As we get older, even our DNA shows signs of wear and tear. Dr Michael Fenech, project leader of Genome Health and Nutrigenomics at CSIRO Human Nutrition in Adelaide, Australia explains: "Damage to your individual DNA – your genome – can lead to all sorts of degenerative diseases and cancer."
Some damage is the result of age, and some is inherited. Fenech said, "we are building the database to be able to predict the best diet for each individual to optimise their genetic health."
The work Fenech did after receiving his doctorate related to the effects of ageing and radiation, which led to internationally renowned work in methods for determining the safety of pharmaceuticals, food ingredients and radiation emitting devices.
After some time as a radiation biologist and work in the Cell Mutation Unit at the Medical Research Council in Britain and post-doctoral studies in molecular biology, Dr Fenech returned to Australia to his current post at CSIRO Human Nutrition. Here he began his current work on individual genome health – and the importance of diet.
One of the first studies compared the DNA damage in a group of vegetarians and non-vegetarians. "The vegetarians tend to take in more natural vitamin C than non-vegetarians, and to be a bit higher in their folate intake," he says.
"The bottom line on the data was that B12 and folate were more important in determining DNA damage than vitamins E and C, and that there was no great difference between the two groups. The upshot was we needed to know the optimum levels of folate and B12 for prevention of genome damage and not, as they were previously set, for preventing anaemia," Fenech says. Subsequent studies have underlined the importance of the individual genotype in predicting the levels of folate and B12 each of us needs.
Dr Fenech hopes to one day establish Genome Health Clinics where we could have our DNA damage assessed and be given an individualized, optimum diet. In the meantime, he says, "we’re living in a low-folate background – 88 per cent of us don’t meet the RDA of 400 micrograms a day. And it’s hard work getting that RDA from foods that are low in folates."
So what are we looking for? If you have the stomache for it, fried chicken liver delivers 1385 micrograms of folate per 100 grams. Just below that is beef liver at 1057 micrograms, and pig liver at 540.
At 58 micrograms per 100g, you’d have to eat around 700g of lettuce a day to get your RDA. Sardines, whitebait and oysters are also good sources of vitamin B12 because you’re eating the whole animal, and folate and B12 are produced by the intestinal flora.
But Dr Fenech suggests you go easy on the wine as you dine. "An excessive amount of alcohol does not help. It destroys folate and damages the DNA."
There is a pressing need to encourage lifestyle changes that can prevent the majority of illness and disease, and a good deal of accidents and injury too. However, there is also a need for the determination of an individualizd diet so people can control and repair their damaged DNA. Let’s all wish Dr Fenech the very best in his continuing efforts to develop just such a form of diet therapy.
British researchers found people with asthma may require less inhaled medication if they also take vitamin C, according to the journal Respiratory Medicine (2006;100:174-9). Inhaled corticosteroids are the most commonly prescribed medications for asthma, but long-term use is associated with a number of undesirable side effects, such as cataracts, bone loss, and immune-system suppression.
In a clever two-part study, the researchers first determined whether vitamin C (1 gram per day for 16 weeks) or magnesium (450 mg per day for 16 weeks) could control asthma symptoms better than placebo in 92 adults with asthma. For good reasons, it was not expected to result in much improvement.
The benefits of supplements are likely to be small and difficult to detect with this study design because the vast majority of people with asthma already control their symptoms using drugs. Thus, there was little opportunity for people in this study to improve as long as they remained on the drugs, which they did at normal doses throughout this part of the study.
As expected, vitamin C and magnesium failed to improve symptom control significantly over baseline levels. Since previous research suggested these nutrients could offer a benefit, the authors designed a second part to the study to discover whether any beneficial effects of the supplements might have been masked by the drugs. To explore this, participants continued their supplement (vitamin C, magnesium, or placebo) while undergoing a ten-week, staged reduction in their corticosteroid medication.
This time vitamin C was found to have a modest effect. Asthma sufferers who took vitamin C were able to reduce their intake of inhaled corticosteroids without any loss of symptom control. This is actually quite important because the side effects of corticosteroid drugs increase when higher doses are used. So reducing daily intake by even a small amount could prevent some adverse effects. Magnesium demonstrated no effect in this study.
The adrenal glands produce the body’s own corticosteroid hormones. Research suggests that the adrenals require vitamin C to make these hormones. It therefore makes sense that taking a vitamin C supplement supports the body’s own production of adrenal corticosteroids, seemingly thereby reducing the amount of hormone needed in drug form.
People taking asthma medications should not abruptly discontinue their steroid medications, even if they are taking vitamin C as rapid withdrawal from steroid medications can cause serious health problems. Discuss the situation with your prescribing doctor to arrange a safe and monitored reduction in the amount of any prescription medication.
Researchers at the Moores Cancer Center at the University of California, San Diego call for prompt public health action to increase intake of vitamin D3 as an inexpensive tool for prevention of diseases that claim millions of lives each year. They recommend taking vitamin D supplements to prevent certain cancers.
