Highlight HEALTH

As the price at the gas pump continues to climb, so does the cost of diary, grain and meat products. Why? Because increasing fuel prices make it more expensive to grow, harvest, transport, process and package food. Indeed, food costs rose by 4 percent in 2007, the highest annual increase since 1990 [1]. In 2008, the U.S. Department of Agriculture predicts the consumer price index for all food will increase 4.5 to 5.5 percent as retailers continue to pass on fuel costs to consumers [1].

There is, however, an upside to the increasing cost of food. Michael Pollan, author of the book In Defense of Food: An Eater’s Manifesto, argues that as the price of fuel and commodities rise, nutritionally questionable, high-profit ingredients like high-fructose corn syrup will also cost more [2]. And as prices rise, consumer demand for products containing such ingredients will fall.

This is good news for producers of sustainable foods — locally grown produce and locally raised meat — that don’t rely on fossil fuels. Locally grown foods are fresher, better tasting and healthier than food that’s been shipped or flown in from further away (we won’t even discuss heavily processed foods). Sustainable food producers haven’t felt the increasing cost of fuel like factory farms, making them more economically competitive in today’s marketplace. Even so, a recent Ohio State University study found that grocery store shoppers are willing to spend more for locally grown foods [3].

photo credit: alykat

The study was published in the May issue of the American Journal of Agricultural Economics. Researchers evaluated data from 477 surveys at 17 Midwestern locations, including retail grocery stores, on-site farm markets and farmers markets. In the survey, shoppers were presented with two baskets of strawberries under 80 different combinations of price, freshness, farm location and farm type. After presenting the options, shoppers were asked which basket of strawberries they would buy. The average retail shopper was willing to pay 48 cents more for strawberries produced locally (in the study, local meant grown within Ohio). Shoppers at farm markets were willing to pay even more at 92 cents extra. Freshness was also found to be important factor for shoppers. Retail shoppers were willing to pay 54 cents more for fresh produce that was recently harvested. Again, farm market shoppers were willing to pay even more at 73 cents extra.

According to Marvin Batte, Ph.D., a co-author of the study and professor of Agricultural, Environmental and Development Economics at Ohio State University [4]:

Statistically, we sorted out what explains each person choosing one basket over the other. We were able to determine how important price was, how important where the strawberries were produced was and whether the freshness guarantee was a factor. Basically what made the biggest difference was local production.

The Washington Post ran a great story earlier this week about the benefits of fruit and vegetables. To Produce Good Health, Bite Into Fruit and Veggies reveals some of the reasons why these food provide so many health benefits. The article also suggests that fresh fruits and vegetables are inexpensive and more accessible over the summer months:

Scientists are just beginning to fully understand the power of produce. And the start of summer provides a great opportunity to expand your nutritional horizons by sampling the foods that will come into peak season during the coming months. Seasonal fruit and vegetables cost less than produce available at other times of year, so they can help stretch your food dollars.

Nobody likes to pay more for food. But if increased food costs force people to find locally grown alternatives and eat healthier, there is indeed an upside to the high price of food. For more information on farmers markets, family farms and other sources of sustainably grown food in your area where you can buy locally grown produce and grass-fed meats, visit LocalHarvest.org.

What are your concerns about the cost of food? How are you dealing with increasing food prices?

References

1. Food CPI, Prices, and Expenditures: CPI for Food Forecasts. United States Department of Agriculture, Economic Research Service. Accessed 2008 Jun 20.
2. Some Good News on Food Prices. The New York Times. 2008 Apr 2.
3. Darby et al. Decomposing Local: A Conjoint Analysis of Locally Produced Foods. American Journal of Agricultural Economics. 90(2):476-486. 2008 May.
4. Average shoppers are willing to pay a premium for locally produced food. Ohio State University Research Communications. 2008 May 20.

On Saturday afternoon, September 29th, 2007, the cable television channel Nickelodeon showed nothing for three hours to celebrate “Worldwide Day of Play”, encouraging children to get off the couch and be active. The “Worldwide Day of Play” is part of Nickelodeon’s “Let’s Just Play” campaign, in partner with the Alliance for a Healthier Generation, to encourage kids to participate in active, healthy and playful lifestyles. The goal of the Alliance for a Healthier Generation is to create a new generation of healthy Americans by addressing one of the nation’s leading public health threats — childhood obesity.

So it should be simple, right? Don’t let kids spend so much time in front of the television … get them to be more active and they won’t be overweight. Or is there more to it? Let’s explore some of the science.

