Eating a daily handful of nuts—about one ounce or three tablespoons—could reduce your risk of dying from the

most common causes of death. Results from the largest study of its kind, follow-ing nearly 119,000 men and women for up to 24 years, show that regular consumers of any type of nuts were less likely to die from heart disease, cancer and lung disease or from all causes than non-nut eaters. As frequency of nut consumption went up, mortality risk dropped.

“This is a good study,” comments Jeffrey Blumberg, PhD, director of Tufts’ HNRCA Antioxidants Research Laboratory and co-author of a recent review of the evidence for nuts’ health benefits (see the May 2012 newsletter Special Supplement). “As with most good research, it is an incremental and logical next step in the continuing investiga-tion of the health benefits of this food group.”

CRACKING NUTS’ BENEFITS: Why are nuts good for you? “Nuts are rich in healthy un-saturated fats, protein and fiber and vitamin E and low in carbohydrates,” Blumberg explains. “The total antioxidant capacity of a serving of nuts is comparable to one of broccoli or tomatoes.” Previous studies have linked nut consump-tion to improvements in cholesterol, blood pressure and blood-sugar control, among other benefits that might underlie the mortal-ity findings.

Although nuts are also high in calories, ranging from 160 to 204 calories per ounce, the new research found that more-frequent nut eaters actually tend-ed to be leaner. “There’s a general percep-

tion that if you eat more nuts you’re going to get fat,” commented lead researcher Ying Bao, MD, ScD, of Brigham and Women’s Hospital in Boston. “Our results show the

opposite.”Other studies have

reported similar results. Says Blumberg, “Some of the fat in nuts is not actually digested and so does not contribute to actual calorie intake as much as would be calculated from the con-tent—and, thus, the lack of

association with nut consumption and over-weight/obesity; indeed, there is a slight inverse correlation between the two.” Also, several

Daily Handful of Nuts Linked to Lower Mortality RiskStudy finds nuts can be a healthful contributor to your diet.

2 NEWSBITES: Food safety, 2014 trends, trans fats and more.

3 Risk from too much phosphorus.

4 SPECIAL REPORT: Are you wasting your money on multivitamins?

6 New doubts about D beyond bones.

7 Exercise combats chronic conditions.

8 ASK TUFTS EXPERTS: Yerba maté tea, alcohol and bones, and more.

4-PAGE SPECIAL SUPPLEMENT: The truth about the war on wheat.

INSIDE

NUTS continued on page 3

“Natural” Labeling for GMOs Puts FDA in Middle

The US Food and Drug Administration (FDA)

finds itself in the middle of the tussle over whether foods labeled as “natural” can contain genetically modified (GMO) ingredients. The Grocery Manufacturers Association is petitioning the agency to specifically authorize “natu-ral” labeling on GMO prod-ucts, such as those containing bioengineered corn, soy, canola or sugar. The trade associa-tion cited the proliferation of lawsuits challenging “natural” labeling, with 65 pending class-action cases across the country. At the same time, three federal judges presiding over such cases have asked the FDA to rule on whether GMO ingredients belong in “natural” foods.

Current FDA regula-tions state only that “natural” products cannot contain added color, artificial flavors or syn-

NEWSBITES

NEWSBITES continued on page 2

MARCH 2014 ■ VOL. 32, NO.1 ■ $5

To add a daily handful of nuts to your diet, start by simply reaching for your favorite

nuts instead of snacking on chips, sweets or other less-nutritious choices. Other ways to eat more nuts include:

➧ Top green salads with nuts instead of cheese or meats.

➧ Sprinkle on low-fat yogurt, ice cream or frozen yogurt.

➧ Add to steamed vegetables or vegeta-ble stir-fries.

➧ Use ground nuts to thicken sauces.➧ Substitute ground nuts for some of the

flour in baked goods.Because of their high fat content, nuts

can quickly go bad if not stored properly. Keep in an airtight container in your refrig-erator or a sealed plastic bag in your freezer; don’t store near foods whose odors might be absorbed by the nuts.

TAKE CHARGE!

