Here are the ’straight goods’ based on evidence provided by dietitians – your trusted source for food and nutrition advice:

Vitamin C

The Facts: Optimal vitamin C status has been identified as important for the immune cells involved in defense against viruses. The main function of vitamin C is to help heal cuts and wounds; keep gums, teeth, and bones healthy; keeps blood vessel walls strong and helps absorb iron from the foods we eat. Despite being studied for over 40 years, there is insufficient evidence to advise taking more vitamin C to prevent colds or the flu. The Recommended Daily Allowance [RDA] is 75 mg for women and 90 mg for men (an additional 35 mg should be added for smokers). This is easily obtained by having 1-2 servings of vitamin C rich citrus fruits (such as oranges), or vegetables like sweet peppers and broccoli. Vitamin C is also added to a number of foods that are routinely consumed by Canadians, such as apple juice. A higher dose of vitamin C is not without side effects such as causing digestive problems.

Zinc

The Facts: Zinc is important for the cells involved in defense against viruses. Zinc is also involved in many bodily functions. It supports normal growth and development during pregnancy, childhood and adolescence. It is also required for a proper sense of smell and taste so that low zinc status can influence your appetite and enjoyment of food. The current RDA for zinc is 8 mg for women and 11 mg for men. The best sources of zinc are seafood, meat, seeds, cooked dried beans, peas and lentils. A serving of beef (75 g or 2 ½ oz) provides approximately 4.6 mg of zinc and a serving of lentils (175 mL or ¾ cup) provides almost 2 mg of zinc. Plant sources are less reliable as the level of zinc in plants depends on the content in the soil. As a result, vegetarians who mainly depend on plant sources of nutrients are advised to consult with a dietitian to insure their needs are being met.

Selenium

The Facts: Although selenium is important for a healthy immune system, there is little evidence of a deficiency in the Canadian population or evidence that consuming selenium supplements will reduce the risk of viral infections. Recommended amounts are small, only 55 micrograms daily for adults, readily obtained from nuts, seafood, organ meat, pork and whole grains. Half a cup (125 mL) of cooked brown rice provides 8-10 micrograms of selenium and a serving of mixed nuts (60 mL or ¼ cup) has about 150 micrograms of selenium.

Feed a cold and starve a fever? Not good advice!

The Facts: Viral infections, such as the flu, are often associated with a fever. However, there is no evidence that “starving a fever” by reducing the amount of food eaten will reduce a fever. In fact, a fever is a helpful means used by our own immune system in order to fight off the viral infection. If we stop eating, the immune system doesn’t work as well and all of the nutrients mentioned above, as well as many others, are important to the immune system. “While it may be tempting to eat less when you’re feeling unwell, try to eat smaller, more frequent meals and healthy snacks to support your body’s defenses and drink plenty of water,” says Field.

The Bottom Line - “Optimal health doesn’t require a complicated diet based on a certain number of ’super foods’. The key to good health is eating a well-planned balanced diet that focuses on variety,” concludes Dr. Field. While following these tips alone may not be enough to prevent you from catching the flu this season, they will help your immune system respond to its effects and contribute to life-long health.

Planning a healthy eating pattern can be challenging for busy families and individuals. A registered dietitian has the training and expertise to sort nutrition facts from fiction and to translate the science into easy tips you can use every day. Find a dietitian near you at www.dietitians.ca/find.

About Catherine Field

Dr. Catherine Field PhD, RD is currently a Professor in the Alberta Institute for Human Nutrition in the Department of Agricultural, Food and Nutritional Science at the University of Alberta. Her research focuses on the role of nutrition and specific nutrients on the function of the immune system in health and disease with a primary interest in characterizing the role of nutrients on the development and function of the immune system both in health and in disease states, including cancer.

Source
Dietitians of Canada

Americans are eating healthier diets than they did in 1965, but college-educated people are doing better than high school dropouts, new research indicates.

That may seem obvious, but it wasn’t the case in 1965. Then, people who had not finished high school, those who were high school graduates and those who went to college all had about the same level of diet quality.

But a more recent survey by Barry Popkin, Ph.D., and colleagues from the Department of Nutrition at the University of North Carolina at Chapel Hill found that while dietary quality has improved overall, those with more education now have much healthier diets.

‘In fact, the gap in diet between higher educated persons and lower educated persons may explain the large disparity in health between higher and lower socioeconomic groups in the United States,’ Popkin says.

The research is published in the July issue of the American Journal of Preventive Medicine. Popkin emphasized that this study examined the composition of the diet, not energy intake or obesity.

Comparing dietary habits from 1965 and 1994-96, Popkin and colleagues measured the overall healthfulness of the diets of 6,475 respondents in 1965 and 9,241 in 1994-96. In two telephone calls on different days, respondents were asked to recall what they had eaten in the previous 24 hours.

They tabulated results using the Revised Dietary Quality Index, a rating of a diet’s overall healthfulness.

The effects of income and education were rarely significant in 1965, Popkin says. There were a few differences back then: College-educated people took in more calcium, iron and servings of fresh fruit than less-educated people did, but they also ate more saturated fats — which decreased their Dietary Quality Index.

Between 1965 and the mid-1990s, the overall Dietary Quality Index improved for all education groups. But better-educated people not only have better diets today compared to their counterparts 30 years ago, they also eat better than today’s high school dropouts.

Thirty years later, the effects of education are more pronounced. For instance, white men with no high school diploma scored 61.9 on the Dietary Quality Index, while their college-educated peers scored 68.3.

A similar gap separated black men in the same educational categories. Income variations produced far smaller differences, said Popkin.

‘In general,’ Popkin says, ‘extra years of schooling related to small upward shifts in diet quality. The highest diet quality level was found among white women who attended college and for those with income far above the poverty line.’

Comparison of the two surveys found some anomalies, as well. For instance, race alone did not always predict results. Black male high school graduates saw no change in their dietary quality scores, while black women with the same level of education saw significant gains.

An exception to the general dietary improvement was a drop in calcium intake, which Popkin blames on reduced milk consumption. Other researchers have noticed the same pattern with calcium, which is needed to build and maintain strong bones.

Besides calcium, the most striking dietary shortcoming in the 1994-96 survey came with a disappointingly small shift downward in the use of added sugar, discretionary fat, salt and alcohol.

Popkin said that by the 1994-96 survey, people were consuming less fat and cholesterol and more grains and vegetables. But this good news was overshadowed by the increasing prevalence of obesity in the United States, he said.

The Dietary Quality Index research model reflects proportion, variety and moderation in diet, but does not account for total energy intake, Popkin said. So while it showed a lower percentage of calories coming from fat (a sign of dietary improvement) because the consumption of fats remained constant, total calories increased, leading to a net weight gain.

Exactly why more education is linked to better diets wasn’t clear, Popkin says. Previous research showed that, more than income or occupation, lower levels of education were associated with higher disease risk.

‘It may be caused by a diffusion of knowledge, skills, attitudes and beliefs that occur while individuals are participating in the educational system,’ he says. Better-educated people may get better nutritional information or are more likely to act on it than those with less schooling.

‘Improving the education system in the United States may help to eliminate disadvantages in diet quality,’ Popkin concludes.

By Aaron Levin, staff writer
Health Behavior News Service

For more information:
Health Behavior News Service: 202-387-2829 or www.hbns.org.
Interviews: Contact Barry M. Popkin at 919-966-1732 or popkin@unc.edu.
American Journal of Preventive Medicine:
Contact the editorial office at 619-594-7344.