Featured Research

from universities, journals, and other organizations

Zinc Deficiences A Global Concern

Date:
September 17, 2009
Source:
Oregon State University
Summary:
Other vitamins and nutrients may get more headlines, but experts say as many as two billion people around the world have diets deficient in zinc -- and studies are raising concerns about the health implications this holds for infectious disease, immune function, DNA damage and cancer. One new study has found DNA damage in humans caused by only minor zinc deficiency.

Other vitamins and nutrients may get more headlines, but experts say as many as two billion people around the world have diets deficient in zinc – and studies at Oregon State University and elsewhere are raising concerns about the health implications this holds for infectious disease, immune function, DNA damage and cancer.

One new study has found DNA damage in humans caused by only minor zinc deficiency.

Zinc deficiency is quite common in the developing world. Even in the United States, about 12 percent of the population is probably at risk for zinc deficiency, and perhaps as many as 40 percent of the elderly, due to inadequate dietary intake and less absorption of this essential nutrient, experts say. Many or most people have never been tested for zinc status, but existing tests are so poor it might not make much difference if they had been.

"Zinc deficiencies have been somewhat under the radar because we just don't know that much about mechanisms that control its absorption, role, or even how to test for it in people with any accuracy," said Emily Ho, an associate professor with the Linus Pauling Institute at OSU, and international expert on the role of dietary zinc.

However, studies have shown that zinc is essential to protecting against oxidative stress and helping DNA repair – meaning that in the face of zinc deficiency, the body's ability to repair genetic damage may be decreasing even as the amount of damage is going up.

Two studies recently published, in the Journal of Nutrition and the American Journal of Clinical Nutrition, found significant levels of DNA damage both with laboratory animals and in apparently healthy men who have low zinc intake. Zinc depletion caused strands of their DNA to break, and increasing the intake of zinc reversed the damage back to normal levels.

"In one clinical study with men, we were able to see increases in DNA damage from zinc deficiency even before existing tests, like decreased plasma zinc levels, could spot the zinc deficiency," Ho said. "An inadequate level of zinc intake clearly has consequences for cellular health."

Many zinc studies, Ho said, have focused on prostate cancer – the second leading cause of cancer deaths in American men – because the prostate gland has one of the highest concentrations of zinc in the body, for reasons that are not clearly known.

When prostate glands become cancerous, their level of zinc drops precipitously, and some studies have suggested that increasing zinc in the prostate may at least help prevent prostate cancer and could potentially be a therapeutic strategy. There are concerns about the relationship of zinc intake to esophageal, breast, and head and neck cancers. And the reduced zinc status that occurs with aging may also contribute to a higher incidence of infection and autoimmune diseases, researchers said in one study in the Journal of Nutrition.

Zinc is naturally found associated with proteins in such meats as beef and poultry, and in even higher levels in shellfish such as oysters. It's available in plants but poorly absorbed from them, raising additional concerns for vegetarians. And inadequate intake is so prevalent in the elderly, Ho said, that they should usually consider taking a multivitamin to ensure adequate levels.

Zinc is an essential micronutrient for numerous cellular processes. But taking too much zinc can also be a concern, because in excess it can interfere with the absorption of other important nutrients such as iron and copper. The recommended daily allowance is eight milligrams a day for women, 11 for men, and anything over 50 milligrams a day could be considered excessive, Ho said.

"The consequences of zinc deficiency in adults have been understudied despite the recognition of symptoms of zinc deficiency for decades," researchers wrote in one recent report. "A considerable body of evidence suggests that zinc deficiency may increase the risk of some chronic diseases, including cancer. This link may be attributed to the role of zinc in antioxidant defense and DNA damage repair."


Story Source:

The above story is based on materials provided by Oregon State University. Note: Materials may be edited for content and length.


Cite This Page:

Oregon State University. "Zinc Deficiences A Global Concern." ScienceDaily. ScienceDaily, 17 September 2009. <www.sciencedaily.com/releases/2009/09/090917115700.htm>.
Oregon State University. (2009, September 17). Zinc Deficiences A Global Concern. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2009/09/090917115700.htm
Oregon State University. "Zinc Deficiences A Global Concern." ScienceDaily. www.sciencedaily.com/releases/2009/09/090917115700.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins