Headlines in major news publications and TV news stations drew attention yesterday with various headlines stating something like "Vitamins cause cancer." It's always interesting how the small number of studies on the use of vitamins and minerals that show a possible association with health concerns draw much more media attention than the large number of studies showing their benefit.

Folic Acid, Vitamin B12 and Cancer

The study that generated the "Vitamins Cause Cancer" headlines was published November 18 in the Journal of the American Medical Association. The study was completed in Norway. Performing the research study in Norway was interesting in that the country does not have a standardized policy for folic acid fortification like the United States does, so people have less exposure to higher levels of folic acid. The researchers concluded that folic acid plus vitamin B12 was associated with increased cancer outcomes and all-cause (any reason for) mortality in patients with ischemic heart disease in Norway. The main cancer that occurred during the study was lung cancer. The published review included data from two different research studies, the Norwegian Vitamin Trial (NORVIT) and the Western Norway B Vitamin Intervention Trial (WENBIT). The structure of the study and the results have been questioned by some experts in the world of vitamin and mineral research.

Daniel Fabricant, PhD, is the Vice President of Scientific and Regulatory Affairs for the Natural Products Association (NPA). He pointed out that participants in both studies were also being treated with beta-blockers and statins, and some were also being treated with ACE inhibitors and diuretics. The studies did not adjust for these. Without adjusting for these additional therapies, it cannot be determined how the results came to be.

Andrew Shao, PhD, Vice President, Scientific and Regulatory Affairs for the Council for Responsible Nutrition (CRN), Washington, D.C. was quoted as saying the results from this study:

"are inconsistent with the larger body of data and that this effect has not been observed previously. In fact, as the authors themselves point out, 'Epidemiological studies have demonstrated no associations between intakes of folate or folic acid and lung cancer risk. Consumers, as well as researchers and healthcare professionals, must not lose sight of the safe, well-established benefits of folic acid supplementation and fortification for women of childbearing age to prevent neural tube defects, as well as other potential benefits of folic acid supplementation, such as for cardiovascular health and cognitive function in the general population."

Another unique aspect of the study was the very high prevalence of smoking in the Norwegian population compared with the averages in the United States. In fact, 40% of the participants were current smokers. Of all of the lung cancers diagnosed, 70% were current and 24% were former smokers. While this single study in a a very specific subset of the population may have raised some red flags, it should not stop people from ensuring they take in optimal levels of these vitamins.

An additional article, also published in the November 18 issue of JAMA, titled Assessing Cancer Prevention Studies - A Matter of Time, the authors explain that the occurrence of cancer has actually decreased during the time that folic acid fortification has taken place in the United States, which goes against the study findings. They also said:

"Cancer prevention efforts to not start or end with folic acid. Cessation of cigarette smoking and prevention of smoking in youth and adolescents remains the highest priority for cancer prevention. For those who do not smoke, eating a healthy diet and exercising to avoid weight gain or maintain weight loss will translate to lower risk of cancer, diabetes, and other chronic conditions. These are population-wide changes that take time, and the benefits of such lifestyle changes can take years, even decades to realize."

Benefits of Folic Acid and Vitamin B12

There is a significant amount of research on the benefits of folic acid and Vitamin B12 supplementation. Some of the conclusions from other studies on Vitamin B12 and folic acid are listed below:

Taking a daily supplement including both folic acid and vitamin B12 would reduce the risk of coronary heart disease, as well as provide a cost effective means of maintaining health
A daily regime of aspirin or B-Vitamins may help reduce the risk of dementia and cognitive impairment
The use of vitamin B12, B6 and folate supplements aids in recovery after heart surgery
Folate, vitamin B6 and vitamin B12 help to improve cognitive functions such as memory, processing speed and verbal abilities
Vitamin B12 has been proven to be a pain reliever, and is safe and well-tolerated

This is a very small sample of the conclusions of other studies on folic acid and vitamin B12 which doesn't begin to describe all of the potential benefits of optimal folic acid and vitamin B12 intake. The evidence overall suggests a strong need for the use of folic acid and vitamin B12, consumed through food and supplements. Even though the headlines make for an attention-grabbing story, be sure to get all of the facts surrounding the use of vitamin and mineral supplements before you consider giving up on an an important component of a sound nutrition program. They don't replace the need for nutrition from food, but are an important part of ensuring your take in optimal levels of these essential micronutrients.

In health,

References:

Tice JA, Ross E, Coxson PG, Rosenberg I, Weinstein MC, Hunik MG, Goldman PA, Williams L, Goldman L. Cost-effectiveness of vitamin therapy to lower plasma levels for the prevention of coronary heart disease: effect of grain fortification and beyond. JAMA. 286(8):936-43, 2001 Aug 22-29

Clarke R, Harrison G, Richards S. Effects of vitamins and aspirin on markers of platelet activation, oxidative stress and homocysteine in people at high risk of dementia. Journal of Internal Medicine. 254(1):67-75, 2003 Jul.

Schnyder G, Roffi M, Pin R, Flammer Y, Lange H, Eberli FR, Meier B, Turi ZG, Hess OM. Vitamin B12 aids Heart Surgery Recovery. New Eng Jour Med. 345(22)1593-600, 2001 Nov 29

Bryan J, Calvaresi E, Hughes D.  Vitamin B12 Helps to Improve Memory. Jour of Nutr. 132(6)1345-56, 2002 Jun.

