Food costs may influence your diet and health

Food costs may influence your diet and health

Do we need to pay more to eat healthy food?

Frontier Voice of Nutrition Remarks (December 26, 2012)

Nalin Siriwardhana, Ph.D., interviewed Dr. Anju Aggarwal, Ph.D., a pioneer scientist with training in nutritional epidemiology.

Is it true that healthy foods are always expensive? Can we be wise and pick healthy foods at a reasonable cost? What are the factors that ultimately decide the cost of healthy foods? These are some of the FAQs when it comes to healthy foods and prices. Reasonable and reliable answers can be found only after in depth systematic analyses based on nutritional and economical parameters. A recent scientific publication from Center for Public Health Nutrition, School of Public Health, University of Washington, Seattle, Washington has answered several nutrient and cost related questions. Nutrition Remarks interviewed Dr. Aggarwal, the leading author of the article and expert in nutritional epidemiology, obesity and chronic diseases.

Question from Nutrition Remarks: Why healthy foods are expensive in terms of nutrient content?

Answer from Dr. Aggarwal: In this context, I define healthy foods as those foods which provide you with nutrients without too many empty calories. In other words, healthy foods are nutrient dense and preferably energy poor foods, which help to achieve the daily nutrient requirements within the calorie needs.

Now what makes a given food cheap or expensive? It all depends on what it contains. Added sugars and fats make food energy dense but relatively cheap. Therefore, processed foods rich in added sugars and fats are not healthy but cheap. By contrast, fruits and vegetables are relatively higher in water and nutrient content but lower in added sugars and fats, which make them healthy but expensive.

Question: According to your study, what are the nutrients that cost more and why are they important?

a) The present study has shown that, based on the dietary patterns of our sample, intake all beneficial nutrients (vitamins and minerals) cost more as compared to food components-to-limit (fats and added sugars).

b) Among beneficial nutrients, some nutrients are relatively more expensive than the other depending on the food source. For example: potassium, magnesium, vitamin C, beta carotene obtained from fruits and vegetables are much more expensive than calcium and vitamin D that are obtained from dairy products and fortified foods.

c) All nutrients are important in one’s diet ranging from fats to vitamins and minerals. However, 2010 Dietary Guidelines have identified four nutrients as nutrients of concern – potassium, fiber, vitamin D and calcium.

d) In the present sample – nutrients like potassium and fiber came from expensive sources whereas calcium and vitamin D came from cheaper sources.

It should be noted that the observed relation between diet costs and dietary intakes are based on dietary patterns followed by Americans. Eating healthy need not cost more if consumers are willing to change their dietary habits and are wise enough to choose healthier less expensive options.

Question: What are the nutrients in less expensive food and how they affect health in short and long term basis?

Answer: You can get all the nutrients in less expensive forms. However, the general rule is that foods with higher proportion of added sugars and fats (such as fried foods, grain based desserts, soft drinks, meats) are less expensive. Higher consumption of such foods, over short term, lead to higher calorie intakes without meeting daily nutrient requirements. Over long term, this may increase the risk of metabolic syndrome, obesity, diabetes and put you at a risk of cardiovascular diseases.

Additionally, if you are not able to meet your daily nutrient requirements, it may lead to various nutritional deficiencies as well over time.

Question: Whatchronic diseases are common for those who consume less expensive food?
Answer:
There are no studies, to my knowledge, that have directly linked diet costs with health outcomes. However, what we already know from existing cross sectional studies is that:

a) Socioeconomic status (SES) is positively associated with diet cost and diet quality,

b) diet cost is positively associated with diet quality, and

c) diet quality is positively associated with health outcomes.

Findings from all these studies combined imply that lower SES tends to consume less expensive diets which tend to be lower in diet quality. Those with poor diet quality are in turn associated with higher risk of various chronic diseases, ranging from metabolic syndrome to cardiovascular diseases to nutritional deficiencies.

Question: How you suggest improving the food quality in low SES groups?

