Tag Archives: women

FDA Cuts the Women’s Dose of Sleeping Pill Ambien (Zolpidem) By Half

Details are at MedPageToday.

The Role of Exercise in Maintenance of Weight Loss In Women

A 2008 article in Archives of Internal Medicine teaches us the role of regular physical activity in keeping lost weight from returning to once-overweight women.

Methodology

201 overweight women (body mass index 27-40) aged 21 to 45 wanted to lose excess weight. They were sedentary at baseline, exercising fewer than three days a week for under 20 minutes. Sound familiar? Depending on baseline weight, the participants were assigned to eat either 1200 or 1500 calories per day, and to exercise according to one of four different exercise programs. Exercise recommendations were to burn a certain number of calories per week (1000 or 2000 calories) at either moderate or vigorous intensity. There were weekly group meetings for discussion of eating and exercise for the first six months, twice monthly meetings during the next 6 months, and monthly for the next six months. There was telephone contact for between months 19 to 24. This is pretty intense contact. Each participant was given a treadmill to use at home, but my impression is that other forms of exercise were permitted and discussed.

Ten subjects were excluded from follow-up analysis, mostly because they got pregnant. Nineteen others lost interest and dropped out.

Participants self-reported their physical activity levels.

At 24 months into the study, 170 of the original 201 participants were able to provide objective weight loss data.

Findings

Of the 170 subjects available for full analysis at 24 months, 54 either gained weight or lost none. Thirty-three lost 0 to 4.9% of initial body weight, 36 lost 5 to 9.9% initial body weight, and 47 (24.6%) lost 10% or more of initial body weight. (Who says diets don’t work?)

People who lost 10% or more of initial body weight at 24 months reported performing more physical activity – 275 minutes a week – compared with those who lost less than 10% of initial body weight. This amount of exercise equates to 55 minutes of exercise on five days per week above the baseline level of activity, which was sedentary as you recall. Whether they were assigned to “moderate” or “vigorous” exercise intensity didn’t seem to matter. Whether they actually performed at the assigned level is unclear.

These women who sustained a weight loss of 10% or more of initial body weight at 24 months were burning 1835 calories a week in physical activity.

Women who lost less than 10% of initial body weight, or lost no weight, exercised an average of 34 minutes a day on five days a week.

By 24 months, participants on average had regained about half of the weight they had lost during the first six months [which is typical].

Take-Home Points

After six months of dieting, many people start to regain half of what they lost. We saw this phenomenon recently in the Israeli study of low-fat vs low-carb vs Mediterranean diet.

If you have a lot of excess fat to lose, you have to wonder if it would make sense to start a different diet program every six months, until you reach your weight goal. Maybe there’s something about the novelty and excitement of a new diet program that keeps you motivated and disciplined for six months.  For someone with lots of weight to lose, I wonder if they’d do better switching to a new diet every six months.

The authors note there are few similar long-term studies examining the amount and intensity of physical activity needed to improve weight loss success. So this is important new information.

In using exercise to help prevent weight regain, it may not matter whether the exercise is moderate or intense.

The authors write:

…the inability to sustain weight loss appears to mirror the inability to sustain physical activity.

Long-term sustained weight loss is possible for a significant portion of overweight women. Although most women won’t do it, success is enhanced by exercising for 55 minutes on five days a week. Most men won’t exercise that much either. Which camp do you fall into?

For physical activity instruction and information, visit Shape Up America!, Physical Activity for Everyone, or Growing Stronger: Strength Training for Older Adults.

Steve Parker, M.D.

Reference: Jakicic, John M., et al. Effect of Exercise on 24-Month Weight Loss Maintenance in Overweight Women. Archives of Internal Medicine, 168 (2008): 1,550-1,559.

Alcohol Consumption and Cancer in Women

The Million Women Study (2009) looked at the association between alcohol consumption and the incidence of various cancers in middle-aged women in the United Kingdom.

Here’s the conclusion from the abstract in the Journal of the National Cancer Institute:

Low to moderate alcohol consumption in women increases the risk of certain cancers. For every additional drink regularly consumed per day, the increase in incidence up to age 75 years per 1000 for women in developed countries is estimated to be about 11 for breast cancer, 1 for cancers of the oral cavity and pharynx, 1 for cancer of the rectum, and 0.7 each for cancers of the esophagus, larynx and liver, giving a total excess of about15 cancers per 1000 women up to age 75.

Other cancers seemed to be reduced by increasing levels of alcohol consumption: thyroid, non-Hodgkin lymphoma, renal cell carcinoma.

Comparing wine with other alcohol types, no differences in cancer risks were found.

