by Marion Nestle

Currently browsing posts about: Vitamins

Nov 14 2013

The dismal news about supplements. Why bother?

It’s not a good time for the makers of herbal and vitamin supplements.  The better the research, the fewer benefits it shows.

Herbal supplements

DNA testing is demonstrating what many of us have long suspected: herbal supplements are not necessarily what they say they are.

As the New York Times reports, a recent study shows that many products purporting to be herbal supplements, actually contain rice, corn, or wheat (gluten-sensitive folks beware):

I would feel sorry for supplement manufacturers, if they hadn’t brought this on themselves.

First, they lobbied to get Congress to pass the Dietary Supplement Health and Education Act of 1994 (DSHEA).  This lets them advertise the benefits of supplements without much in the way of scientific substantiation.  It also excused the FDA from doing much regulation.

But DSHEA also required research.  Oops.   Although the point of asking for research was to demonstrate the benefits of supplements, things haven’t worked out that way.  Most of the research shows no benefit and, sometimes, harm.

And investigations like this one show what many have long suspected.  Without federal oversight, some supplement manufacturers will do whatever they can get away with.

Fortunately, rice substituted for St. John’s Wort is harmless and hardly matters, since St. John’s Wort doesn’t seem to do much anyway.

Vitamin Supplements

The latest review of the benefits—or lack thereof—of vitamin supplements for prevention of heart disease or cancer comes to cautious conclusions.

Limited evidence supports any benefit from vitamin and mineral supplementation for the prevention of cancer or CVD. Two trials found a small, borderline-significant benefit from multivitamin supplements on cancer in men only and no effect on CVD.

Borderline significance?  Not impressive.

The Natural Products Association, which represents supplement makers, issued a response:

  • Multivitamin supplements should not be expected, without the combination of a healthy lifestyle, to prevent chronic disease.
  • Dietary supplements are used by more than 150 million Americans on a daily basis. Research has shown that when taken in combination with other healthy lifestyle practices, such as consuming a wholesome diet and exercising regularly, people can benefit from dietary supplements.

Translation: if you consume a wholesome diet and exercise regularly, you really don’t need supplements.  And if you are not doing those things, supplements won’t do any good.

As for the 150 million Americans who take supplements: the ones I know tell me that they don’t care what the science says; they feel better when they take the pills.

Let’s hear it for placebo effects!

Aug 26 2013

FDA study: Do added nutrients sell products? (Of course they do)

The FDA has announced that it will be studying the effects of nutrient-content claims on consumers attitudes about food products.

FDA does not encourage the addition of nutrients to certain food products (including sugars or snack foods such as [cookies] candies, and carbonated beverages). FDA is interested in studying whether fortification of these foods could cause consumers to believe that substituting fortified snack foods for more nutritious foods would ensure a nutritionally sound diet.

Here’s one of my favorite examples of what the FDA is talking about.

New Picture

 

I’m guessing the FDA’s new research project is a response to increasing pressure from food companies to be allowed to add nutrients to cookies, candies, and soft drinks.

Food marketers know perfectly well that nutrients sell food products.  The whole point of doing so is to be able to make nutrient-content claims on package labels.

The FDA has never been happy about the practice of adding nutrients to junk foods just to make them seem healthy.   Its guidance includes what is commonly known as the “jelly bean rule.”   You may not add nutrients to jelly beans to make them eligible to be used in school lunches.

But this does not stop food manufacturers—especially soft drink manufacturers—from trying.  Hence: Vitamin Water (now owned by Coca-Cola).

Plenty of research demonstrates that nutrients sell food products.  Any health or health-like claim on a food product—vitamins added, no trans fats, organic—makes people believe that the product has fewer calories and is a health food.

As I keep saying, added vitamins are about marketing, not health.

Jan 30 2013

Cookies are health foods!

What is there to say about Girl Scout cookies.  Everybody loves them (or is forced to).

But now, if you worried that promoting cookies maybe wasn’t the best public health strategy, ABC Bakers, the company that makes them, has solved your problem.