The results of a study on television viewing and body weight in children earlier this year concluded that kids who watched the most TV or ate the fewest meals with their families were at risk of being or becoming overweight [1]. The analysis addressed the eating and activity factors associated with the onset of becoming overweight and persistent overweight in 8,000 children from kindergarten to third grade. Researchers identified three groups of children: never overweight, overweight onset and persistent overweight. Children who were never overweight watched approximately 14 hours of television per week (approximately 2 hours per day). Children who were persistently overweight were watching almost 16 hours of television per week.

Did you catch that? Children who watched just 2 more hours per week — 17 minutes of “extra TV” per day — were constantly overweight. That’s a rather surprising result, isn’t it!

Nevertheless, the results are consistent with a number of other investigations, including a pivotal study done in 1998 by researchers at Johns Hopkins University School of Medicine along with experts at the Centers for Disease Control and Prevention and the National Institutes of Health. The study assessed the participation in vigorous activity and television watching habits and their relationship to body weight and overweight in U.S. children, concluding that a child’s weight increases with the number of hours they spend watching television each day [2]. These experts called it an “epidemic” of childhood obesity.

However, in the years since, studies have shown that while reducing TV viewing time of preschool- and school-aged children may reduce their risk of being of becoming overweight, most report small significant associations [3]. Perhaps the problem isn’t so much children watching too much TV, but what they’re watching on it.

A diary-survey study was conducted recently, studying the associations between children’s television advertising exposure and their food consumption patterns [4]. The study in 234 households with children aged 4-12 years investigated the associations between children’s exposure to food advertising and their consumption of advertised food brands, advertised energy-dense food product categories and food products overall. The results showed that children’s exposure to food advertising was significantly related to their consumption of advertised brands and energy-dense product categories. The relation between advertising exposure and overall food consumption only held in low-income families.

Another study just published found that exposure to television is negatively associated with the intake of fruit and vegetables [5]. The cross-sectional survey was performed in nine European countries to explore exposure to food commercials on TV. The study of over 13,000 children aged 11 years found that most children reported seeing a number of TV ads for food, more frequently unhealthy food ads than ads for healthy foods such as fruit and vegetables. The authors suggest that television ads may influence children’s eating behavior by:

… influencing their cognitions as expressed though attitudes toward fruit and vegetable consumption and preferences for these foods products.

Indeed, a study on the nutritional content of television food advertisements seen by children and adolescents in the U.S. found that the overwhelming majority of commercials related to food products are of poor nutritional content [6]. The results of the study showed that 98% of the food product advertisements viewed by children aged 2 to 11 were high in fat, sugar or sodium. The results weren’t much better for adolescents aged 12 to 17, with 89% of the advertisements of poor nutritional content.

In March, 2007 the Kaiser Family Foundation, a non-profit, private operating foundation focusing on the major health care issues facing the U.S., released the largest study ever conducted of TV food advertising to children [7]. Some of the study’s key findings show that:

• 50% of all ad time on children’s shows is for food.
• 34% of the food products in ads targeting children and teens are for candy and snacks; 28% are for cereal; and 10% are for fast food; 4% are for dairy products; 1% are for fruit juices. Of the 8,854 ads analyzed, none were for fruits or vegetables.
• Among all food ads targeting children and teens, the most common primary appeal is taste (34%), fun (18%), the inclusion of premiums or contests (16%) and the fact that the product is unique or new (10%). Only 2% use claims about health or nutrition as a primary or secondary appeal in the ad.

I think there are a couple of take-home messages from all of this:

1. Make sure your kids get plenty of exercise and limit their television viewing time. Obviously, spending too much time in front of TV takes away from other activities, whether it be physical, social or personal.
2. Recognize that many of the food associations kids have are related to television advertising. Changing a child’s eating attitudes and behavior can be and probably will be difficult.

In some cases, trying to control your child’s diet can be counterproductive. A few years ago, a study of snack intake, eating motivations and body dissatisfaction revealed that children whose parents indicated greater attempts to control their child’s diets reported higher intakes of both healthy and unhealthy snack foods [8]. The authors suggested that a positive parental role model may be a better method for improving a child’s diet than trying to change the foods they eat.

It’s not necessarily bad for your kids to watch TV. It’s monitoring what they watch that may be more important than how much they watch.

What do you think? Do you monitor your children’s TV viewing? How much exposure do they get to food advertisements?