Low to moderate alcohol consumption is associated with prolonged life, lesser risk of dementia, and lower rates of cardiovascular disease. The article abstract doesn’t mention these issues, nor the possibility that the benefits of judicious alcohol consumption may outweigh the cancer risks. 

Steve Parker, M.D.

References:

Allen, Naomi, et al. Moderate Alcohol Intake and Cancer Incidence in Women. Journal of the National Cancer Institute, 101 (2009): 296-305.

Lauer, Michael and Sorlie, Paul. Alcohol, Cardiovascular Disease, and Cancer: Treat With Caution. Journal of the National Cancer Institute, 101 (2009): 282-283.

Szwarc, Sandy. In Vino Veritas – Part Two. Junkfood Science blog, March 1, 2009. Accessed March 10, 2009. A quote from Ms. Szwarc regarding the Million Women Study:

The bottom line is that scary claims that “there is no level of alcohol consumption that can be considered safe,” simply was not supported by the data. This study actually found no credible link between alcohol consumption and cancers at all. Or, if you want to split hairs and believe the small computed numbers, it found that the lowest risk for cancers was associated with women drinking up to 1-2 drinks a day.

Mediterranean Diet Failed to Prevent Mental Decline in Women With Vascular Disease

Unfortunately, the Mediterranean diet failed to preserve cognitive function over the course of five years in the Women’s Antioxidant Cardiovascular Study (WACS).  The 2,500 women in the study, all over 65, at baseline had vascular disease or at least three risk factors for vascular disease.

Note that this research says nothing about prevention of age-related cognitive decline and Alzheimer dementia in women who don’t have baseline vascular disease.  The Mediterranean diet seems to help that population.

Steve Parker, M.D.

Glycemic Index and Chronic Disease Risk (Mostly in Women)

I’ve written about glycemic index (GI), glycemic load (GL), and glycemic diets in preparation for today’s post.

The concept of glycemic index was introduced by Jenkins et al in 1981 at the University of Toronto.

Studies investigating the association between disease risk and GI/GL have been inconsistent. By “inconsistent,” I mean some studies have made an association in one direction or the other, and other studies have not. Diseases possibly associated with high-glycemic diets have included diabetes, cardiovascular disease, cancer, gallbladder disease, and eye disease.

“Diet” in this post refers to a habitual way of eating, not a weight loss program.

Researchers with the University of Sydney (Sydney, Australia) identified the best-designed published research reports investigating the relationship between certain chronic diseases and glycemic index and load. The studied diseases were type 2 diabetes, coronary heart disease, stroke, breast cancer, colorectal cancer, pancreatic cancer, endometrial cancer, ovarian cancer, gallbladder disease, and eye disease.

Methodology

Literature databases were searched for articles published between 1981 and March, 2007. The researchers found 37 studies that enrolled 1,950,198 participants ranging in age from 24 to 76, with BMI’s averaging 23.5 to 29. These were human prospective cohort studies with a final outcome being occurrence of a chronic disease (not its risk factors). Twenty-five of the studies were conducted in the U.S., five in Canada, five Europe, and two in Australia. Ninety percent of participants were women [for reasons not discussed]. Food frequency questionnaires were used in nearly all the studies. Individual studies generated between 4 to 20 years of follow-up, and 40,129 new cases of target diseases were identified.

Associations between GI, GL, and risk of developing a chronic disease were measured as rate ratios comparing the highest with the lowest quantiles. For example, GI and GL were measured in the study population. The population was then divided into four groups (quartiles), reflecting lowest GI/GL to medium to highest GI/GL diets. The lowest GI/GL quartile was compared with the highest quartile to see if disease occurrence was different between the groups. Some studies broke the populations into tertiles, quintiles, deciles, etc.

Findings

Comparing the highest with the lowest quantiles, studies with a high GI or GL independently

  • increased the risk of type 2 diabetes by 27 (GL) or 40% (GI)
  • increased the risk of coronary heart disease by 25% (GI)
  • increased the risk of gallbladder disease by 26% (GI) or 41% (GL) (gallstones and biliary colic, I assume, but the authors don’t specify)
  • increased the risk of breast cancer by 8% (GI)
  • increased risk of all studied diseases (11) combined by 14% (GI) or 9% (GL)

Overall, high GI was more strongly associated with chronic disease than was high GL

So low-GI diets may offer greater protection against disease than low-GL diets.

Comments from the Researchers

They speculate that low-GI diets may be more protective than low-GL because the latter can include low-carb foods such as cheese and meat, and low-GI, high-carb foods. Both eating styles will reduce glucose levels after meals while having very different effects in other areas such as pancreas beta cell function, free fatty acid levels, triglyceride levels, and effects on satiety.

High GI and high GL diets, independently of known confounders, modestly increase the risk of chronic lifestyle-related diseases, with more pronounced effects for type 2 diabetes, coronary heart disease, and gallbladder disease.

Direct quotes:

. . . 90% of participants were female; therefore, the findings may not be generalizable to men.

There are plausible mechanism linking the development of certain chronic diseases with high-GI diets. Specifically, 2 major pathways have been proposed to explain the association with type 2 diabetes risk. First the same amount of carbohydrate from high-GI food produces higher blood glucose concentrations and a greater demand for insulin. The chronically increased insulin demand may eventually result in pancreatic beta cell failure, and, as a consequence, impaired glucose tolerance. Second, there is evidence that high-GI diets may directly increase insulin resistance through their effect on glycemia, free fatty acids, and counter-regulatory hormone secretion. High glucose and insulin concentrations are associated with increased risk profiles for cardiovascular disease, including decreased concentrations of HDL cholesterol, increased glycosylated protein, oxidative status, hemostatic variables, and poor endothelial function

Low-GI and/or low-GL diets are independently associated with a reduced risk of certain chronic diseases. In diabetes and heart disease, the protection is comparable with that seen for whole grain and high fiber intakes. The findings support the hypothesis that higher postprandial glycemia is a universal mechanism for disease progression.

My Comments

Studies like this tend to accentuate the differences in eating styles since they compare the highest with the lowest post-prandial (after meal) glucose levels. Most people are closer to the middle of the pack, so a person there has potentially less to gain by moving to a low-GI diet. But still some to gain, on average, particularly in regards to avoiding type 2 diabetes and coronary heart disease.

(To be fair, many population-based studies use this same quantile technique. It increases the odds of finding a statistically significant difference.)

Only two of the 37 studies examined coronary heart disease, the cause of heart attacks. One study was the massive Nurses’ Health Study database with 75,521 women. The other was the Zutphen (Netherlands) Elderly Study which examined men 64 and older. Here’s the primary conclusion of the Zutphen authors verbatim:

Our findings do not support the hypothesis that a high-glycemic index diet unfavorably affects metabolic risk factors or increases risk for CHD [coronary heart disease] in elderly men without a history of diabetes or CHD.

So there’s nothing in the meta-analysis at hand to suggest that high-GI/GL diets promote heart disease in males in the general population.

However, the recent Canadian study in Archives of Internal Medicine found strong evidence linking CHD with high-glycemic index diets. Although not mentioned in the text of that article, Table 3 on page 664 shows that the association is much stonger in women than in men. Relative risk for women on a high-glycemic index/load diet was 1.5 (95% confidence interval = 1.29-1.71), and for men the relative risk was 1.06 (95% confidence interval = 0.91-1.20). See reference below.

Nine of the 37 studies examined the occurrence of type 2 diabetes. Only one of these studied men only – 42,759 men: the abstract is not available online and the Sydney group does not mention if high-GI or high-GL was positively associated with onset of diabetes in this cohort. Two of the diabetes studies included both men and women, but the abstracts don’t break down the findings by sex. (I’m trying to deduce if the major overall findings of this meta-analysis apply to men or not.)

I don’t know anybody willing to change their diet just to avoid the risk of gallstones. It’s only after they develop symptomatic gallstones that they ask me what they can do about them. The usual answer is surgery.

The report is well-done and seems free of commercial bias, even though several of the researchers are authors or co-authors of popular books on low-GI eating.

Steve Parker, M.D.

References:

Barclay, Alan W.; Petocz, Peter; McMillan-Price, Joanna; Flood, Victoria M.; Prvan, Tania; Mitchell, Paul; and Brand-Miller, Jennie C. Glycemic index, glycemic load, and chronic disease risk – a meta-analysis of observational studies [of mostly women]. American Journal of Clinical Nutrition, 87 (2008): 627-637.

Brand-Miller, Jennie, et al. “The New Glucose Revolution: The Authoritative Guide to the Glycemic Index – The Dietary Solution for Lifelong Health.” Da Capo Press, 2006.

Mente, Andrew, et al. A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart Disease. Archives of Internal Medicine, 169 (2009): 659-669.

Mediterranean Diet Cuts Stroke Risk In Women

The journal Circulation in 2009 reported that the Mediterranean diet reduces risk of stroke in women by 13%. This supplements our prior knowledge that the healthy diet is associated with lower risk of coronary heart disease in both men and women.

