Nutritional factors play a key role in normal functioning of the skin, the body’s largest organ. However, little is known about the effects of diet on skin-aging appearance. Recent research indicates that higher intakes of vitamin C and linoleic acid and lower intakes of fats and carbohydrates are associated with better skin-aging appearance.

Using data from the first National Health and Nutrition Examination Survey (NHANES I), scientists examined associations between nutrient intakes and skin aging in 4,025 women between the ages of 40 and 74 years. Clinical examinations of the skin were conducted by dermatologists. Skin-aging appearance was defined as having a wrinkled appearance, dryness associated with aging (senile dryness), and skin atrophy (shriveling or shrinking).

Higher vitamin C intakes were associated with a lower likelihood of a wrinkled appearance. Higher linoleic acid (an omega-6 essential fatty acid) intakes were associated with a lower likelihood of senile dryness and skin atrophy. A higher than average fat and carbohydrate intake also increased the likelihood of a wrinkled appearance and skin atrophy. These associations were independent of age, race, education, sunlight exposure, income, menopausal status, body mass index, supplement use, physical activity, and energy intake.

Elevated intakes of vitamin C and linoleic acid and reduced intakes of fats and carbohydrates are associated with better skin-aging appearance. Promoting healthy dietary behaviors may have added benefit for the appearance of skin in addition to other beneficial health outcomes in the population.

American Journal of Clinical Nutrition Vol. 86, No. 4, 1225-1231, October 2007

Source: USANA Health Sciences

Meta-analysis of glycemic index and glycemic load effects on chronic disease

The American Journal of Clinical Nutrition recently published a meta-analysis to evaluate the association between GI, GL, and chronic disease risk.

A total of 37 prospective cohort studies of GI and GL and chronic disease risk were included. In 4 to 20 years of follow-up across studies, a total of 40,129 incident cases of degenerative diseases were identified. For the comparison between the highest and lowest quantiles of GI and GL, significant positive associations were found for type 2 diabetes, coronary heart disease, gallbladder disease, breast cancer, and all diseases combined.

Low-GI and/or low-GL diets are independently associated with a reduced risk of certain chronic diseases. Relating to cardiovascular disease and type 2 diabetes, the protection is similar with that seen in diets high in whole grains and fiber. The findings support the hypothesis that higher GI and GL diets, and their resulting increases in postprandial (after meal) blood glucose levels, increase the risk of several chronic, degenerative diseases.

American Journal of Clinical Nutrition, Vol. 87, No. 3, 627-637, March 2008

Source: USANA Health Sciences

To date, clinical trials have not shown significant benefit of vitamin C supplementation in reducing stroke risk, but they have not examined the relation between plasma vitamin C concentrations and stroke risk in a general population.

A recent study published in the American Journal of Clinical Nutrition examined the relation between baseline plasma vitamin C concentrations and risk of incident stroke in a British population of over 20,000 adult men and women. The participants completed a health questionnaire and attended a clinic during 1993″1997. After an average follow-up time of 9.5 years, the participants in the top fourth of plasma vitamin C levels had a 42% lower risk of stroke compared to those with the lowest levels. These results were independent of age, sex, smoking, BMI, blood pressure, cholesterol, physical activity, diabetes, social class, alcohol consumption, and any supplement use.

Plasma vitamin C concentrations, therefore, may act as an indicator of lifestyle or other factors associated with reduced stroke risk and may be helpful in determining those at high risk of stroke.

American Journal of Clinical Nutrition, Vol. 87, No. 1, 64-69, January 2008

Source: USANA Health Sciences

A combination of prolonged exercise and fish oil can dramatically reduce levels of a fat that can cause hardening of the arteries, a leading cause of heart disease. Fat in the bloodstream is a primary contributor to atherosclerosis, or partial blockage of the arteries.

A recent study found that people who do prolonged aerobic exercise have muscle cells that are able to quickly break down and reduce levels of a fat called triglycerides. Taking a fish oil supplement can reduce triglyceride levels even more.

The researchers studied triglyceride levels in recreationally active men after they’d eaten high-fat meals. One group ate a fatty meal after they exercised. A second group ate a high-fat meal after taking a four-gram fish oil supplement. A third group ate a high-fat meal after exercising and taking the fish oil supplement. A control group ate a high-fat meal only.

The study found a 38 percent decline in peak triglyceride levels in the men who took a fish oil supplement before they ate a high-fat meal. Peak triglyceride levels dropped 50 percent in the men who exercised and took a fish oil supplement before they ate a high-fat meal.