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NEWSBITES

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Editor Irwin H. Rosenberg, MD

University ProfessorManaging Editor

David A. FryxellRecipe Editor

Patsy Jamieson

FRIEDMAN SCHOOL Robin B. Kanarek, PhD, Professor, Nutrition and Behavior; Interim Dean

Mark Krumm, Director of Communications

EDITORIAL ADVISORY BOARD Jeffrey B. Blumberg, PhD,

Professor; Senior Scientist and Director, Antioxidants Research Laboratory

Bess Dawson-Hughes, MD, Professor of Medicine, Endocrinology; Senior Scientist and Director, Bone Metabolism Laboratory

Alice H. Lichtenstein, DSc, Senior Scientist and Director, Cardiovascular Nutrition Laboratory;

Stanley N. Gershoff Professor of Nutrition Joel B. Mason, MD,

Professor, Nutrition and Medicine; Senior Scientist and Director, Vitamins and Carcinogenesis Laboratory

Miriam E. Nelson, PhD, ProfessorHelen M. Rasmussen, PhD, RD, Instructor; Senior

Research Dietitian, Metabolic Research UnitSusan B. Roberts, PhD, Professor, Nutrition and

Psychiatry; Senior Scientist and Director, Energy Metabolism Laboratory

Robert M. Russell, MD, Emeritus Professor, Nutrition and Medicine

Jean Mayer USDA Human Nutrition Research Center on Aging

The Friedman School gratefully acknowledges ongoing support for research and education from

John Hancock Financial Services, Inc.

Tufts University Health & Nutrition Letter (ISSN 1526-0143) is published monthly for $36 per year

by Tufts University. Managed by Belvoir Media Group, LLC. © 2014 Tufts University.

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thetic substances, and that the labeling term must not be used in a “misleading” way. The Grocery Manufacturers Association argued, “There is no material difference between foods derived from biotechnology and their traditional counterparts…. There is nothing synthetic or artificial about foods derived from biotechnology as that term has been applied by the agency.”

The FDA has not responded to the peti-tion, but told the judges it would “respectful-ly decline” their request for administrative guidance. (For more on the pros and cons of GMOs, see our No-vember Special Report.)

Food Companies Exceed Calorie-Cutting Goal

Since 2007, 16 of the na-tion’s leading food and

beverage companies have cut 6.4 trillion calories out of the American diet—equivalent to 78 daily calories per person. That’s the conclusion of a report by the Robert Wood Johnson Foundation, which worked with the companies to help combat childhood obesity. The firms had originally pledged to slash 1 trillion calories by 2010, and a foundation spokesman said he was encouraged by the progress beyond that goal: “Now we hope that others see the suc-cess these companies have had and make the same commitment.” Participating producers account for more than a third of all packaged food and beverage sales, by total calories.

It wasn’t clear, however, how much of the calorie reduction was due to consum-ers simply buying less during the recession, rather than manufacturers’ reformulation of their products.

Fessing Up on Unsafe Food Handling

When it comes to safe food handling for parties and other gatherings, Ameri-

cans’ motto seems to be: Do as I say, not as I do. A new Kitchen Pet Peeve Survey by NSF International finds a double standard in attitudes about food for a crowd, with 82% admitting to food-safety mistakes when preparing for others but 96% offended when others make the same slips. We’re turned off

by others’ “double dipping” chips, serving food that’s fallen on the floor, forgetting to wash hands and leaving perishables unre-frigerated—even though we do all those things ourselves. And such errors have con-sequences: 43% said they’d gotten sick after a dinner party or other food gathering away from home.

Dietitians Predict Nutrition Trends

Look for more worries about wheat and increasing interest in ancient grains,

kale, coconut oil and chia seeds as 2014 goes on. That’s the forecast from a

survey of more than 500 reg-istered dietitians conducted

by Today’s Dietitian and Pollock Communications. The dietitians also pre-dicted a continuing decline in low-fat dieting, while “eco-friendly” eating will

be on the rise. Overall, the experts expect a growing interest in health information, with consumers looking to blogs and TV doctors as well as dietitians; “supermarket dietitian” is the fastest-growing job classification in grocery stores. (For more on wheat, see this issue’s Special Report. We covered chia seeds and kale in the March and July 2013 newslet-ters, respectively.)

FDA Extends Trans Fat Comment Deadline

Look for the next step in the FDA’s proposed crackdown on trans fats to

come this spring, as the agency extended its comment period on the rule to March 8. Late last year, the FDA proposed revoking the fats’ status as “generally recognized as safe” (GRAS), which would lead to a phase-out of trans fats in most food products. Food com-panies had asked for an extension beyond the original Jan. 7 comment deadline, citing the complexity of the issue, and are expected to push for alternatives to a ban such as enhanced labeling or a maximum threshold. Trans fats, typically in the form of partially hydrogenated vegetable oils, are convenient for food packagers and restaurants but have been linked to heart disease; the fats increase unhealthy LDL cholesterol while lowering good HDL cholesterol levels.

continued from page 1

Kale: still on the menu in 2014. (Image © Thinkstock)

3MARCH 2014

Phosphorus, a mineral found in foods such as meat and milk, is important for forming bones and

teeth, making proteins for healthy cells, and transporting cellular energy. But too much of a good thing can be harmful among people with kidney disease, and a new study suggests excess phosphorus consumption is associated with increased mortality risk, even in people with nor-mal kidney function.

