August 26, 2013

231 Obesity is Deadly [26 August 2013]

Medical researchers have known for a long time that obesity reduces life expectancy. Previous estimates believed it accounted for 5% of American adult deaths. But a study published last week in the American Journal of Public Health found that obesity is much more deadly than was previously thought.

The study linked data from the National Health Interview Survey with mortality information in the National Death Index from 1986 to 2006 to analyze obesity and mortality among 332,093 men and 385,475 women aged 40 to 85, divided by race into “white” and “black”.

Being overweight or obese accounted for 18.2% of deaths overall. It was highest for women: 26.8% for black women and 21.7% for white women, and lower for men: 5.0% for black men and 15.6% for white men. Although black men and white men had similar rates of obesity, smoking and socioeconomic factors skewed the results.

Not surprisingly the data showed the problem is worse for the younger generations. Obesity-related mortality was higher for those born in the 1960s than those born in the 1930s or 1920s. And the trend will continue to rise as overweight people now in their teens, 20s and 30s grow older.

One of the authors, Ryan Masters, wrote:
Obesity has dramatically worse health consequences than some recent reports have led us to believe. We expect that obesity will be responsible for an increasing share of deaths in the United States and perhaps even lead to declines in U.S. life expectancy.
Being overweight or obese has a much greater effect on you than how it makes you look or feel, or even than the wear and tear on your joints; it can shorten your life. Fortunately there is an easy, safe and effective way to lose that unwanted weight and provide the opportunity to enjoy a longer, healthier life.

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner. See this article on my website for links to sources and further reading.

August 19, 2013

230 Agave Syrup [19 August 2013]

Agave syrup (also called “agave nectar”) is marketed as a healthy natural sweetener. I have some for sale in my store. But just what is agave syrup and how healthy is it?

The syrup is made from the agave plant which grows in Mexico and southwestern USA (and from which Tequila is made). The best quality syrup is made from the leaf sap which is processed at a low temperature using enzymes and chemicals. Most syrup, however, is synthesized from the starch in the root with a similar process that converts cornstarch to high fructose corn syrup (HFCS). Agave syrup comes in two main grades: light syrup which is more highly filtered and has a mild flavor, and the darker colored amber syrup which has a stronger flavor. Agave syrup has become quite popular as a sweetener because of its flavor, sweetness, and perceived health benefits. A strong selling point is its low glycemic index, which is a measure of its effect on blood glucose levels.

But how healthy is it? It has more calories than table sugar but is sweeter so you can use less. It is highly processed so has few trace nutrients, unlike raw honey. But the biggest problem with agave is the amount of fructose it contains, from 60-90 % (compare with high fructose corn syrup at 55%). It is the fructose content that creates the low glycemic index often touted as a benefit. I have written before about the dangers of fructose [#55 22 March 2012]. It increases uric acid which causes gout; it contributes more to insulin resistance and obesity than other sugars; and it has a toxic effect on the liver [“Fructose, weight gain, and the insulin resistance syndrome” Elliott et al, 2002, JAClinNutr].

Dr Joseph Mercola recommends people in good health consume less than 25g of fructose per day (about 1 tablespoon of the syrup). He also advises those with gout, diabetes or insulin resistance to avoid it completely. From what I’ve read, I tend to agree with Mercola, and suggest that agave syrup be used sparingly by healthy people only.

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.

August 12, 2013

229 A Calorie is NOT a Calorie [12 August 2013]

Traditional nutritional wisdom teaches that “A calorie is a calorie”. Whether it comes from carbohydrates, fat or protein, weight gain (and loss) is a simple matter of total calories in minus calories burned. But is it really that simple?

One obvious difference between foods of equal calories is the amount of micronutrients – vitamins, minerals, essential fatty acids, amino acids and fiber – associated with it. If weight loss or maintenance is your goal, you simply can’t afford to eat high-calorie low-nutrient foods. Another difference between foods is how the calories are used – burned for energy or stored as fat. Calories from simple carbohydrates – sugar and refined flour – are more likely to be stored, since carbs stimulate release of insulin which acts as a key to promote fat storage. Carbs also supply the “glyceride” part of triglycerides.

