Vitamin K And Heart Disease Deaths

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

Does Vitamin K Reduce Heart Disease Risk?

Author: Dr. Stephen Chaney

 

viatmin k and heart diseaseYou are trying to live a heart healthy lifestyle, but it is so confusing. It seems like there are new heart healthy diets, foods, and nutrients each week. How can you possibly keep up?

Some of those “heart healthy” recommendations contradict each other. They can’t all be true. Which should you believe? I will answer that question in my new books “Slaying the Food Myths” and “Slaying the Supplement Myths.

Today, however, I am going to add to your confusion by adding another nutrient, vitamin K, to your “heart healthy” list. When it comes to heart health, vitamin K is a neglected nutrient. Most people think it is just needed for blood clotting. It doesn’t have the recognition and glamor of omega-3s, antioxidants, and polyphenols for heart health. However, recent research suggests it may play a crucial role in protecting your heart. So, I will explain how vitamin K and heart disease are related.

Before, I go into today’s study, let me give you some background information on vitamin K metabolism and heart health.

Metabolism 101: Vitamin K and Heart Disease

viatmin k and heart disease vegetablesVitamin K is a coenzyme for enzymes that add carboxyl groups to proteins. Without going into a lot of boring detail, carboxylated proteins:

  • Are more water soluble. That makes them more efficient at catalyzing metabolic reactions in our cells.
  • Chelate calcium. That allows them to catalyze calcium-dependent reactions.

For this discussion there are 3 kinds of calcium-dependent reactions catalyzed by carboxylated proteins that are important to know:

  • Reactions involved in blood clotting. Hence, vitamin K is essential for blood clotting.
  • Reactions involved in depositing calcium in our bones. Hence, vitamin K is essential for bone formation.
  • Reactions involved in removing calcium deposits from soft tissues. Hence, vitamin K is essential for keeping our arteries clear of calcium deposits.

If you think about those last two reactions, vitamin K deficiency is the worst of all possible worlds. Calcium in our bloodstream is less likely to be deposited in our bones and more likely to be deposited in our arteries. Vitamin K deficiency is bad for bone health and bad for heart health.

There is only one other factoid you need to know to understand the study I will discuss below. Because vitamin K is essential for the carboxylation of certain proteins, the uncarboxylated level of those proteins in the bloodstream can be used as an indirect assay for vitamin K deficiency. That is the assay that was used in this study.

How Was The Study Performed?

viatmin k and heart disease deathsIn this study (I.J. Riphagen et al, Nutrients, 9, 1334; doi: 10.3390/nu9121334, 2017 ) the investigators studied 4275 subjects enrolled in a clinical trial called PREVEND (Prevention of Renal and Vascular End-Stage Disease). The study population was recruited from the city of Groningen in the Netherlands.

In terms of study population characteristics, the average age was 53, the population was 46% male, 94% Caucasian, and 60% of the population already had renal disease at the time of enrollment (The significance of this will be discussed later).

Study participants were followed for 10 years. By then 279 had died, with 74 deaths attributable to heart disease. Here are the results of the study:

  • 30% of the population was vitamin K deficient.
  • Vitamin K deficiency was close to 50% for the elderly and for subjects with hypertension, diabetes, kidney disease, and cardiovascular disease.
  • Vitamin K deficiency was significantly correlated with all-cause mortality and cardiovascular mortality.

The authors concluded: “Importantly, a low vitamin K status is not only a clinically relevant risk factor for adverse health outcomes, but it may be a modifiable risk factor. Given the availability of vitamin K supplements, vitamin K insufficiency seems an attractive target for preventative intervention. Future prospective clinical trials are needed to investigate whether correction of low vitamin K status can indeed improve health outcomes.”

Pros and Cons of This Study

Cons:

  • This is an association study. It showed that vitamin K deficiency was associated with cardiovascular mortality, but it didn’t show that vitamin K deficiency caused cardiovascular mortality.
  • Kidney disease reduces the efficiency of vitamin K-dependent carboxylation of proteins. This study relied on levels of uncarboxylated protein for determining vitamin K status, and 60% of the subjects had kidney disease. The study might have overestimated the prevalence of vitamin K deficiency.
  • The population of the study were primarily Caucasian from one city in the Netherlands. It is not clear whether these findings would be equally true for other population groups.

Pros:

  • This study is consistent with previous studies. Several other studies have reported a correlation between vitamin K deficiency and either arterial calcification or heart disease risk. At least one study has shown that vitamin K supplementation can reverse arterial calcification.
  • The levels of vitamin K deficiency seen in this study are consistent with previous studies that have measured blood levels of vitamin K directly.

 

Vitamin K1 Versus K2: What Happens Naturally?

 

viatmin k and heart disease vitamin k1 and vitamin k2There are two forms of vitamin K, vitamin K1 and vitamin K2. Vitamin K1 is used for the blood clotting reactions. Vitamin K2 is used for the reactions involving bone formation and removal of calcium from soft tissues. That has led to a vigorous debate about whether vitamin K1 or K2 supplements are better. I won’t get into that debate, because the data aren’t conclusive yet. However, I will point out that there is a natural relationship between vitamin K1 and K2 that has existed for thousands of years.

Vitamin K1 is the primary dietary form of vitamin K. It is found in heart-healthy foods like green leafy vegetables; cruciferous vegetables like broccoli, Brussels sprouts and cabbage; and other healthy foods like carrots, blueberries, and asparagus. It is converted to vitamin K2 by our intestinal bacteria. Small amounts of vitamin K2 can also be found in less heart-healthy foods like cheeses, egg yolks, butter, chicken liver, and salami.

Simply put, if we eat healthy foods and have healthy gut bacteria, we get vitamin K1 from our diet, and our gut bacteria make all the vitamin K2 we need. This is a system that has worked well for humankind since the dawn of time. It’s only when we start messing up our diet and our gut bacteria that we need to start arguing about whether vitamin K1 or K2 supplements are better. It’s not nice to mess with Mother Nature.

 

The Bottom Line

 

A recent study in the Netherlands found that:

  • 30% of the population was vitamin K deficient.
  • Vitamin K deficiency was close to 50% for the elderly and for subjects with hypertension, diabetes, kidney disease, and cardiovascular disease.
  • Vitamin K deficiency was significantly correlated with all-cause mortality and cardiovascular mortality.

The authors concluded: “…a low vitamin K status is not only a clinically relevant risk factor for adverse health outcomes, but it may be a modifiable risk factor. Given the availability of vitamin K supplements, vitamin K insufficiency seems an attractive target for preventative intervention.”

For more details about vitamin K and heart disease and a brief discussion of vitamin K1 and vitamin K2, 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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Is Our Microbiome Affected By Exercise?

Posted November 6, 2018 by Dr. Steve Chaney

Microbiome Mysteries

Author: Dr. Stephen Chaney

is our microbiome affected by exerciseIn a recent post,  What is Your Microbiome and Why is it Important,  of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify.  Is our microbiome affected by exercise?

 

How Was The Study Designed?

is our microbiome affected by exercise studyThis study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

 

Is Our Microbiome Affected By Exercise?

is our microbiome affected by exercise fitnessThe results of the study were as follows:

  • Fitness, as assessed by VO2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
  • Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

 

What Does This Study Mean For You?

is our microbiome affected by exercise gut bacteriaThere are two important take home lessons from this study.

  • With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

  • With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

 

The Bottom Line

A recent study has reported that:

  • Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
  • These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent on diet, and contingent on the sustainment of exercise.”

For more details and my interpretation of the data, 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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