Showing posts with label Food & Nutrition. Show all posts
Showing posts with label Food & Nutrition. Show all posts

Tuesday, 18 April 2017

Cracking the Coconut Oil Craze

(Source:  Julie Corliss, Executive Editor, Harvard Heart Letter, 10 April 2017)

If you Google “coconut oil,” you’ll see a slew of stories touting the alleged health benefits of this solid white fat, which is easy to find in supermarkets these days. But how can something that’s chock-full of saturated fat — a known culprit in raising heart disease risk — be good for you?

Coconut does have some unique qualities that enthusiasts cite to explain its alleged health benefits. But the evidence to support those claims is very thin, says Dr. Qi Sun, Assistant Professor in the Department of Nutrition at the Harvard T.H. Chan School of Public Health.

“If you want to lower your risk of heart disease, coconut oil is not a good choice.  It’s true that coconut oil tends to raise beneficial HDL cholesterol more than other fats do, possibly because coconut oil is rich in lauric acid, a fatty acid that the body processes slightly differently than it does other saturated fats.”, he said.

Coconut Oil’s Effect On Cholesterol 
But there’s no evidence that consuming coconut oil can lower the risk of heart disease, according to an article in the April 2016 Nutrition Reviews. The study, titled “Coconut Oil Consumption and Cardiovascular Risk Factors in Humans,” reviewed findings from 21 studies, most of which examined the effects of coconut oil or coconut products on cholesterol levels. Eight were clinical trials, in which volunteers consumed different types of fats, including coconut oil, butter, and unsaturated vegetable oils (such as olive, sunflower, safflower, and corn oil) for short periods of time. Compared with the unsaturated oils, coconut oil raised total, HDL, and LDL cholesterol levels, although not as much as butter did.

These findings jibe with results from a study by Dr. Sun and colleagues in the November 23, 2016, issue of The BMJ, which examined the links between different types of saturated fatty acids and heart disease. Compared with other saturated fats (like palmitic acid, which is abundant in butter), lauric acid didn’t appear to raise heart risk quite as much. But that’s likely because American diets typically don’t include very much lauric acid, so it’s harder to detect any effect, Dr. Sun notes.
Tropical Diets Are Different 
Coconut oil proponents point to studies of indigenous populations in parts of India, Sri Lanka, the Philippines, and Polynesia, whose diets include copious amounts of coconut. But their traditional diets also include more fish, fruits, and vegetables than typical American diets, so this comparison isn’t valid, says Harvard Medical School Professor Dr. Bruce Bistrian, who is chief of clinical nutrition at Beth Israel Deaconess Medical Center.

Some of the coconut oil available in stores is labeled “virgin,” meaning that it’s made by pressing the liquid from coconut meat and then separating out the oil. It tastes and smells of coconut, unlike the refined, bleached, and deodorized coconut oil made from the dried coconut meat used in some processed foods and cosmetics. Virgin coconut oil contains small amounts of antioxidant compounds that may help curb inflammation, a harmful process thought to worsen heart disease. But to date, proof of any possible benefit is limited to small studies in rats and mice, says Dr. Bistrian.

Unsaturated Fats 
In contrast, there’s a wealth of data showing that diets rich in unsaturated fat, especially olive oil, may lower the risk of cardiovascular disease, Dr. Sun points out. The evidence comes not only from many observational studies (like those in the aforementioned BMJ report) but also a landmark clinical trial from Spain, which found that people who ate a Mediterranean-style diet enhanced with extra-virgin olive oil or nuts had a lower risk of heart attack, stroke, and death from heart disease than people who followed a low-fat diet.

Of course, there’s no need to completely avoid coconut oil if you like the flavor. Some bakers use coconut oil instead of butter in baked goods, and coconut milk is a key ingredient in Thai cooking and some Indian curry dishes. Just be sure to consider these foods occasional treats, not every day fare.

Thursday, 23 January 2014

BEWARE OF GRAPEFRUIT DRUG INTERACTIONS

Grapefruit and grapefruit juice are good for you -- unless you're on one of an increasingly wide range of medications that interact with them. A report published by CMAJ (Canadian Medical Association Journal) indicates the number of drugs affected by grapefruit juice is on the rise.  More than 85 drugs are now identified as problematic -- and many are commonly used by people over age 45.

The problem centered around compounds in grapefruit called furanocoumarins, which can block an enzyme in the gut that metabolizes certain drugs. This can lead to higher-than-normal levels of certain oral drugs getting into the bloodstream. Less frequently, grapefruit can block drug transporters, leading to an insufficient dose of medication. Just one whole grapefruit or an 8-ounce glass of juice can interact with drugs up to three days after consumption.

Effects vary from person to person. Serious adverse effects can include acute kidney failure, respiratory depression, rhabdomyolysis (muscle breakdown that can lead to kidney damage), gastrointestinal bleeding and torsade de pointes - a potentially fatal increase in heart rhythm.

Current advice from experts is to avoid consuming grapefruit and its juice if you're on a drug that interacts with it. The same recommendation goes for Seville oranges (often used in marmalade), limes, pomelos and tangelos, which have also been found to interfere with drug metabolism. (Sweet oranges, such as navel and Valencia, don't contain furanocoumarins and remain safe to eat.)

In addition, the Food and Drug Administration advises you to:

·     Ask your pharmacist about potential interactions when you fill a prescription.
·    Read the patient information that comes with your prescription and over-the-counter drugs.
·   Check the labels of fruit juices and other drinks to make sure they don't contain grapefruit juice, if you're on one or more drugs that interact.



(Source:  John Hopkins Health Alert, Posted in Healthy Living on 8 January 2014)