Regular exercise and fish oil supplements may be beneficial for people who are concerned about maintaining a healthy triglyceride level.

Metabolism. 2004 Oct;53(10):1365-71.

In a similar, more recent study, combining fish-oil supplements with regular exercise improved both body composition and heart disease risk factors. Overweight participants with various heart disease risk factors were assigned to one of three groups: fish oil (approximately 1.9 grams/day of omega-3 fats), fish oil and exercise, or placebo (sunflower oil). The exercise group walked 3 days/week for 45 minutes. Heart disease risk factors and body composition were measured at 0, 6, and 12 weeks. The group taking fish oil had a significant reduction in triglycerides, increased HDL cholesterol, and improved arterial vasodilation (blood flow). Both fish oil and exercise independently reduced body fat.

This study showed that increasing intake of omega-3 fatty acids could be a useful addition to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk.

Source: USANA Health Sciences

Researchers recently investigated the impact of red wine polyphenols on the levels of malondialdehyde (MDA), a natural by-product of fat digestion known to increase risk for heart disease and other chronic conditions.

In a randomized crossover study, participants were fed three different meals consisting of dark meat turkey cutlets. The control meal consisted of turkey meat and water. The second meal consisted of turkey meat with polyphenols added after cooking (concentrated wine) followed with a glass of red wine (about 7 ounces). The third meal consisted of turkey meat with polyphenols added before cooking and then followed by a glass of wine.

At various stages of the study, researchers measured blood and urine levels of MDA and found that levels nearly quintupled after the control meal, while increases in MDA levels were completely prevented after subjects consumed the meals with polyphenols.

This study suggests that red wine polyphenols exert a beneficial effect by inhibiting absorption of MDA, a compound toxic to cells. In addition, these results demonstrate the potentially harmful effects of oxidized fats found in foods and the important benefit of dietary polyphenols in a meal.

FASEB J. 2008 Jan;22(1):41-6.

Source: USANA Health Sciences

In a recent study, metabolic effects of meals with varying glycemic index (GI) were evaluated. In a group of healthy volunteers, glucose, insulin, and leptin responses to two contrasting breakfast cereals were measured. Leptin is a hormone produced by fat cells that indicates the degree of hunger to the hypothalamus of the brain. Lower leptin levels trigger a sense of satiety and decreased hunger.

Meals were provided on two separate occasions in random order after a 12-hour overnight fast, and consisted of 50 g of available carbohydrate from either Corn Flakes (Kellogg’s), or Fiber One (General Mills). Blood samples were obtained at rest, and 30, 60, 90 and 120 min after eating. The GI was calculated from the glucose response to the test meal normalized against a 50 g oral glucose load.

The average GI for Corn Flakes was 125 and 49 for Fiber One. These meals were classified as high GI and low GI, respectively, and were significantly different from each other. The insulin response following the low glycemic meal was significantly reduced compared to the high glycemic meal. The high glycemic meal significantly suppressed circulating leptin levels compared to the low glycemic meal.

Lower insulin response and higher circulating leptin levels suggest that low-glycemic meals promote a post-meal environment that is favorable for reduced food consumption; this may be advantageous in the control of obesity and related disorders including insulin resistance and type 2 diabetes.

Ann Nutr Metab 2007 Dec 10;51(6):512-518

Source: USANA Health Sciences

Fitness, regardless of body weight, can provide a strong protective effect against premature death in men with metabolic syndrome as well as healthy men.

In a study published in the Archives of Internal Medicine, over 19,000 men were recruited to determine the relationship between cardiorespiratory fitness (CRF) and mortality risk in healthy men and those with metabolic syndrome. The study group, which included about 3,800 men with metabolic syndrome, were evaluated for fitness and then followed for up to 17 years.

Healthy men who were out of shape at the beginning of the study were three times as likely as their fit peers to die of cardiovascular disease. While men with metabolic syndrome were 89 percent more likely than healthy men to die of heart disease over the years, men with metabolic syndrome who were unfit had twice the death rate as their fit counterparts.

According to the researchers, “This study strengthens the argument for aggressive public health campaigns aimed at increasing physical activity levels in the population.” Fitness, regardless of body weight, can provide a strong protective effect against premature death in men with metabolic syndrome as well as healthy men.

Arch Intern Med 2004 May 24;164(10):1092-7

 Source: USANA Health Sciences

Weight control strategies that are both safe and effective are needed to reduce the rate of the current obesity epidemic. A recent study compared the macronutrient and micronutrient levels in the foods chosen by women following two different weight reduction programs.

