Gestational Diabetes Causes: High Folate Levels?

Written by Dr. Steve Chaney on . Posted in Diabetes, Gestational Diabetes?

What Should You Look For In A Prenatal Supplement?

Author: Dr. Stephen Chaney

 

gestational diabetes causesAccording to the CDC, almost 10% of the women in this country will develop diabetes during pregnancy, something referred to as gestational diabetes. After delivery, their blood sugar levels will usually return to normal.

However, gestational diabetes is not a benign condition. It increases your risk of serious complications during both pregnancy and delivery. It also increases the risk that your baby will suffer complications during birth, and it increases their risk of developing obesity and diabetes later in life.

Obesity and a family history of diabetes both increase the likelihood that you will develop gestational diabetes during pregnancy. Beyond that, what could be gestational diabetes causes are not well known.

There have been numerous suggestions in the literature that high folate levels may increase your risk of gestational diabetes. If that is true, it is concerning.  After all you are being told you should probably be taking a folic acid supplement before and during pregnancy to prevent birth defects. Could the very supplement you are taking to prevent birth defects be harming both you and your unborn child?

Before you throw out your folic acid supplements, I should hasten to add that the science is not definitive. Some studies have reported an association between high folate levels and gestational diabetes. Other studies have seen no association. It has been very confusing. No one has been able to figure out why the study results have been so inconsistent.

In this issue of “Health Tips From The Professor,” I share a study that may clear up the confusion.

How Was The Study Done?

pregnancy diabetesThis study (Lai et al, Clinical Nutrition, doi: 10.1016/j.clnu.2017.03.22 ) was part of a larger study,  “Growing Up in Singapore Towards Healthy Outcomes” (GUSTO). The larger study was designed to assess multiple factors related to the health of pregnant mothers and their offspring. This particular study was designed to assess whether there was an association between high blood folate levels and gestational diabetes in Asian women.

The investigators recruited 923 women of Chinese, Malay, and Indian descent when they were less than 14 weeks pregnant. The women returned to the clinic at 26-28 weeks of pregnancy. Fasting blood samples were obtained for analysis of plasma folate, B12, and B6 levels. Gestational diabetes was diagnosed during the same clinic visit based on a fasting blood glucose level followed by a second blood glucose test 2 hours after ingestion of 75 grams of glucose. The women also completed a diet recall during this office visit.

 

Do High Folate Levels Cause Gestational Diabetes?

 

When the data were analyzed:

  • A high blood level of folate was associated with a 30% increase in gestational diabetes.
  • A high blood level of B12 was associated with a 20% decrease in gestational diabetes.
  • A high blood level of B6 showed no association with gestational diabetes.

vitamin b12When the investigators looked at the association between folate status and gestational diabetes in each of the ethnic groups individually, they discovered that the association between high blood folate levels and gestational diabetes occurred almost entirely in the Indian women.

This offered an important clue. A high proportion of the Indian women were following a vegetarian diet, which could predispose to B12 deficiency. When the investigators looked at both folate and B12 status, they found:

  • A high blood level of folate combined with B12 insufficiency was associated with a 97% increase in gestational diabetes.
  • A blood level of folate in women with normal B12 status showed no association with gestational diabetes.

What Does This Study Tell Us?

This is a single study, and it is based on associations which do not prove cause & effect. Additional studies are clearly needed to prove this hypothesis. However, if these data are confirmed, this study has several interesting ramifications.

#1: It offers a possible explanation for the inconsistencies of previous studies looking at the associations of high folate status with gestational diabetes. Most previous studies simply measured folate status without looking at B12 levels. This study suggests it is important to assess both folate and B12 status. Elevated blood folate levels may only predispose to gestational diabetes in populations that are also B12 deficient.

#2: This study suggests a previously unknown interaction between folate and B12. This is not simply a case of high folate levels masking the symptoms of B12 deficiency. The prevalence of gestational diabetes was much greater when blood folate levels were elevated than it was with B12 deficiency alone. In other words, folate made the symptoms worse. The authors offered a potential mechanism for this interaction, but it was speculative. In short, we simply do not understand the mechanism of this interaction at present.

What Does This Study Mean For You?

folic acid pregnancyIf this study is confirmed, it has several important implications for any woman who is pregnant or is considering becoming pregnant.

#1: Methyl folate offers no advantage over folic acid: These data are based on blood folate levels, not on folic acid intake. Methyl folate and folic acid are equally likely to increase blood folate levels.

#2: B12 supplementation is important if you are vegetarian or are restricting meat intake: This is just a reminder of what you have probably heard before. There are many potential causes of B12 deficiency. However, in the younger age range, vegetarianism is the most common cause of B12 deficiency.

#3: A holistic approach to supplementation is better than taking individual vitamins. In this case, it is clearly preferable to take a supplement containing both folic acid and B12 than one just containing folic acid or methyl folate. That is an important message. You are constantly being reminded that optimal folate status is important for a healthy pregnancy. It is easy to find supplements containing just folic acid or methyl folate. Avoid those supplements! Look for ones that contain both folic acid and B12 (preferably with B6 and the other B vitamins as well). The same holds true for prenatal supplements. Make sure they contain all the B vitamins in balance, not just folic acid.

So, could high folate levels be one of the gestational diabetes causes?  We simply don’t know yet.

 

The Bottom Line

 

  • Recent headlines have suggested that high blood folate status is associated with an increased risk of developing gestational diabetes during pregnancy. This raises the question as to whether the supplementation you have been told was essential to prevent birth defects could also put you at risk for another health problem.
  • The study actually showed that high blood folate status only increases the risk of gestational diabetes in women who are also B12 deficient.
  • If you are pregnant or thinking of becoming pregnant, this study has several important implications for you.
    • Methyl folate offers no advantage over folic acid. These data are based on blood folate levels, not on folic acid intake. Methyl folate and folic acid are equally likely to increase blood folate levels.
    • B12 supplementation is important if you are vegetarian or are restricting meat intake. This is just a reminder of what you have probably heard before.
    • A holistic approach to supplementation is better than taking individual vitamins. In this case, it is clearly preferable to take a supplement containing both folic acid and B12 than one just containing folic acid or methyl folate. That is an important message. You are constantly being reminded that optimal folate status is important for a healthy pregnancy. It is easy to find supplements containing just folic acid or methyl folate. Avoid those supplements! Look for ones that contain both folic acid and B12 (preferably with B6 and the other B vitamins as well). The same holds true for prenatal supplements. Make sure they contain all the B vitamins in balance, not just folic acid.
  • For 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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Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

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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