Do Multivitamins Reduce the Risk of Miscarriage?

Written by Dr. Steve Chaney on . Posted in Multivitamins and Miscarriage, Vitamins and Health, Weight Loss

Will A Multivitamin A Day Keep YourBaby Healthy?

Author: Dr. Stephen Chaney

multivitamins reduce risk of miscarriageThe standard medical advice for years has been to take a prenatal supplement (basically a multivitamin with extra folic acid, iron and sometimes calcium) both before and during pregnancy. Does that really make a difference? Will it reduce the risk of miscarriage? Will it give you a healthier baby?  A recent study suggests that multivitamin use may significantly decrease your risk of miscarrying, but before going into the study you need a little background.

 

It’s a new world. It used to be that a woman didn’t know for sure that she was pregnant until she had missed one or two periods and finally got an appointment with her doctor – a month or two after conception actually occurred. In today’s world accuracy in home pregnancy tests allow women to learn they are pregnant much earlier – often before the first missed period.

With the early detection of pregnancy has come the realization that miscarriage rates are much higher than previously assumed. In spite of improved prenatal care, the rate of miscarriages in the US increased by 1% per year between 1985 and 2005. In part that is because women using the in-home pregnancy tests are detecting their pregnancies much early. However, it also reflects the fact that early miscarriages are often asymptomatic. They can only be detected by negative pregnancy tests.

With that in mind, let’s look at the study.

Do Multivitamins Reduce the Risk of Miscarriage?

pregnancy and miscarriageThis study (Louis et al, Fertility and Sterility, doi.org.10.1016/j.fertnstert.2016.03.009, 2016), had a very interesting design. It enrolled 501 couples ages 18-40 from Michigan and Texas who were actively trying to become pregnant into something called the Longitudinal Investigation of Fertility and the Environment (LIFE) Study. The women in the study were instructed in the use of a commercial fertility urine test to help the couples plan their intercourse to maximize the chances of conceiving. They were also instructed in the use of a commercial pregnancy urine test to determine the onset and potential loss of pregnancy (miscarriage).

The couples were given no guidance on health practices to follow before and during pregnancy. They were interviewed individually upon enrolment to obtain sociodemographic, lifestyle, and medical history information. They were asked to keep a daily journal recording things like cigarettes use, consumption of alcoholic or caffeinated beverages, and multivitamin use (The journal did not distinguish between over-the-counter multivitamins and prescribed prenatal vitamins).

Of the couples who enrolled in the study, 347 (69%) of them became pregnant. Three of the women conceived twins and were eliminated from the study. Of the remaining 344 women, 98 (28%) of them experienced a miscarriage during the first 22 weeks. No miscarriages were observed after 22 weeks.

When they looked at risk factors that affected pregnancy loss (miscarriages):

  • The miscarriage rate was almost double for women over 35, which is consistent with previous studies.
  • Consumption of two or more caffeinated beverages/day by either partner prior to conception and during early pregnancy significantly increased the risk of miscarriage
  • Daily multivitamin use by the woman prior to conception reduced the risk of miscarriage by 55%. If the vitamin use was continued through the first 7 weeks of pregnancy, the risk of miscarriage was reduced by 79%.
  • No effect of obesity, cigarette smoking, and alcohol use on miscarriage risk was seen in this study, which is different from most previous studies.

Putting This Study Into Perspective

This was a fairly well designed study, but it is a single study.  Let’s put each of the main findings in the context of previous studies.

Multivitamin Use: Earlier studies have shown that supplements containing extra folic acid probably reduce miscarriages. However, now that foods are routinely fortified with folic acid in the US, the benefit of multivitamins and prenatal supplements has become more controversial. Some studies have shown, like this one, that multivitamins reduce miscarriage risk. Others did not. However, multivitamin use before and during pregnancy has relatively few risks, so it is still probably a good idea.

Caffeinated Beverages: There have been relatively few studies to date on the effect of caffeinated beverages on miscarriage risk, but the few that have been performed tend to agree that caffeinated beverages may increase the risk of miscarriage. While the data are far from definitive at this point, it is probably a good idea to limit your caffeinated beverages before and during pregnancy.

Age: Age is a well-established risk factor for miscarriages. While many consider 40 as the threshold for increased risk, this study and several other recent studies suggest it may be closer to 35. That doesn’t mean that you shouldn’t try to have a baby if you are over 35, but it does mean that you will probably want to avoid any lifestyle factors that might increase your risk of miscarriage.

Other Factors:This study did not find an effect of obesity, smoking or alcohol on pregnancy risk. However, many other studies have shown that each of these increases the risk of miscarriage. It’s probably a good idea to drop a few extra pounds and avoid both smoking and alcohol if you wish to maximize your chances of a successful pregnancy outcome.

If You Are Pregnant, What Does This Study Mean For You? 

preventing miscarriageThis study supports multivitamin use before and during pregnancy and suggests that excessive consumption of caffeinated beverages may have a negative effect on pregnancy outcome. However, it doesn’t significantly alter the standard medical advice for what you should do before and during pregnancy.

  • Daily multivitamin use, both prior to and during pregnancy, is probably a good idea. Not all studies agree, but some studies suggest that it will significantly decrease the risk of miscarriage.
  • Obesity and diabetes increase miscarriage risk. The good news is that even a 5-10% weight loss often is sufficient to reverse diabetes and may improve pregnancy outcome as well.
  • If you are over 35, your risk of suffering a miscarriage is significantly increased.
  • Smoking and alcohol use should be avoided. Both are likely to increase your risk of miscarriage.
  • Recent studies suggest that the consumption of two or more caffeinated beverages a day may also increase your risk of miscarriage, so don’t overindulge in caffeinated beverages. Be aware that it’s not just coffee and tea that are caffeinated. Many sodas are caffeinated as well.

 

The Bottom Line

 A recent study showed:

 

  • Daily multivitamin use by the woman prior to conception reduced the risk of miscarriage by 55%. If the vitamin use was continued through the first 7 weeks of pregnancy, the risk of miscarriage was reduced by 79%.
  • Consumption of two or more caffeinated beverages/day by either partner prior to conception and during early pregnancy significantly increased the risk of miscarriage
  • The miscarriage rate was almost double for women over 35, which is consistent with previous studies.
  • No effect of obesity, cigarette smoking, and alcohol use on miscarriage risk was seen in this study, which is different from most previous studies.
  • This study reinforces the recommendation for multivitamin or prenatal vitamin use, but the standard medical advice for a successful pregnancy isn’t really changed:
  • Daily multivitamin use, both prior to and during pregnancy, is probably a good idea. Not all studies agree, but some studies suggest that it will significantly decrease the risk of miscarriage.
  • Obesity and diabetes increase miscarriage risk. The good news is that even a 5-10% weight loss often is sufficient to reverse diabetes and may improve pregnancy outcome as well.
  • If you are over 35, your risk of suffering a miscarriage is significantly increased. That doesn’t mean that you shouldn’t try to have a baby if you are over 35, but it does mean that you will probably want to avoid any lifestyle factors that might increase your risk of miscarriage.
  • Smoking and alcohol use should be avoided. Both are likely to increase your risk of miscarriage.
  • Recent studies suggest that the consumption of two or more caffeinated beverages a day may also increase your risk of miscarriage, so don’t overindulge in caffeinated beverages. Be aware that it’s not just coffee and tea that are caffeinated. Many sodas are caffeinated as well.

 

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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Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, 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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