Cancer prevention specialists have concluded that taking 1,000 international units (IU) of vitamin D3 per day may lower an individual’s risk of developing certain cancers, including breast, colon, prostate, and ovarian, by up to 50 percent.
The high prevalence of vitamin D deficiency, combined with the discovery of increased risks of certain types of cancer in those who are deficient, suggest that vitamin D deficiency may account for several thousand premature deaths from colon, breast, ovarian and other cancers annually, according to the Moores Center research group.
"African-American women who develop breast cancer are more likely to die from the disease than White women of the same age," notes co-author Cedric F. Garland. "African-Americans also have substantially poorer survival rates for colon, prostate and ovarian cancers as well." After making adjustments for socioeconomic status and access to healthcare, researchers conclude the difference in survival rate is linked to vitamin D deficiency.
The institution of a national public health action is strongly indicated, based on twenty-five years of worldwide studies on the benefits of vitamin D, Garland concludes. "Primary prevention of these cancers has largely been neglected, he suggests, but we now have proof that the incidence of colon, breast, prostate, and ovarian cancer can be reduced dramatically by increasing the public’s intake of vitamin D."
Many people are deficient in vitamin D because it is difficult to reach the recommended daily dosage without taking supplements. Foods such as milk, yogurt, cheese, and orange juice are fortified with vitamin D, but not in sufficient amounts to readily supply the daily target. A glass of milk, for example, has only 100 IU. I recommend the avoidance of dairy products for sound health reasons anyway, so supplementation is certainly supported.
Sunlight is an abundant source of vitamin D, since it plays a direct role in the body’s own production of this vitamin. Remember that sun exposure should be measured and controlled to avoid dangerous levels of solar radiation. Like the researchers, I recommend no more than 15 minutes of exposure daily over 40 percent of the body, other than the face, which should be protected from the sun.
Garland cautions that "Some fair-skinned people shouldn’t try to get any vitamin D from the sun" but I disagree. Cautious exposure to direct sunlight is by far the best way to meet the bulk of vitamin D needs for everyone.
"Breast cancer will strike one in eight American women in their lifetime," notes Garland, and "use of vitamin D might prevent this cancer in the first place."
Residents of the northern United States are at higher risk of deficiency during the winter months. This relates to the seasonally much reduced skin exposure to sunlight.
Expanded use of vitamin D supplements should not be delayed, according to the authors and I agree. The proposed intake of 1,000 IU is half the safe upper intake established by the National Academy of Sciences. It is estimated that the cost will be about five cents per day.
Many health-conscious consumers have switched to margarine or, increasingly, one of the low-fat alternatives on the market believing that replacing butter was important for heart-health. It’s understandable, with the latest breed of spreads promising to lower levels of low-density lipoprotein, the so-called "bad" cholesterol or LDL, thereby cutting your risk of heart attack.
These spreads contain plant sterols, also known as phytosterols, which are naturally occurring parts of all plants and have been shown to lower blood cholesterol levels by an average of 10 percent. Plant sterols block the body’s ability to absorb cholesterol from foods, thereby reducing it’s quantity in the blood. But as with most good things, there is a hitch.
Unfortunately, they do this at a price. They certainly can lower LDL cholesterol levels, but they deplete the levels of beta carotene and other carotenoids in the body. This is not a good thing to do. Beta carotene is the major source of vitamin A in the western diet and there is growing evidence that carotenoids protect the eyes and have anti-cancer properties.
Clearly this is a problem for people marketing these spreads. If you look very closely at the superfine print on margarine labels for instance, you will see things that would put you off using the product, if you knew at least a little about what it means. Believe me, you would be wise to read the fine print.
So what did the industry do? It sponsored research to find a solution. Australian research supervised by Peter Clifton at the CSIRO (Australia’s government research organization) and supported by the margarine industry found that eating extra fruit and vegetables could overcome the adverse effects that these margarines had on carotenoid levels (Journal of Lipid Research 2004;45(8):1493-9). In theory that sounds like a very positive solution.
Unfortunately, in practice, most people don’t eat enough fruit or vegetables to begin with so the chances of them eating "extra" servings every day are remote. Another problem that receives very little attention is the fact that phytosterol spreads are also not recommended for pregnant women or children. Like I said, read the fine print.
Another problem is that people tend to eat far too much of these spreads. Even if cholesterol lowering was a significant motivator, there can be too much of a good thing. While phytosterols do help to reduce LDL cholesterol, Clifton’s research found that eating more than the recommended amount will have no extra effect. More is definitely not better.
So is it true that butter is indeed better? If you must choose between butter and margarine, I would avoid margarine. That’s right, I can’t bring myself to promote butter, but margarine should definitely be avoided. If you absolutely must have something, then very little butter is better. But ask yourself if you really do need all that yellow grease. In the Mediterranean, people eat twice as much bread as we do, usually without any spread, and this is reflected in their lower levels of coronary heart disease.