Girl Scout cookies are now health foods.  How?

NutriFusion.

Translation: “major vitamins.”

Mango Creme cookie

As the company explains, NutriFusion is delicious made nutritious.

These crunchy vanilla and coconut cookies with a mango-flavored crème filling have all the nutrient benefits of eating cranberries, pomegranates, oranges, grapes, and strawberries.

As I keep saying, you can’t make this stuff up.

Jan 28 2013

Some views on vitamin supplements, mostly from their makers

NutraIngredients.com reports frequently on current research and opinion on dietary supplements.  Lots of people take these products and swear by them, but proving that they do much good is another matter.  It has been hard to find evidence that they make healthy people—those who take them most often—any healthier.

Here are some recent NutraIngredient reports on this topic, largely reflecting views of the supplement industry.

May 1 2012

Nutritionist’s Notebook: Estimating nutrient requirements

My Tuesday question from student readers of NYU’s Washington Square News:

Question: How can we determine our individual caloric, vitamin, carbohydrates, fats and other intake requirements per day based on our own individual weight, height and lifestyle?

Answer: You can’t. You will have to be satisfied with estimates based on measurements performed years ago on a small number of study subjects.

We require calories and nutrients — 40 to 50 separate substances that our bodies cannot make, we must get from food. Because these interact, studying one at a time gives results that may well be misleading.

Early nutrition scientists got “volunteers”— in quotes because study subjects often were prisoners — to consume diets depleted in vitamin C, for example. They waited until the subjects began to develop scurvy, a sign of vitamin C deficiency. Then they fed the subjects the smallest amount of vitamin C that would eliminate symptoms.

Because individuals vary in nutrient requirements, scientists used this data to estimate the range of nutrient intake that would meet the needs of practically everyone.

The Institute of Medicine compiles such data into Dietary Reference Intakes and presents the estimates by sex and age group. You can look up your requirements in DRI tables. DRIs account for the needs of 98 percent of the population. If your requirements are average, you will need less.

Few American adults show signs of nutrient deficiencies, but if you are worried about your own intake of nutrients, you can take a multivitamin supplement. Note, however, that we have no evidence to show supplements make healthy people healthier.

You can estimate calories by looking up everything you eat or drink in food composition tables, but it is easier to weigh yourself at regular intervals. If you are gaining weight, you are eating too many calories for your activity level.

With nutrition, it’s best to get comfortable with estimates and probabilities.

Fortunately, eating a healthy diet takes care of nutrients without your having to give them a thought. Eat your veggies!

A version of this article appeared in the Tuesday, May 1 print edition. Marion Nestle is a contributing columnist. Email her questions at dining@nyunews.com.

Nov 30 2010

IOM: vitamin D, calcium supplements not needed!

In a report likely to send shock waves through the dietary supplement industry, the Institute of Medicine (IOM) released new Dietary Reference Intakes for vitamin D and calcium.   The report summary says Americans are getting all the vitamin D and calcium we need, and we do not need more.

The committee emphasizes that, with a few exceptions, all North Americans are receiving enough calcium and vitamin D. Higher levels have not been shown to confer greater benefits, and in fact, they have been linked to other health problems, challenging the concept that “more is better.

In an account of the report in today’s New York Times, Gina Kolata writes that the committee was puzzled about how vitamin D became the hot nutrient of the year.  Sales rose 82% from 2008 to 2009.

Some of this surely had to do with testing.  A method for testing existed, so doctors used it.  The test, however, looked at an intermediate in vitamin D synthesis—not at the vitamin itself.  And the test did not have a standard until recently.

And groups like the Vitamin D Council promote much higher intakes of vitamin D supplements.  According to the Council:

Current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease, and more.

In my San Francisco Chronicle column on this topic a year or so ago, I pointed out that “vitamin” D is not really a vitamin.  It is a hormone. This means that vitamin D supplements are a form of hormone replacement therapy—not necessarily a good idea.

Are vitamin D supplements needed?  Not if you expose your skin to sunlight for a few minutes a day, even in winter.