The danger of too much dietary phosphorus may be on the rise because of the growing popularity of phosphorus-based additives in packaged foods. These phosphate compounds are employed as preservatives, anti-caking agents, stabilizers, leavening agents and acidi-fiers. A second study (see box) recently reported that nearly half of the best-selling grocery products in the United States contain phosphorus additives. In an analysis of dietary data, more than one-third of American adults were found to consume in excess of 1,400 milligrams of phosphorus daily—double the RDA and apparently enough to increase their mortality risk.

“When intake of phosphorus chroni-cally exceeds nutrient needs, there is a disruption in the endocrine regula-tion of phosphorus balance,” explains Madhumathi Rao, MD, an assistant

professor at Tufts University School of Medicine. “A ‘trade-off’ takes place, with the elevation of hormones that force the excretion of phosphorus by the kidney, but at the expense of the effects of these hormones on tissues. The con-sequences are calcium deposition in the blood vessels, enlargement of the heart, bone loss and progression of kidney disease. While these consequences are readily apparent in individuals with kidney disease often in the setting of abnormally elevated serum phosphorus, they are also seen in healthy individu-als without an overt elevation of serum phosphorus.”

ADDITIVES ADD UP: The latest study, pub-lished in the American Journal of Clinical Nutrition, looked at data on 9,686 healthy US adults, ages 20 to 80, who participated in a national nutrition survey (NHANES III). Over a followup period of 12 to 18 years, those whose diets meant they consumed more than 1,400 milligrams of phosphorus daily were at increased risk of dying from any cause.

“Because of the prevalence of high phosphorus intake in healthy adults and the widespread use of inorganic phosphorus additives in processed food, our findings may have… public health implications,” concluded Alex R. Chang,

studies indicate that nuts are particularly satiating, so people tend to eat less during a subsequent meal or snack.

Nonetheless, it’s still a good idea to substitute nuts for less-healthy foods, such as chips and cookies or salad top-pings. Nuts can also stand in for meat and even help thicken sauces. (See box.)

ALL TYPES OF NUTS: The new research, published in the New England Journal of Medicine, combined data from two large observational studies—the Nurses’ Health Study of women and the Health

Professionals Follow-Up Study of men. During the follow-up period of 20 to 24 years, 27,429 participants died. Those who ate nuts at least daily were 20% less likely to die of all causes than those eat-ing no nuts. The reduced risk was most apparent for deaths from heart disease (29%), followed by deaths from cancer and lung disease.

Participants ate all types of nuts, including peanuts, which are legumes and not true tree nuts but have a similar nutrient profile. An analysis found no significant difference in mortality benefit between types of nuts.

The study was supported by the

National Institutes of Health and the International Tree Nut Council Nutri-tion Research and Education Founda-tion (which had no role in designing the study or reporting the results).

As an observational study, the find-ings can’t prove cause and effect. But Dr. Bao said she was very confident the observations reflect a true benefit from nut consumption, adding, “We did so many analyses, very sophisticated ones” to eliminate other possible explanations for nut eaters’ reduced mortality risk. Possible confounding factors the study eliminated included smoking status, exercise habits and diabetes.

NUTS continued from page 1

Does Your Diet Deliver Too Much Phosphorus?One-third of Americans may be getting more than the recommended amount.

MD, of Geisinger Health System, and colleagues.

Some experts believe that even those high levels of phosphorus consumption are understated, because it’s difficult for cal-culations to account for all food additives. Food manufacturers do not always supply complete information on such additives. On food labels, these appear as ingredients with the word phosphate or ending in –phosphate, as well as phosphoric acid.

“People are not generally aware of the importance of avoiding phosphorus over-load or of the need to inspect food labels more carefully,” says Tufts’ Dr. Rao. “Poor quality foods and fast foods, often con-sumed by individuals with lower socioeco-nomic status, have the highest phosphorus content from food additives.”

If you want to avoid consuming too much phosphorus, it pays to cook more

of your meals from scratch rather than relying on packaged foods. According to a study in the Journal of Renal Nutrition, 44% of the most popular grocery items in the US contain phosphorus additives. The products most likely to contain such addi-tives were:

➧ Prepared frozen foods➧ Dry food mixes➧ Packaged meats➧ Bread and baked goods➧ Soups

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SPECIALREPORT

You’ve seen the TV commercials. A daily multivitamin “supports” heart and breast health, boosts your im-

mune system and protects your eyes. A smiling couple feel pretty darned smart after learning that a study showing multi-vitamins reduce cancer risk used the very brand she’s been making him take.