The problem with butter lies in its saturated fat content, the type that raises blood cholesterol levels and heightens the risk of heart disease. Butter has 60 percent saturated fat whereas margarine has between 25 and 30 percent. Evidence to support the case against butter can be found in a Finnish study which began in the 1970s (International Journal of Epidemiology 1991;20(3):651-62). With a diet high in saturates from full-cream milk and butter, the Finns had the highest incidence of coronary heart disease in the world. A drive by the Government to reduce this was successful, and through the adoption of better diet and anti-smoking initiatives, the level of coronary heart disease fell by 60 percent in 20 years.
But let’s get back to margarine. If you have been fooled by margarine marketers into believing that it is less fattening than butter, you’re mistaken. Butter and margarine have the same high calorie level and fat content. Those who wrongly believe that margarine is less fattening sometimes tend to eat more, adding to the overweight risk or reality.
So if you eat breads or other foods that you just can’t face without a spread here’s a suggestion. Use ripe avocardo instead of margarine or butter. It will spread just like the yellow peril but will be good for you rather than damage your health. I recommend you try it.
Among patients hospitalized with heart failure, about one in three has deficient levels of thiamin, although thiamin deficiency was less common among those patients who were taking vitamin supplements, according to a new study in the Jan. 17, 2006, issue of the Journal of the American College of Cardiology.
"We found that one-third of congestive heart failure patients admitted to our hospital had red blood cell levels of thiamin that were lower than normal and would suggest deficiency. In contrast to some previous studies, we did not find a relationship between the development of thiamin deficiency and the amount or duration of diuretic use and urinary thiamin excretion. In fact, what was important was that a relatively small dose of thiamin from a multi-vitamin was protective against developing thiamin deficiency," said Mary E. Keith, Ph.D. from St. Michael’s Hospital in Toronto, Ontario, Canada.
Dr. Keith said that heart failure may increase the body’s need for certain nutrients, including thiamin, so even patients who are eating relatively well may not be getting enough of them. At the same time, the illness may make it harder to maintain a proper diet. She said that this study helps focus attention on the role of diet in managing serious conditions, such as heart failure.
"Physicians and the public have exclusively focused on drug therapy to the detriment of at least one of the foundations of good health-appropriate nutrition," she said.
Thiamin, also called vitamin B1, helps the body to digest carbohydrates and perform other functions. Like other B vitamins, thiamin is not stored in the body, so poor diet can lead to deficiency in a relatively short period of time and possibly worsen the symptoms of heart failure. Although thiamin deficiency has not been extensively studied among heart failure patients, the researchers said that there are several reasons to be concerned about the problem. For instance, many heart failure patients have poor diets, and some earlier studies have indicated that diuretic medicines prescribed to help treat the condition may increase the losses of thiamin.
This study is the largest study yet of thiamin deficiency among hospitalized heart failure patients, and it included participants with various degrees of illness. The researchers, including lead author Stacy A. Hanninen, R.D., M.S.C., measured the thiamin levels of 100 consecutively admitted patients with heart failure. They also measured the thiamin levels of 50 healthy people. The heart failure patients were almost three times as likely to be deficient in thiamin as the control subjects (33 percent versus 12 percent, p = 0.007).
"Our sample is quite representative of our hospitalized population of heart failure patients. We also used a direct measurement of thiamin status–the erythrocyte thiamin pyrophosphate–which is more specific than earlier assays that indirectly measured enzyme activity. Finally, our study also investigated factors other than diuretic medication, such as diet, medical status and demographic factors that might be contributing to the development of thiamin deficiency," Dr. Keith said.
Dr. Keith also pointed out that although they observed that patients taking supplements were less likely to be deficient in thiamin, the association did not reach statistical significance (p = 0.06). Further studies are needed to determine whether improving thiamin levels, either with supplements or via other means, will improve heart failure symptoms.
Professor John G.F. Cleland, F.A.C.C., from the University of Hull in Hull, U.K, who was not connected with this study, said that there are many reasons for heart failure patients to have difficulties maintaining proper nutrition, so it is surprising that so little attention has been paid to nutrition in heart failure.
"Patients with advanced heart failure commonly suffer from cardiac cachexia, but little is known about the mechanisms underlying this problem or how to treat it. Deficiency in one dietary component, such as thiamin, is unlikely to occur in isolation and might be a marker for shortages of other micronutrients. Recent research suggests that targeted multi-micronutrient supplementation may improve quality of life and left ventricular function in elderly patients with heart failure," Dr. Cleland said.
Jill Kalman, M.D. from the NYU Medical Center in New York, N.Y., who also was not connected with this study, said the results help point the way toward improving care for heart failure patients.
"If we can start to point out where there are certain metabolic deficiencies in heart failure, learn where we can replace them in an effective and safe fashion, and make a difference eventually in terms of outcomes, I think that’s where this is an important article," Dr. Kalman said. It is also important to find out whether any heart failure treatments may be causing metabolic deficiencies.