The Fifth Taste

November 12th, 2010

Glutamic acid

I was reading an article in the Harvard's HEALTHbeat, one titled "An assault on salt?" and saw a reference to something I knew next to nothing about, umami--"the so-called fifth taste." That lead me to an April, 2010 publication crafted jointly by Harvard's Department of Nutrition and the other CIA, the Culinary Institute of America. That latter publication, "Strategies for cutting back on salt" is something I'll write about another time. In the meantime I decided to look up  more about umami.

I knew about the other four tastes: sweet, sour, salty and bitter, but had only heard the term umami used in context, not what it meant or how long it's been around. Apparently sweet, sour and salty were the original three recognized tastes, then a Greek philospher, Democritus deduced, probably after eating something he didn't like, that some foods are bitter. And things stayed that way, with four basic tastes (some would add spicy and astringent) until the late ninetenth centurywhen the famous French chef Escoffier invented veal stock.

About the same time a Japanese chemist, Kikunae Ikeda, while trying a seawees soup called dashi, sensed there was another taste. He wrote that it was the component that produced the flavor of meat, seaweed and tomatoes. Eventually, in 1908, he isolated a single chemical, a glutamate and later patented MSG. He used the Japanese word for delicious as the name for this new flavor and synthesized it; perhaps adversely affecting the seaweed industry in doing so. I got some of this from an online extract I found from a book titled Bozo Sapiens: why to err is human by Michael and Ellen Kaplan. I really enjoyed the short piece I read and ordered a copy of the book.

Subsequently scientists have found a receptor for umami; these cells don't have nerve synapses to other nerves, but instead secrete a neurotransmitter, ATP, that excites the sensory fibers which convey taste stimuli to the brain.

So like salt and sugars, food chemists can add umami to fats and induce us to want more and more. David Kessler, MD, JD, the former FDA head, is quoted as saying the standard joke in the restaurant chain business is, "When in doubt, throw cheese and bacon on it." Aged cheese has umami and bacon is said to have six different kinds of umami.

We just ate daikon and beets for dinner, both from our CSA, Grant Family Farms; we'll have grapes for dessert. If umami is a road to obesity and staying away from prepared foods the road to weight control, we were on the mark tonight.

Posted in Food Additives, Healthy eating, medically-oriented background info, Obesity, Weight Loss | No Comments »

Dietary therapy in hypertension

November 5th, 2010

High blood pressure, commonly called hypertension by physicians and other medical professionals, is a major problem in the united Sates, Canada and Europe. The numbers are staggering; roughly 30% of the adult population in the US and Canada, over 405 in a survey done in six European countries.

Why is this connected to diet? The incidence figures have gone up over the past twenty years and are most likely closely tied to the increased weight in members of our Western civilization. The consequences of poorly controlled hypertension are dire: strokes, kidney disease, cognitive impairment and heart problems are all more likely in the hypertensive group.

So what came first, the high blood pressure or the increased weight? And what can we do about hypertension?

I read an article in thew June 3rd, 2010 edition of The New England Journal of Medicine (NEJM 362:2102-2112) and then read a host of comments to the editor that were published in October 2010.

The article itself was something I saw mentioned in the "Harvard heart letter." It seemed fairly straight-forward at first. The two authors, Dr. Frank M. Sacks and Hannia Campos have published lots of research articles together; one is a physician and a senior Harvard professor; the other a PhD and a member of the Department of Nutrition at Harvard. This time they focused on hypertension, beginning with a breif case study, then telling us the astounding figures about high blood pressure and it's consequences.

It isn't just a BP of 140 over 90 and above; any blood pressure over 115 is associated with all those medical problems. Worldwide, according to Sacks and Campos, that level of blood pressure, 115 and above, is the most important determinant of the risk of death. In the cardiovascular arena alone it's a major factor in over seven and a half million deaths a year.