That TV-commercial couple might be smiling a little less these days. A new finding from the same study reports no benefit from a daily multivitamin against cognitive decline. Another study says multivitamins were no better than placebo in protecting patients who’ve suffered a heart attack. In a draft report, the US Preventive Services Task Force recently concluded that there’s not enough evidence to tell whether supple-ments, including multivitamins, reduce the average person’s risk of cancer or heart disease. And in an editorial accompanying the two studies, five ex-perts stated flatly, “Evidence is sufficient to advise against routine supplementa-tion, and we should translate null and negative findings into action.… Enough is enough.”

Are the estimated 40% of American adults who take a daily multivitamin simply wasting their money? Irwin H. Rosenberg, MD, editor of the Tufts University Health & Nutrition Letter, says, “Seven decades after we learned to synthesize vitamins and package them as multivitamins for ‘insurance’ against nutritional shortfalls, we still too often define our nutritional status in terms of what vitamin supplements we use. Over and over again, we’ve seen that obtain-ing nutrients from supplements does not confer the same benefits as consuming a well-chosen diet.”

NO BRAIN BENEFIT: Both new studies were published in the Annals of Internal

Medicine. One looked at data from the Physicians Health Study II, which had previously shown a modest reduction in cancer risk associated with multivitamin use—but no protection against cardio-vascular events (not mentioned by those TV ads). This analysis focused on cogni-tive function, combin-ing five tests of global cognitive function as well as testing verbal memory. Participants were 5,947 men, average age 71.6, who were ran-domly assigned to either a daily multivitamin or a placebo.

Over an aver-age follow-up of 8.5 years, changes in mental function were no different in the multivitamin group than those taking a placebo. Researchers Francine Grodstein, ScD, of Brigham and Women’s Hospital in Boston, and colleagues concluded, “These data do not provide support for use of multivitamin supplements in the prevention of cognitive decline.”

They noted, however, that multivi-tamins may have other benefits, such as the previously reported association with cancer risk. Moreover, since the study focused on physicians, who tend to have healthy diets and be well-nourished, the multivitamins may not have made much difference in their overall nutrient status. Grodstein added that she thinks there is room for more research, although she conceded the challenges of such studies: “We don’t and probably never will have randomized trial data over decades.”

CASE CLOSED?: The second new study, led by Gervasio Lamas, MD, of Mount Sinai Medical Center in Miami Beach, focused on patients who had previously suffered a heart attack. Data came from the TACT

Are You Really Benefiting from Your Multivitamins?A new task-force report and two studies say evidence of benefit lacking.

study, conducted at 134 centers across the US and Canada, and involved 1,708 mostly male patients, average age 65.

The study looked at total deaths, car-diovascular deaths, recurrent heart at-tacks, stroke, coronary revascularization and hospitalization for angina. After an average follow-up of 4.6 years, there was no significant difference between patients randomly assigned to a daily multivi-tamin or placebo, either overall or for any specific measure. Nor was there any evidence of harm from taking the multi-vitamins, with only a slightly higher rate

of adverse events among that group.

In the editorial ac-companying the two studies, Eliseo Guallar, MD, DrPH, of the Johns Hopkins Bloomberg School of Public Health, and colleagues inter-preted the dual findings as the nail in the coffin

for supplement use: “Other reviews and guidelines that have appraised the role of vitamin and mineral supplements in pri-mary or secondary prevention of chronic disease have consistently found null results or possible harms.… The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided. This message is especially true for the general population with no clear evidence of micronutrient de-ficiencies, who represent most supplement users in the US and in other countries.”

The unusually blunt editorial contin-ued, “Although available evidence does not rule out small benefits or harms or large benefits or harms in a small sub-group of the population, we believe that the case is closed—supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful.”

The Natural Products Association, a supplements trade organization, reacted with shock to what they termed “an at-tack” on their $30 billion industry. “Our members market and sell their products in order to assist people to achieve a

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SPECIALREPORT SPECIALREPORT

healthier lifestyle,” a spokesman said.

EVIDENCE LACKING: A few days before, the US Preventive Services Task Force (USPTF) had dealt an only somewhat softer blow to the supplement industry. In a draft of an update to its 2003 advice, the USPTF found inadequate evidence to rec-ommend either for or against vitamin and mineral supplementation, including mul-tivitamins, for the primary prevention of cardiovascular disease or cancer. The task force is an independent, volunteer panel of national experts that makes reports to Congress; it’s expected to issue its final report on supplements later this year.

