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Nutrition

Cardiovascular Medicine, Nutrition, Science

What’s not to love? Chocolate’s feel-good chemicals

Cabdury2Spring is here and symbols of new life abound. If Cadbury Cream Eggs (yes, gross, but I love them anyway) and Mini Eggs on drugstore shelves have you, too, thinking about chocolate, check out this piece in the Washington Post on the history and chemistry of the “feel-good” components of the stuff, including “the world’s most widely consumed psychoactive drug,” caffeine.

Chemist Simon Cotton, PhD, writes:

Another chocolate molecule believed to be important was discovered less than 20 years ago: anandamide. This binds to receptors in the brain known as cannabinoid receptors. These receptors were originally found to be sensitive to the most important psychoactive molecule in cannabis, Δ9-THC. Likewise, anandamide and similar molecules found in chocolate are also thought to affect mood.

Phenylethylamine, another family of chemicals, is found in chocolate in very small amounts. It is a naturally occurring substance with a structure that is closely related to synthetic amphetamines, which of course, are also stimulants. It is often said that our brain produces phenylethylamine when we fall in love. It acts by producing endorphins, the brain’s natural “feel-good” molecules. The bad news, however, is that eating chocolate is probably not the best way of getting our hands on phenylethylamine as enzymes in our liver degrade it before it can reach the brain.

There are other molecules in chocolate – especially in dark chocolate – such as flavonoids, which some scientists think may help improve cardiovascular health. But chocolate manufacturers have been known to remove bitter flavanols from dark chocolate.

One last feel-good factor, which isn’t a molecule: the melt-in-your mouth sensation. The fatty triglycerides in cocoa butter can stack together in six different ways, each resulting in a different melting point. Only one of these forms has the right melting point of about 34 degrees, so that it “melts in your mouth, not in your hand.” Getting the chocolate to crystallize to give this form is the product of very careful chocolate engineering.

I’m curious to know what kinds of chemicals give the sugary “whites” and “yolks” of the cream eggs their appeal, though maybe it’s better kept a foil-wrapped secret.

Previously: When caffeine dependence affects quality of lifeDo you (heart) chocolate? Evaluating the cocoa “prescription” for cardiac health and Mapping the DNA of wild strawberries and fine chocolate
Photo by Joel Kramer

Clinical Trials, NIH, Nutrition, Obesity, Research, Stanford News

Stanford seeks participants for weight-loss study

Stanford seeks participants for weight-loss study

Should diets come in different shapes and sizes? Stanford researchers are exploring that question and are seeking participants for a year-long weight-loss study that aims to understand why people may respond differently to the same diet. Titled “One Diet Does Not Fit All,” the study will examine how factors such as genetic influences and eating and sleeping habits have an impact on a diet’s effectiveness.

From a release:

Participants will be assigned randomly to either a very low-fat or very low-carbohydrate diet for 12 months. They will be required to attend weekly classes at Stanford for the first three months, once every other week for the following three months, and once a month for the remainder of the study. Participants must also be willing to have fasting blood samples drawn four times during the 12-month period and participate in online and written surveys. They will receive all test results at the end of the study.

The study is part of a five-year project funded by the National Institutes of Health and the Nutrition Science Initiative. Following an enrollment last year of 200, this spring researchers hope to enroll at least 135 men and women (pre-menopausal only) between the ages of 18 and 50 who are overweight or obese and are generally in good health.

For a complete list of inclusion criteria, click here. To determine eligibility for this study, complete a brief online survey. For more information, contact Jennifer Robinson at nutrition@stanford.edu.

Previously: How physicians address obesity may affect patients’ success in losing weight, To meet weight loss goals, start exercise and healthy eating programs at the same time, The trouble with the current calorie-counting system, Smaller plates may not be helpful tools for dieters, study suggests and Losing vitamins – along with weight – on a diet

Nutrition, Stanford News, Videos

Improving your health using herbs and spices

Can certain herbs and spices really boost immunity, control blood sugar, lower blood pressure and ease joint pain? As registered dietician Alison Ryan discusses in this Stanford Hospital & Clinics video, a growing body of scientific evidence suggests the answer is yes. During the 90-minute presentation, she explains in detail how ginger, turmeric, cinnamon and other ingredients can add a healthful punch to any meal, snack, or beverage by working to curb inflammation and prevent or delay certain types of cell damage. The talk is part of the Healthy Strides Ernest Rosenbaum Cancer Survivorship Lecture Series presented by the Cancer Supportive Care Program at Stanford.

