Adolescent obesity increases future coronary heart disease risk

A rising trend of adolescent obesity is projected to result in an increase of heart disease events (including death) by up to 16% between the years of 2020 and 2035.

The effect of adolescent obesity on future adult heart disease risk has not been clearly established. In a recent publication, researchers estimated the prevalence of obese 35-year-olds in 2020 on the basis of adolescents overweight in 2000 and historical trends regarding overweight adolescents who become obese adults. A state-transition computer simulation was used to project the annual excess incidence and prevalence of heart disease, the total number of excess heart disease events, and excess deaths from both heart disease and other causes related to obesity from 2020 to 2035.

The number of overweight adolescents is projected to increase the prevalence of obese 35-year-olds in 2020 to a range of 30-37% in men and 34-44% in women. As a result of this increased obesity, an increase in the incidence of heart disease and related deaths is projected to occur in young adulthood. By 2035, it is estimated that the prevalence of heart disease will increase by a range of 5-16%, with more than 100,000 excess cases caused by the increased obesity.

Although projections 25 or more years into the future are subject to numerous uncertainties, based on current data it is a reasonable assumption that adolescent obesity will increase rates of heart disease among future young and middle-aged adults, resulting in substantial increases in disease and death rates.

Researchers concluded that aggressive treatment with currently available therapies to reverse obesity-related risk factors may reduce, but not entirely eliminate, the calculated increase in the number of heart disease events.

N Engl J Med. 2007 Dec 6;357(23):2371-9.

Multivitamins and Healthy Immune Function

Adequate intakes of micronutrients are required for the immune system to function efficiently. A good multivitamin/mineral can enhance the immune system by supporting the body's natural defenses on both structural and cellular levels.

A recent article published in the British Journal of Nutrition summarizes the roles of selected vitamins and trace elements in immune function.

Adequate intakes of micronutrients are required for the immune system to function efficiently. Micronutrient deficiency suppresses immunity by affecting antibody responses, leading to imbalances in the immune system. This situation increases susceptibility to infections, which increases disease and death risk. In addition, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Inadequate intakes of micronutrients are common in people with eating disorders, smokers (active and passive), individuals with chronic alcohol abuse, certain diseases, during pregnancy and lactation, and in the elderly.

Micronutrients contribute to the body's natural defenses on three levels by supporting physical barriers (skin/mucosa), cellular immunity and antibody production. Vitamins A, C, E and the mineral zinc assist in enhancing the skin barrier function. The vitamins A, B6, B12, C, D, E and folic acid and the minerals iron, zinc, copper and selenium work in synergy to support the protective activities of the immune cells. Finally, all these micronutrients, with the exception of vitamin C and iron, are essential for the production of antibodies. Overall, inadequate intake and status of these vitamins and minerals may lead to a suppressed immune system, which increases the risk of infections and aggravates malnutrition. Therefore, supplementation with a multivitamin/mineral that includes these micronutrients can support the body's natural defense system by enhancing all three levels of immunity.

Br J Nutr. 2007 Oct;98 Suppl 1:S29-35.

Junk food makes up nearly one-third of calories in American diet

According to a large national survey, nutrient-poor food, or "junk food," contributes nearly 30% of all the energy (calories) consumed in the US population. Efforts to reduce obesity should focus on both individual and policy actions to reduce the importance of nutrient-poor foods in the US diet.

A study of 4,700 adults showed that despite the increased popularity of low-carbohydrate diets, almost one-third of Americans' calories are coming from 'empty calorie' foods such as sweets and desserts, soft drinks, and alcoholic beverages. Salty snacks and fruit-flavored drinks make up another five percent. Lead researcher Gladys Block, a professor of epidemiology and public health nutrition at University of California, Berkeley, used data from a U.S. government survey called the National Health and Nutrition Examination Survey. She analyzed the answers of participants interviewed in 1999 and 2000 who were asked to report all the foods they ate in the previous 24 hours.

"We know people are eating a lot of junk food, but to have almost one-third of Americans' calories coming from those categories is a shocker. It's no wonder there's an obesity epidemic in this country," Block said in a statement.

Sodas contributed 7.1 percent of the total calories eaten. Sweets topped the list, followed by hamburgers, pizza, and potato chips. By contrast, fruits and vegetables made up only about 10 percent of calories in the diet.

"It's important to emphasize that sweets, desserts, snacks, and alcohol are contributing calories without providing vitamins and minerals," said Block.

"You can actually be obese and still be undernourished with regard to important nutrients. We shouldn't be telling people to eat less - we should be telling people to eat differently."

