All posts in Knowledge

Trans Fats Interfere with Blood Flow

Print pagePDF pageEmail page

Trans fats are made through hydrogenation, which involves bubbling hydrogen through hot vegetable oil, changing the arrangement of double bonds in the essential fatty acids in the oil and “saturating” the “unsaturated” carbon chain with hydrogen. Because double bonds are rigid, altering them can straighten or twist fat molecules into new configurations that give the fats their special qualities, such as the lower melting point of margarine that makes it creamy at room temperature.

Kummerow, 94, has spent nearly six decades studying lipid biochemistry, and is a long-time advocate for a ban on trans fats in food.

While the body can use trans fats as a source of energy for maintenance and growth, Kummerow said, trans fats interfere with the body's ability to perform certain tasks critical to good health. Because these effects are less obvious, many researchers have missed the underlying pathologies that result from a diet that includes trans fats, he said.

Trans fats displace – and cannot replace – the essential fatty acids linoleic acid (omega-6) and linolenic acid (omega-3), which the body needs for a variety of functions, including blood flow regulation. Studies have shown that trans fats also increase low-density lipoproteins (LDLs) in the blood, a factor which some believe contributes to heart disease.

Trans fats are associated with increased inflammation in the arteries. And trans fats have been found to change the composition of cell membranes, making them more leaky to calcium. Inflammation, high LDL cholesterol and calcified arteries are the signature ingredients of atherosclerosis.

Trans fats also were shown to interfere with an enzyme that converts the essential fatty acid linoleic acid into arachidonic acid, which is needed for the production of prostacyclin (a blood-flow enhancer) and thromboxane (which regulates the formation of blood clots needed for wound healing). While some in the food oil industry believed this problem could be overcome simply by adding more linoleic acid to partially hydrogenated fats, in 2007 Kummerow's team reported that extra linoleic acid did not overcome the problem.

“Trans fats inhibited the synthesis of arachidonic acid from linoleic acid, even when there was plenty of linoleic acid available,” he said.

The new study reports that in addition to interfering with the production of arachidonic acid from linoleic acid, trans fats also reduce the amount of prostacyclin needed to keep blood flowing. Thus blood clots may more easily develop, and sudden death is possible.

According to the American Heart Association, each year more than 330,000 people in the U.S. die from coronary heart disease before reaching a hospital or while in an emergency room. Most of those deaths are the result of sudden cardiac arrest, the Heart Association reports.

“This is the first time that trans fatty acids have been shown to interfere with yet another part of the blood-flow process,” Kummerow said. This study adds another piece of evidence to a long list that points to trans fats as significant contributors to heart disease, he said.

Kummerow believes the U.S. Food and Drug Administration's new requirement (begun in 2006) that trans fats be included on food labels is inadequate and misleading. Anything less than one-half gram of trans fats per serving can be listed as zero grams, Kummerow said, so people are often getting the mistaken impression that their food is trans fat-free.

“Go to the grocery store and compare the labels on the margarines,” he said. “Some of them say zero trans fat. That's not true. Anything with partially hydrogenated oils in it contains trans fat.”

“Partially hydrogenated fats can be made trans fat-free,” Kummerow said. “The industry would be helped by an FDA ban on trans fat that would save labeling costs, medical costs and lives.”

More

12 Ways Vitamin D Can Help

Print pagePDF pageEmail page

Vitamin D, the “sunshine” vitamin, does a lot more than help keep bones strong — scientists are finding that it impacts all aspects of our health.

Vitamin D can be obtained from exposure to sunlight, vitamin supplements (vitamin D-3 is recommended by many experts), and foods such as salmon and tuna.

Recent studies show that having high levels of vitamin D in our blood can help protect against many diseases, while low levels are linked with several disorders.

Here are 12 critically important ways vitamin D can help protect your health:

1. Colon cancer. A study by cancer prevention specialists at the Moores Cancer Center at the University of California found that high amounts of vitamin D could slash colorectal cancer rates by two-thirds. A European study found that high levels of vitamin D cut the odds of colon cancer by almost 40 percent.

2. Breast cancer. Research using data from two earlier studies found that women with the highest amounts of vitamin D in their blood lowered their risk of breast cancer by 50 percent when compared to women with the lowest levels. A Canadian study found that women who took a vitamin D pill of least 400 international units every day lowered their risk of developing breast cancer by 24 percent.

3. Heart disease. A British study has found that middle-aged and elderly people with high levels of vitamin D reduce their risk of developing cardiovascular disease by 33 percent. Utah scientists found that patients who raised their blood levels of vitamin D after being diagnosed as deficient lowered their risk of having a heart attack by 33 percent, their risk of heart failure by 20 percent, and their risk of dying from any cause by 30 percent.

4. Brain health. A European study of men between the ages of 40 and 79 found that high levels of vitamin D were associated with high scores on memory tests.