Previously: How food may influence our cells and overall health and Nature/nurture study of type 2 diabetes risk unearths carrots as potential risk reducers

Behavioral Science, Nutrition, Obesity, Research, Women's Health

Obesity and smoking together may decrease taste of fat and sweet but increase consumption

puddingA study from Washington University School of Medicine in St. Louis and Philadelphia’s Monell Center has found that obese women who smoke cigarettes may have reduced sensitivity to the tastes of sweetness and fat in food and may be more likely to eat more calories.

Researchers engaged 47 female participants ages 21 to 41, grouped as follows: obese smokers, obese nonsmokers, normal-weight smokers, and normal-weight nonsmokers. All of the participants tasted vanilla puddings and were asked to rate the sweetness and creaminess of each one. The researchers found that the women who were obese and smokers rated less creaminess and sweetness in the puddings than the other three groups did.

From a release:

[Study author Yanina Pepino, PhD,] cautioned that the study only identified associations between smoking and taste rather than definitive reasons why obese smokers were less likely to detect fat and sweetness. But the findings imply that the ability to perceive fat and sweetness — and to derive pleasure from food — is compromised in female smokers who are obese, which could contribute to the consumption of more calories.

“Obese people often crave high-fat foods,” she said. “Our findings suggest that having this intense craving but not perceiving fat and sweetness in food may lead these women to eat more. Since smoking and obesity are risk factors for cardiovascular and metabolic diseases, the additional burden of craving more fats and sugars, while not fully tasting them, could be detrimental to health.”

The results were published in the journal Obesity.

Previously: Obesity is a disease – so now what?How eating motivated by pleasure affects the brain’s reward system and may fuel obesity and The brain’s control tower for pleasure
Photo by dutchfulthinking.blogspot.com

Clinical Trials, Nutrition, Science, Stanford News

Bad news for pill poppers? Little clear evidence for Vitamin D efficacy, says Stanford’s John Ioannidis

Bad news for pill poppers? Little clear evidence for Vitamin D efficacy, says Stanford's John Ioannidis

Vitamin DVitamin D is a darling of the supplementation world. Deficiencies in the vitamin have been blamed for all manner of ailments, including diseases of the skeletal system, autoimmunity, infections and cancer.

Now researchers from the University of Edinburgh, Imperial College London and the University of Ioannina School of Medicine in Greece have analyzed 107 systematic literature reviews and 161 meta-analyses regarding vitamin D supplementation or levels in blood plasma and the occurrence of 137 various medical outcomes. They’ve published their findings in today’s issue of the British Medical Journal, where they wrote:

In conclusion, although vitamin D has been extensively studied in relation to a range of outcomes and some indications exist that low plasma vitamin D concentrations might be linked to several diseases, firm universal conclusions about its benefits cannot be drawn.

In particular, the researchers found that the evidence does not support a role for vitamin D in increasing bone mineral density or reducing the risk of falls and fractures in older people. As senior author and Stanford study design expert John Ioannidis, MD, DSc, explained to me in an e-mail:

Vitamin D has been evaluated in thousands of studies in terms of its relationship to at least 137 health outcomes. We hope that systematic consideration of the available evidence will help avoid hot debate about health decisions involving vitamin D  that have mostly depended on speculations rather than evidence to-date.

Rather than writing off vitamin D altogether, the researchers note that additional, well-designed studies and trials are necessary before any firm conclusions can be drawn about its efficacy. The paper is accompanied by a second from researchers at the University of Cambridge analyzing relationships between vitamin D levels and the risk of mortality from several causes, as well as an editorial declaring that, despite much study, vitamin D is “no magic bullet.”