The recommendations apply to healthy adults without nutrient deficien-cies. The draft also reaffirmed advice against beta-carotene supplements, because of lack of benefit and evidence of increased lung-cancer risk among smokers, and added a recommendation against vitamin E supplements. There is a clear lack of benefit, according to the expert panel, for vitamin E against either cardiovascular disease or cancer.

Despite findings from two trials, including the Physicians Health Study II, showing a slightly lower risk of cancer among men taking multivitamins, the USPTF said the evidence wasn’t strong enough to recommend the pills for can-cer prevention.

Stephen P. Fortmann, MD, of the Kaiser Center of Health Research, who led the USPTF evidence review, told the New York Times that vitamin purchasers may be “throwing their money away.” He added, “Don’t think it makes up for a bad diet, that you can eat a lot of fast food and then take a bunch of supple-ments. That’s not a good idea.”

TOO LITTLE, TOO MUCH: Only a handful of individual supplemental nutrients have been shown in rigorous testing to have real benefits, including some that cer-tain people can’t obtain adequately from dietary sources. These include the AREDS formula of antioxidants for people at risk of macular degeneration, folic acid for pregnant women to prevent spina bifida

and other neural-tube defects in their children, and synthetic vitamin B12 (as a supplement or in fortified foods) for older adults who don’t produce enough stomach acid to separate natural B12 from food. Some people, especially premeno-pausal women, may also need extra iron. In their editorial, Dr. Guallar and col-leagues single out vitamin D as another supplement on which the jury is still out.

Tufts’ Dr. Rosenberg explains, “Tar-geted individual vitamin supplements have established benefits for those with diseases or conditions which impose spe-cial nutrient requirements. These benefits are usually achieved by doses higher than those in multivitamin supplements.”

Multivitamins may help supply these nutrients, but more often they don’t contain enough—and in the case of folic acid may add up to too much. Here’s a look at each:

➧ Antioxidants for eyes—Clinical-trial data from the Age-Related Eye Dis-ease Study (AREDS) supports a formula-tion of 500 milligrams (mg) of vitamin C, 400 International Units (IU) of vitamin E, 10 mg lutein, 2 mg zeaxanthin, 80 mg of zinc as zinc oxide and 2 mg of copper as cupric oxide for those at risk for age-re-lated macular degeneration (AMD)—the leading cause of blindness among older Americans. Most multivitamins contain much lower amounts of these nutrients. Even multivitamins sold as specially for-mulated for vision health are mostly inad-equate for obtaining the proven amounts. (Compare, for example, one leading brand that delivers only 90 mg vitamin C, 60 IU

vitamin E and 15 mg of zinc.)➧ Folic acid—While vital for women

who are or might become pregnant, folic acid (the supplement form of folate) in excess might enhance the risk of cancer, according to research by Tufts’ Joel Mason, MD. The amount in a typical multivitamin (about 400 micrograms) isn’t enough to exceed the 1,000 mcg up-per limit set by the Institute of Medicine. But Dr. Mason cautions that combining a multivitamin with fortified cereal or energy bars, plus a B-complex supple-ment, could put someone at risk.

➧ Vitamin B12—Most multivitamins deliver 10 times or more of the daily recommended 2.4 mcg of vitamin B12; there’s no danger to getting extra, but no proven benefit, either. Older adults at risk of deficiency can easily obtain enough synthetic B12, which is more readily absorbed, from fortified cereal and other fortified foods or from supplements.

➧ Iron—While premenopausal women often need extra iron, the recom-mendation for women over 50 and adult men is only 8 mg daily. Multivitamins formulated for older adults typically omit iron—check the label—because of the risk of iron overload.

➧ Vitamin D—Essential for bone health, vitamin D can be difficult to obtain in adequate amounts from food alone. With age, the body also loses some of its natural ability to make vitamin D in the skin from sun exposure. The 400 IU in a typical multivitamin might be just what you need to tip the scales, but most studies showing a bone-health benefit from supplemental vitamin D have tested higher amounts. (For more on vitamin D, see page 6.)

Before you decide to take a daily multivitamin, “just in case,” check the Supplement Facts label carefully and consider any other supplements and fortified foods you consume. More of any individual nutrient isn’t necessarily better, and may not even be safe. Make sure your physician knows about what supplements you’re taking, and discuss any health concerns before counting on a multivitamin as a cure-all.

BEHIND THE NUMBERSThe percentages in the Supplement Facts box on labels of multivitamins and other supplements (as well as in Nutrition Facts labels on food) are calculated using the Daily Value (DV) for each nutrient. Recommended intakes of nutrients vary by age and gender and are known as Recommended Dietary Allowances (RDAs) and Adequate Intakes (AIs). One value for each nutrient is selected as the DV; the DV is often, but not always, similar to one’s RDA or AI for that nutrient. These recommendations for healthy people do not reflect special requirements for those with diseases or chronic conditions.