So Sacks and Campos looked at three major factors in this problem: eating a healthy diet, cutting body fat and decreasing salt intake. Once again a diet rich in fruits and veggies, along with low-fat dairy, fish, nuts and poultry were their answer. They looked at the DASH study (Dietary Approaches to Stop Hypertension)  and subsequent diet-therpay studies, mostly those with reduced salt being a major component.

Their conclusions were along the lines I had suspected: people with high blood pressure should reduce their salt intake, eat fish, nuts and legumes instead of red meat, consume more fruits and veggies insated of desserts, eat whole grain products, use healthy oils (olive, canola, soybean etc.) and stay away from juices as substitues for whole friuts.

Well, we do that now, I thought. Then I read the letters to the editor. I've already written a post on iodized salt, but another letter wanted Sacks and Campos to mention the benefits of more potassium in the diet, quoting a study that showed a 50% reduction in the need for BP meds with increased dietary potassium. That one I'd leave up to your own doc; I agree with the general premise...as long as you don't have significant kidney disease.

One of the other letters focused on dietary sugar and sugar-sweetened beverages, with a recent, but not randomized and controlled study, saying that cutting sugar intake lowers blood pressure. And one group of docs didn't seem to have the time for all that; they'd just start the patient on BP meds.

Whew! That was a bit of information overload. I think what I carried away was a lesson learned over and over; we're too fat as a civilization and eat the wrong things. That's unhealthy in many ways. It's time to make a change in both spheres.

Posted in Complications of Obesity, Healthy eating, medically-oriented background info, Obesity | No Comments »

I changed topics in mid-post; now it's on iodine

November 3rd, 2010
Salt pig with kosher salt

salt pig with kosher salt

I read an article from the Harvard Heart Letter on beating high blood pressure with food. I wanted to trace back the source data, a study published in The New England Journal of Medicine (NEJM) in June 2010, especially after reading a number of NEJM letters to the editor in an October edition of the journal.

Then I got sidetracked by the iodine aspects of the diet, noting that one of the letters suggested a low salt intake could result in iodine deficiency.

I'm on a no-added-salt diet myself (for high blood pressure). I've been on one for thirty years and my BP is excellent, especially now that I'm lean (151.6 pounds this morning, about what I weighed in 8th grade). So I probably meet the new, lower United States salt intake recommendations, about 1,200 mg of sodium for those of us who are over 50, are African Americans, have hypertension or diabetes; that's 70% of all Americans.

My wife and I frequently use kosher salt when we cook. It contains no iodine, whereas common table salt is iodized. So do I need to switch to using regular salt? My calculations said iodized salt, added at 1/2 tsp. per day would contribute 1190 milligrams of sodium and about 100 micrograms of iodine.

Iodized salt

So where should we get our 150 micrograms a day of iodine (that's the suggested intake for adult men and women, although pregnant women should get 220 micrograms and lactating women 270 micrograms). Those seem to be standard recommendations, although I've read some that vary a little from those figures.

I found a stark reference in another NEJM letter saying iodine deficiency affects more than 1/3 of the world's population, an estimated 2.2 billion people. It is the foremost cause of preventable mental retardation worldwide and even in its mild forms can affect the brain function of  kids.

My wife and I take a senior multivitamin daily; my reading indicates that almost all of those contain 150 micrograms of iodine. But a Boston University Medical Center study of prenatal vitamins, found considerable variance from the listed iodine content in many brands, both OTC and prescription. They suggested pregnant women should take prenatals that contain potassium iodide and urged the drug companies to make sure their products contain enough iodine as potssium iodide, since the amount of iodine in kelp varies considerably.

Then there's the question of dietary iodine. Another study, reported at the April 2010 meeting of the American Association of Clinical Endocrinologists (AACE) was titled "Iodine Content of Fast Foods Contributes Little to Iodine Levels in the Body." That study noted only one fast food chain consistently used iodized salt and that milkshakes and one chain's chicken sandwiches had the most iodine (the primarily latter from constituents other than the chicken).

Over the years since the 1971 National Health and Nutrition Examination Survey (NHANES), to the 2000-2001 NHANES, mean urine iodine levels fell by over 50%. We haven't got a widespread iodine deficiency problem in this country...yet.