Previously: The Lancet documents waste in research, proposes solutions, “US effect” leads to publication of biased research, says Stanford’s John Ioannidis and Shaky evidence moves animal studies to humans, according to Stanford-led study
Photo by Colin Carmichael

Nutrition, Research

Cereal-eaters: How much are you really consuming?

cereal_smallAs any fan of lightweight, delicate Cocoa Krispies knows (though perhaps I’m generalizing my experience), sometimes it’s difficult to judge how much cereal you’re really eating. A study from Penn State on flake size, portion control and calorie consumption in breakfast cereals has shown that participants given smaller flakes poured a smaller volume into their bowls but still consumed greater heft and more calories than participants given larger flakes.

From a release:

According to [nutritional sciences professor Barbara Rolls, PhD], national dietary guidelines define recommended amounts of most food groups in terms of measures of volume such as cups.

“This can be a problem because, for most foods, the recommended amounts have not been adjusted for variations in physical properties that affect volume, such as aeration, cooking, and the size and shape of individual pieces.” Rolls said. “The food weight and energy required to fill a given volume can vary, and this variation in the energy content of recommended amounts could be a challenge to the maintenance of energy balance.”

In the study, 41 adult participants ate cereal for breakfast once a week for four weeks. Some ate the standard-sized wheat flakes, while others consumed the same cereal crushed to 80, 60 or 40 percent of its original volume. All participants poured as much as they wanted from opaque containers of equal-weight amounts of cereal and ate as much as they wanted.

The study authors report that “as flake size was reduced, subjects poured a smaller volume of cereal, but still took a greater amount by weight and energy content.” Still, the study notes, “subjects estimated that they had taken a similar number of calories of all versions of the cereal.”

The study (registration required), funded in part by the National Institutes of Health, was published in the Journal of the Academy of Nutrition and Dietetics.

Previously: Can dish color influence how much you eat? and Smaller plates may be a tool to curtail childhood obesity
Photo courtesy of Barbara Rolls, Penn State

History, Nutrition

When Irish eyes prefer not to see dyed-green food

When Irish eyes prefer not to see dyed-green food

MrPotatoHeadHaving grown up in a large Irish-Catholic family that ate potatoes nearly every night for dinner, my dad all but banished the tubers from our table. Relatives of his had passed down stories (perhaps fables) of their ancestors peeling away rotten skins during the potato famine back in the Old Country, and the relative abundance of edible, inexpensive ones in Northern California during the mid-20th century had led to a reactive potato saturation, as far as he was concerned.

NPR’s The Salt blog commemorates St. Patrick’s Day 2014 with an historical note on the Great Famine and foods dyed green for the March 17 holiday: Some Irish don’t find the color so charming, much less appetizing. From the post:

The reason, [historian Christine Kinealy, PhD] explains, is the Irish potato famine of the 1840s, which forced so many Irish to flee mass starvation in their homeland in search of better times in America and elsewhere. Those who stayed behind turned to desperate measures.

“People were so deprived of food that they resorted to eating grass,” Kinealy tells The Salt. “In Irish folk memory, they talk about people’s mouths being green as they died.”

At least a million Irish died in the span of six years, says Kinealy, the founding director of Ireland’s Great Hunger Institute at Quinnipiac University in Connecticut. Which is why, for an Irishwoman like Kinealy, who hails from Dublin and County Mayo, the sight of green-tinged edibles intended as a joyous nod to Irish history can be jolting, she says.

“Before I came to America, I’d never seen a green bagel.” She says. “For Irish-Americans, they think of dying food green, they think everything is happy. But really, in terms of the famine, this is very sad imagery.”

Previously: What do Americans buy at the grocery store?
Photo by Mike Licht, NotionsCapital.com

Behavioral Science, Medicine and Society, Mental Health, Nutrition

Learning tools for mindful eating

Learning tools for mindful eating

applecakeWhat’s the ideal diet for you? Ask your body. Practicing mindful eating involves subtle work that may be easier said than done. In a BeWell Q&A, wellness advisor Patty McLucas describes a class she teaches on the topic, leading students to quiet social cues and impulses that drive a person to eat for reasons other than hunger.

