{"id":618,"date":"2010-06-24T11:38:12","date_gmt":"2010-06-24T16:38:12","guid":{"rendered":"http:\/\/www.theteatable.com\/blog\/?p=618"},"modified":"2010-07-14T17:56:48","modified_gmt":"2010-07-14T22:56:48","slug":"so_many_questions_so_few_answers","status":"publish","type":"post","link":"https:\/\/www.theteatable.com\/blog\/so_many_questions_so_few_answers\/ ","title":{"rendered":"So many questions, so few answers!"},"content":{"rendered":"<p>By Lori Bricker, MS, RD<\/p>\n<p>I hate giving people answers they don&#39;t want to hear.&nbsp; As a tea shop owner, I get a lot of questions about the health effects of tea.&nbsp; Since I have a background in nutrition, I have some insight into how complicated the question really is, so my answers are never what people expect.&nbsp; People ask pretty specific questions, but sadly, the specific answers they want are not available yet.<\/p>\n<p>Here are some really good questions that have no known answers:<\/p>\n<p>&nbsp;&nbsp;&nbsp; &bull;&nbsp;&nbsp; &nbsp;Which tea is the most healthful?<br \/>\n\t&nbsp;&nbsp; &nbsp;&bull;&nbsp;&nbsp; &nbsp;Which tea has the least caffeine?<br \/>\n\t&nbsp;&nbsp; &nbsp;&bull;&nbsp;&nbsp; &nbsp;Which tea will cure my [fill in the blank]?<br \/>\n\t&nbsp;&nbsp; &nbsp;&bull;&nbsp;&nbsp; &nbsp;How much tea should I drink in a day?<\/p>\n<p>\tThe science of tea (<em>Camellia sinensis<\/em>)&nbsp; is too young to offer definitive answers to these and other popular questions. But there are a lot of studies being done, and many get written up in the popular press.&nbsp; So many, in fact, that it&#39;s easy to get the impression that tea is a real cure-all.&nbsp; I&#39;d like to talk about why you should be cautious when you read these articles.&nbsp; For this post, I&#39;ll just talk about<strong> cohort studies<\/strong>, and another post will discuss research studies.<\/p>\n<p>Here&#39;s what you need to know about cohort studies:<\/p>\n<ul>\n<li>Cohort studies involve<strong> large numbers of people<\/strong> (not rats!) who have something in common and following them for several years, then studying data collected during that time and to look for trends in the various outcomes.&nbsp; For example, you might look at everyone born before 1950 in a particular town, and follow them for 15 years to determine the rates of a certain disease.&nbsp; You compare the disease trends with the information the participants give you about their diet, health history, medications, etc.<\/li>\n<\/ul>\n<ul>\n<li>Their major strength is that because cohort studies last so long, you can see <strong>real outcomes<\/strong>, like death and disease, that you just don&#39;t get with shorter experiments.<\/li>\n<\/ul>\n<ul>\n<li>The downside is that lots and lots of things happen to the people in your cohort, and you have<strong> less control<\/strong> over it than you would in an experiment.<\/li>\n<\/ul>\n<ul>\n<li>Cohort studies usually use <strong>questionnaires<\/strong> to gather data from the participants.&nbsp; For food and beverage intake data, researchers use a tool called a <strong>food frequency questionnaire<\/strong>, which will ask you potentially hundreds of questions such as, &quot;How often do you eat broccoli in a month and what is the serving size?&quot;&nbsp; By the time you get to the end, your mind is mush.&nbsp; Even in a well-designed food frequency tool, self-reported data is only as good as the participants&#39; memories, patience, and honesty.<\/li>\n<\/ul>\n<ul>\n<li>Cohort studies usually do not show cause and effect.&nbsp; <strong>They show correlations<\/strong>, but they don&#39;t tell if one thing caused the other. To illustrate the point, you might notice a correlation between the occurrence of rain the the appearance of umbrellas.&nbsp; Of course, you would be wrong to conclude that umbrellas caused the rain.<\/li>\n<\/ul>\n<p>Another confounding factor for ANY tea research is that <strong>tea preparation methods<\/strong> can affect how concentrated a brew you are consuming, which in theory should affect the results.&nbsp; I might brew an 8 oz. cup of tea for 8 minutes in boiling water using 3 tsp of leaves.&nbsp; You might drag a tea bag through 8 oz. of tepid water and be done.&nbsp; There could be a huge difference in the amount of tea catechins and other active compounds in these two beverages.<\/p>\n<p>Now, of course, the scientists doing this research know all these things, but sometimes these concerns don&#39;t get addressed in media stories about the research.&nbsp;<\/p>\n<p><strong>When reading an article in the popular press about a research article involving a cohort:<\/strong><\/p>\n<ul>\n<li>&nbsp;Read carefully to see if they use the word, &quot;correlation,&quot; and if so, don&#39;t misread causation into that.<\/li>\n<\/ul>\n<ul>\n<li>Notice details about the cohort itself&#8211; is it all women, all men, all people from one country or another, do they have any diseases, what kind of tea do they drink?<\/li>\n<\/ul>\n<ul>\n<li>What do they say about the kind of questionnaire used?&nbsp; Was it filled out just once at the beginning or multiple times?&nbsp; Do they tell you what they asked regarding tea consumption?<\/li>\n<\/ul>\n<ul>\n<li>Read more than one article about the same research to see if you get a consistent message.<\/li>\n<\/ul>\n<p>Be aware that it takes mounds of research before you can really say something with confidence.&nbsp;In this <a href=\"http:\/\/www.nlm.nih.gov\/medlineplus\/news\/fullstory_100149.html\" target=\"_blank\">online article<\/a> reporting on a heart disease study that involved tea and coffee, Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health, is quoted as saying,<\/p>\n<p><strong>&quot;Based on current evidence, it is very difficult to come up with an optimum amount of coffee or tea for the general population.&quot;&nbsp;<\/strong><\/p>\n<p>After years of research on tea (and coffee), this is where we are?&nbsp; Yes, and we are likely to be here for a while.<br \/>\n\t&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>By Lori Bricker, MS, RD I hate giving people answers they don&#39;t want to hear.&nbsp; As a tea shop owner, I get a lot of questions about the health effects of tea.&nbsp; Since I have a background in nutrition, I have some insight into how complicated the question really is, so my answers are never&#8230; <\/p>\n","protected":false},"author":54,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[16,84],"_links":{"self":[{"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/posts\/618"}],"collection":[{"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/users\/54"}],"replies":[{"embeddable":true,"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/comments?post=618"}],"version-history":[{"count":0,"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/posts\/618\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/media?parent=618"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/categories?post=618"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.theteatable.com\/blog\/wp-json\/wp\/v2\/tags?post=618"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}