Nov 18 2010

Soft drinks as a solution to childhood malnutrition? I don’t think so.

Here is another one you can’t make up.  An article in Pediatrics, entitled “Malnutrition and the role of the soft drink industry in improving child health in sub-Saharan Africa,” advocates for fortifying soft drinks with micronutrients (vitamins and minerals).

Oddly, it does this after explaining how consumption of soft drinks actually”perpetuates problems of undernutrition in children, pregnant women, and other vulnerable populations in the developing world.”   Why?  Because in “sub-Saharan Africa, for example, distribution of soft drinks and other beverages produced by soft drink companies is extensive, and consumption is high given the extensive poverty in this part of the world.”

The authors justifiably complain about how little attention has been paid to the ways in which soft drink companies perpetuate malnutrition.

But instead of suggesting public health measures to counter the well documented effects of soft drinks on rising rates of obesity or on tooth decay rates among children in developing countries, the authors want soft drink companies to add vitamins and minerals to the drinks.

The Bill Gates foundation recently partnered with Coca-Cola in Uganda to increase production and distribution of mango and passion fruit juice as a way to stimulate production of local mango and passion fruit juice and meet Coca-Cola’s demand for
increased fruit to stimulate sales; however, such a partnership should also ideally involve micronutrient fortification, because Coca-Cola estimates that this partnership will extend sales in coming years. The World Economic Forum recommends fortification of food and beverages by private companies as an approach to reduce malnutrition, to
boost a productive workforce, and to stimulate the global economy.

Translation: Coca-Cola’s economy.

Fortunately, colleagues in Brazil have written a letter in response: “Can the soft drink industry prevent child malnutrition?  No way.”

What the impoverished populations of Africa, Asia and Latin America need, are the means with which to lead a decent life. These include secure local food systems and supplies, access to safe water and adequate sanitation, decently resourced primary health care services, ability to produce and prepare meals from immediate and local resources, universal primary education, and empowered mothers and other caretakers. Substantial reduction of child undernutrition can be achieved in a relatively short period of time with improved income distribution, population and community self-determination, and public investments in public goods such as education, health, social security, water supplies and sanitation.

What they do not need is more Coca-Cola.

Or, for that matter, Pepsi Cola, which tried the same ploy earlier this year (see previous post).

Sales of Coke and Pepsi are declining in the United States.  What better way to protect sales than to foist these products on the poor populations of emerging economies.

We need to be exporting health, self-determination, and democracy, not sugary drinks.

For shame!

Mar 13 2010

The fate of vitamins in vegetables, stored and cooked

Nothing about nutrition is simple.

I was intrigued by the Observatory column in the New York Times last week.  USDA researchers showed that supermarket spinach stored under continuous fluorescent light retained more vitamins than spinach stored in the dark for at least 9 days.  Their hypothesis: the light promotes continued photosynthesis and protects against degradation.

I was curious to know whether they measured vitamin C.  I checked the article in the Journal of Agricultural and Food Chemistry (February 2010, DOI: 10.1021/jf903596v).  Indeed they did.  This seems odd because this vitamin is well known to be degraded by light.  That is why orange juice is usually stored in opaque containers.  One explanation might be that orange juice is stored a lot longer than 9 days.

Cooking also destroys vitamin C.  While I was looking for that article I came across this one, which describes experiments looking at the effects of common cooking practices (boiling, microwaving, and steaming) on beneficial antioxidants and phytochemicals in Brussels sprouts.

Steaming increased phytochemicals in fresh and frozen sprouts.  Boiling did too, but only in the fresh vegetables.  Cooking reduced phytochemical content in frozen samples.  Microwaving was the best cooking method for retaining color and vitamin activity.  As expected, all cooking methods destroyed vitamin C.

So what to make of this?  Eat a mixture of cooked and uncooked vegetables and the vitamins will take care of themselves.  If you do cook, steaming is great and microwaving is better for preserving vitamin activity.  For vitamin C, raw wins every time.

Happy weekend!