The AACE president said, "The way to protect the general public from iodine deficiency is to make sure there is more regular use of multivitamins containing  potassium iodide,"

So with all that as background, and reading that we can tolerate iodine intakes of 1,000 to 1,1000 micrograms a day if we're over age 4, I'm not going to increase my salt intake, but I will continue my varied diet, perhaps eat more seafood, and take my senior vitamin daily.

Posted in Food Additives, Governmental Efforts, medically-oriented background info | 1 Comment »

What's an obese person going to do now?

October 29th, 2010

It's not surprising to me; the drug Qnexa wasn't approved by the FDA for use in weight loss. Why not? After all it's a combination of low doses of two medications that are already approved. Phentermine was first approved by the FDA in 1959 and for weight loss even, although we're talking short-term use in combination with dieting. The other drug, topiramate, was approved in 1996 for epilepsy and more recently for prevention of migraines.

I hadn't heard of Qnexa when I saw the article in the New York Times yesterday, but today I've had time to look at it's pros and cons and put the risks in perspective.

Qnexa is made by a company called Vivus; their stock went up 28.06% today; I guess that was in anticipation of the medication being approved. When I looked at the company's website, they detail the problem of obesity. It's a major factor in diabetes type 2, high blood pressure, cardiovascular disease and stroke. Some have called it the second leading cause of preventable deaths in America.

Over 400 million people worldwide are obese and it's said to be responible for 9.1% of the annual US healthcare spending; that nearly 150 billion dollars.

And Qnexa has gone through Phase 3 trials on over 4,500 patients with three trials. Its results were impressive; one article mentioned a 14.7% (37 pound) weight loss over a 56-week period. Another controlled trial result said 10.6% compared to 1.7% for those who got placebos.

So why not approve the drug? Well, the answer lies in what pre-clinical and clinical trials do and don't show.

Let's start with Phase Zero through III. Those are conducted with human subjects, initially with tiny doses looking at how the body processes the drug and how it works, progressing to is the drug reasonably safe and tolerable studies with small groups closely observed. Then we go to larger groups for activity and safety and finally to randomized controlled multi-center studies.

At that point the dug may be approved, but, there is Phase IV, post marketing surveillance. That is to detect rare or long-term adverse effects in much larger groups of patients.

Several drugs have been withdrawn or subjected to limited use in Phase IV.  There have been some risks shown in early trials; millions of people would potentially take the drug if it were to be approved. Side effects would conceivably be greater and more serious than smaller studies have shown. Lots of lawsuits could result.

So it's not just the name of the drug being hard to pronounce (who came up with Qnexa?).

I suspect the medication may eventually be approved, but time will tell.

Posted in Governmental Efforts, Obesity | No Comments »

Calcium supplements, heart attacks and statistics

October 26th, 2010

After I looked through the November issue of the Harvard Heart Letter I decided to revisit the calcium supplement issue I wrote about several months ago.

Harvard researchers published an article in Annals of Internal Medicine in March of this year. They did a meta-analysis of 17 studies that examined results from calcium supplementation, or vitamin D supplementation, or both, with an emphasis on cardiovascular disease (CVD). A meta-analysis statistically combines the results of several studies that address a shared research hypotheses.

A friend gave me Tom Siegfried's article on statistical significance from the March 27, 2010 edition of Science News. It's title is "Odds are, it's Wrong." What it basically said was our way of deciding if a conclusion is valid is flawed much of the time. We really often need to examine the results of several studies and then see if the studies were actually designed to look at the general population.

We also need to examine at the level of confidence in the results. The standard we most often use is a p value of 0,05; that translates as one possibility in twenty that a result happened by chance. Is that good enough? I'd be very comfortable if the possibility was one in ten thousand, but one in twenty? A later comment in the same journal added casuality, e.g, Although 100% of people who die of stomach cancer drank milk as kids, that doesn't mean milk causes stomach cancer.