5. Diabetes. Researchers at Warwick Medical School found that adults with the highest blood levels of vitamin D lowered their risk of developing Type 2 diabetes by 55 percent.

6. Asthma. Asthmatics who have high levels of vitamin D have better lung function and respond to treatment better than those who have low levels, according to researchers at National Jewish Health in Denver.

7. Bone health. Vitamin D and calcium reduce the risk of hip fractures in the elderly. Studies show that people who are deficient in vitamin D absorb 65 percent less calcium than those with normal levels. One recent study from the United Kingdom found that 95 percent of patients with hip fractures were deficient in vitamin D, and having adequate levels could reduce hip fractures by up to 50 percent.

8. Depression. University of Toronto researchers found that people who suffer from depression, especially those with seasonal affective disorder, improved as the levels of vitamin D in the blood rose. Researchers in Norway found that high doses of vitamin D helped relieve the symptoms of depression.

9. Multiple sclerosis. Australian scientists discovered that people who live in the state furthest from the equator — and get less sunlight — are seven times more likely to develop multiple sclerosis than those who live in the sunniest state.

10. Colds and flu. Scientists at the University of Colorado found that people with the lowest amounts of vitamin D in their blood had the highest incidence of colds and flu.

11. Rheumatoid arthritis. Researchers from the University of Alabama, Birmingham, found that women with the highest levels of vitamin D in their blood lowered their chances of developing rheumatoid arthritis by 30 percent.

12. Crohn's Disease. Vitamin D switches on genes responsible for fighting Crohn's disease (a chronic inflammatory disease primarily affecting the small and large intestine), according to Canadian researchers. “Our data suggests that vitamin D deficiency can contribute to Crohn's disease,” Dr. John White, endocrinologist at the Research Institute of the McGill University Health Center in Montreal, Canada, said in a statement.

(Source: National Institute of Health UK)

 

More

Calcium may help you live longer

Print pagePDF pageEmail page

All had reported on their diet at the beginning of the study. During follow-up, about 2,358 died.

The top calcium consumers had a 25 percent lower risk of dying from any cause and a 23 percent lower risk of dying from heart disease during follow-up relative to men that had the least amount of calcium in their diet. Calcium intake didn't significantly influence the risk of dying from cancer.

Men in the top third based on their calcium intake were getting nearly 2,000 milligrams a day, on average, compared to about 1,000 milligrams for men in the bottom third. The US Recommended Dietary Allowance (RDA) for calcium intake is 1,000 milligrams for men 19 to 50 years old and 1,200 milligrams for men 50 and over. “Intake of calcium above that recommended daily may reduce all-cause mortality,” Kaluza and her colleagues conclude.

Calcium could influence mortality risk in many ways, they note, for example by reducing blood pressure, cholesterol, or blood sugar levels. For the men in the study, the main sources of calcium in the diet were milk and milk products and cereal products. In contrast to calcium, there was no relationship between magnesium consumption and overall mortality or deaths from cancer or heart disease. Study participants' intakes ranged from around 400 milligrams per day to around 525 milligrams; the RDA for magnesium is 420 milligrams for men 31 and older.

This analysis, the researchers say, may have found no effect for magnesium because all of the men in the study seemed to be getting enough of the mineral in their diet. “Further studies are needed in other populations with lower dietary magnesium intakes to address this issue,” they say. Future research should also look into calcium and magnesium intake from drinking water, they add, which can be a significant source of these minerals.

SOURCE: American Journal of Epidemiology

More

Eating oily fish can protect women from infertility

Print pagePDF pageEmail page

 

Eating a diet of plenty of oily fish daily can protect women against infertility, says a new study. Researchers have carried out the study of 70,000 nurses and found those who ate the most tuna, salmon, mackerel and other fish high in omega-3 fatty acids were nearly 22 per cent less likely to develop endometriosis which is known to causes infertility.

However, the study found that those whose diets were heavily laden with harmful transfats – chemically altered vegetable oils – found in thousands of products from cakes and biscuits to pies and chips were 48 per cent more at risk of developing endometriosis. The condition arises when cells normally found in the womb lining attach themselves to other parts of the pelvic area, causing inflammation and often leading to infertility.

The study, the largest to have investigated the link between diet and endometriosis, followed the nurses for 12 years from 1989. It found while the total amount of fat consumed did not matter, the type did.

Gynaecologist Dr Stacey Missmer, of Harvard Medical School, Boston, said her findings, not only suggest that diet may be important in the development of endometriosis but also provide more evidence for eliminating trans fats, which are used to bulk up foods and increase their shelf life.

“Millions of women worldwide suffer from endometriosis. Many have been searching for something they can do for themselves, or their daughters, to reduce the risk of developing the disease. These findings suggest dietary changes may be something they can do. The results need to be confirmed by further research, but this study gives us a strong indication that we are on the right track in identifying food rich in omega-3 oils as protective for endometriosis and trans fats as detrimental,” she said.

The study is published in the 'Human Reproduction' journal.

