Vitamin C and Diabetes

Written by Dr. Steve Chaney on . Posted in Vitiman-C and Blood Sugar

Author: Dr. Stephen Chaney

 

vitamin c and blood sugar glucose testType 2 diabetes is increasing at an alarming rate. Between 1990 and 2010, the number of people in the US living with diabetes has more than tripled. In 2017 the CDC reported that 30.3 million Americans (9.4% of the population) had diabetes. Another 84.1 million had pre-diabetes, a condition which, if left untreated, will develop into diabetes within 5 years.

That is concerning, because type 2 diabetes can have devastating health consequences. It increases inflammation and oxidative damage. It significantly increases your risk of heart disease, Alzheimer’s Disease and some cancers. Then there is kidney disease, nerve pain, and loss of limbs.

It is the hyperglycemia (high blood sugar levels) associated with diabetes that plays a major role in many of these poor health outcomes. That is why so much effort is focused on helping people with type 2 diabetes gain better control of their blood sugar. Management of blood sugar levels in people with diabetes involves both medications and a healthy lifestyle (weight control, a healthy diet, and exercise). Unfortunately, despite their best efforts and the best efforts of their doctors, millions of Americans with diabetes struggle to control their blood sugar levels.

Is there a positive relationship between vitamin C and diabetes?

What if there were a simple, inexpensive intervention that could help diabetics control their blood sugar levels? Recent research suggests that vitamin C might be that intervention. Nobody is claiming that vitamin C is THE solution to blood sugar control. However, the recent research suggests it may be a useful addition to diabetes drugs and a healthy lifestyle.

 

Does Vitamin C Improve Blood Sugar Control?

 

vitamin c and blood sugar pillsThe idea that vitamin C may improve blood sugar control has been around for decades based on studies showing that vitamin C helps clear glucose from the circulation. Now, however, we are starting to understand how vitamin C does that.

But before I discuss how vitamin C may improve blood sugar control, the professor in me feels a need to explain what I call Diabetes 101. In type 1 diabetes the pancreas has become unable to produce insulin. In type 2 diabetes tissues have become resistant to the effects of insulin. I will focus on type 2 diabetes.

Glucose is the primary sugar in the bloodstream. Whenever blood sugar (glucose) increases, our pancreas responds by producing insulin. Insulin binds to receptors on our tissues and signals them to take up glucose and rapidly metabolize it. As a result, glucose is rapidly cleared from the circulation and blood sugar levels return to normal.

Type 2 diabetes is caused by insulin resistance. Simply put, our pancreas is still producing insulin, but our tissues have become less efficient at responding to it. Initially, the pancreas responds by overproducing insulin. A new homeostasis is achieved. Blood insulin levels are abnormally high, but glucose is still cleared from the circulation reasonably well. We call this pre-diabetes.

Eventually the pancreas loses the ability to overproduce insulin. Because our tissues are still insulin resistant, glucose is cleared from the circulation slowly. We now have trouble keeping blood sugar levels under control. We call this type 2 diabetes.

There are two major theories at present for why vitamin C may help diabetics control their blood sugar levels:

  • One theory holds that oxidative stress reduces the ability of the pancreas to release insulin. This theory suggests vitamin C improves insulin release from the pancreas, and the extra insulin overcomes insulin resistance and improves the ability of our tissues to clear glucose from the circulation.
  • The other theory holds that oxidative stress plays an important role in causing insulin resistance. This theory suggests vitamin C reduces insulin resistance and improves the clearance of glucose from the circulation by this mechanism.

There is some experimental evidence for both mechanisms. It may be that both play a role in vitamin C’s ability to improve blood sugar control.

How Were The Studies Done?

vitamin c and blood sugar studyIn terms of the effect of vitamin C on blood sugar control, there are two recent studies that have provided intriguing results.

The first study (Y. Song et al, Diabetes Care, 34: 108-114, 2011) was designed to see if supplementation with multivitamins or individual vitamin and mineral supplements affected the risk of developing diabetes among older US adults. It utilized data from the National Institutes of Health – American Association of Retired Persons Diet and Health Study.

The study enrolled 566,402 AARP members ages 50-71 in 1995-1996. Upon entry into the program, participants filled out a dietary survey that included supplement usage. In 2004-2006 a follow-up survey was mailed out to surviving participants that asked about occurrences of major chronic diseases.

