Whole Grains, Fiber, and Colon Cancer: Some Whole Grains are More Whole Than Others

GrainsThose who eat more whole grains have a lower risk of colon cancer, and there are ways to eat your whole grains that are healthier than others. Read more at DrFuhrman.com.

Refined carbohydrates and excess fats may drive the insulin gene in colon cells to promote cancer

Colon cancer is the third most common cancer type, and the second leading cause of cancer death in the U.S.1 These cancers are the ones most closely linked to lifestyle; the good news is, that means that colon and rectal cancers are also highly preventable by following healthful lifestyle habits – including avoiding disease-causing foods.

Scientists believe that elevated insulin levels contribute to cancer development; insulin in high concentrations may promote growth and division of cancer cells, and cancerous cells often have elevated levels of insulin receptors.2 Foods with a high glycemic load (GL) such as white bread, white rice, sugar, and white potatoes, produce dangerous spikes in blood glucose, and consequently insulin levels. Diets including large quantities of high GL foods increase the risk of several chronic diseases, and a recent meta-analysis of several studies found a 26% increase in colorectal cancer risk in people who consumed the most high glycemic load foods in their diets.3,4

Examples of high, medium and low GL carbohydrate sources:5,6

High GL (20 or higher)  
White potato (1 medium baked) 29
White rice (1 cup cooked) 26
Medium GL (11-19)  

Black rice (1 cup cooked)

14
Low GL (1-10)  
Butternut squash (1 cup cooked) 8
Kidney beans (1 cup cooked) 7

DNA. Flickr: ynse

According to the American Institute for Cancer Research, there is suggestive evidence that cheese and foods containing animal fats increase the risk of colon and rectal cancers. Cheese, the fattiest food in the American diet, is particularly high in saturated fat, which is known to impair insulin sensitivity.7,8

New research suggests that over time, these dietary factors – excess, low-nutrient carbohydrate and fat – may disturb carbohydrate and fat metabolism in the colon by altering DNA methylation in colon cells.

DNA methylation acts essentially as an on/off switch for a gene, usually decreasing (but sometimes increasing) the amount of protein made from that genetic code. Dietary factors are known to affect DNA methylation, and too much or too little methylation can contribute to the development of cancer.9

A recent study compared methylation patterns of thousands of genes in the colon mucosa of control subjects without colon cancer to normal mucosa of colon cancer patients; the researchers found hundreds of genes whose methylation patterns differed in the two sets of subjects. When they looked at those genes with the greatest differences in methylation, they made an interesting observation: a common theme among many of these genes was that they are involved in carbohydrate and lipid metabolism – one of these was the insulin gene. In short, “normal” colon cells in colon cancer patients were making more insulin than normal colon cells from healthy subjects – and we know that excess insulin promotes cancer.

The authors hypothesize that an unhealthy diet full of refined carbohydrate and excess fat may cause this metabolic change – and once excess insulin is being produced by colon cells, it then feeds the growth of cancerous cells.10

Though the research may be complex, the message is simple: refined foods like sugar and white bread, and low-nutrient fats like oils and cheeses are harmful to the health of your colon. Colon cancer is a preventable disease – whole, natural foods provide the fiber, resistant starch, and phytochemicals that will keep the cells of the colon healthy and expressing the proper genes in the proper amounts.

 

References:

1. American Cancer Society. What are the key statistics about colorectal cancer? [http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics ]
2. Vigneri P, Frasca F, Sciacca L, et al: Diabetes and cancer. Endocr Relat Cancer 2009;16:1103-1123.
3. Gnagnarella P, Gandini S, La Vecchia C, et al: Glycemic index, glycemic load, and cancer risk: a meta-analysis. Am J Clin Nutr 2008;87:1793-1801.
4. Barclay AW, Petocz P, McMillan-Price J, et al: Glycemic index, glycemic load, and chronic disease risk--a meta-analysis of observational studies. Am J Clin Nutr 2008;87:627-637.
5. Carbohydrates and the Glycemic Load. Harvard School of Public Health: The Nutrition Source. http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/carbohydrates-and-the-glycemic-load/. 
6. Atkinson FS, Foster-Powell K, Brand-Miller JC: International tables of glycemic index and glycemic load values: 2008. Diabetes Care 2008;31:2281-2283.
7. WCRF/AICR Expert Report, Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective.: World Cancer Research Fund; 2007.
8. Vessby B, Uusitupa M, Hermansen K, et al: Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study. Diab tologia 2001;44:312-319.
9. Kulis M, Esteller M: DNA methylation and cancer. Adv Genet 2010;70:27-56.
10. Study shows how high-fat diets increase colon cancer risk. 2012. EurekAlert! http://www.eurekalert.org/pub_releases/2012-03/tu-ssh030712.php. Accessed March 28, 2012.


 

 

Which foods are most protective against colon cancer?

It is estimated that there are more than 100,000 new cases of colon cancer diagnosed each year in the U.S. alone, and colon and rectal cancers are the third leading cause of cancer-related deaths.1  The American Institute for Cancer Research estimates that forty-five percent of these new cases could be prevented by following a few simple lifestyle habits: avoiding processed and red meat, exercising regularly, maintaining a healthy weight, and limiting alcohol consumption.2  But we can do better – imagine the level of protection if we not only avoided carcinogenic foods, but also focused on eating the foods that work on a cellular level to prevent  colon cancer.

So which foods offer us the best protection?

Anti-cancer compounds have been identified in many plant foods: for example cruciferous vegetables, mushrooms, and the onion and garlic family are known to contain substances that can prevent cellular processes involved in cancer development. Certainly, a diet high in fruits and vegetables in general is protective3-5, but many observational studies on diet have not investigated specific food groups, only broad categories like “fruits,” “vegetables,” etc.  But there is a wide range of anti-cancer activity in the wide range of plant foods – for example, kale is more protective than iceberg lettuce.  Identifying these protective plant foods helps us to construct an anti-colon cancer diet.

A recent study aimed to find some specific foods and food groups that protect against colon cancer. Twenty-six years after reporting information about their diets, subjects were asked whether they had undergone screening colonoscopy, and if so, whether they had physician-diagnosed polyps. The majority of colorectal cancers originate from polyps, so polyps are considered a precursor to the development of cancer. This study was part of the larger Adventist Health Study, which studies relationships between diet and chronic disease in members of the Seventh-day Adventist Church, which emphasizes healthy living in its teachings.

The researchers examined about 25 different foods and food groups. Those that were associated with reduced risk of polyps were cooked green vegetables, dried fruit, legumes (beans, lentils, etc.), and brown rice. All of these displayed dose-dependent effects, meaning that the more of these foods the subjects ate, the more protection they had from colon cancer.6

Green vegetables are rich in folate and isothiocyanates, nutrients with potent anti-cancer properties. Folate is a B vitamin that is involved in turning genes on and off – this is important in preventing the early cellular events that lead to cancer.  Adequate folate levels are protective against several cancers, including colon cancer. It is important to note, however, that synthetic folic acid from supplements is not protective.7,8  Isothiocyanates are a group of nutrients found in cruciferous vegetables that have a wide variety of cancer preventive properties – they can detoxify or remove carcinogens from healthy cells, kill cancer cells, have anti-inflammatory and antioxidant effects, and prevent tumors from acquiring a blood supply.9 

The protection from beans and other legumes was likely due to their soluble fiber and resistant starch, carbohydrates that are not broken down by digestive enzymes.  Intestinal bacteria ferment these carbohydrates, forming short chain fatty acids such as butyrate.  Butyrate has a number of anti-cancer effects including disrupting cancer cell growth, increasing levels of detoxification enzymes, limiting DNA damage, and preventing tumors from acquiring a blood supply.10-13