Block G. Journal of Food Composition and Analysis. Volume 17, June-August 2004, 439-447.

Vitamin D and endometrial cancer

New research indicates that low serum vitamin D may be associated with an increased incidence of endometrial cancer.

The November 16, 2007 issue of the journal Preventive Medicine reported an association between ultraviolet light exposure and a reduced risk of endometrial cancer. Two previous investigations have already linked a lower rate of kidney and ovarian cancer with greater UV exposure, which increases the formation of vitamin D3 in the body.

Researchers analyzed data made available through GLOBOCAN, a database of cancer incidence and mortality in 175 countries. In general, the incidence of endometrial cancer was highest at the highest latitudes in both hemispheres. The correlation between low UV exposure and low vitamin D levels and endometrial cancer incidence remained strong even after adjusting for variables such as fat intake, weight, cloud cover, skin pigmentation and others.

Most previous studies have focused on hormone levels and dietary fat intake and their role in the development of the disease. This is the first study linking low serum vitamin D levels to an increased risk of endometrial cancer. Along with other preventive measures, vitamin D adequacy should be considered as part of a comprehensive program for prevention of endometrial cancer.

Prev Med 2007 Nov;45(5):323-4.

Zinc supplements decrease incidence of infections in the elderly

Elderly adults are increasingly susceptible to infections, oxidative stress and immune dysfunction. According to new research, supplementing with zinc for one year decreased the incidence of infections and lowered markers of oxidative stress in a group of adults aged 55-87 years.

Adults over the age of 55 years are more susceptible to infections, immune dysfunction, increased oxidative stress, and zinc deficiency. Since zinc has anti-inflammatory and antioxidant properties, new research sought to determine the effect of zinc on the incidence of total infections in the elderly. Researchers also tested the effect of zinc on markers of oxidative stress.

A randomized, double-blind, placebo-controlled trial of zinc supplementation was conducted in 50 healthy subjects of both sexes aged 55-87 years. The zinc-supplemented group received 45 mg of zinc orally for 12 months. Incidence of infections during the supplementation period was documented. Plasma zinc concentrations and markers of oxidative stress were measured at the beginning and after supplementation.

After zinc supplementation, the incidence of infections was significantly lower, plasma zinc was significantly higher, and generation of oxidative stress markers was significantly lower in the zinc-supplemented than in the placebo group.

American Journal of Clinical Nutrition, Vol. 85, No. 3, 837- 844, March 2007

Vitamin D supplementation lowers fracture risk

Researchers have found that doses of 700 to 800 IU of vitamin D3 per day may reduce the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent.

The May 11 2005 issue of the Journal of the American Medical Association published the results of a meta-analysis of 12 clinical trials involving vitamin D supplementation in the prevention of fracture. The analysis concluded that supplementation with higher than the commonly recommended 400 international unit (IU) doses of vitamin D reduces the risk of hip and nonvertebral fractures in older individuals.

The vitamin D studies included a total of 19,114 men and women aged 60 and older. The trials used the form of the vitamin known as cholecalciferol, or vitamin D3, which, according to studies cited in the current review, may be much more effective than the dietary form of the vitamin.

The researchers found that doses of 700 to 800 IU of vitamin D3 per day reduced the risk of hip fracture by 26 percent and nonvertebral fracture by 23 percent. Studies that used 400 IU vitamin D3 or less found no significant benefit for either type of fracture. The role of additional calcium supplementation could not clearly be defined from the studies, but it appears that at least 700 milligrams calcium per day may also be necessary for nonvertebral fracture prevention.

JAMA 2005 May 11;293(18):2257-64.

Supplemental vitamin D and calcium reduces risk of diabetes

The incidence of type-2 diabetes is lower among women who get adequate calcium and supplement with vitamin D. Researchers used data from the Nurses Health Study, which includes over 83,000 women, to study the relationship of calcium and vitamin D intake to type-2 diabetes.

After 20 years of follow-up, it was concluded that a combined daily intake of over 1,200 mg of calcium and more than 800 IU of vitamin D was associated with a 33 percent lower risk of type-2 diabetes. Interestingly, dietary vitamin D intake did not appear to provide any statistically significant benefit. But the women who supplemented with at least 400 IU of vitamin D had a 13% lower risk of diabetes when compared to those who took less than 100 IU per day. Both dietary and supplemental calcium resulted in decreased risk of type-2 diabetes, and those with overall intakes above 1,200 mg had a 21% lower risk than those who got less than 600 mg per day.

Elevated intakes of calcium and vitamin D, especially from supplements, are significantly associated with lower incidence of type-2 diabetes.

Diabetes Care 29:650-656, 2006