Because the onset of a major disease is known to affect supplement usage, all participants with pre-existing diabetes or who developed diabetes prior to 2,000 were excluded from this analysis. Of the remaining 232,007 participants, 217,877 did not have diabetes and 14,130 had developed diabetes between 2000 and the end of the study.

The second study (SA Mason et al, Diabetes, Obesity and Metabolism, 21: 674-682, 2019 ) was a double blind, placebo controlled study design to determine whether supplemental vitamin C improved blood sugar control in people who already had type 2 diabetes.

In this study 31 adults (average age 62 years) were enrolled in the study. All the subjects were borderline obese and had type 2 diabetes. Five of the patients were being managed with lifestyle changes only. The other 26 patients were on one or more diabetes medications to help control their blood sugar levels.

The subjects were advised to avoid supplementation prior to the study. They were then given either 1,000 mg of vitamin C (two 500 mg capsules) or a placebo to take for 4 months. After the first 4-month period they were put on a “washout” protocol with no supplementation. Then they were put on a second 4-month regimen in which they received the opposite tablets (Those who received vitamin C during the first 4 months received a placebo during the second 4 months and vice versa.) Compliance with the protocol was determined by measuring blood levels of vitamin C.

The subjects were outfitted with a continuous blood glucose monitor for a 48-hour period at the beginning and end of each 4-month regimen. They were given standardized meals during those 48-hour test intervals and their blood sugar response to the meals was continuously monitored over the next 48 hours.

Vitamin C and Diabetes

 

vitamin c and blood sugar glucose meterThe results of the first study were:

  • Multivitamins and most of the individual supplements tested had no effect on the risk of developing diabetes over the next 10 years. The only supplements that reduced the risk of developing diabetes were vitamin C and calcium.
  • Vitamin C reduced the risk of developing diabetes by 9%.
  • The benefits of vitamin C appeared to be limited to individuals who did not use multivitamins and who had low dietary intake of vitamin C (No surprises there. Supplementation is usually most effective when it is filling in nutritional gaps).

This study has several obvious limitations:

  • It is an association study, so it does not prove cause and effect.
  • It does not tell us whether vitamin C prevents diabetes or simply improves blood sugar control in people who are borderline diabetic.
  • It did not measure how much supplemental vitamin C people were taking. However, based on what is available in the marketplace, it is probably safe to assume it was between 500 and 1,000 mg/day.

However, this study did lay the groundwork for the second study.

The results of the second study were that 4 months of vitamin C supplementation reduced:

  • The blood sugar response to standardized meals by 36%.
  • The duration of high blood sugar following a standardized meal by 1.7 hours.
  • The amount of time during the day with high blood sugar levels by 2.8 hours.

These are all important improvements for anyone with type 2 diabetes. In the words of the authors: “The improvement in total daily time spent with hyperglycemia [high blood sugar] is of potential clinical importance as the risk of complications in type 2 diabetes is strongly associated with previous hyperglycemia.”

The authors went on to say: “Compliance in the present study was high [people did not find it difficult to take 2 tablets a day] and the number of reported adverse effects was low, suggesting that vitamin C may be safely and consistently used in addition to [emphasis mine] primary diabetes treatment. Given the potential side effects with common anti-diabetic medications…, the idea that a relatively benign and inexpensive vitamin supplement might play a role in managing diabetes has particular appeal.”

Note: This was a very well-designed study. Its weakness is its small size. While it is consistent with other recent studies, larger clinical trials are needed to confirm this effect. 

What Do These Studies Mean For You?

vitamin c and blood sugar meaningThe idea that vitamin C may help with blood sugar control has been around for decades. These studies provide experimental support for that idea. While both studies have limitations, they are consistent with other recent studies. Much more research is needed, but it is good to finally see the hypothesis being rigorously tested.

So, what do these studies mean for you? Here is the take home message:

  • Although more studies are needed, vitamin C appears to help with blood sugar control.
  • We don’t know how much vitamin C is needed, but the most recent study was done with 1,000 mg/day. That is more than can be obtained from diet alone.
  • The improvement in blood sugar control was significant, but it was not huge. Vitamin C will not replace a healthier weight, a healthy lifestyle, and exercise.
  • You should think of vitamin C as something you add to the treatment plan your doctor recommends for type 2 diabetes. At best it may allow your doctor to reduce the amount of medication they prescribe.