Researchers in Boston analyzed the records of 74,886 middle-aged women in the Nurses’ Health Study to deteremine how closely they followed a Mediterranean diet pattern. They followed participants’ health status for 20 years, noting how many women developed stroke, coronary heart disease, and “cardiovascular death” (fatalities from strokes and coronary heart disease combined).

Compared with the women who adhered minimally to the Mediterranean diet pattern, the women with highest compliance had 13% fewer strokes. Consistent with earlier studies, the Mediterranean dieters had 39% lower risk of cardiovascular death and 29% lower risk for coronary heart disease (again, comparing the women with highest and lowest compliance).

Take-Home Points

To gain the health benefits of the Mediterranean diet, consider making changes to the way you eat.

Here are the characteristics of the traditional Mediterranean diet:

  • It maximizes natural whole foods and minimizes highly processed ones
  • Small amounts of red meat
  • Less than four eggs per week
  • Low to moderate amounts of poultry and fish
  • Daily fresh fruit
  • Seasonal locally grown foods with minimal processing
  • Concentrated sugars only a few times per week
  • Wine in low to moderate amounts, and usually taken at mealtimes
  • Milk products (mainly cheese and yogurt) in low to moderate amounts
  • Olive oil as the predominant fat
  • Abundance of foods from plants: vegetables, fruits, beans, potatoes, nuts, seeds, breads and other whole grain products

Steve Parker, M.D.

Reference: Fung, Teresa, et al. Mediterranean diet and incidence of and mortality from coronary heart disease and stroke in women. Circulation, 119 (2009): 1,093-1,100.

High-Carbohydrate Eating Promotes Heart Disease in Women

Women double their risk of developing coronary heart disease if they have high consumption of carbohydrates, according to research published in the Archives of Internal Medicine.

Men’s hearts, however, didn’t seem to be affected by carb consumption. I mention this crucial sex difference because many experts believe that replacing saturated fat with carbohydrates is a major cause of heart disease. If true, it seems to apply only to women.

(Another nutrition science trend to keep an eye on is the thought that excessive consumption of omega-6 fats contributes to hardening of the arteries, including coronary heart disease. I’m talking about soy oil, safflower oil, corn oil, among others. No doubt, we’re eating a lot more omega-6 now than at the start of the 20th century.)

We’ve known for a while that high-glycemic-index eating was linked to heart disease in women but not men. Glycemic index is a measure of how much effect a carbohydrate-containing food has on blood glucose levels. High-glycemic-index foods raise blood sugar higher and for longer duration in the bloodstream.

High-glycemic-index foods include potatoes and white bread, for example.

The study at hand included over 47,000 Italians who were interrogated via questionnaire as to their food intake, then onset of coronary heart disease—the cause of heart attacks—was measured over the next eight years.

Among the 32,500 women, 158 new cases of coronary heart disease were found.

Researchers doing this sort of study typically compare the people eating the least carbs with those eating the most. The highest quartile of carb consumers and glycemic load had twice the rate of heart disease compared to the lowest quartile.

The Cleave-Yudkin theory of the mid-20th century proposed that excessive amounts of refined carbohydrates cause heart disease and certain other chronic systemic diseases. Gary Taubes has also written extensively about this. The research results at hand support that theory in women, but not in men.

Practical Applications

Do these research results apply to non-Italian women and men? Probably to some, but not all. More research is needed.

Women with a family history coronary heart disease—or other CHD risk factors—might be well-advised to put a limit on total carbs, high-glycemic-index foods, and glycemic load. I’d stay out of that “highest quartile.” Don’t forget: heart disease is the No. 1 killer of women.

See NutritionData’s Glycemic Index page for information you can apply today.

FYI, the Low-Carb Mediterranean Diet and Ketogenic Mediterranean Diet are also low in glycemic index.

Steve Parker, M.D.

Disclaimer: All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status. Always consult your personal physician before making any dietary or exercise changes.

Addendum: Alert reader Nadia Hassan brought to my attention that I had originally written that pasta has a high glycemic index. Citing appropriate references, Nadia convinced me that pasta has a low-to-moderate glycemic index, from around 30 to 60. Its GI also is higher if over-cooked. I corrected my original post.

References:

Sieri, Sabina, et al. Dietary glycemic load and index and risk of coronary heart disease in a large Italian cohort. The EPICOR study. Archives of Internal Medicine, 170 (2010): 640-647.

Barclay, Alan, et al. Glycemic index, glycemic load, and chronic disease risk – a meta-analysis of observational studies [of mostly women]. American Journal of Clinical Nutrition, 87 (2008): 627-637.