So let's go back to the Harvard paper and see how it applies to you and me. The Harvard folk started with 1,484 possible articles and came up with only17 that met their criteria. They wanted to limit their included research projects to prospective controlled studies in adults. They excluded, among others, review articles, letters to the editor, papers where there was no control group, retrospective studies or studies in children.

So far, so good. But when I drilled down into the remaining articles, many were done on dialysis patients, not a general population. Some were projects were only vitamin D was taken, some where just calcium was given, some where both were supplemented.

In terms of the general population they only found one study where just vitamin D was taken by the participants.  Even that one was flawed; it didn't include sufficient information on sun exposure or duration of vitamin D supplementation. It did conclude that postmenopausal women (34,486 of them), not only didn't increase their CVD risk by taking vitamin D; they likely decreased it. Other studies I've ready recently aren't as sure of the cardiovascular benefits of vitamin D.

We really do need vitamin D; it helps us absorb calcium and has other roles including maintaining healthy bones.  The NIH says most healthy adults can safely take vitamin D in doses up to 2,000 IU/day, The Harvard Heart Letter said 800 to 1,000 IU/day.  Sun exposure is the other place we get it, 10 to 15 minutes a day without sunscreen is enough.

The New Zealand article, published in the British Medical Journal in August 2010, said there was a 30% increase in cardiovascular events in people taking calcium supplements. But...the increase in heart attack frequency was one person in 200. Additionally their study excluded anyone also taking vitamin D; that makes less sense to me. The only study reviewed by the Harvard researchers that looked at combined calcium and vitamin D supplements showed no increase in CVD risk.

So I'm still not taking calcium tablets, but I am drinking skim milk (low-fat is another choice if you hate skim milk) and eating some non-fat yogurt daily. And I'm taking vitamin D.

Posted in medically-oriented background info, supplements | 6 Comments »

Healthy School Snacks

October 22nd, 2010

I read an interesting article in the Wall Street Journal yesterday and then perused lots of background information on the Web. The article itself described the challenges of designing a vending machine that could dispense healthier snacks, especially for schools. I had heard that many school districts and even some states were concerned about the obesity epidemic and wanted to quit offering candy bars and sugared sodas. It's not that easy.

One company now offers a vending machine with two major compartments, one for bananas and the other for fresh-cut fruits and veggies. The banana compartment is kept at 57 degrees and the other area at 34 degrees.  They're working on the issue of keeping the fruit, especially the bananas, from getting bruised when it's selected and falls to the delivery area.

The Center for Science in the Public Interest has a website which I found by Googling "Healthy School Snacks." They noted that over a nineteen-year period (1977 to 1996), our kids' calorie consumption from snacks had increased by 120 calories per day. That's roughly equivalent to a ten pound a year weight gain.

They estimated that cost of serving fresh, frozen or canned fruits and veggies would be about 25 cents a day. That's a lot less than their estimates for single-serving bags of potato chips at 69 cents or candy bars at 80 cents.

They gave some suggestions for kid-friendly snacks, including a clever recipe for "Ants on a Log." made by spreading peanut butter on celery sticks and adding raisins.

Then I found the December 2009 Massachusetts Food and Beverage Standards to Promote a Healthier School Environment. They mention the national Action for Healthy Kids (AFHK) initiative (http://www.ActionForHealthyKids.org). That website is well worth looking at, but I concentrated on the Massachusetts plan itself.

A survey done in Massachusetts in 2005 showed over a quarter of students at risk for overweight or already overweight. So state officials and a bevy of advisors were concerned about so-called "competitive foods," which often are high in fats and sugars.  These are sold in vending machines, in school stores or in fundraisers and compete with the well-regulated school lunch and breakfast programs.

Now the state has published a set of well-reasoned guideline for various foods and beverages that might be offered in the schools. The John Stalker Institute website has links for the information.

Take a look, whether you have kids or grandkids in school or not. We need to get behind efforts like this. Adults may be set in their eating habits and reject sound advice; school kids are a captive audience in a sense and their lifetime eating habits can be influenced for their good.