If you have type diabetes, here are my recommendations:

  • If you are overweight, try to attain and maintain a healthier weight.
  • Eat a whole food, primarily plant-based diet. Avoid sodas, sweets, and highly processed foods. Eat a variety of fruits, vegetables, whole grains, and beans in their natural, unprocessed state. Include small amounts of meat, eggs, and dairy. Think of them as the garnish, not the main course.
  • Add a daily vitamin C supplement.
  • If that is not enough, ask your doctor what medications he or she recommends.

Other nutrients that may help are chromium, taurine and alpha lipoic acid. Herbs that may help are bitter melon and gymnema.

 

The Bottom Line

 

What is the association between vitamin C and diabetes? The idea that vitamin C may help with blood sugar control has been around for decades. Two recent studies provide experimental support for this idea. The second study showed that 4 months of 1,000 mg/day vitamin C supplementation reduced:

  • The blood sugar response to standardized meals by 36%.
  • The duration of high blood sugar following a standardized meal by 1.7 hours.
  • The duration of the day with high blood sugar levels by 2.8 hours.

These are all important improvements for anyone with type 2 diabetes. In the words of the authors: “The improvement in total daily time spent with hyperglycemia [high blood sugar] is of potential clinical importance as the risk of complications in type 2 diabetes is strongly associated with previous hyperglycemia.”

While this study has limitations, it is consistent with other recent studies. Much more research is needed, but it is good to finally see the hypothesis that vitamin C improves blood sugar control being rigorously tested.

So, what do these studies mean for you? Here is the take home message:

  • Although more studies are needed, vitamin C appears to help with blood sugar control.
  • We don’t know how much vitamin C is needed, but the most recent study was done with 1,000 mg/day. That is more than can be obtained from diet alone.
  • The improvement in blood sugar control was significant, but it was not huge. Vitamin C will not replace a healthier weight, a healthy lifestyle, and exercise.
  • You should think of vitamin C as something you add to the treatment plan your doctor recommends for type 2 diabetes. At best it may allow your doctor to reduce the amount of medication they prescribe.

For more details and my recommendations 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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What Is The Planetary Diet?

Posted May 21, 2019 by Dr. Steve Chaney

Is Your Diet Destroying The Planet?

Author: Dr. Stephen Chaney

 

Earth Day has come and gone, but you are still committed to saving the planet. You save energy. You recycle. You drive an electric car. But is your diet destroying the planet?

This is not a new question, but a recent commission of international scientists has conducted a comprehensive study into our diet and its effect on our health and our environment. Their report (W. Willet et al, The Lancet, 393, issue 10170, 447-492, 2019 ) serves as a dire warning of what will happen if we don’t change our ways. I touched on this report briefly in a previous issue of “Health Tips From The Professor,” What Is The Flexitarian Diet , but this topic is important enough that it deserves an issue all its own.

The commission carefully evaluated diet and food production methods and asked three questions:

  • Are they good for us?
  • Are they good for the planet?
  • Are they sustainable? Will they be able to meet the needs of the projected population of 10 billion people in 2050 without degrading our environment.

The commission described the typical American diet as a “lose-lose diet.” It is bad for our health. It is bad for the planet. And it is not sustainable.

In its place they carefully designed their version of a primarily plant-based diet they called a “win-win diet.”  It is good for our health. It is good for the planet. And, it is sustainable.

In their publication they refer to their diet as the “universal healthy reference diet” (What else would you expect from a committee?). However, it has become popularly known as the “Planetary Diet.”

I have spoken before about the importance of a primarily plant-based diet for our health. In that context it is a personal choice. It is optional.

However, this report is a wake-up call. It puts a primarily plant-based diet in an entirely different context. It is essential for the survival of our planet. It is no longer optional.

If you care about global warming…If you care about saving our planet, there is no other choice.

How Was The Study Done?