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people who do not have a prior history of these illnesses. The multiyear Vitamin D and Type 2 Diabetes (D2d) study, based at Tufts Medical Center (see box), will include about 2,500 people. It will inves-tigate whether daily supplements of 4,000 IU of vitamin D3 will prevent or delay type 2 diabetes in adults aged 30 or older with prediabetes.

Until these studies begin to produce more definitive answers, several years from now, the best advice is to follow the Institute of Medicine recommendation of 600 IU of vitamin D daily for people under age 70, 800 IU for ages 70-plus. People at risk of osteoporosis and those who live in northern latitudes with in-adequate sunshine to make vitamin D in the skin may want to take a supplement to help protect their bones.

“After a careful review, the Institute of Medicine found no evidence of danger from vitamin D intake up to 4,000 IU per day,” Dr. Dawson-Hughes says. “You won’t be hurting yourself.”

Whether you will help yourself be-yond bone health, however, is a question scientists are working hard to answer.

If you’ve been popping vitamin D supplements for benefits beyond bone health—such as preventing heart

disease, cancer or diabetes—it’s too soon to know if those pills are really doing you any good. That’s the lesson, experts say, from a sweeping new review of 290 observational studies and 172 random-ized trials of vitamin D, chronic disease and mortality. Although vitamin D deficiency was associated with a variety of health problems in the observational studies, the trials in which participants were actually given extra vitamin D failed to prove a benefit.

This apparent paradox could be be-cause the doses of extra vitamin D tested were too low to make a difference; the largest trial in the review, the Women’s Health Initiative, tested supplements of only 400 International Units (IU). It’s also possible, however, that vitamin D deficiency is a sign of poor health status, rather than a cause of or contributor to chronic disease.

“To me the take-away is that we don’t yet have random-ized clinical trial evidence on the scale needed to answer questions about non-skeletal benefits of vitamin D,” says Bess Dawson-Hughes, MD, director of Tufts’ HNRCA Bone Metabolism Laboratory.

SEEING BUT NOT PROVING: In the new review, Philippe Autier, MD, of the In-ternational Prevention Research Institute in France, and colleagues found that low blood levels of vitamin D were associated with greater risk of all-cause mortality as well as cardiovascular disease, inflam-mation, glucose metabolism disorders, infectious diseases, mood disorders and cognitive decline. Participants in obser-vational studies with sufficient vitamin

D, on the other hand, were less likely to suffer cardiovascular events, diabetes and colorectal cancer.

But when put to the test in interven-tion trials of vitamin D supplementation, extra vitamin D failed to reduce the risk of disease occurrence or progression, or to benefit all-cause mortality. The excep-tion was supplementation of 800 IU in a group of older patients, mostly women, which did slightly reduce all-cause mortality.

Publishing their findings in The Lancet Diabetes & Endocrinology, Dr. Autier and colleagues observed, “The discrepancy between observational and intervention studies suggests that low 25(OH)D [a measure of vitamin D levels in the blood] is a marker of ill health. Inflammatory processes involved in disease occurrence and clinical course would reduce 25(OH)D, which would explain why low vitamin D status is reported in a wide range of disorders. In

elderly people, resto-ration of vitamin D deficits due to aging and lifestyle changes induced by ill health could explain why low-dose supple-mentation leads to slight gains in survival.”

ANSWERS AHEAD: Tufts’ Dr. Dawson-Hughes adds, “To answer these questions is why the National Institutes of Health (NIH) has funded the large VITAL study at Harvard and the D2d trial in predia-betics being done here at Tufts, among others.”

The VITamin D and OmegA-3 TriaL (VITAL), involving 20,000 men and women across the US, will test whether taking daily supplements of vitamin D3 (2,000 IU) or omega-3 fatty acids (1 gram) reduces the risk for develop-ing cancer, heart disease and stroke in

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New Questions About Benefits from Vitamin D Beyond BonesSo far, randomized trials fail to back up benefits seen in observational studies.

D FOR DIABETES PREVENTION?

Announced in October, the D2d study based at Tufts Medical Center will test

vitamin D supplementation in adults with prediabetes. Anastassios G. Pittas, MD, the study’s principal investigator, ex-plains, “Past observational studies have suggested that higher levels of vitamin D may be beneficial in preventing type 2 diabetes, but until this large, randomized and controlled clinical trial is complete, we won’t know if taking vitamin D sup-plements lowers the risk of diabetes.”

