The stories you want. The opinions that matter.
No, thanks
Tag: caffeine
Will The New Dietary Guidelines Change Absolutely Everything?

Will The New Dietary Guidelines Change Absolutely Everything?

Well, no, actually.

When any new study or report is released in the field of nutrition, you can safely bet that it will be heralded with a deluge of gushing headlines, breathlessly announcing a sea change in the way we should consume bread, eggs, chocolate, coffee, red wine, salt, and who knows what else. Everything bad is good again, and vice versa. So the cycle goes.

Health science is, to paraphrase Medical Daily, a predominantly unsexy enterprise. Cause-and-effect is the bedrock of narrative and digestible journalism, but clinical research operates in the gray zone of correlations, trends, and suggestions that vary in their power to persuade and nab attention, but never quite achieve the status of a “sure thing.”

The orthodoxy of food science is not as prone to flip-flopping as the click-hungry web news cycle (guilty as charged) might make it seem. Fad diets that promote the absolute rejection or embrace of any one type of food, as we’ve discussed before, are perennially in disfavor. But the basics of eating a balanced, healthy diet are — surprise — fairly steadfast.

The Scientific Report from the Dietary Guidelines Advisory Committee (DGAC) is produced every five years to aggregate and distill new research and evidence in nutritional science, and to inform and guide the adoption and revision of new nutritional policies — the Dietary Guidelines for America — that affect laws, initiatives, and standards in health care, food production, and education.  The 2015 report was submitted this week to the U.S. Department of Health and Human Services and U.S. Department of Agriculture, and will form the basis of the new guidelines that those agencies will release later this year.

It is heartening to note that the new recommendations do not rewrite the rules of eating healthy. And as to the state of healthy eating, the report affirms the grim facts we already knew: Half the American population suffers from preventable chronic conditions caused by poor dieting. Two-thirds of all adults and one-third of all children in the U.S. are either overweight or obese. This country’s eating habits are, in the delicate language of the report, “suboptimal.”

So if this is what it takes, if we need to hear it again and again — as it seems we desperately do — then yes, please! Bring on the “new” guidelines. We are not eating enough whole grains, fruit, and vegetables. We are eating too much in the way of processed grains, added sugars, sodium, and whole-fat dairy items. It doesn’t grab headlines, but it should.

The status of some of the more dubious food items are spelled out below:

Cholesterol: The big story kicked off by the release of these guidelines was the DGAC’s rollback on cholesterol. The currently-in-effect 2010 Dietary Guidelines set the upper limit for cholesterol consumption at 300 mg/day (or a little less than one-and-a-half eggs). But reports have shown for some time now that there is no compelling link between dietary cholesterol (what you consume) and blood cholesterol (what wrecks your arteries). Do we need to say it? This is not a license to eat “all of the eggs,” but a guide for making sensible, better informed decisions.

Seafood: The new guidelines straighten out a few things about seafood; namely, they make explicit that the benefits of eating seafood outweigh the potential risks of mercury and organic pollutants. In fact, the guidelines suggest the recommended amount of seafood consumption to be increased to 8 oz per week, because it provides a cocktail of necessary nutrients.

Caffeine: Coffee, perennially see-sawing as one of those is-it-or-isn’t-it-a-vice daily pleasures, gets a clean bill in the new guidelines. Current intakes of caffeine on average (three to five cups per day) do not exceed what is currently considered safe in any age group, at least for adults. Children, adolescents, and women who are pregnant should proceed with more caution.

Alcohol: As we’ve suspected (and hoped), moderate amounts of alcohol can be an acceptable part of a healthy dietary pattern. Which does not exactly mean “bottoms up,” as some outlets have suggested. But whatever gets the message out there.

The new guidelines, in all their glory, are here [pdf]. Dig in.

Photo: Josh Russell via Flickr

The Health Perks Of Caffeine

The Health Perks Of Caffeine

If you’re like many adults, caffeine is part of your daily routine. But it doesn’t just help get your morning off to a snappy start or power you through a mid-afternoon slump. It’s good for you too. The latest research offers new insight about the health perks of this potent pick-me-up.

Caffeine is the ultimate power tool.

“Caffeine boosts brain power and memory, makes you feel more vigorous and improves mood,” says Harris R. Lieberman, Ph.D., a research psychologist with the U.S. Army Research Institute of Environmental Medicine in Natick, Massachusetts. Caffeine blocks the action of adenosine, an organic compound that promotes sleep, to stimulate brain cells to fire up. Blood levels of caffeine peak about 30 to 45 minutes after you’ve consumed it. But don’t gulp down two cups first thing to turbocharge your day. A study Lieberman led involving U.S. Navy Seals found that an average of 300 mg of caffeine (equivalent to three cups of coffee or four cups of tea) consumed throughout the day is optimal for most people for peak mental and physical performance.

Coffee cuts endometrial cancer risk.

Downing daily cups of coffee can reduce the risk of endometrial cancer, the most common cancer of the female reproductive organs. Researchers from the Harvard School of Public Health found that women who drank three to four daily cups of java reduced their risk of endometrial cancer by 29 percent compared to women who drank little or no coffee. Drink think: Coffee contains chlorogenic acid, an antioxidant that may prevent DNA damage. Its caffeine and other bioactive compounds may alter the levels of estrogen, insulin, C-peptide and other hormones to inhibit the growth of cancer cells. Be careful how you take your coffee though. Adding sugar and cream could contribute to weight gain and insulin resistance. Keeping your weight in check and exercising regularly are the most powerful ways to prevent endometrial cancer.

Coffee helps derail diabetes.