The study (W. Willet et al, The Lancet, 393, issue 10170, 447-492, 2019 ) was the report of the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems. This Commission convened 30 of the top experts from across the globe to prepare a science-based evaluation of the effect of diet on both health and sustainable food production through the year 2050. The Commission included world class experts on healthy diets, agricultural methods, climate change, and earth sciences. The Commission reviewed 356 published studies in preparing their report.

 

Is Your Diet Destroying The Planet?

When they looked at the effect of food production on the environment, the Commission concluded:

  • “Strong evidence indicates that food production is among the largest drivers of global environmental change.” Specifically, the commission reported:
  • Agriculture occupies 40% of global land (58% of that is for pasture use).
  • Food production is responsible for 30% of global greenhouse gas emissions and 70% of freshwater use.
  • Conversion of natural ecosystems to croplands and pastures is the largest factor causing species to be threatened with extinction. Specifically, 80% of extinction threats to mammals and bird species are due to agricultural practices.
  • Overuse and misuse of nitrogen and phosphorous in fertilizers causes eutrophication. In case you are wondering, eutrophication is defined as the process by which a body of water becomes enriched in dissolved nutrients (such as phosphates from commercial fertilizer) that stimulate the growth of algae and other aquatic plant life, usually resulting in the depletion of dissolved oxygen. This creates dead zones in lakes and coastal regions where fish and other marine organisms cannot survive.
  • About 60% of world fish stocks are fully fished and more than 30% are overfished. Because of this, catch by global marine fisheries has been declining since 1996.
  • “Reaching the Paris Agreement of limiting global warming…is not possible by only decarbonizing the global energy systems. Transformation to healthy diets from sustainable food systems is essential to achieving the Paris Agreement.”
  • The world’s population is expected to increase to 10 billion by 2050. The current system of food production is unsustainable.

When they looked at the effect of the foods we eat on the environment, the Commission concluded:

  • Beef and lamb are the biggest contributors to greenhouse gas emissions and land use.
  • The concern about land use is obvious because of the large amount of pasture land required to raise cattle and sheep.
  • The concern about greenhouse gas emissions is because cattle and sheep are ruminants. They not only breathe out CO2, but they also release methane into the atmosphere from fermentation in their rumens of the food they eat. Methane is a potent greenhouse gas, and it persists in the atmosphere 25 times longer than CO2. The single most important thing we can do as individuals to reduce greenhouse gas emissions is to eat less beef and lamb. [Note: grass fed cattle produce more greenhouse gas emissions than cattle raised on corn because they require 3 years to bring to market rather than 2 years.]
  • In terms of energy use beef, lamb, pork, chicken, dairy and eggs all require much more energy to produce than any of the plant foods.
  • In terms of eutrophication, beef, lamb, and pork, all cause much more eutrophication than any plant food. Dairy and eggs cause more eutrophication than any plant food except fruits.
  • In contrast, plant crops reduce greenhouse gas emissions by removing CO2 from the atmosphere.

 

What Is The Planetary Diet?

In the words of the Commission: “[The Planetary Diet] largely consists of vegetables, fruits, whole grains, legumes, nuts, and unsaturated oils. It includes a low to moderate amount of seafood, poultry, and eggs. It includes no or a very low amount of red meat, processed meat, sugar, refined grains, and starchy vegetables.”

When described in that fashion it sounds very much like other healthy diets such as semi-vegetarian, Mediterranean, DASH, and Flexitarian. However, what truly distinguishes it from the other diets is the restrictions placed on the non-plant portion of the diet to make it both environmentally friendly and sustainable. Here is a more detailed description of the diet:

  • It starts with a vegetarian diet. Vegetables, fruits, beans, nuts, soy foods, and whole grains are the foundation of the diet.
  • It allows the option of adding one serving of dairy a day (It turns out that cows produce much less greenhouse emissions per serving of dairy than per serving of beef. That’s because cows take several years to mature before they can be converted to meat, and they are emitting greenhouse gases the entire time).
  • It allows the option of adding one 3 oz serving of fish or poultry or one egg per day.
  • It allows the option of swapping seafood, poultry, or egg for a 3 oz serving of red meat no more than once a week. If you want a 12 oz steak, that would be no more than once a month.