Posted in Governmental Efforts, Healthy eating, our kids and their weight issues | No Comments »

Does sleeping longer help us lose more fat?

October 20th, 2010

I read an intriguing article in the 5 October, 2010 edition of Annals of Internal Medicine, then saw the accompanying editorial. The article was titled "Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity" and was densely scientific, even for me; the editorial was titled "Sleep Well and Stay Slim: Dream or Reality." I decided to start with the commentary and then return to the study itself.

Having read both in detail, I'm comfortable with what's said and what the limitations of the study, done at the University of Chicago and the University of Wisconsin, might be. So let's start there.

The researchers put newspaper ads in local papers to recruit a small number of subjects for a short-term study. They ended up with ten volunteers who didn't smoke, were overweight, but otherwise healthy. The study protocol was detailed ,but basically each of the subjects was on a two-week diet with eight hours or sleep and another similar period with five and a half hours of sleep.

They lost similar amounts of weight in both study periods, but lost more fat during the time they when they dieted and slept well. So sleeping less and dieting resulted in the loss of "fat-free body mass." In other words they lost more fat and less muscle when they slept longer and vice versa when they slept less.

How does this apply to the rest of us? Well there is some data linking a decreased sleep duration with an increase in obesity rates in larger groups. There are rodent studies supporting the theory. There are some larger human studies showing shorter periods of sleep are associated with changes in two hormones that affect appetite and one that showed an association between snacking and less sleep.

So there's a lot of data accumulating that strongly suggests, but does not yet, from a strictly scientific point of view prove, that if we need to lose fat we should diet and also get adequate amounts of sleep.

It makes sense to me. I wouldn't hold my breath waiting for large studies in general populations that confirm this small-scale research. We are a chronically under-slept nation, a number of sources have proclaimed, and I think they're right.

So cutting your hours of sleep while you diet appears to be self-defeating and sleeping a full eight hours, give or take a little, is probably better if you want to lose fat.

Posted in Dieting, medically-oriented background info, Obesity, Weight Loss | 2 Comments »

Walmart weighs in on local produce

October 15th, 2010

Let me start with a disclaimer. I don't have any personal connection with Walmart and I'm aware of the issues that unions, small locally-owned stores and others have had with the corporation. We rarely even set foot in our local Walmart mega-store.  We do have a Sam's Club card and occasionally buy something there, but do most of our non-CSA grocery shopping at another chain entirely.

We've continued to get the majority of our veggies and fruits from our CSA, Grant Family Farms. The organic produce, mostly grown locally, or in the case of apples, regionally has been wonderful. On the other hand, I've been fully aware we're in a minority. There are lots of people who could afford the extra price, but have never tried farmers' markets. Others don't have access to a CSA organization. Many more wouldn't be able to afford the prices even if they wanted to purchase these kinds of groceries. I've seen articles implying governmental support would be needed before this happened.

I doubted that was likely to occur, but wondered if one of the huge grocery chains could start the process of giving making healthier choices available for almost anyone. Now that seems to have started.

A article in the October 14, 2010 edition of the New York Times gave me some measure of optimism in this arena  and some background information that I was unaware of.

Walmart is the world's largest grocer. What it does can influence markets and manufacturers across the  globe. That being said, up until now I hadn't heard much that linked the chain with sustainable agriculture.

Apparently Walmart has been edging toward sustainability goals for five years and set a series of these targets. Now they're turning their sights toward food with a goal of doubling the percentage of produce grown in a given area, actaully the same state a given store is located in.

Still they are only aiming at a 9% local foods goal in the United States. That's a sliver, a nice sliver to be sure, but they're already set much higher targets in Canada (30% by the end of 2013 according to the article).

They're also planning to spend a billion dollars on food from farms much smaller than the enormous ones most of their groceries come from now, cut down on food waste by improving their farm to market shipping patterns, and query their large-scale producers on their use of water, fertilizer and chemicals. There's even a beef-purchase clause in their new plan that is aimed at prevention of further loss of the Amazon forest.