Ninety-six generally healthy overweight or obese women randomly placed into two treatment groups: Traditional Food Group (TFG) or a Meal Replacement Group (MRG). The MRG included the use of 1-2 meal replacement drinks or bars per day. Both groups aimed to restrict energy levels to approximately 1,300 calories per day.

After one year, weight loss was not significantly different between the groups, and both groups had macronutrient (Carbohydrate:Protein:Fat) ratios that were within the ranges recommended. Both groups experienced an improved dietary pattern with respect to decreased saturated fat, cholesterol, and sodium, with increased total servings/day of fruits and vegetables. However, the TFG had a significantly lower dietary intake of several vitamins and minerals compared to the MRG and was at greater risk for inadequate intake.

Although both groups successfully lost weight while improving overall dietary adequacy, the group incorporating fortified meal replacements tended to have a more adequate essential nutrient intake compared to the group following a more traditional food group diet. This study supports the need to incorporate fortified foods and/or dietary supplements while following an energy- restricted diet for weight loss.

Nutr J. 2007 Jun 25;6:12

 Source: USANA Health Sciences

A study conducted at Duke University and published in the journal Chest compared the effects of three different exercise regimens on fitness improvements in overweight men and women who were at risk for heart disease.

Broken into four groups, the volunteers either did not exercise, walked briskly for 12 miles a week at a moderate intensity, walked briskly or jogged slowly 12 miles a week at a vigorous intensity, or jogged 20 miles a week at a vigorous intensity.

Two measurements of fitness – time-to-exhaustion and oxygen consumption – were measured before and after 7 to 9 months of training.

All exercise groups saw fitness improvements compared to baseline. Results indicated that two to three hours of mild exercise a week at a moderate intensity is sufficient to increase aerobic fitness and cut the risk of cardiovascular disease. Increasing either the intensity or the amount of exercise provided additional improvements in fitness.

Although more vigorous exercise should still be encouraged for maximum benefit, this study demonstrates that it is appropriate to recommend mild exercise to improve fitness levels and reduce cardiovascular disease risk, especially in those who are overweight and sedentary.

Chest. 2005;128:2788-2793.

Source: USANA Health Sciences

Adolescent obesity increases future coronary heart disease risk

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.

Source: USANA Health Sciences

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.

Source: USANA Health Sciences

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.

 Source: USANA Health Sciences

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.

Source: USANA Health Sciences

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

Source: USANA Health Sciences

Beta-carotene supplementation long-term may delay mental decline

In a newly published study, researchers tested the cognitive function of participants in the Physicians’ Health Study II (PHSII), a continuation of the Physicians’ Health Study (PHS) trial looking at the effects of beta-carotene and other vitamin supplements on chronic disease. The subjects included participants from the original PHS (started in 1982) and newer recruits from 1998.

The researchers tested the general cognition, verbal memory, and category fluency of 5,956 participants, including 4,052 participants from the PHS with a minimum supplementation period of 18 years.

Among the 1,904 newly recruited subjects (average supplementation of 1 year) no differences in cognition were evident whether they took beta-carotene or the placebo.

However, among the long-term supplement users from the PHS, the mean global score (average of all tests) was significantly higher in the beta carotene group than in the placebo. On verbal memory, men receiving long-term beta carotene supplementation also performed significantly better than the placebo group. The potential mechanism for the protective effects could be related to the role of vitamin A and beta-carotene on beta-amyloid protein production in the brain. The build-up of plaque from beta-amyloid deposits is associated with oxidative stress, cell death, and increased risk of Alzheimer’s disease.

The study is the first to look at long-term antioxidant supplementation in relation to a decline in cognitive function that occurs naturally with age, and that precedes diseases such as Alzheimer’s.

Arch Intern Med. 2007;167(20):2184-2190.

Source: USANA Health Sciences

Beta-carotene linked to reduced mortality risk in the elderly

In a study published in the American Journal of Clinical Nutrition, researchers have demonstrated an association between plasma carotene levels and lower death rates among the elderly. This prospective study involved 1168 elderly men and women who were followed for 10 years. After the follow-up period, researchers looked at causes of mortality in the study population. The subjects with higher plasma carotene concentrations had a lower overall mortality risk, and a lower risk of mortality from cancer and cardiovascular disease specifically. To put the results in context, researchers performed a meta-analysis of 5 studies on plasma antioxidants and all-cause mortality in elderly populations.