References

1. Gable et al. Television watching and frequency of family meals are predictive of overweight onset and persistence in a national sample of school-aged children. J Am Diet Assoc. 2007 Jan;107(1):53-61.
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2. Andersen et al. Relationship of physical activity and television watching with body weight and level of fatness among children: results from the Third National Health and Nutrition Examination Survey. JAMA. 1998 Mar 25;279(12):938-42.
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3. Sherry B. Food behaviors and other strategies to prevent and treat pediatric overweight. Int J Obes (Lond). 2005 Sep;29 Suppl 2:S116-26.
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4. Buijzen et al. Associations between children’s television advertising exposure and their food consumption patterns: A household diary-survey study. Appetite. 2007 Jul 25; [Epub ahead of print]
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5. Klepp et al. Television viewing and exposure to food-related commercials among European school children: associations with fruit and vegetable intake: a cross sectional study. Int J Behav Nutr Phys Act. 2007 Sep 27;4(1):46 [Epub ahead of print]
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6. Powell et al. Nutritional content of television food advertisements seen by children and adolescents in the United States. Pediatrics. 2007 Sep;120(3):576-83.
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7. Food for Thought: Television Food Advertising to Children in the United States. Kaiser Family Foundation. 2007 March.
8. Brown and Ogden. Children’s eating attitudes and behaviour: a study of the modelling and control theories of parental influence. Health Educ Res. 2004 Jun;19(3):261-71.
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Quercetin is a polyphenol, one of a number of water-soluble plant pigments called flavonoids (meaning class of plant secondary metabolites known for their antioxidant activity) that are largely responsible for the color of many flowers, fruits and vegetables. High concentrations of quercetin are found in apples, onions, tea and red wine [1]. Other sources of quercetin include olive oil, grapes, broccoli, cauliflower, cabbage, dark cherries and dark berries such as blueberries, blackberries and bilberries. The average U.S. citizen eating a normal, healthy diet including fruits and vegetables consumes approximately 25-50 mg of quercetin/day. Quercetin and other flavonoids (also referred to as bioflavonoids) cannot be produced in the human body.

Quercetin is a powerful antioxidant; from a range of dietary flavonoids, quercetin was found to be the most effective inhibitor of oxidative damage to LDL (bad) cholesterol in vitro [2], thereby reducing the risk of developing atherosclerosis [3]. In contrast, another study found that quercetin had mostly prooxidant effects [4]. However, when mixed with other phenolic compounds, significant antioxidant capacity was identified, indicating a synergistic effect. Quercetin may lower blood pressure by exhibiting coronary vasorelaxation (meaning reduction in tension of the blood vessel walls) properties [5-7].

A number of research studies have demonstrated that quercetin is a natural antihistamine and anti-inflammatory [8-10]. Indeed, quercetin is unique in its ability to inhibit TNF-alpha (a cytokine involved in systemic inflammation) gene expression [11]. Quercetin may also function as an antiviral agent [12-13]. A recent study reports that it may boost the immune system and help maintain mental performance.

Studies have shown that quercetin exhibits anticancer effects [14]. A number of phase I clinical trials have been performed with quercetin evaluating pharmacokinetics [15] and adenoma regression [16]. A combination of curcumin and quercetin was evaluated to regress adenomas in patients with familialadenomatous polyposis (FAP), an autosomal-dominant disorder characterized by the development of colorectal adenomas and eventual colorectal cancer. The study found that the combination appeared to decreased polyp number and size from baseline after 6 months of treatment [16].

Epidemiologic data indicates that reduction in colorectal cancer risk associated with the highest 25% of data vs. the lowest 25% was largest for quercetin and catechin [17]. Overall, flavonoids showed strong and linear inverse associations with colorectal cancer risk. Large-scale genomic studies in colon cancer cells suggest that quercetin affects the expression of genes involved in cell cycle control [18-19]. Flavonoids also modulate cell cycle progression in prostate cancer cells [20-21].

A recent review assessing the contribution of dietary flavonoids to the total antioxidant capacity of plasma in humans concluded that the large increase in plasma total antioxidant capacity observed after the consumption of flavonoid-rich foods is not caused by the flavonoids themselves, but is likely the consequence of increased uric acid levels [22]. A potent antioxidant, uric acid is a normal constituent of the body and is the end product of purine (meaning the nucleotides adenine and guanine, two of the four building blocks of RNA and DNA) metabolism. Because the increased plasma concentration of uric acid is much greater than the concentration of flavonoids, the change in uric acid levels is thought to be responsible for the relatively large increase in plasma total antioxidant capacity after consumption of flavonoid-rich foods. Most uric acid produced in the body is excreted by the kidneys. However, it has been proposed that renal uric acid clearance is regulated by an unknown signal that is issued in response to the level of oxidative stress [23], allowing the kidneys to reabsorb the potent antioxidant when needed.

Flavonoids have been shown to induce detoxifying Phase II enzymes [24-25], indicating that they are recognized by the body as foreign compounds. Thus, it has been proposed that the ability of flavonoids to induce detoxifying enzymes may be a major mechanism by which flavonoids protect against mutagens and carcinogens, and act as cancer chemopreventive agents [22].