The pooled results of 18 studies involving over 450,000 people found that each daily cup of coffee consumed is associated with a 7 percent lower risk of diabetes. Follow-up studies show that coffee may reduce inflammation and improve insulin sensitivity. But again, don’t OD on the stuff. Some studies link coffee consumption — more than three cups of coffee per day — with an increased risk of rheumatoid arthritis.

That cup of joe won’t make you go.

Women with urinary incontinence (UI) — the strong, sudden urge to go when you may not be anywhere near a bathroom — have long been told to avoid coffee and other caffeinated foods and beverages. It was thought that caffeine, a diuretic, may irritate the bladder and make things worse. But a recent study shows that caffeine isn’t the culprit once thought. Researchers analyzed food questionnaire data from the Nurses’ Health Study and Nurses’ Health Study II from 21,564 women with moderate UI — who leaked urine one to three times per month — over two years. They found that caffeine didn’t cause more problems. Whether women routinely drank just one cup of coffee daily or downed four or more cups, those who kept up their caffeine habit didn’t experience more bouts of UI over time. In women whose symptoms had gotten worse, there was no link to caffeine, the researchers found. If you’ve got UI, there’s no need to give up caffeine to manage the condition.

Coffee won’t weaken your bones.

Although a teeny bit of calcium does leach from your bones when you drink full-strength Java, it’s not enough to be harmful, even if you drink a lot of coffee. Still, if you want to make up the difference, pour in one to two tablespoons of skim milk or have a skim latte (half steamed skim milk, half coffee) instead.

How Much is Too Much? 

“On average, most adults will notice no side effects from caffeine at 300 milligrams orfewer a day,” says Herbert Muncie Jr., M.D., professor of family medicine at LSU School of Medicine in New Orleans. That’s the caffeine equivalent of roughly 28 ounces (or three and a half cups) of regular coffee. But know your limit and stick to it.

“Find out what’s right for you. There are genetic differences that seem to predict how quickly people metabolize caffeine. Some people need less caffeine than others,” Lieberman says. If your blood pressure is elevated or you’re sensitive to the effects of caffeine (the jitters, restlessness, anxiety, heart palpitation, heartburn, insomnia), consider avoiding caffeine altogether.

Likewise, if you’re pregnant or trying to conceive, “reduce your intake to one caffeinated beverage a day or less,” says Lisa Mazzullo, M.D., an ob/gyn in Chicago and coauthor of Before Your Pregnancy. Consuming too much caffeine may increase your risk of low birth weight or miscarriage.

Timing is important too. Caffeine generally takes 8 to 12 hours to get out of your system. If sleeping well is a problem, avoid any caffeine after lunchtime. Besides obvious sources, such as caffeinated coffee (103 mg caffeine in 6 ounces), tea (36 mg in 6 ounces) and cola beverages (49 mg in 12 ounces), try to steer clear of hidden caffeine in foods like coffee-flavored yogurt (44.5 mg in 8 ounces) and chocolate (6 mg in 1 ounce).

The Buzz on Energy Drinks

To tackle your to-do list, it may be tempting gulp down an energy drink or two. The trendy tonic packs a concentrated dose of caffeine — as much as 207 milligrams, which is double the caffeine content of an 8-ounce cup of coffee. Energy products could be an emergency solution if, for example, you have to drive at night for a long distance and you’re tired.

But over the long run, energy drinks aren’t so healthy for your heart. A study in the Journal of the American Medical Association found that the potent products can increase blood pressure, irregular heart rate and heart palpitations. If you have high blood pressure, downing these products could spike it into a dangerous range. Elevated blood pressure may lead to heart disease, heart failure, stroke and kidney failure. Energy products could also trigger atrial fibrillation, a common heart rhythm problem that’s associated with stroke. At the very least, the caffeine load in an energy drink could cause irritability and anxiety. The upshot? Skip energy drinks and enjoy less potent forms of caffeine.

Photo: Jonathan McIntosh via Flickr

Study: Caffeine Stirs Memory

Study: Caffeine Stirs Memory

Paris (AFP) – A jolt of caffeine can boost memory, according to a study published Sunday that provides a scientific motive for students slurping coffee, tea or energy drinks when cramming for exams.

A team at Johns Hopkins University in Baltimore, Maryland, found that caffeine enhances certain memories for at least a day after they were formed.

Evidence for caffeine as a memory booster has been anecdotal until now.

This is because the process of registering memories — say, reading a book ahead of an exam — may happen in conditions where the person is eager to absorb and retain information.

This makes it hard to distinguish between someone’s natural alertness and that derived from caffeine.

To strip out this confounding factor, a team led by Michael Yassa, an assistant professor of psychological and brain science, tried a different tack.

They asked 73 volunteers to look at images of a number of objects — for instance, a plant, a basket, a saxophone, or a seahorse.

Afterwards, half of the group were given a 200 milligram dose of caffeine — roughly equivalent to two cups of strong espresso — and the others a dummy pill known as a placebo.

Saliva samples were taken one, three and 24 hours later to measure caffeine levels.

The following day, both groups were asked to look at another set of pictures.

Some of the images were the same, others were new, and a few were similar — for instance, a basket as before, but this time with one handle instead of two.

Both groups did well at distinguishing between old and new pictures, the researchers said.

But those on caffeine were much sharper at identifying the “similar” items in the lineup.

The test sought to discern the effect of caffeine on the hippocampus, a part of the brain that distinguishes between patterns — requiring both short- and long-term memory.

“If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine,” Yassa said.

“However, using these items requires the brain to make a more difficult discrimination — what we call pattern separation, which seems to be the process that is enhanced by caffeine in our case.”

The study, published in the journal Nature Neuroscience, could be valuable in the study of brain cell health.

“Caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer’s disease,” said Yassa.

“These are certainly important questions for the future.”

Photo: AFP.com