 High fiber foods, including dried fruit and brown rice (as well as vegetables and beans) help to reduce transit time of gastrointestinal contents through the colon – this reduces the potential contact between dietary toxins or carcinogens and the cells that line the colon.  Reduced transit time is believed to be an important contribution of fiber to the prevention of colon cancer. 14,15  Raisins, probably the most popular dried fruit, have been shown to increase short chain fatty acid production and decrease colon transit time.16,17 In addition to fiber content, dried fruit likely also contributed antioxidant protection of colon cells from DNA damage, which is an early event in the development of cancer.18 

Previous studies found a protective effect of berries, citrus fruits, and yellow-orange vegetables, which was likely due to their high concentration of flavonoid and carotenoid antioxidants, respectively.10,19,20Additional studies on specific food groups have also found a reduced risk of colon polyps with high intake of green leafy vegetables (many of which are cruciferous), onions, and garlic.12,19

All of these foods contain known anti-cancer compounds, and of course there are thousands of anti-cancer compounds in plant foods that scientists have not yet discovered.  Each of these colorful plant foods contains a spectrum of micronutrients and phytochemicals that work in concert to protect the body against carcinogenic influences. Future studies will continue to reveal these phytochemicals and their anti-cancer properties.

My new book Super Immunity, which will be released September 20, 2011, discusses in depth the connections between diet and cancer. 

 

References:

1. American Cancer Society. What are the key statistics about colorectal cancer? [http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics ]

2. American Institute for Cancer Research. What you need to know about preventing colorectal cancer. http://www.aicr.org/reduce-your-cancer-risk/cancer-site/cancersite_colon_rectum.html. Accessed September 2, 2011.

3. Reedy J, Krebs-Smith SM: A comparison of food-based recommendations and nutrient values of three food guides: USDA's MyPyramid, NHLBI's Dietary Approaches to Stop Hypertension Eating Plan, and Harvard's Healthy Eating Pyramid. J Am Diet Assoc 2008;108:522-528.

4. van Duijnhoven FJ, Bueno-De-Mesquita HB, Ferrari P, et al: Fruit, vegetables, and colorectal cancer risk: the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr 2009;89:1441-1452.

5. Wirfalt E, Midthune D, Reedy J, et al: Associations between food patterns defined by cluster analysis and colorectal cancer incidence in the NIH-AARP diet and health study. Eur J Clin Nutr 2009;63:707-717.

6. Tantamango YM, Knutsen SF, Beeson WL, et al: Foods and food groups associated with the incidence of colorectal polyps: the Adventist Health Study. Nutr Cancer 2011;63:565-572.

7. Kim YI: Role of folate in colon cancer development and progression. The Journal of nutrition 2003;133:3731S-3739S.

8. Kim YI: Folate and colorectal cancer: an evidence-based critical review. Molecular nutrition & food research 2007;51:267-292.

9. Higdon J, Delage B, Williams D, et al: Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacol Res 2007;55:224-236.

10. O'Keefe SJ, Ou J, Aufreiter S, et al: Products of the colonic microbiota mediate the effects of diet on colon cancer risk. J Nutr 2009;139:2044-2048.

11. Dronamraju SS, Coxhead JM, Kelly SB, et al: Cell kinetics and gene expression changes in colorectal cancer patients given resistant starch: a randomised controlled trial. Gut 2009;58:413-420.

12. Williams EA, Coxhead JM, Mathers JC: Anti-cancer effects of butyrate: use of micro-array technology to investigate mechanisms. The Proceedings of the Nutrition Society 2003;62:107-115.

13. Hamer HM, Jonkers D, Venema K, et al: Review article: the role of butyrate on colonic function. Aliment Pharmacol Ther 2008;27:104-119.

14. Jacobs LR: Modification of experimental colon carcinogenesis by dietary fibers. Adv Exp Med Biol 1986;206:105-118.

15. Gear JS, Brodribb AJ, Ware A, et al: Fibre and bowel transit times. Br J Nutr 1981;45:77-82.

16. Spiller GA, Story JA, Furumoto EJ, et al: Effect of tartaric acid and dietary fibre from sun-dried raisins on colonic function and on bile acid and volatile fatty acid excretion in healthy adults. The British journal of nutrition 2003;90:803-807.