From the piece:

So many factors are at play in our culture here in Silicon Valley — and in the Western world — that result in a disconnect between the body’s natural sensation of hunger and the response to feed ourselves well. In other words, food has become disconnected from its primary function, which is to fuel our bodies.

How can we reconnect our eating with our hunger?

Ultimately, the only method that works over the long term is re-sensitizing our instrument — that is, our bodies — to perceive true hunger and fullness. And we do this through learning the practice of mindfulness. 

We all know that babies cry when hungry and absolutely refuse food when full. If no longer hungry, a baby won’t eat even one extra mouthful — not even one bite of Aunt Hildegard’s prizewinning apple cake! So the good news is that we are all born with this capacity; however, it gets obscured by our upbringing and other conditioned habits. Mindfulness of the body helps us see that.

Previously: Mindful eating tips for the desk-boundSix mindfulness tips to combat holiday stress and How mindfulness-based therapies can improve attention and health
Photo by joyosity

Nutrition, Research, Stanford News

Stanford study spoils hopes that raw milk can aid those who are lactose-intolerant

Stanford study spoils hopes that raw milk can aid those who are lactose-intolerant

milk in fridge

I have a few friends who can tell pretty quickly when they’ve eaten a food that contains milk or lactose, the sugar found in milk. The signs are unpleasant — mostly gas and diarrhea (yuck!). So they were interested when I told them that a nutrition researcher at Stanford was conducting a clinical trial to test the validity of claims that people who are lactose-intolerant can digest raw milk more easily than pasteurized milk.

Unfortunately for them, the claims don’t hold up.

In my news release about the study, which was published today in the Annals of Family Medicine, professor of medicine Christopher Gardner, PhD, found no difference in digestibility between the two.

Although the study was small — just 16 participants who were lactose-intolerant — the results were highly consistent among all the participants. As Gardner notes in the press release, “It’s not that there was a trend toward a benefit from raw milk and our study wasn’t big enough to capture it; it’s that there was no hint of any benefit.”

One thing that surprised Gardner was how many people believe they are lactose-intolerant because of the symptoms they experience, yet don’t meet the clinical standard for the condition. In fact, Gardner originally recruited 63 potential study participants, but only 43 percent of them actually met the standard.

So, what’s causing the discomfort that this group of people feel when they consume milk products? And would raw milk — which hasn’t been pasteurized and which proponents say contains “good” bacteria that may aid digestion — help folks who don’t meet the clinical definition of being lactose-intolerant? Gardner says he hopes other researchers will try to answer those questions.

Previously: Stanford pediatrician and others urge people to shun raw milk and products
Photograph by chrisdat

Nutrition, Obesity, Patient Care, Research

How physicians address obesity may affect patients’ success in losing weight

How physicians address obesity may affect patients' success in losing weight

docvisitFor some patients, the need to begin a weight-loss program to lower health risks connected with obesity is urgent. But losing weight and keeping it off for the long term can be a challenging journey for a person – and patient-doctor conversations about weight loss can be complex.

study (purchase required) recently published online in Preventive Medicine looked at the way patients perceive their physicians’ attitudes about obesity, and the patients’ change in weight following the delivery of weight-loss advice. For their work, the researchers conducted Internet-based surveys in 500 adults with a body-mass index of 25 or more.

As explained in a Johns Hopkins release:

The participants were asked, “In the last 12 months, did you ever feel that this doctor judged you because of your weight?” Twenty one percent of participants said they believed they had been.

Further, 96 percent of those who felt judged did report attempting to lose weight in the previous year, compared to 84 percent who did not. But only 14 percent of those who felt judged and who also discussed weight loss with their doctor lost 10 percent or more of their body weight, while 20 percent who did not feel judged and also discussed shedding pounds lost a similar amount.

“Negative encounters can prompt a weight loss attempt, but our study shows they do not translate into success,” study leader Kimberly Gudzune, MD, MPH, an assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine, said in the release. “If we are their advocates in this process — and not their critics — we can really help patients to be healthier through weight loss.”

Previously: Study: When discussing childhood obesity, words carry weight and A medical student calls for increased nutrition education for doctor
Photo by Stanford EdTech

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