These findings are somewhat surprising since some of the previous supplemental trials have been negative or inconclusive. The researchers suggested that the confusing evidence so far may indicate that beta-carotene needs to be taken in concert with other antioxidants to have a beneficial effect on health.

American Journal of Clinical Nutrition, Vol. 82, No. 4, 879-886, October 2005

Source: USANA Health Sciences

Vitamin D has long been known only for its role in bone health and proper calcium absorption. However, the explosion of research over the past few years has revealed that vitamin D plays a key role in cell growth regulation in the body, and may be related to the prevention of 22 forms of cancer as well as heart disease, multiple sclerosis, osteoporosis, and many other disorders.

Due to what is being considered a Canadian crisis and worldwide problem, the Vitamin D Society is recognizing the month of November as Vitamin D Awareness Month.

For the complete story and more information about the society and vitamin D research, go to the following link:

http://www.newswire.ca/en/releases/archive/October2007/31/c2359.html

Source: USANA Health Sciences

Researchers at the University of Utah, in collaboration with USANA Health Sciences, conducted a randomized, double-blind, placebo-controlled, crossover study to test the effectiveness of quercetin supplementation in lowering unhealthy blood pressure levels. The subjects were divided into two groups: prehypertensives (120-139 mm Hg systolic/80-89 mm Hg diastolic) or stage 1 hypertensives (140-159 mm Hg systolic/90-99 mm Hg diastolic). The participants were given either 730 mg quercetin/day or placebo for 28 days.

Blood pressure remained unchanged in prehypertensives after supplementation with quercetin. In contrast, stage 1 hypertensive subjects showed significant reductions in both systolic (-7 mm Hg) and diastolic (-2 mm Hg) blood pressure after quercetin supplementation. This is the first published study to show that quercetin supplementation can reduce blood pressure in hypertensive adult humans. Additionally, it is important to note that quercetin supplementation did not influence the blood pressure of non-hypertensive individuals.

J. Nutr. 137:2405-2411, November 2007

Source: USANA Health Sciences

Cells in the brain and nervous system depend on optimal mitochondrial function for energy. A research study published in the journal Neurobiology of Disease showed that oxidative stress causes mitochondria to produce excessive free radicals, leading to nerve cell damage and destruction. Due to its function in the mitochondrial energy process and its role as an antioxidant, researchers evaluated CoEnzyme Q10 for its ability to protect nerve cells.

The results of this study revealed that CoEnzyme Q10 inhibits the production of free radicals by the mitochondria and stabilizes the mitochondrial membrane when nerve cells are subjected to oxidative stress. CoEnzyme Q10 may therefore have a potential benefit in reducing the risk of various neurodegenerative diseases.

Neurobiol Dis. 2005 Apr;18(3):618-27

Source: USANA Health Sciences

Age-Related Macular Degeneration (AMD) is a degenerative eye disease that causes damage to the macula (central retina) of the eye, impairing central vision. People affected by Age-Related Macular Degeneration have difficulty reading, driving and performing activities that require clear central vision. AMD is the most common cause of vision loss in developed countries.

A recent report published in the September, 2007 issue of the journal Archives of Ophthalmology added more evidence to support previous research showing that carotenoids zeaxanthin and lutein are protective against AMD. Dark green leafy vegetables are the primary dietary sources of lutein and zeaxanthin, but they are also found in some other colorful fruits and vegetables. Average dietary intake in the U.S. is only 2 mg/day, far below the 6 mg/day level most studies indicate as a minimum needed to reduce the risk of AMD.

In the current report, members of the Age-Related Eye Disease Study (AREDS) Research Group evaluated the diets of 4,519 AREDS participants aged 60 to 80 years. Retinal photographs were used to divide the subjects into five categories of macular disease severity, from individuals with little or no evidence of macular degeneration (the control group) to severe, neovascular disease. Dietary questionnaires were analyzed for lutein, zeaxanthin, beta- carotene, lycopene, and other nutrient levels.

Participants whose intake of lutein and zeaxanthin were greatest had a significantly lower risk of AMD than those whose intake was least, and were less likely to have large or extensive intermediate drusen, the deposits on the retina or optic nerve that characterize the disease. No risk reductions were associated with the other nutrients examined in this study.

The Relationship of Dietary Carotenoid and Vitamin A, E, and C Intake With Age-Related Macular Degeneration in a Case-Control Study: AREDS Report No. 22. Age-Related Eye Disease Study Research Group. Arch Ophthalmol. 2007;125:1225-1232.

Source: USANA Health Sciences