17. Spiller GA, Story JA, Lodics TA, et al: Effect of sun-dried raisins on bile acid excretion, intestinal transit time, and fecal weight: a dose-response study. Journal of medicinal food 2003;6:87-91.

18. Federico A, Morgillo F, Tuccillo C, et al: Chronic inflammation and oxidative stress in human carcinogenesis. International journal of cancer Journal international du cancer 2007;121:2381-2386.

19. Wu H, Dai Q, Shrubsole MJ, et al: Fruit and vegetable intakes are associated with lower risk of colorectal adenomas. J Nutr 2009;139:340-344.

20. Michels KB, Giovannucci E, Chan AT, et al: Fruit and vegetable consumption and colorectal adenomas in the Nurses' Health Study. Cancer Res 2006;66:3942-3953.

 

Eat fiber-rich foods now, not later!

There are a few different classifications of fiber, and their common characteristic is resistance to digestion in the human small intestine.   Eating fiber-rich foods is associated with a number of health benefits:

  • Fiber promotes weight maintenance by slowing gastric emptying; and adding volume to food, promoting satiety
  • Fiber helps to prevent diabetes by slowing entrance of glucose into the bloodstream, curbing glucose (and insulin) spikes after meals
  • Soluble fiber (a type of fiber abundant in oats and beans) has cholesterol-lowering effects.
  • Cardiovascular health – a pooled analysis of 10 prospective studies found that an increase of 10 grams of dietary fiber per day was associated with a 24% decrease in deaths from coronary heart disease.1
  • Digestive health – fiber adds bulk and acts as a stool softener, making bowel movements faster and easier, and preventing constipation and diverticular disease.
  • Fermentation of fiber and resistant starch by bacteria in the large intestine helps to prevent colorectal cancers 2

Fiber vs. fiber-rich foods: Fiber can be isolated and taken as a supplement or added to a processed food, but these are not the recommended ways to get your fiber.  Although fiber itself has beneficial properties, fiber-rich whole foods come packaged with disease-fighting phytochemicals.  There have been inconsistencies in the results of studies on fiber and colorectal cancer, probably because it appears to be high-fiber foods, not fiber alone that reduces risk. 3-8

The American Heart Association recommends consuming 25 grams of fiber each day –a nutritarian diet far exceeds that recommendation, providing about 60-80 grams of fiber each day, since the vast majority of my recommended food pyramid is made up of fiber-rich foods like vegetables, fruits, seeds and beans.  

Beans. Flickr: cookbookman17

A study relating dietary fiber intake to lifetime risk of cardiovascular disease was presented at the American Heart Association’s Nutrition, Physical Activity, and Metabolism conference last week. Data from the 2003-2008 U.S. National Health and Nutrition Examination Surveys were analyzed. The researchers used a mathematical algorithm to predict lifetime risk for cardiovascular disease, based on diet, blood pressure, cholesterol, smoking, and history of diabetes.  All of the participants were free of cardiovascular disease at the start.  

The algorithm placed participants in groups of either high or low lifetime risk of cardiovascular disease.  Then they were arranged into four groups according to the ratio of their intake of dietary fiber to calories - dietary fiber only, no fiber supplements were included.  The lowest fiber intake was 0.1g/1000 calories, and the highest was on par with a nutritarian diet, 49.1g/1000 calories.

Individuals aged 20-39 in the highest quartile of fiber intake were almost twice as likely to be in the low risk category than those in the lowest quartile. Middle aged individuals in the highest quartile were about 50% more likely to be in the low risk category. Interestingly though, a similar association was not seen in 60-79 year olds.  The researchers theorized that many older adults with high fiber intake may have already developed significant risk for heart disease before they added more high-fiber foods to their diet.   They concluded that starting to increase fiber intake at a younger age helps to decrease the risk of cardiovascular disease later in life.9,10

It is important to eat healthfully your entire life to get maximum benefits, however once you have not eaten properly for the first 60 years, then to get the disease-protective benefits to dramatically reduce heart attack, stroke and cancer risk from a plant-based diet (vegan or flexitarian) later in life, it is not good enough to just be good, you have to be great.  In other words, a nutritarian diet with attention to the most nutritionally powerful and protective plant foods is necessary, not just the dietary mediocrity practiced by most vegans and vegetarians.