This is obviously very different from the way most Americans currently eat. According to the Commission:

  • “This would require greater than 50% reduction in consumption of unhealthy foods, such as red meat and sugar, and greater than 100% increase in the consumption of healthy foods, such as nuts, fruits, vegetables, and legumes.”
  • “In addition to the benefits for the environment, “dietary changes from current diets to healthy diets are likely to substantially benefit human health, averting about 10.8-11.6 million deaths per year globally.”

What Else Did The Commission Recommend?

In addition to changes in our diets, the Commission also recommended several changes in the way food is produced. Here are a few of them.

  • Reduce greenhouse gas emissions from the fuel used to transport food to market.
  • Reduce food losses and waste by at least 50%.
  • Make radical improvements in the efficiency of fertilizer and water use. In terms of fertilizer, the change would be two-fold:
    • In developed countries, reduce fertilizer use and put in place systems to capture runoff and recycle the phosphorous.
    • In third world countries, make fertilizer more available so that crop yields can be increased, something the Commission refer to as eliminating the “yield gap” between third world and developed countries.
  • Stop the expansion of new agricultural land use into natural ecosystems and put in place policies aimed at restoring and re-foresting degraded land.
  • Manage the world’s oceans effectively to ensure that fish stocks are used responsibly and global aquaculture (fish farm) production is expanded sustainability.

What we can do: While most of these are government level policies, we can contribute to the first three by reducing personal food waste and purchasing organic produce locally whenever possible.

What Does This Mean For You?

If you are a vegan, you are probably asking why the Commission did not recommend a completely plant-based diet. The answer is that a vegan diet is perfect for the health of our planet. However, the Commission wanted to make a diet that was as consumer-friendly as possible and still meet their goals of a healthy, environmentally friendly, and sustainable diet.

If you are eating a typical American diet or one of the fad diets that encourage meat consumption, you are probably wondering how you can ever make such drastic changes to your diet. The answer is “one step at a time.”  If you have read my books “Slaying The Food Myths” or “Slaying the Supplement Myths,”  you know that my wife and I did not change our diet overnight. Our diet evolved to something very close to the Planetary Diet over a period of years.

The Commission also purposely designed the Planetary Diet so that you “never have to say never” to your favorite foods. Three ounces of red meat a week does not sound like much, but it allows you a juicy steak once a month.

Sometimes you just need to develop a new mindset. As I shared in my books, my father prided himself on grilling the perfect steak. I love steaks, but I decided to set a few parameters. I don’t waste my red meat calories on anything besides filet mignon at a fine restaurant. It must be a special occasion, and someone else must be buying. That limits it to 2-3 times a year. I still get to enjoy good steak, and I stay well within the parameters of the Planetary diet.

Develop your strategy for enjoying some of your favorite foods within the parameters of the Planetary Diet and have fun with it.

The Bottom Line

 

Is your diet destroying the planet? This is not a new question, but a recent commission of international scientists has conducted a comprehensive study into our diet and its effect on our health and our environment. Their report serves as a dire warning of what will happen to us and our planet if we don’t change our ways.

The Commission carefully evaluated diet and food production methods and asked three questions:

  • Are they good for us?
  • Are they good for the planet?
  • Are they sustainable? Will they be able to meet the needs of the projected population of 10 billion people in 2050 without degrading our environment.

The Commission described the typical American diet as a “lose-lose diet.”  It is bad for our health. It is bad for the planet. And it is not sustainable.

In its place they carefully designed their version of a primarily plant-based diet they called a “win-win diet.”  It is good for our health. It is good for the planet. And, it is sustainable.

In their publication they refer to their diet as the “universal healthy reference diet” (What else would you expect from a committee?). However, it has become popularly known as the “Planetary Diet.”

The Planetary Diet is similar to other healthy diets such as semi-vegetarian, Mediterranean, DASH, and Flexitarian. However, what truly distinguishes it from the other diets is the restrictions placed on the non-plant portion of the diet to make it both environmentally friendly and sustainable (for details, read the article above).

I have spoken before about the importance of a primarily plant-based diet for our health. In that context it is a personal choice. It is optional.

However, this report is a wake-up call. It puts a primarily plant-based diet in an entirely different context. It is essential for the survival of our planet. It is no longer optional.

If you care about global warming…If you care about saving our planet, there is no other choice.

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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