From Heartwire

New US Dietary Guidelines to Be Issued by Year-End

Lisa Nainggolan

June 17, 2010 (Washington, DC) — The US Dietary Guidelines Advisory Committee (DGAC) has issued its recommendations for the new Dietary Guidelines for Americans 2010, which are now open for a period of public comment [1]. The dietary guidelines are jointly issued and updated every five years by the Departments of Agriculture (USDA) and Health and Human Services (HHS).

"This DGAC report is expected to provide USDA and HHS with a strong foundation for preparing the 2010 Dietary Guidelines for Americans, which will be released at the end of the year," said USDA Secretary Tom Vilsack and HHS Secretary Kathleen Sebelius in a joint statement [2].

Commenting on the DGAC report for heartwire , chair elect of the AHA Nutrition Committee, Dr Rachel Johnson (University of Vermont, Burlington), said the recommendations differ from the last guidelines, published in 2005, in that "this is the first time they are being focused on the overweight/obese–an unhealthy population–and they are intended to meet the needs of the American public because the majority of people now are overweight or obese. They take a strong position about the need for people to be aware of their energy needs and try to achieve a healthy weight."

Another first is a chapter on total diet and how to integrate all of the nutrient and energy recommendations into practical advice that encourages personal choice but results in a healthy eating pattern, she says. A second new chapter complements this by articulating steps that can be taken by all Americans to adopt better lifestyles.

A key component of this chapter is "a huge emphasis on what we are now calling SoFAS–solid fats and added sugars," says Johnson, which contribute approximately 35% of calories to the American diet but contain few, if any, nutrients. "And they have now come out and said people should avoid sugar-sweetened beverages; that word ‘avoid’ is very strong language for a public-policy document like this. In the past, we have seen things like ‘moderate your intake of sugars,’ or ‘limit,’ but now they are actually saying ‘avoid,’ " she notes.

"Also there is this very strong emphasis on sodium, with a move to limit sodium intake to 1500 mg per day for all Americans, which is lower than the past dietary guidelines, but it does align with the current AHA position on sodium," Johnson adds.

Finally, she says the DGAC report encourages a focus on children, stating that primary prevention of obesity must begin in childhood. Key among recommendations here are to "bring back home economics," she says, because "it’s very difficult to eat a healthy diet without cooking."

Written comments on the DGAC report are welcomed until July 15, 2010, and oral testimony may be provided at a public meeting to be held on July 8, 2010 in Washington.

June 2010

Increased intakes of flavonol-rich foods may reduce the risk of stroke by 20%, according to a meta-analysis involving more than 110,000 people.

"We showed for the first time, to our knowledge, that flavonol intake was inversely associated with stroke incidence," wrote the Dutch researchers, led by Dr. Peter Hollman, an associate professor of nutrition and health.

"We conclude that evidence is accumulating that flavonol intake is inversely related to different cardiovascular disease outcomes," they added.

Strokes occur when blood clots or an artery bursts in the brain and interrupts the blood supply to a part of the brain. It is the leading cause of disability and the third leading cause of death in Europe and the U.S.

Flavonols make up a sub-group of flavonoids, which can be split into a number of sub-classes, including anthocyanins found in berries, flavonols from a variety of fruit and vegetables, flavones from parsley and thyme, for example; flavanones from citrus, isoflavones from soy, mono- and poly-meric flavonols like the catechins in tea and proanthocyanidins from berries, wine and chocolate.

According to an editorial in the American Journal of Clinical Nutrition (July 2008, Vol. 88, pp. 12-13), Hollman, along with Johanna Geleijnse, stated that the contribution of flavanones to a person’s antioxidant capacity was significant.

"More than 6,000 different flavonoids in plants have been described, and their total intake could amount to 1 g/d, whereas combined intakes of beta-carotene, vitamin C and vitamin E from food most often are less than 100 mg/d," they said in the AJCN.

Hollman and his co-workers conducted a meta-analysis of prospective cohort studies using data from individuals free of CVD or at the start of their respective studies.

