Dietary intakes of carbohydrates in relation to prostate cancer risk: A prospective study in the Malmo Diet and Cancer cohort

American Journal of Clinical Nutrition December 2012; Vol. 96; No. 6; pp. 1409 – 18 Isabel Drake, Emily Sonestedt, Bo Gullberg, Goran Ahlgren, Anders Bjartell, PeterWallstrom, and Elisabet Wirfalt KEY PONTS FROM THIS STUDY: 1) Dietary carbohydrates have been implicated in relation to prostate cancer. 2) This analysis included 8,128 men aged 45 – 73 y without a history of cancer,cardiovascular disease, or diabetes. After a median follow-up time of 15 y, prostatecancer was diagnosed in 817 men. 3) This study found that overall, total carbohydrates consumption did notincrease the risk for prostate cancer. However there was an increase rate ofprostate cancer as related to the consumption of low-fiber cereals, cake, biscuits,rice, and pasta. 4) A high intake compared with zero consumption of sugar-sweetenedbeverages was associated with increased risk of symptomatic prostate cancer, by38%. 5) Results from this large study with high-validity dietary data suggest that ahigh intake of refined carbohydrates may be associated with increased risk ofprostate cancer. 6) Lifestyle and environmental factors play an important role in prostate cancer. 7) Both insulin and insulin-like growth factor I stimulate prostate cancer growthin vitro and have been associated with prostate cancer risk in epidemiologicstudies. 8) Because one of the most potent stimulants for insulin production iscarbohydrate consumption, it has been proposed that diets high in carbohydratesmay affect prostate cancer risk. 9) The nutrient and food variables investigated in this study were totalcarbohydrates, monosaccharides, sucrose, dietary fiber, whole grains, vegetables,fruit and berries, fruit juices, potatoes, low-fiber cereals, low-fiber bread, high-fiberbread, cakes and biscuits, rice and pasta, sweets and sugar, sugar-sweetenedbeverages, alcohol, calcium, selenium, vitamin E, total protein, red meat, processed meat, total fat, SFAs, PUFAs, fish and shellfish, and dairy products.Other measured variables included BMI, waist circumference, smoking,educational level, and total physical activity. 10) A high intake of cake and biscuits was associated with increased risk of low-riskprostate cancer. 11) A high intake of low-fiber cereals was associated with increased risk of totaland low-risk prostate cancer. 12) A high intake of rice and pasta was associated with increased risk of low riskprostate cancer by 33%. 13) Significantly increased risk of symptomatic prostate cancer was seen for ahigh intake of sugar-sweetened beverages by 41%. 14) Refined carbohydrates (ie, cakes and biscuits, low-fiber cereals, rice andpasta, and sugar-sweetened beverages), may be associated with incident prostatecancer. 15) Although no association was seen with total carbohydrates or sucrose, highintake of sugar-sweetened beverages was shown to be associated with 40%increased risk of symptomatic prostate cancer in our study population. 16) Our findings suggest that high intake of foods typically high in refinedcarbohydrates (including cakes and biscuits, low-fiber cereals, rice and pasta, andsugar-sweetened beverages) may increase risk of this disease. COMMENTS FROM DAN MURPHY Article Review 52-12 indicates that the primary fuel for cancer cells is throughthe very inefficient anaerobic glycolysis pathway; because of this inefficiency,cancer cells require large amounts of carbohydrates to fuel their high energyrequirements. Consequently the authors suggest that cancer cells starve whendietary carbohydrates are sharply restricted. [Is There a Role for Carbohydrate Restriction in the Treatment and Prevention of Cancer? Nutrition and Metabolism; October 2011; 8(75)]The bottom line is that this article adds to the evidence that consumption of refinedcarbohydrates is a cancer risk and should be avoided or minimized. Accompanying Editorial Soft Drinks, Aspartame, and the Risk of Cancer and Cardiovascular DiseaseDagfinn Aune 1) The consumption of sugar-sweetened soft drinks has been associated withexcess weight and an increased risk of type 2 diabetes in systematic reviews andmeta-analyses of the evidence, and these conditions are by themselves related toan increased risk of mortality, cardiovascular disease, some cancers, and other chronic diseases. 2) Sugar-sweetened soft drinks are the primary source of added sugars in theAmerican diet. 3) Artificially sweetened diet soft drinks have been marketed as a healthieralternative due to their lack of calories, but studies have linked them to increasedrisk of type-2 diabetes and cardiovascular disease. 4) In animals, aspartame, is linked to an increased risk of lymphomas,leukemias, and transitional cell carcinomas of the pelvis, ureter, and bladder in adose-dependent manner within ranges that are considered to be safe for humanconsumption. 5) In a 2012 study published in the American Journal of Clinical Nutrition, menconsuming one or more diet sodas per day had a 31% increased risk of nonHodgkinlymphoma (NHL) and a 102% increased risk of multiple myelomacompared with no intake. In the same study, intake of regular sugar-sweetenedsodas was associated with a 66% increased risk of NHL in men. In the same study there was a 42% increased risk of leukemia with a high intake of diet soft drinks.[Apparently, both sugar sodas and diet sodas are bad for health]Intake of aspartame was directly associated with risk of NHL and multiple myelomaand suggestively associated with leukemia in men. 6A) With regard to the mechanism that may explain the findings for diet softdrinks, it is known that aspartame breaks down to methanol, aspartic acid, andphenylalanine if stored near or above room temperature. The cancer risk is greaterin men apparently because men are enzymaticly superior in converting methanol to carcinogenic formaldehyde. 6B) Ironically, alcohol consumption inhibits the enzymatic conversion of methanolto carcinogenic formaldehyde; consequently in men who consumed less than 6 oz.of alcohol/day, there was a 134% increased risk of NHL. [Translation: if onedrinks diet sodas, one should also drink more than 6 oz. of alcoholdaily].