Answer: That is a big question that everyone is trying to find an answer to! We need to take a multi-factorial approaches such as:

a) Promote nutrition education to motivate and help consumers make healthier food choices and shop wisely: Existing studies have shown that, based on current dietary patterns in the US, healthier diets do cost more. However, eating healthy need not be expensive as long as people know what to buy and are willing to make healthier food choices. Although lower SES groups may not be able to accommodate most expensive forms of fruits and vegetables in their diet; however, there are relatively cheaper sources of the same which can very well be adopted in the diet.

b) Dietary Guidelines need to take diet cost into account: Current dietary guidelines (DGAC 2010) promote intake of all the nutrients, particularly the four nutrients of concern – potassium, fiber, calcium and vitamin D. However, based on current dietary patterns of Americans, following dietary guidelines is likely to entail higher diet costs for the consumers. DGAC needs to identify and promote inexpensive forms of variousnutrients, to make these guidelines practical and feasible for the consumers.

c) Ensuring physical access to healthy foods: Recent research has proposed that not all Americans have physical access to supermarkets or healthy foods, which may be one of the reasons for their poor diet quality. Thus, improving access to supermarkets has become the focus of recent public health policy and initiatives. While this may be one of the pre-requisites to improve diets of the population; it may not be the solution until the above strategies are adopted simultaneously.

Question: Are there any regional or cultural differences that further worsen food quality in low SES groups?

Answer: I am sure there is a huge regional and cultural variation. It would be very interesting to see how the observed associations of diet cost, diet quality and health among lower SES groups in developed countries differ from developing countries. My long term goal is to extend out my current research to developing countries.

Question: Whatare the important information that we did not discuss here?

Answer: We have already talked about the potential role of diet costs in influencing diets and health, particularly among lower socioeconomic groups. However, I would like to re-emphasize that one’s decision about what to buy, where to buy and what to eat is influenced by interplay of many other factors such as taste, convenience, physical access to food, culture and food preferences, and food-related attitudes. Further research is needed to fully understand the role of these factors across socioeconomic groups in determining dietary intakes and health.

This news release was a follow-up based on the following original scientific article published by Dr. Aggarwal.

Aggarwal et al Nutrient Intakes Linked to Better Health Outcomes Are Associated with Higher Diet Costs in the US PLOS one -May 25, 2012

Additional general background information was acquired from PubMed and NIH sources.

Dr. Aggarwal would like to acknowledge that the funding was provided by National Institute of Health – NIDDK R01DK076608. She would also like to acknowledge the Principal Investigator of the study, Dr. Adam Drewnowski. He is the Director of Center for Public Health Nutrition at the University of Washington.

Dr. Anju Aggarwal, Ph.D., Dr. Aggarwal’s research interests are in the area of nutritional epidemiology, obesity and chronic diseases. In particular, she is interested in better understanding of the pathways that may explain socioeconomic disparities in diets and health. Her current research is focusing on examining the role of four A’s – access to food environment, availability, affordability and attitudes in determining diet quality and obesity across socioeconomic strata. She is also interested in examining culture-based beliefs and behaviors in relation to diets and health, both in developed and developing countries.

More about Dr. Aggarwal

http://depts.washington.edu/epidem/fac/facBio.shtml?Aggarwal_Anju

Written by NalinSiriwardhana, PhD.

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Can the Mediterranean diet reduce colon cancer risk?

Can the Mediterranean diet reduce colon cancer risk?

Frontier Voice of Nutrition Remarks (December 20, 2011)

Nalin Siriwardhana, PhD, interviewed Prof. Zora Djuric from the Departments of Family Medicine and Environmental Health Sciences at the University of Michigan

Diet and cancer expert, Prof. Zora Djuric, highlighted that the Mediterranean diet contains promising active compounds to reduce colon cancer risk. According to her most recent publication in the Nutrition Review journal, the Mediterranean diet contains not only plenty of beneficial components such as fruits, vegetables, herbs, fish, and olive oil but also low levels of harmful fats and red meat.

