatory medications.

Blood samples were collected at the time of their enrollment in the study and frozen for subsequent determination of Omega-3 Index. Blood pressure was also measured at their time of enrollment in two different ways. The first was a standard blood pressure measurement in a doctor’s office.

For the second measurement they were given a wearable blood pressure monitor that recorded their blood pressure over 24 hours every 15 minutes during the day and every 30 minutes while they were sleeping. This is considered more accurate than a resting blood pressure measurement in a doctor’s office because it records the variation in blood pressure, while you are sleeping, while you are exercising, and while you go about your everyday activities.

 

Do Omega-3s Lower Blood Pressure In Young, Healthy Adults?

omega-3s lower blood pressure young adults equipmentNone of the participants in the study had significantly elevated blood pressure. The mean systolic and diastolic office blood pressures were 120±13 and 78±9 respectively. The average Omega-3 Index in this population was 4.6%, which is similar to the average Omega-3 Index in the United States.

When they compared the group with the highest Omega-3 Index (average = 5.8%) with the group with the lowest Omega-3 Index (average = 4.6%):

  • The office measurement of systolic and diastolic blood pressure was decreased by 3.3% and 2.6% respectively
  • While those numbers appear small, the differences were highly significant.
  • The 24-hour blood pressure measurements showed a similar decrease.
  • Blood pressure measurements decreased linearly with increasing Omega-3 Index. [In studies of this kind, a linear dose-response is considered an internal validation of the differences observed between the group with the highest Omega-3 Index and the group with the lowest Omega-3 Index.]

The authors concluded: “A higher Omega-3 Index is associated with statistically significant, clinically relevant, lower systolic and diastolic blood pressure in normotensive, young and healthy individuals. Diets rich omega-3 fatty acids may be a strategy for primary prevention of hypertension.”

 

What Does This Mean For You?

omega-3s lower blood pressure young adults questionPerhaps I should first comment on the significance of the relatively small decrease in blood pressure observed in this study.

  • These were young adults, all of whom had normal or near normal blood pressure.
  • The difference in Omega-3 Index was rather small (5.8% to 4.6%). None of the participants in the study were at the 8% or above that is considered optimal.
  • Liechtenstein is a small country located between Switzerland and Spain. Fish consumption is low and omega-3 supplement consumption is rare.

Under these conditions, even a small, but statistically significant, decrease in blood pressure is remarkable.

We should think of this study as the start of the investigation of the relationship between omega-3 status and blood pressure. Its weakness is that it only shows an association between high Omega-3 Index and low blood pressure. It does not prove cause and effect.

Its strength is that it is consistent with many other studies showing omega-3 fatty acids lower blood pressure. Furthermore, it suggests that the effect of omega-3s on blood pressure may also be seen in young, healthy adults who have not yet developed high blood pressure.

Finally, the authors suggested that a diet rich in omega-3s might reduce the incidence of high blood pressure by slowing the age-related increase in blood pressure that most Americans experience. This idea is logical, but speculative at present.

However, the GAPP study is designed to provide the answer to that question. It is a long-term study with follow-up examinations scheduled every 3-5 years. It will be interesting to see whether the author’s prediction holds true, and a higher Omega-3 Index is associated with a slower increase in blood pressure as the participants age.

 

Why Is The Omega-3 Index Important?

 

The authors of this study said: “The Omega-3 Index is very robust to short-term intake of omega-3 fatty acids and reliably reflects an individual’s long-term omega-3 status and tissue omega-3 content. Therefore, the Omega-3 Index has the potential to become a cardiovascular risk factor as much as the HbA1c is for people with diabetes…” That is a bit of an overstatement. HbA1c is a measure of disease progression for diabetes because it is a direct measure of blood sugar control.

In contrast, Omega-3 Index is merely a risk factor for cardiovascular disease. However, if it is further validated by future studies, it is likely to be as important for predicting cardiovascular risk as are cholesterol levels and markers of inflammation.

However, to me the most important role of Omega-3 Index is in the design of future clinical studies. If anyone really wants to determine whether omega-3 supplementation reduces cardiovascular risk, high blood pressure, diabetes or any other health outcome they should:

  • Start with a population group with an Omega-3 Index in the deficient (4-5%) range.
  • Supplement with omega-3 fatty acids in a double blind, placebo-controlled manner.
  • Show that supplementation brought participants up to an optimal Omega-3 Index of 8% or greater.
  • Look at health outcomes such as heart attacks, cardiovascular deaths, hypertension, stroke, or depression.
  • Continue the study long enough for the beneficial effects of omega-3 supplementation to be measurable. For cardiovascular outcomes the American Heart Association has stated that at least two years are required to obtain meaningful results.

These are the kind of experiments that will be required to give definitive, reproducible results and resolve the confusion about the health effects of omega-3 fatty acids.

 

The Bottom Line

 

An accurate measure of omega-3 status has been developed and validated in recent years. It’s called the Omega-3 Index. Simply put, the Omega-3 Index is the percentage of EPA and DHA compared to 26 other fatty acids found in cellular membranes.

Although more work needs to be done, an Omega-3 Index of 4% or less is generally considered indicative of high cardiovascular risk while 8% or better is considered indicative of low cardiovascular risk.

Previous studies have shown an inverse correlation between Omega-3 Index and blood pressure. However, these studies have been done with older populations, many of whom had already developed high blood pressure.

From a public health point of view, it is much more interesting to investigate whether it might be possible to prevent high blood pressure in older adults by optimizing omega-3 intake in a young, healthy population, most of whom had not yet developed high blood pressure. Until now, there have been no studies looking at that population.

The study described in this article was designed to fill that gap. The participants in this study were ages 25-41, were healthy, and none of them had elevated blood pressure.

When the group with the highest Omega-3 Index (average = 5.8%) was compared with the group with the lowest Omega-3 Index (average = 4.6%):

  • Both systolic and diastolic blood pressure were decreased
  • Blood pressure measurements decreased linearly with increasing Omega-3 Index.

The authors concluded: “A higher Omega-3 Index is associated with statistically significant, clinically relevant, lower systolic and diastolic blood pressure in normotensive, young and healthy individuals. Diets rich omega-3 fatty acids may be a strategy for primary prevention of hypertension.”

Let me translate that last sentence into plain English for you. The authors were saying that optimizing omega-3 intake in young adults may slow the age-related increase in blood pressure and reduce the risk of them developing high blood pressure as they age. This may begin to answer the question “Do omega-3s lower blood pressure in young, healthy adults?”

Or even more simply put: Aging is inevitable. Becoming unhealthy is not.

For more details, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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