References

1. Sampson et al. Flavonol and flavone intakes in US health professionals. J Am Diet Assoc. 2002 Oct;102(10):1414-20.
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2. O’Reilly et al. Flavonoids protect against oxidative damage to LDL in vitro: use in selection of a flavonoid rich diet and relevance to LDL oxidation resistance ex vivo? Free Radic Res. 2000 Oct;33(4):419-26.
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3. Negre-Salvayre et al. Quercetin Prevents the Cytotoxicity of Oxidized LDL on Lymphoid Cell Lines. Free Radic Biol Med. 1992;12(2):101-06.
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4. Cirico and Omaye. Additive or synergetic effects of phenolic compounds on human low density lipoprotein oxidation. Food Chem Toxicol. 2006 Apr;44(4):510-6. Epub 2005 Oct 10.
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5. Rendig et al. Effects of red wine, alcohol, and quercetin on coronary resistance and conductance arteries. J Cardiovasc Pharmacol. 2001 Aug;38(2):219-27.
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6. Duarte et al. Effects of chronic quercetin treatment on hepatic oxidative status of spontaneously hypertensive rats. Mol Cell Biochem. 2001 May;221(1-2):155-60.
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7. Flesch et al. Effects of red and white wine on endothelium-dependent vasorelaxation of rat aorta and human coronary arteries. Am J Physiol. 1998 Oct;275(4 Pt 2):H1183-90.
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8. Middleton and Drzewiecki. Flavonoid inhibition of human basophil histamine release stimulated by various agents. Biochem Pharmacol. 1984 Nov 1;33(21):3333-8.
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9. Taguchi et al. Pharmacological studies of Houttuyniae herba: the anti-inflammatory effect of quercitrin. Yakugaku Zasshi. 1993 Apr;113(4):327-33.
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10. Loggia Della et al. Anti-inflammatory Activity of Benzopyrones that are Inhibitors of Cyclo- and Lipo-oxygenase. Pharmacol Res Commun. 1988 Dec;20 Suppl 5:91-4.
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11. Wadsworth et al. Effects of Ginkgo biloba extract (EGb 761) and quercetin on lipopolysaccharide-induced signaling pathways involved in the release of tumor necrosis factor-alpha. Biochem Pharmacol. 2001 Oct 1;62(7):963-74.
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12. Kaul et al. Antiviral effect of flavonoids on human viruses. J Med Virol. 1985 Jan;15(1):71-9.
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13. Lyu et al. Antiherpetic activities of flavonoids against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in vitro. Arch Pharm Res. 2005 Nov;28(11):1293-301.
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14. Morrow et al. Dietary supplementation with the anti-tumour promoter quercetin: its effects on matrix metalloproteinase gene regulation. Mutat Res. 2001 Sep 1;480-481:269-76.
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15. Ferry et al. Phase I clinical trial of the flavonoid quercetin: pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res. 1996 Apr;2(4):659-68.
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16. Cruz-Correa et al. Combination treatment with curcumin and quercetin of adenomas in familial adenomatous polyposis. Clin Gastroenterol Hepatol. 2006 Aug;4(8):1035-8. Epub 2006 Jun 6.
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17. Theodoratou et al. Dietary flavonoids and the risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev. 2007 Apr;16(4):684-93.
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18. van Erk et al. Integrated assessment by multiple gene expression analysis of quercetin bioactivity on anticancer-related mechanisms in colon cancer cells in vitro. Eur J Nutr. 2005 Mar;44(3):143-56. Epub 2004 Apr 30.
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19. Murtaza et al. A preliminary investigation demonstrating the effect of quercetin on the expression of genes related to cell-cycle arrest, apoptosis and xenobiotic metabolism in human CO115 colon-adenocarcinoma cells using DNA microarray. Biotechnol Appl Biochem. 2006 Jul;45(Pt 1):29-36.
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20. Kobayashi et al. Effect of flavonoids on cell cycle progression in prostate cancer cells. Cancer Lett. 2002 Feb 8;176(1):17-23.
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21. Knowles et al. Flavonoids suppress androgen-independent human prostate tumor proliferation. Nutr Cancer. 2000;38(1):116-22.
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22. Lotito and Frei. Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomenon? Free Radic Biol Med. 2006 Dec 15;41(12):1727-46. Epub 2006 Jun 3.
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23. Kirschbaum B. Renal regulation of plasma total antioxidant capacity. Med Hypotheses. 2001 Jun;56(6):625-9.
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24. Kong et al. Induction of xenobiotic enzymes by the MAP kinase pathway and the antioxidant or electrophile response element (ARE/EpRE). Drug Metab Rev. 2001 Aug-Nov;33(3-4):255-71.
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25. Walle and Walle. Induction of human UDP-glucuronosyltransferase UGT1A1 by flavonoids-structural requirements. Drug Metab Dispos. 2002 May;30(5):564-9.
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