Based on observations from earlier studies, researchers speculate that vi-tamin D could reduce the diabetes risk by 25%. The study will also examine if sex, age or race affect the potential of vitamin D to reduce progression to dia-betes.

The $40 million study will take place at 20 medical centers in 17 different states across the country. For more infor-mation about D2d, including how to par-ticipate, see <www.d2dstudy.org>.

7MARCH 2014

Rx for Combating Chronic Conditions: ExerciseSurprising study finds benefits of exercise as great as those of medication.

A potentially life-saving prescription for fighting heart disease, diabe-tes and stroke could be as close as

those walking shoes gathering dust in your closet. According to an unusual new study, the benefits of exercise in reducing mortality from those lead-ing causes of death match or even exceed the effects of prescription drugs for the same condi-tions. Patients with heart disease who exercised, for in-stance, had the same odds of surviving the condition as those given medications such as statins or antiplatelet drugs.

“This doesn’t mean you should stop taking your medications,” comments Miriam E. Nel-son, PhD, a professor in Tufts’ Friedman School and author of the “Strong Wom-en” series of books. “But it does suggest how effective exercise can be whether or not it is added to whatever drug regimen your physician prescribes.”

MOVING VS. MEDS: In the new study, published in the journal BMJ, So Huseyin Naci, a graduate student at the London School of Economics and Politi-cal Science, and John Ioannidis, MD, DSc, director of the Stanford Prevention Research Center, looked at 305 previous experiments totaling almost 305,000 participants. All were randomized clini-cal trials, considered the “gold standard” of scientific research. Most, however, focused on medications, with only 57 involving almost 15,000 volunteers test-ing the benefits of exercise—reflecting, researchers said, how “we need far more information” on the effectiveness of exer-cise against chronic conditions.

Nonetheless, the pool of prior research was enough for Naci and Dr. Ioannidis to develop an elaborate cross-comparison of outcomes for drugs, ex-ercise or, more rarely, both. Most of the exercise studies involved rehabilitation programs; walking or other aerobic exer-

cises were most com-monly studied, but some trials looked at weight training or other routines.

The available studies tracked mortality among patients with heart disease, diabetes, stroke or chronic heart failure. Over-all, the results were almost identical for patients assigned to medications and those who exercised.

As the researchers put it, “All interven-tions were not different beyond chance.”

When analyzed by specific diseases, patients with heart disease and diabe-tes had the same relative risk of dying whether they exercised or took medica-tions. Those who had suffered a stroke actually did better if they exercised, compared to drug treatment—possibly because stroke patients who exercised

were healthier to begin with. Only patients with chronic heart failure did not live at least as long in experiments where they exercised compared to those where they were assigned to drugs such as diuretics.

ADDING EXERCISE: “Our results suggest that exercise can be quite potent” in treating such conditions, Dr. Ioannidis said. Co-author Naci added, “Maybe people could think long and hard about their lifestyles and talk to their doctors” about incorporating exercise into their care along with prescription drugs.

Tufts’ Nelson agrees, advising, “You may never have exercised regularly before, or it may be a long time since you did. For that reason, the key to long-term success is to take it slowly but deliberate-ly, increasing the duration and intensity of your exercise a little bit at a time. That will allow you to gain the greatest benefit without burning out. And for aerobic ex-ercise, in particular, choose exercises that you enjoy. That’s also crucial for sticking with it.”

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If you’re walking for health, does it mat-ter how fast you go? Contrary to some

previous findings, a new analysis of data on almost 39,000 participants in the Na-tional Walkers’ Health Study reports that a brisk pace has more benefits—even if the distance traveled is the same. Looking at 2,000 deaths among walkers, research-ers found mortality disproportionately higher among those with the slowest pace (17 minutes or more per mile, with most taking at least 20 minutes and many even longer). The death rate for the slow-est walkers remained higher even if they walked as far per day as faster walkers. Overall, the risk was especially higher for those dawdling along at 24 minutes a mile or slower. Picking up your pace even a little seemed to pay off, however: Those classified in the third-slowest category of walkers (about 15-17 minutes per mile) saw a significant reduction in their risk of dying prematurely compared to the slow-est group.

TAKE CHARGE!

ARE YOU DOING ENOUGH?

How much exercise do you need? Cur-rent guidelines for older adults call

for 150 minutes per week of moderate-intensity aerobic activity, such as brisk walking, or 75 minutes a week of vig-orous aerobic activity, such as jogging. Or you can aim for an equivalent mix of moderate and vigorous activity. Plus you should do muscle-strengthening activi-ties on two or more days a week that work all major muscle groups.

