Does It Work for Weight Loss or Cancer Prevention? Intermittent Fasting, Alkaline Diet and Functional Food Sarah Gunnell Bellini, PhD, RDN, CD Intermountain Nutrition Update 2016
Objectives Evaluate quality of research related to intermittent fasting, alkaline diet, and functional food Provide evidence-based nutrition interventions
Intermittent Energy Restriction/Fasting Fast Diet Eat normal 5 days a week and calorie restrict 2 days per week Fast days can t be back-to-back Fast days around 500 to 600 calories Eat lean protein, vegetables, and fruit on fasting days Eat anything on 5 off days 5:2 diet
Benefits Improve biomarkers of disease Reduce oxidative stress Preserve learning and memory functioning Cardiovascular protection
Why it works Cells under mild stress during fasting period Enhance ability to cope with stress and maybe resist disease Ketones Protect memory and learning functionality Slow disease process in the brain Overall weight reduction
Animal Models Adaptive Stress Response Prevent age-related decrements in antioxidant enzymes in livers cells of rats Increased levels of antioxidant enzymes in muscle cells of mice Protect neurons against oxidative, metabolic, and proteotoxic stress in animal models of neurodegenerative disorders Stimulates neuroprotective proteins
Harvie MN and Howell T. Could intermittent energy restriction and intermittent fasting reduce rates of cancer in obese, overweight, and normalweight subjects? A summary of evidence Adv Nutr 2016; 7:690-705.
Intermittent Fasting and Tumors in Rodents Mammary tumor rates reduced by 40-80% Antitumor effect proportional to degree of overall energy restriction and reduced body weight Intermittent fasting had no antitumor effects when mice were allowed to overeat on unrestricted days Harvie MN and Howell T. Could intermittent energy restriction and intermittent fasting reduce rates of cancer in obese, overweight, and normal-weight subjects? A summary of evidence Adv Nutr 2016; 7:690-705.
Intermittent Fasting and Tumors in Rodents Four studies in estrogen-responsive mouse mammary tumor virus found intermittent fasting superior to ad libitum Prostrate rates not influenced by 2 week 50% energy restriction and 2 week ad libitum Harvie MN and Howell T. Could intermittent energy restriction and intermittent fasting reduce rates of cancer in obese, overweight, and normal-weight subjects? A summary of evidence Adv Nutr 2016; 7:690-705.
Are animal cancer models the same as human cancers? No direct data on the effects of intermittent energy restriction/fasting on cancer rates in humans Adverse effects of hyperphagia seen in animal models not in human studies Reduction in IGF-I in rodents good but does not relate to bioactivity within tissues in humans Harvie MN and Howell T. Could intermittent energy restriction and intermittent fasting reduce rates of cancer in obese, overweight, and normal-weight subjects? A summary of evidence Adv Nutr 2016; 7:690-705.
Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Body Weight Changes 2 Intermittent Fasting Studies 7 Alternate Day Fasting Studies 3-8% reduction in body weight after 3-24 weeks Providing food to subjects on fast day key factor 6-8% weight loss 10 Continuous Restriction Studies 4-14% reduction in body weight after 6-24 weeks Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Visceral Fat Changes 2 Intermittent Fasting Studies 5 Alternating Day Fasting Studies 4-7% reduction in visceral fat after 6-24 weeks of treatment Assessed indirectly using waist circumference Paralleled weight reduction 8 Continuous Restriction 2-38% reduction in visceral fat 38% was in 50% energy reduction for 24 weeks Paralleled weight reduction Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Fasting Glucose Levels in Prediabetes 2 Intermittent Fasting Studies 7 Alternate Day Fasting Studies 3-6% reduction in fasting glucose after 8-12 weeks treatment 10 Continuous Restriction (25-30%) Studies No effect on fasting glucose concentrations Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Insulin Sensitivity 2 Intermittent Fasting Studies 4 Alternate Day Fasting Studies Consistent improvement in normoglycemic and prediabetes after 3-24 weeks Best improvement found with greatest weight loss 23% decreases seen in one IF after 8 weeks of fasting 1 day/week 9 Continuous Restriction Studies Substantial improvements after 6-24 weeks Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Limitations Heterogeneous study protocols and interventions Limited number of studies with intermittent and alternate day fasting Weight loss not quantified per week Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research 2014;164:302-311.