Data was available for 111,067 people and follow-up ranged from six to 28 years. Overall, 2,155 non-fatal and fatal strokes were documented and the researchers noted that a high intake of flavonols, predominantly from tea in the Dutch population and from tea, onions, apples and broccoli in U.S. studies, was associated with a 20% reduction in stroke risk.

The differences between flavonol intakes between the populations are important, said the researchers, since this has an effect on the levels of the compounds in the blood and tissue. "The bioavailability of flavonols in onions is much better than that of tea and apples," said Hollman and his co-workers. "As a consequence, plasma and tissue concentrations of flavonols depend also on the type of dietary flavonol source.

"In the etiology of stroke, these plasma and tissue concentrations are relevant. Flavonol bioavailability determines the relation between flavonols consumed and plasma and tissue levels. Flavonol bioavailability of a food is dependent on the type of flavonol glycoside in that food," they added.

Despite this association, the researchers noted that the results should be interpreted with caution since only a small number of studies were available for the meta-analysis.

Journal of Nutrition Published online ahead of print.

Lee Swanson Research Update

Family physicians can treat obesity. The science is extensive; the art of treatment is exciting. This blog, for family physicians, debates the major issues in successful treatment of obesity.

• Neil Peace

  Dr. Neil Peace is a family physician who has had a special interest in treating overweight and obese patients since 1982. He studied medicine at Queens University, Kingston, Ontario, Canada, and now lives in Sydney, Australia. His medical practice in Sydney deals exclusively with treating overweight and obese patients, and he takes a scientific approach to treatment. Dr. Peace believes that family physicians can and should be primary managers of their obese patients.

Weighing in With Neil Peace

Weight Control Is Applied Physiology

Neil Peace, MD, General Practice, 07:52PM May 17, 2010

Success at weight control requires a long term view. Family Physicians, as "applied physiologists" are perfectly placed to help patients take this long term view. I firmly believe that doctors must lead the attack on obesity.

Knowing how the body works metabolically and the brain in particular, allows one to construct tactics to fool the physiology.

Obesity results from genetics out of sync with the environment. Success at weight control depends on understanding the physiology of glucose metabolism and the hormones of food seeking. These hormones and brain centres cannot be changed. The are in the hard drive. But understanding the physiology allows the creation of tricks to circumvent the drives to seek food, eat food and eat extra. Knowing the physiology allows one to overcome the body’s relentless drive to lay down body fat.

The brain uses only glucose for fuel (with rare exceptions). This explains much of our behaviour towards food seeking. If too long a time has passed since the last meal then the brain will be struggling to find enough glucose. This sets off alarm bells. The brain is central to survival.

Those alarm bells wake up a posse of hormones. The hormones mount their horses and charge into action. "Must save the brain" is the rallying cry for Leptin and Ghrelin (Leprechauns and Gremlins). They initiate intense food seeking. The patient overindulges.

As Family Physicians (applied physiologists) we can warn patients to eat often enough to avoid this hormonal over reaction. How often to eat to avoid this "charge"? It varies but I usually start by suggesting patients eat three hourly – whether hungry or not. I can hear the nutritionists throwing up their hands in horror. "Only eat when hungry" is their catch cry. Well – it hasn’t worked.

By eating before hunger sets in, food seeking hormones are kept quiet. The tendency to over indulge is reduced.

I believe the application of physiology is the path to weight control and this implies a long term view.

How do we convince patients to take this long term view? Patients have had decades of quick fix weight loss scams. Hundreds have come and gone. There will be many more before we get it right.

It would help if governments mandated that weight loss plans must have the same scientific proof as they expect for say a new blood pressure medication.

This would eliminate false advertising. The patient would have a chance of taking a long term view. Then we could practice our applied physiology for weight control.

Free market folk will point out that such restriction of advertising is contrary to the freedom of speech. Indeed it is but if that principle were fully applied we would have complete freedom to deceive the public on smoking, alcohol and many other areas where truth in advertising is applied.

I say, let’s get weight control out of the hands of the quick fix merchants and back into the hands of the applied physiologists – the Family Physician.

What do you think?