Eating to Live is a lifetime commitment – just like it takes years for heart disease to develop, it takes years to build up protection against heart disease.  No matter what your age, you can benefit from improving your diet – but the point is, the time to start is right now and the place to start is with a nutritarian diet that pays attention to the disease-fighting nutrients in foods. Once you are past middle age, the way to start is not with some wishy-washy low fat, high fiber diet.  That is not good enough, you have to do better than that and pay attention to the micronutrient-richness of your meals and achieve comprehensive nutritional adequacy, which is the core of my message.  

 


References:

1. Pereira MA, O'Reilly E, Augustsson K, et al: Dietary fiber and risk of coronary heart disease: a pooled analysis of cohort studies. Arch Intern Med 2004, 164:370-376.

2. O'Keefe SJ, Ou J, Aufreiter S, et al: Products of the colonic microbiota mediate the effects of diet on colon cancer risk. J Nutr 2009, 139:2044-2048.

3. Singh PN, Fraser GE: Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol 1998, 148:761-774.

4. Uchida K, Kono S, Yin G, et al: Dietary fiber, source foods and colorectal cancer risk: the Fukuoka Colorectal Cancer Study. Scand J Gastroenterol 2010, 45:1223-1231.

5. Park Y, Hunter DJ, Spiegelman D, et al: Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies. JAMA : the journal of the American Medical Association 2005, 294:2849-2857.

6. Michels KB, Fuchs CS, Giovannucci E, et al: Fiber intake and incidence of colorectal cancer among 76,947 women and 47,279 men. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2005, 14:842-849.

7. Terry P, Giovannucci E, Michels KB, et al: Fruit, vegetables, dietary fiber, and risk of colorectal cancer. J Natl Cancer Inst 2001, 93:525-533.

8. Wakai K, Date C, Fukui M, et al: Dietary fiber and risk of colorectal cancer in the Japan collaborative cohort study. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2007, 16:668-675.

9. Northwestern University (2011, March 23). Load up on fiber now, avoid heart disease later. . In ScienceDaily; 2011.

10. Ning H, Van Horn L, Shay CM, et al: Dietary Fiber Intake and Long Term Cardiovascular Risk: Findings from the National Health and Nutrition Examination Surveys (NHANES) 2003-2008. In American Heart Association: Nutrition, Physical Activity, and Metabolism 2011.


 

Vitamin D may protect against colon cancer

Vitamin D insufficiency is widespread, and is now thought to contribute to a variety of disease states, including osteoporosis, cardiovascular disease, diabetes, autoimmune diseases, depression, and cancers.

Vitamin D affects calcium absorption and metabolism in the bone, kidney, and intestine, but it also acts as a regulator of gene transcription in many tissues, affecting genes that control cell growth, adhesion, differentiation, proliferation, and programmed cell death. Vitamin D’s action on such genes has been shown to suppress proliferation of human colon cancer cells and tumor growth.1,2

Also, the cells of the colon, whether they are normal or cancerous, are capable of converting 25(OH)D to its active form 1,25(OH)2D. It is likely that this ability has purpose – vitamin D may have yet unidentified actions specific to the cells of the colon.

Colon

Researchers analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which has over 520,000 participants. Blood levels of vitamin D, which were measured at the start of the study, were compared between 1248 colorectal cancer patients and matched controls after diagnosis.

Circulating 25(OH)D levels of below 20 ng/ml were associated with increased risk of colorectal cancer compared with levels between 20-30 ng/ml.  When the researchers arranged the data into 5 quintiles of Vitamin D levels, they found a dose-dependent reduction in colon cancer risk; highest quintile (greater than 40 ng/ml) had 40% reduced risk compared to lowest quintile (less than 10 ng/ml). When cancers were distinguished by site, the association between Vitamin D levels and colon cancer was even stronger – the highest quintile showed a 60% risk reduction.3

This is the largest study on the subject to date, following up at least 25 previous studies since 2002. A 2009 review of these previous studies confirmed that there is indeed an inverse relationship between vitamin D levels and colorectal cancer. Even after a diagnosis of colon cancer, vitamin D levels are associated with increased survival – in colon cancer patients, higher vitamin D levels were predictive of a decreased risk of death from any cause, not only colon cancer.4

The 2009 review concluded that 25(OH)D levels of 32 ng/ml would be sufficient to achieve the protection against colorectal cancers seen in the literature, and the current study saw benefits with as low as 20 ng/ml. A minimum of 30 ng/ml 25(OH)D is thought to be required for vitamin D to properly exert its many beneficial effects.5 Accordingly, I  recommend that levels be maintained in the range of 35-55 ng/ml. 

About 50% of the U.S. population is deficient in vitamin D and cannot rely on sun exposure because of indoor jobs, skin color, and their climate. Plus, with the depletion of the ozone layer, the amount of sun most people would require to achieve these levels may result in too much skin damage and skin cancer.6 

 

 References:

1. Ingraham BA, Bragdon B, Nohe A. Molecular basis of the potential of vitamin D to prevent cancer. Curr Med Res Opin. 2008 Jan;24(1):139-49.

2. Journal of Clinical Investigation (2009, July 7). Understanding The Anticancer Effects Of Vitamin D3. ScienceDaily. Retrieved April 6, 2010, from http://www.sciencedaily.com /releases/2009/07/090706171500.htm

Emory University (2008, April 14). Vitamin D And Calcium Influence Cell Death In The Colon, Researchers Find. ScienceDaily. Retrieved April 6, 2010, from http://www.sciencedaily.com /releases/2008/04/080413161052.htm

Rockefeller University Press (2008, November 26). Vitamin D Can Alter Color Cancer Cells In Many Ways, Through One Pathway. ScienceDaily. Retrieved April 6, 2010, from http://www.sciencedaily.com /releases/2008/11/081117091614.htm

3. Jenab M, Bueno-de-Mesquita HB, Ferrari P, et al. Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations:a nested case-control study. BMJ. 2010 Jan 21;340:b5500.

High vitamin D levels linked to lower risk of colon cancer. ScienceDaily. Retrieved April 6, 2010, from http://www.sciencedaily.com /releases/2010/01/100122002340.htm

4. Dana-Farber Cancer Institute (2008, June 20). Vitamin D Linked To Colon Cancer Survival. ScienceDaily. Retrieved April 6, 2010, from http://www.sciencedaily.com /releases/2008/06/080619090749.htm

5. Holick MF, Chen TC. Vitamin D deficiency: a worldwide problem with health consequences.Am J Clin Nutr 2008;87(suppl):1080S– 6S.

6. Terushkin V, Bender A, Psaty EL, et al. Estimated equivalency of vitamin D production from natural sun exposure versus oral vitamin D supplementation across seasons at two US latitudes. J Am Acad Dermatol. 2010 Apr 2. [Epub ahead of print]

 

Diet high in omega-6 fats increases risk for ulcerative colitis

Ulcerative colitis falls under the category of inflammatory bowel diseases (IBD). It is an autoimmune disease in which excessive inflammation kills cells in the lining of the colon, leaving ulcers behind. Ulcerative colitis is a chronic condition that commonly causes abdominal pain and bloody diarrhea, and it carries with it an increased risk of colorectal cancer. In some severe cases, the colon must be surgically removed. Clearly, this condition also causes a great deal of emotional trauma.1

Recent studies have identified dietary patterns that may predispose individuals to ulcerative colitis. High intake of fats, refined sugars, and fried potato products were positively associated with ulcerative colitis, and fruit consumption was found to be protective.2

Fruit

Most recently, omega-6 fatty acids have been investigated. Omega-6 fatty acids are essential fatty acids, meaning that we must obtain them from our diet for good health, but the typical American diet contains an excessive amount of omega-6, which can produce a pro-inflammatory environment in the body.