Conclusion Difficult to determine if overall calorie reduction is the cause of improved biomarkers and decrease inflammatory markers or the intermittent fasting makes a difference More randomized controlled studies in humans are needed
What if a patient/client wants to do it? Recommend around 300 to 500 calories on the restriction days Not recommended for patients with diabetes taking insulin or medication Choose healthy foods on the non-restricted days Discuss the social implications
Alkaline Diet
Alkaline Diet Systematic review of Fenton TR and Huang T. the association between dietary acid load, alkaline water and cancer. BMJ Open 2016;6:e010438.
Alkaline Diet Based on the concept that mineral components of food make the body acidic, alkaline or neutral Acid-ash hypothesis suggests one must consume more fruits and vegetables and moderate amounts of meat to raise ph of blood Some evidence cancer cells and tumors grow in acidic environment
Results 8278 citations identified and 252 abstracts reviewed No randomized trials 1 study met inclusion criteria Prospective cohort study (27,096 male smokers) Relative risk of bladder cancer Diet estimated renal NAE compared to urinary organic acid secretion No significant difference in risk factor
Conclusion There is no evidence following an alkaline diet changes the ph of blood and prevents cancer or other diseases
Functional Foods
Functional Foods Foods defined as whole foods along with fortified, enriched, or enhanced foods that have a potentially beneficial effect on health when consumed as part of a varied diet on a regular basis at effective levels. Academy of Nutrition and Dietetics Position Paper 2013
Health Functional Foods Foods or food components that provide benefits beyond basic nutrition Developed in Japan in 1980s Nutraceuticals 87% of Americans believe certain foods have health benefits beyond basic nutrition 2011 Functional Foods/Foods for Health Consumer Trending Survey
Categories of Functional Foods Conventional foods containing natural bioactive food compounds Vegetables, fruits, grains, dairy, fish, and meats Isoflavones in soy-based foods Modified foods containing bioactive food compounds Fortified margarine spreads with omega-3 fatty acids Food ingredients that are synthesized Indigestible carbohydrates
Functional Foods Omega 3 fatty acids EPA and DHA Prebiotics Probiotics Oat soluble fiber Psyllium seed soluble fiber Soy protein Sterol-and stanol fortified Cranberries Garlic Nuts Grapes Chocolate Green tea Tomatoes
Qualified Claims About Cancer Risk Tomatoes and tomato-based foods ½ to 1 cup of tomatoes and/or tomato sauce per week may reduce the risk of prostrate cancer Consumption of tomato sauce 2 times per week may reduce the risk of ovarian cancer Limited scientific evidence
Wang Y, Jacobs EJ, Newton CC, McCullough. Lycopene, tomato products and prostate cancer-specific mortality among men diagnosed with nonmetastatic prostate cancer in the Cancer Prevention Study II Nutrition Cohort. Int. J Cancer 2016; 138 (12):2846-2855. 5,643 men with nonmetastatic prostrate cancer Prediagnosis and postdiagnosis dietary intake of lycopene and tomato products was not associated with prostrate-cancer specific mortality
Qualified Claims About Cancer Risk Antioxidant Vitamins and Cancer Vitamin E and Vitamin C Limited and non-conclusive research antioxidant vitamins reduce risk of certain times of cancer Selenium May produce anticarcinogenic effects in the body
Conclusion Scientific substantiation Establish bioavailability and efficacy of compounds that are physiologically achievable Human studies needed- most in vitro models Interactive effects of compounds
What do I do? National Center for Complementary and Integrative Health https://nccih.nih.gov/health/herbsataglance.htm Cochrane Library http://www.cochranelibrary.com/ Evidence Analysis Library FDA Health Claims http://www.fda.gov/food/ingredientspackaginglabeling/labelingnutrition/ucm 2006876.htm