More

Vitamin K tied to lower cancer risk

Print pagePDF pageEmail page

In the current study, vitamin K2 — which study participants most frequently got through cheese — was linked to the odds of developing or dying from cancer, whereas vitamin K1 was not.

The findings are based on data from 24,340 German adults who were between the ages of 35 and 64, and cancer-free at the outset. The researchers estimated the participants' usual vitamin K intake based on a detailed dietary questionnaire. Over the next decade, 1,755 participants were diagnosed with colon, breast, prostate or lung cancers, of whom 458 died during the study period.

In general, the researchers found, the one quarter with the highest intakes of vitamin K2 were 28 percent less likely to have died of any one of the cancers than the one-quarter of men and women with the lowest intakes of the vitamin. That was with factors like age, weight, exercise habits, smoking and consumption of certain other nutrients, like fiber and calcium, taken into account.

Of the one-quarter of study participants who got the least vitamin K2, 156 — or 2.6 percent — died of one of the four cancers. That was true of 1.6 percent of participants with the highest intakes of the vitamin from food.

When Linseisin's team looked at the cancer types individually, there was no clear link between either form of vitamin K and breast cancer or colon cancer. However, greater consumption of vitamin K2 was linked to lower risks of developing or dying from lung cancer — a disease for which smoking is the major risk factor — or of developing prostate cancer.

Of the one-quarter of study participants with the lowest vitamin K2 intakes, 47 — or 0.8 percent — developed lung cancer, versus 0.4 percent of the one-quarter who got the most vitamin K2 in their diets. When it came to prostate cancer, there were 111 cases among the one-quarter of men with the lowest vitamin K2 intakes, and 65 cases in the group with the highest consumption.

In theory, vitamin K itself could offer some protection against cancer. It's often used to counteract too-high doses of blood thinners, although this does not have an obvious link to cancer. In lab research, however, Linseisin and his colleagues point out, the vitamin has been shown to inhibit cancer cell growth and promote apoptosis — a process by which abnormal cells kill themselves off.

But whether vitamin K intake itself is responsible for the lower cancer risks in this study is unclear, according to the researchers. One limitation is that they estimated vitamin K intake based on participants' reported eating habits; most of their vitamin K came from eating cheese, and it's possible, Linseisin and his colleagues note, that some other components of that food are related to cancer risk.

Future studies, the researchers say, should measure people's blood levels of vitamin K and look at the relationship of those levels with cancer risks.

SOURCE: American Journal of Clinical Nutrition

More

Vitamin D – What you need to know

Print pagePDF pageEmail page

Some people may be at risk of not getting enough vitamin D because they don’t get enough in their diet or because they have more limited sun exposure which reduces the amount of vitamin D their bodies make. Those at risk include:

  • Breastfed infants require 400 IU vitamin D per day from birth. Because breast milk is naturally low in vitamin D and infants are not usually exposed to the sun, a vitamin D supplement of 400 IU is recommended. Healthy term infants fed infant formula do not require a vitamin D supplement as it is already added to the formula.
  • Pregnant women should consume vitamin D from food (for example, from a least 3 glasses of milk der day) or supplements (usually 200-400 IU is provided in a supplement) to ensure the baby is born with optimal vitamin D in their body. If a supplement is taken, be sure not to exceed 2000 IU vitamin D per day.
  • Adults over 50 years may not prodce vitamin D in skin as well as when they were younger. It is recommended that adults (men and women) over 50 years take a supplement of 400 IU / day.
  • People with skin darkly pigmented with melanin are less able to make vitamin D from exposure to sunlight. Since many people with darker skin colour also avoid vitamin D fortified milk due to lactose intolerance, their dietary intake of the vitamin may be low, so extra vitamin D, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU) would be a good idea.
  • People with limited sun exposure sun exposure is limited due to mostly living or working indoors, wearing clothing such as long robes and head coverings, then it is wise to carefully choose vitamin D rich foods (see above) or to take a vitamin D supplement, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU).
  • Some medical conditions such as Crohn's disease, cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease, interfere with absorption of vitamin D. Being overweight and obese causes fat to stay stored in fat tissues and not be released into the blood, preventing vitamin D from being available to the body. If you have one of these conditions, check with your doctor to ask if a vitamin D supplement is needed.
  • Can I take too much vitamin D?

    Yes. Too much vitamin D can be harmful. The total daily intake from food and supplements combined should not exceed 1000 IU for infants and young children and 2000 IU for adults.

    The Bottom Line

    Most people, except those in the risk groups noted above, can get enough vitamin D if they eat enough vitamin D rich foods (for example, milk, vitamin D fortified foods and some fatty fish) and if they engage in safe sun practices. If you are concerned about your vitamin D status, discuss the issue with Nastaran.

    Source: Dietitians of Canada. Reproduced with Permission. Note: The Australian adequate intake is 200 IU however Nastaran recommends 400 IU as per the Canadian recommended intake.

     

More