A study published in JAMA in June 2012 discovered a third difference between foods of equal calories – how they affect metabolism. A significant problem with weight management is that after losing weight on a diet, the metabolism slows (referred to as metabolic adaptation) which makes it more difficult to keep it off. This study compared the effects of three different diets on obese people who had just lost weight. All participants were put on each diet for a month: a) low-fat high-carb; b) low glycemic index; and c) low-carb high-fat high-protein. The results showed that the fewer carbs consumed, the smaller the metabolic adaptation. On average, the low-carb group expended only 100 fewer calories than before (and 8 of 21 actually expended more) while the high-carb group expended 400 fewer calories. This 300 calorie difference is equivalent to an hour of moderate exercise. This shows that a low-carb diet gives dieters the best chance at losing weight and keeping it off, and may prevent susceptible people from becoming overweight in the first place.

This study also found that the low-carb diet reduced triglycerides and HDL cholesterol more than the other diets; and improved insulin sensitivity – a measure of insulin resistance believed behind metabolic syndrome – the most.

"What Really Makes Us Fat", Gary Taubes, New York Times, June 30, 2012
Good science, bad interpretation”, Peter Attia MD, on his blog The Eating Academy

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.

August 5, 2013

228 Omega-3 & Prostate Cancer [5 August 2013]

Men - did you see any of the headlines last week about fish oil causing prostate cancer? If so, I hope you didn’t swear off salmon and throw away your Omega-3 capsules. The evidence the headlines were based on is pretty flimsy.

In an observational study published July 10 in the Journal of the National Cancer Institute, data from the SELECT Selenium and Vitamin E Cancer Prevention Trial were extracted to examine a possible link between omega-3 levels in blood and prostate cancer risk. A positive association was found with DHA, one of the fish oil Omega-3 EFAs and both low-grade and high-grade prostate cancer (44% and 71% increase respectively).

These numbers sound pretty significant, but are they? First of all, correlation does not necessarily mean causation. The lowest risk of prostate cancer in this study happened to correlate with the highest trans fatty acid levels, but no one is even suggesting that TFAs, with well-known harmful effects, prevent cancer.

Blood levels of EFAs depend on your most recent meal, not on long term eating habits, which is not included in the data. So we don’t know how much fish, if any, the men in this study ate or if they took omega-3 supplements.

The total omega-3 levels, as a percent of total blood lipids, in both groups was quite low – 3.66% in the group who got cancer and 3.62% in the group who didn’t, and the difference very slight. Yet Japanese men, who consume 8 times as much omega-3s as Americans, have a much lower prostate cancer rate.

The researchers in this study did not control for age, race or diet and other known risk factors may not have been completely accounted for. Of the men who got cancer, 53% were smokers, 64% regularly consumed alcohol and 80% were overweight or obese.

The overwhelming majority of valid studies – larger and much better designed – show that omega-3s lower cancer risk, including prostate cancer. One study from Harvard School of Public Health which followed 20,000 men for over 22 years found that men who ate fish 5 or more times per week had a 48% lower risk of prostate cancer death than those who ate fish less than once a week. And a 30 year study from Sweden concluded that eliminating fish from your diet could increase your risk of prostate cancer by up to 300%. Now that’s significant!

The only way to explain the study’s conclusions - and the news stories that promoted them – is a desire for sensational headlines and a strong anti-supplement bias. And I don’t think I’m stretching it here. One of the researchers, Alan Kristy, was quoted: “We’ve shown once again that use of nutritional supplements may be harmful.” Baloney! What they have shown is that following nutritional advice from mainstream media may be harmful.

Dr. Jonny Bowden in Huffington Post
Dr. Michael Murray
Dr Robert Rountree, Chief Medical Officer at Thorne Research, in Dr Nalini blog

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.