Linoleic acid is an omega-6 fat that is highly concentrated in red meat, cooking oils, and margarines. In the digestive system, linoleic acid is metabolized into arachidonic acid, which incorporates into cell membranes of the colon. When arachidonic acid is broken down further, its products are pro-inflammatory – these products are found in excess in the intestinal cells of patients with ulcerative colitis. For these reasons, scientists believed that excess linoleic acid might be linked to ulcerative colitis risk.

Fries

A prospective study of over 200,000 men and women in Europe found that the subjects who consumed the highest levels of omega-6 linoleic acid were 2.5 times more likely to be diagnosed with ulcerative colitis. The researchers also found a negative association between the omega-3 fatty acid DHA and ulcerative colitis – subjects in the highest level of DHA intake decreased their risk by 77%.3

Avoiding excess levels of linoleic acid is simply accomplished by eating a diet that is based on whole plant foods and limits animal products and added fats. A diet of natural whole foods provides us with omega-6 fatty acids in appropriate amounts - not in excess – producing an anti-inflammatory environment.

For those who already have ulcerative colitis, it is important to know that the condition can be improved and sometimes completely resolved with dietary changes – conventional treatment of IBD often includes immunosuppressive drugs with dangerous side effects.  Dr. Fuhrman outlines specific dietary recommendations for sufferers of IBD in his Inflammatory Bowel Disease newsletter

References:

1. http://www.nlm.nih.gov/medlineplus/ulcerativecolitis.html#cat59

2. Shah S. Dietary Factors in the Modulation of Inflammatory Bowel Disease Activity. MedGenMed 2007; 9(1):60

3. Tjonneland A et al. Linoleic acid, a dietary n-6 polyunsaturated fatty acid, and the aetiology of ulcerative colitis: a nested case-control study within a European prospective cohort study. IBD in EPIC Study Investigators. Gut. 2009 Dec;58(12):1606-11. Epub 2009 Jul 23.

http://www.reuters.com/article/idUSTRE5B15S720091202

Dr. Fuhrman warns: DO NOT take multivitamins or prenatal vitamins that contain folic acid

Folic acid supplementation is dangerous – especially for pregnant women

In a 10-year study,1,2 scientists found that women who take multivitamins containing folic acid increase their breast cancer risk by 20-30%.

Even more alarming are the associations between supplemental folic acid during pregnancy and death from breast cancer,8 and asthma and respiratory tract infections in children.5-6

Read full article

broccoli

Folic acid is the synthetic form of folate, a B vitamin, which is abundant in green vegetables. Folate protects against birth defects known as neural tube defects (NTDs). Pregnant women could safely increase their folate status and prevent NTDs by eating green vegetables, but instead they are instructed to take folic acid supplements, putting them and their children at risk. Folic acid supplements are not a substitute for folate-containing green vegetables – there are inverse associations between maternal vegetable intake and childhood cancers.12-13

Unlike synthetic folic acid, folate obtained from food sources – especially green vegetables – protects against breast and prostate cancer.

There is inverse relationship between dietary folate intake and breast and prostate cancer.14,3 Chemical differences between folate and folic acid translate into differences in uptake and processing of these two substances by the cells in the intestinal wall – excess folic acid in the circulation can occur. Luckily, folate from food comes naturally packaged in balance with other micronutrients and the body regulates its absorption.9

Rich sources of food folate

As a reference point, the U.S. RDA for folate is 400μg. Below is the approximate folate content for a 100-calorie serving.8

Spinach, raw

843 μg

Romaine lettuce

800 μg

Asparagus, cooked

750 μg

Mustard greens, raw

700 μg

Collards, raw

550 μg

Broccoli, cooked

300 μg

Edamame

225 μg

Chickpeas

150 μg

Papaya

90 μg

Orange

70 μg

Blackberries

55 μg

Avocado

50 μg

Sunflower seeds

40 μg

Quinoa, cooked

35 μg

Additional foods listed in full article

Clearly, we do not need synthetic folic acid supplements to meet our daily folate requirements.