W W W . N U T R I T I O N L E T T E R . T U F T S . E D U8

ASK TUFTS EXPERTS

Send your question for possible publication to: Tufts University Health & Nutrition Letter, PO Box 5656, Norwalk, CT 06856-5656.

Sorry, because of the volume of questions, we cannot respond to each inquiry individually.

If you have a condition that may need medical attention, or personal questions related to our articles, please consult your physician.

HAVE A QUESTION FOR TUFTS EXPERTS?

Irwin H. Rosenberg, MD Health & Nutrition Letter Editor Professor of Nutrition, Friedman School of Nutrition Science and Policy Tufts University

QAre there actually health benefits from drinking yerba maté tea? What is yerba maté, anyway?

ADiane L. McKay, PhD, an assistant professor at Tufts’ Friedman School, replies: “Yerba maté

tea is made with the dried leaves of Ilex para-guariensis, a subtropical evergreen tree native to South America. Fresh maté leaves undergo several stages of processing including blanching, drying and aging prior to packaging. During blanching, the maté leaves are flash-heated over an open flame. The leaves are then dried very slowly, often using wood smoke, and aged for up to 12 months for flavor development. The name maté is derived from the Quechua word maté meaning a cup or vessel used for drinking. Other names for bever-ages made with I. paraguariensis include Jesuit’s tea, Paraguayan tea, cimarrόn and chimarraõ. In the United States, maté is commercially packed in individual tea bags or as a tea concentrate.

“Maté has long been used by the indig-enous peoples of South America, especially the Guarani Indians. In folk medicine, maté is used as a central nervous system stimulant, diuretic and anti-rheumatic. The German Commission E (a scientific advisory board to the equivalent of the FDA) approved the internal use of maté for mental and physical fatigue.

“Although in vitro and animal studies suggest a potential anti-carcinogenic effect of maté, the available epidemiological evidence does not. Several case control studies conducted in South America reported an association be-tween the consumption of yerba maté tea and an increased risk of oral, laryngeal, esopha-geal, lung, kidney and bladder cancers.

“These negative effects may be due to the way the tea leaves are processed in South America. That is, during the dry-ing process there is some introduction of carcinogens from the smoke used; the carcinogens are called polycyclic aromatic hydrocarbons.

“Few clinical trials of maté have been published, and none have reported any statisti-cally significant findings that can be attributed to maté consumption.

“Bottom line, yerba maté is an effective pick-me-up (due to the presence of naturally occurring stimulants), but the jury is still out on whether any of the potential benefits suggested by cell culture or animal studies will pan out in humans.”

QMy physician tells me that I am pre-diabetic, so I am very careful about my sugar and carbohy-

drate intake. Do artificial sweeteners raise blood-sugar levels?

AAnastassios G. Pittas, MD, professor of medicine in the Division of Endocrinology,

Diabetes & Metabolism at Tufts Medical Center, responds: “The quick answer is that artificial sweeteners do not raise blood sugar levels since they have no caloric value. However, switching to artificially sweetened food and/or beverages to prevent diabetes may not have the desired result, which may be counterintuitive. Artificial sweeteners may ‘mess’ with the areas of the brain that control appetite and satiety and, when used long-term, MAY have the opposite effects than desired.”

QI’ve read conflicting reports on the effects of alcohol on bones. Assuming one is drinking in

moderation, is alcohol good or bad for bones?

AKatherine L. Tucker, PhD, a professor at the University of Massachusetts-Lowell and

adjunct professor at Tufts’ Friedman School, answers: “It has long been thought that alcohol is bad for bones, and it is clear that very heavy al-cohol consumers have higher risk of osteoporo-sis. However, the evidence does not support that for moderate consumers. Most studies show that moderate alcohol consumers have higher bone mineral density (BMD) than non-consumers, but that there is an inverse U-shaped curve, with

lower BMD for high consumers.”A 2009 Tufts study by Tucker and

colleagues, for example, concluded, “The positive relation between intake of alcohol and BMD in men and post-menopausal women, the reproducibility

of these effects across the different bone sites, and the consistency of these find-

ings with other published studies of total alcohol intake suggest that alcohol

intake, particularly from beer and wine, may protect bone health. However, intake of more than two drinks per day of liquor in men was clearly harmful.”

These apparent beneficial effects, Tucker adds, “are thought to be related to the estrogen-ic effects of alcohol itself, polyphenolics in wine or beer, and silicon in beer.”

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➧ The facts about VITAMIN E and Alzheimer’s disease

IN COMINGISSUES …

Yerba maté tea … Artificial sweeteners and diabetes … Alcohol and bones

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