Mauro Gl, Martorana U, Ctaldo P, Brancato G, Letzia G.  Vitamin B12 for Lower Back Pain. Europ Rev for Med & Pharm Sci. 4(3):53-8, 2000 May-Jun

Neutraceuticals World. Study Links Folic Acid with Cancer Risk. neutraceuticalsworld.com

Ebbing M, Bonna KH, Nygard O, Arnesen E, Ueland PM, Nordrehaug JE, Rasmussen K, Njolstad I, Refsum H, Nilsen D, Tverdal A, Meyer K, Vollset SE. Cancer Incidence and Mortality After Treatment With Folic Acid and Vitamin B12. JAMA. 2009;302(10):2119-2126

Drake B, Colditz G. Assessing Cancer Prevention Studies - A Matter of Time. JAMA 2009;302(19):2152-2153

This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.

In the first two parts of this series we learned about how to identify glucose intolerance and some techniques for using exercise to manage blood sugar.  In this last section we will look at food choices and supplements that are most helpful for blood sugar control.

Sugary Snacks

Let’s face it sometimes we just want a little something sweet.  If you are going to indulge your sweet tooth why not make it as healthy as possible?  Dried figs and dates make a great choice for a sweet indulgence that also provides a powerful dose of nutrition.  Try to limit intake to 2 or 3 at a time.

With baked goods make sure that your choice is free of trans fats such as margarine and hydrogenated oils.  You may sacrifice some calories but the natural fats found in butter and egg yolk provide nutrients that will help the body burn off the sugar.

Include Some Fiber

Fiber slows down the introduction of sugar from sweet and starchy foods into the bloodstream.  Especially when consuming starchy foods like bread, rice, pasta, or potato, make sure to include a fresh salad, steamed vegetables, or beans to balance the meal. Whole grain breads and pastas, and brown rice still have the naturally occurring fiber within them so it is not as critical to add an extra source of fiber.

Get More Protein

Protein has a balancing effect on blood sugar. Eating protein stimulates the body to secrete hormones that act to lower blood sugar and turn down hunger signals.  Do your best to include a protein source at every meal and snack in the form of meats or fish, eggs, dairy, nuts or seeds, and beans.

Consider Supplementation

There are a number of herbs and supplements that have been shown to help normalize blood sugar metabolism.  Here are a few with the most promising research behind them:

ECGC found in green tea has been found in some studies to lower blood glucose levels, though the effects seem to be more pronounced at higher concentrations, such as can be found in a pill, rather than brewed tea.

Zinc is a trace mineral that plays an important role in blood sugar metabolism and low zinc levels have been correlated to glucose intolerance in humans.  Shellfish as well as sunflower and sesame seeds are excellent dietary sources of zinc.

Korean red ginseng (Panax ginseng) has been shown to benefit glucose in metabolism, although studies of American ginseng (Panax quinquefolius) have not shown the same benefit.

Make sure to consult with a professional trained in the use of dietary supplements before starting any supplement program.  Not all brands contain the same quality of ingredients and certain substances used in many weight loss formulas contain ingredients which could cause damage to the body or interact with certain medications.

References

Maruyama K, Iso H, Sasaki S, Fukino Y. The Association between Concentrations of Green Tea and Blood Glucose Levels.  J Clin Biochem Nutr. 2009 Jan;44(1):41-5. Epub 2008 Dec 27.

Nagao T, Meguro S, Hase T, Otsuka K, Komikado M, Tokimitsu I, Yamamoto T, Yamamoto K. A catechin-rich beverage improves obesity and blood glucose control in patients with type 2 diabetes. Obesity (Silver Spring). 2009 Feb;17(2):310-7. Epub 2008 Nov 13.

Masood N, Baloch GH, Ghori RA, Memon IA, Memon MA, Memon MS. Serum zinc and magnesium in type-2 diabetic patients. J Coll Physicians Surg Pak. 2009 Aug;19(8):483-6.

Jansen J, Karges W, Rink L.  Zinc and diabetes--clinical links and molecular mechanisms.  J Nutr Biochem. 2009 Jun;20(6):399-417.

Ma SW, Benzie IF, Chu TT, Fok BS, Tomlinson B, Critchley LA.  Effect of Panax ginseng supplementation on biomarkers of glucose tolerance, antioxidant status and oxidative stress in type 2 diabetic subjects: results of a placebo-controlled human intervention trial. Diabetes Obes Metab. 2008 Nov;10(11):1125-7. Epub 2008 Mar 18.

Vuksan V, Sung MK, Sievenpiper JL, Stavro PM, Jenkins AL, Di Buono M, Lee KS, Leiter LA, Nam KY, Arnason JT, Choi M, Naeem A.  Korean red ginseng (Panax ginseng) improves glucose and insulin regulation in well-controlled, type 2 diabetes: results of a randomized, double-blind, placebo-controlled study of efficacy and safety.  Nutr Metab Cardiovasc Dis. 2008 Jan;18(1):46-56. Epub 2006 Jul 24.