Dr. Fuhrman’s Gentle Care Formula Multivitamin does not contain folic acid

Supplemental folic acid has also been linked to prostate cancer3, colorectal cancer4, and overall cancer mortality.7 Because folate is abundant in the nutritarian diet, and synthetic folic acid is so potentially dangerous, folic acid is not included in Dr. Fuhrman’s Gentle Care multivitamin.

Dr. Fuhrman does not recommend prenatal vitamins because of the potentially harmful ingredients, such as folic acid.

Dr. Fuhrman’s special recommendations for pregnant women:

(See full article for references)

 

Exercise Improves Quality of Life After Cancer

A good half hour in the gym is a great way to blow off some steam and according to a new study in the journal Cancer, exercise also helps improve life after cancer, specifically breast, prostate and colorectal cancer.

They interviewed 753 men and women, all at least 65 years old, who had survived 5 or more years after a breast, prostate, or colorectal cancer diagnosis. All were overweight to some degree, but none was morbidly obese.

When the interviewers asked about exercise, diet, weight status, and quality of life, they found that half the group got no more than 10 minutes of moderate-to-vigorous exercise per week, and only 7% had healthful eating habits…

…However, those who exercised more and had better diet quality also had better physical quality of life outcomes (e.g., better vitality and physical functioning) than those who exercised less and ate poorly. Also, the greater the body weight, the poorer the physical quality of life.

In general, conclude [researchers], the results point to "the potential negative impact of obesity and the positive impact of physical activity and a healthy diet on physical quality of life in cancer survivors.

In related news, doing moderate to high-intensity exercise for 30 minutes a day cuts cancer risk in men by 50%. Regular exercise helps strengthen bones too.

Via Reuters.

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Cutting Alcohol, Meat and Smoking Lowers Colon Cancer Risk

Geez, I know people who do all three—in one sitting! If you know someone like this too, show them this.

New research in the International Journal of Cancer suggests lifestyle changes—such as eating less red meat, not smoking, avoiding alcohol and exercising—may lower your risk of colon cancer.

Scientists analyzed 100 studies on colon cancer risk, finding that high intake of red and processed meats, smoking, obesity and diabetes were associated with a 20% increased in the risk.

As for alcohol, people averaging one drink or more each day had a 60% higher risk of cancer. However, people who exercised regularly were 20% less likely to develop colorectal cancer.

Makes sense! Especially since last week a report came out saying vegetarians—i.e. people who don’t eat meat—have less cancer than meat eaters.

And previous findings reveal smoking and drinking heighten risk of bowel cancer, but eating fruits and vegetables, protect against cancer. Sweet!

Via Reuters.

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Fast Food, Obesity Blamed for Increased Colorectal Cancer

A new study in the journal of Cancer Epidemiology Biomarkers and Prevention reveals the rate of colon cancer among young adults—under the age of 50—is increasing. Data showed regardless of sex, race and age incidences of colon cancer between 1992 and 2005 rose 1.5% in men and 1.6% in women, with the largest increases in men and women, ages 20 to 29, with 52% and 5.6% respectively. Experts blame consumption of fast foods and high rates of obesity; via EurekAlert!

It’s a good idea to kick fast food as soon as possible. In April, a study showed kids eating fast food are more likely to develop poor eating habits. And given the unhealthiness of fast food, some Los Angeles officials don’t want any more fast food restaurants in their neighborhoods.

In related news, eating lots of fruits and veggies helps cut colon cancer risk in men, but taking high-dose folic acid supplements can raise colon cancer risk, by as high as 162%. Eek!

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