All this will result in more money in the Walmart coffers, but I don't care. They have such incredible clout, on such a wide scale that their new goals will influence agricultural and marketing practices in a major fashion.

It's a good start.

Posted in Corporations and healthy foods, Healthy eating, Healthy food shopping | 1 Comment »

Do your genes determine the size of your jeans?

October 12th, 2010

An article in the the October 10th edition of the journal Nature Genetics looked at the overall body mass index, BMI (a height to weight ratio that's is commonly used to determine if you're lean, overweight or obese), in nearly a quarter of a million people. The researchers involved in these studies found a number of genes, nearly half of which were previously unknown, linked to obesity.

This news doesn't translate well into common English for most of us, even those of us who've been involved in medicine for most of our lives. So let's go a step or two into what is actually going on.

We all know people who seem like they can eat anything and not gain weight; most of us also know others who say they 'eat "like birds" and just can't lose weight.

Many of the genes that have been linked to obesity seem to play a role here, both in terms of how much we eat (appetite regulation) and how we burn calories (energy balance). Does that help us solve who is going to become obese and who isn't?

One obesity guru commenting on the article relating to BMI said asking patients if their parents were obese or not is a more accurate predictor of that person's  person's likelihood of obesity than all the genetic information in these studies.

Another was quoted as saying the information obtained by all this genetic information is little better "than a flip of (a) coin" in predicting someone's risk of becoming obese.

So I think these studies are important, but suggest you don't rush out to get a DNA analysis. We're a long ways from being able to use this information clinically. If someone recommends you get a lab test based on this new data, they're probably going to make money from the test and you're probably not going to find out anything that will help you lose weight.

I've done basic science research, in my case many years ago, and it's critically important to the advancement of knowledge. But it usually doesn't give us direct answers to real-world problems, at least not immediately.

We've got physicians and researchers from other disciplines exploring obesity in detail. Let's applaud their work and support their studies.

But wait for the breaking news before opening your purses and wallets.

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Posted in medically-oriented background info, Obesity | No Comments »

Food Stamps and Obesity

October 7th, 2010

In 2004 the state of Minnesota tried, unsuccessfully, to ban the purchase of "junk food" with food stamps. The request was eventually denied by the USDA on rather strange grounds, that it would "perpetuate the myth" that food-stamp users made bad choices in their grocery shopping.

In the meantime the obesity epidemic in the United States rolled on and now, in an article in today's New York Times, I read that the mayor of New York City has asked the federal government for permission to stop food-stamp recipients from purchasing sugared drinks, sodas, of course, being the major culprit in this case.

I'm waiting for the answer, but my bet is the request is denied, although we already, according to the article, ban the use of food stamps to purchase other items that can be health-detrimental, especially cigarettes and alcoholic beverages. The beverage industry will obviously lobby against the plan.  Even the Center for Science in the Public Interest, a non-profit consumer advocacy group with a focus on nutrition and health, food safety, and alcohol policy, suggested we should instead use educational programs to teach food-stamp recipients about the dangers of sugared drinks.

So is Mayor Blomberg in favor of a Big Brother era? He already has lobbied for a state tax on sugared drinks (unsuccessfully), tightened rules on food advertising and brought the city's schools a tougher policy on which food items they can sell.

Yet almost 40% of the kids in NYC's public schools at the K-8th grade level are overweight or obese, with rates still higher in poorer areas of the city. In those same neighborhoods, studies are said to show sugared beverages are consumed at higher rates than in leaner sections of the metro area. Diabetes is twice as prevalent in poor areas of NYC as it is in more affluent ones.

So where do we stop? I totally agree that we're at a crisis point as a society, one fueled by the food industry. I personally deplore the use of food stamps to purchase sugared beverages as much as I do their being used to procure cigarettes and alcohol-containing drinks.  But who gets to decide what our choices are in a free society?

Tough questions without easy answers.

Posted in Governmental Efforts, Healthy eating, Obesity | 3 Comments »

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