Unhealthy inflammation associated with unhealthy dietary patterns can increase colon cancer risk. Further, she added that the colon cancer risk is high for those who live in parts of the industrialized world such as the United States. Although in Greece, where people routinely consume a Mediterranean diet, the colon cancer rate is very low. However, the rate has increased among the people who migrated from Greece to industrialized countries. Using validated scientific information, Prof. Djuric clearly explained that the Mediterranean diet has multiple beneficial effects to lower colon cancer risk and improve colon health.

Nutrition Remarks interviewed Prof. Djuric due to the importance of her information for public health. A simplified version of the conversation is as follows:

Question from Nutrition Remarks: What are the major differences between a Mediterranean diet and a typical American or Western diet?

Answer from Dr. Djuric: The Mediterranean diet has higher amounts of plant-based foods like fruits, vegetables, herbs, cereals, legumes, and olive oil compared to the American or Western diet. Also, a Mediterranean diet has a higher variety of plant-based nutrients than the American or Western diet. The Mediterranean diet also includes plentiful fish while American and Western diets contain more red meat/meat products. Another significant difference is that the Mediterranean diet contains beneficial olive oil, but the American and Western diets contain high levels of other fats such as trans fats from processed foods and saturated fats from meat.

Question: Why is the variety of fruits and vegetable important?

Answer: Different fruits, vegetables, and herbs contain different beneficial compounds such as anti-oxidants, vitamins, minerals, and nutrients. Importantly, different fruits, vegetables, and herbs also contain different types and amounts of beneficial phytochemicals such as resveratrol, catechins, flavonoids, carotenoids, etc. Therefore, the preventive benefits are increased with increased varieties versus using a single or few varieties in the diet.

Question: What is the link between colon cancer and inflammation?

Answer: There are multiple links between inflammation and cancer. Specifically, one of the harmful compounds produced by omega 6 fats is associated with inflammation in the colon. It is called prostaglandin E2 (PGE2), and this metabolite of omega-6 fats is well-known to be increased in colon cancer. Omega-3 fats, such as those found in fish, cannot be metabolized to form harmful PGE2. Instead omega-3 makes PGE3 that is less inflammatory.

Question: Howdoes the Mediterranean diet reduce inflammation?

Answer: The Mediterranean diet can reduce inflammation in several ways.

Fish contain higher levels of beneficial omega-3 fats called eicosapentaenoic acid (EPA) and docashexanoic acid (DHA). EPA plays a major role by reducing PGE2 production, thus greatly reducing inflammation.

Several anti-inflammatory phytochemicals such as resveratrol, catechins, flavonoids, carotenoids, etc. have multiple benefits including PGE2-reducing effects.

Components of a Mediterranean diet have activities similar to the popular multifunctional drug aspirin. Like aspirin, compounds in the Mediterranean diet can also reduce PGE2 and the enzymes that produce PGE2, called cyclooxygenase (COX), to reduce inflammation. Dr. Rothwell from the University of Oxford showed that long-term aspirin use can reduce colon cancer risk.

Original work: Zora Djuric , The Mediterranean diet: Effects on proteins that mediate fatty acid metabolism in the colon. Nutrition ReviewsVol. 69, No. 12, 730-744 (2012).

Written by Nalin Siriwardhana, PhD

Zora Djuric, PhD, is a Research Professor in the Departments of Family Medicine and Environmental Health Sciences (Nutrition program) at the University of Michigan. She is also a member of the University of Michigan Comprehensive Cancer Center. Dr. Djuric has expertise with research on cancer risk biomarkers related to different dietary patterns, focusing mainly on clinical studies. Her studies have typically included individuals at increased cancer risk. Her current focus is on colon cancer prevention using a Mediterranean exchange list diet.

More about Prof. Zora Djuric and work

http://sitemaker.umich.edu/fm-zdjuric/research

http://www.med.umich.edu/opm/newspage/2007/meddiet.htm

http://www.med.umich.edu/cancer/news/med_diet10.shtml

Copyright © 2011 Nutrition Remarks. All rights reserved