Does alcohol help sleep?
Dietary fat and weight loss
Vitamin D and breast cancer
Lifestyle changes may cure diabetes
People often think of a “nightcap” as an alcoholic beverage that puts them to sleep and helps improve their quantity and quality of sleep, but this conclusion is questionable. A recent review of known scientific studies on healthy volunteers consuming various doses of alcohol showed that while sleep onset is hastened at all levels of consumption, the total result for the night is not improved. (Ebrahim IO, et al., Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013 Jan 24. doi: 10.1111/ acer.12006. [Epub ahead of print]
The important REM (rapid eye movement) sleep is decreased during the first half of the night at higher alcohol doses, while lower doses show no clear trend early on. All doses cause a delay in the onset of the first REM sleep. Later in the night, REM sleep is disrupted. At lower doses, REM sleep is not as affected, but the overall effect is to decrease the quality of sleep.
REM sleep is important in helping to maintain motor skills, as well as memory and concentration. Based on this information, it is best not to depend on alcohol as a sleep aid. Delaying the onset of REM sleep is clearly undesirable. Whether a glass of wine or beer with dinner several hours before bedtime will affect sleep is not clear from this review.
In the United States, about 70 percent of the adult population is overweight or obese. Weight management is one of the most difficult health goals for people who are overweight. Being overweight or obese contributes to numerous health problems. The problem is almost certainly not genetic (just check the immigrant ancestors of people who are overweight and you will find that the vast majority were normal weight until they switched to the American diet). First generation immigrants often maintained their native diets and their weight, while their children and grandchildren would grow up with new food habits once they left the home. The result was increasing weight that could not be ascribed to genetics.
Fatty foods are attractive for their taste and “mouth feel,” and many of them contain essential or nutritionally valuable components. These include omega-3 and omega-6 essential fatty acids. However, most conventionally available fats are heavily processed, overcooked, and stripped of nutritional worth, or they are modified to include damaging trans fats. (My own diet includes organic extra-virgin olive oil or organic flaxseed oil, but little other oil.)
A new study shows that reducing total dietary fat intake can lead to weight loss. This is not a total surprise, as fat is the food source with the most concentrated calories. One gram of carbohydrate or protein contains about four calories, while one gram of fat contains nine calories. In this latest review of studies, researchers evaluated studies of adults and children with low fat intake or more typical higher fat consumption. They examined body weight, body mass index, or waist circumference over a study period of at least six months for controlled trials or one year for cohort studies. (Hooper L, et al., Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies. BMJ. 2012 Dec 6;345:e7666. doi: 10.1136/bmj.e7666.)
Overall there were 33 randomized, controlled trials (with 73,589 participants) and 10 cohort studies. None of the studies were for programs with interventions with the intent of losing weight. This means that the weight and body mass index changes were incidental associations with the diets. Across all trials, lower dietary fat was associated with lower weight at baseline, and less weight gain over the course of the trials. Lower total fat intake also led to lower body mass index and lower waist circumference. Interestingly, fat intakes ranged from 28 to 43 percent of calories, and 28 percent is not a very low fat intake. A healthier diet is closer to 15 to 20 percent fat (and without the typical heavily processed fats and animal fats in the western diet).
The studies were as long as eight years, and the evidence showed the lower weights were sustained for many years. The authors noted that the evidence points to similar effects in children and young people. Dieting produces greater weight loss in the short term, but most of the time that weight loss is not sustained for the long term. This is likely due to the nature of the diets that are designed for weight loss rather than health, and people often can’t stay on them for the long term.
A recent headline about vitamin D surprised me: “Vitamin D Levels Link to Higher Premenopausal Breast Cancer Risk.” It surprised me because it seemed to indicate that vitamin D could increase breast cancer risk, when I thought the evidence showed the opposite. I showed the headline to someone else and asked what her impression was, and it coincided with mine. Well, it turns out that the entire article indicated that low levels of vitamin D were associated with increased risk, not that vitamin D led to an increased risk. (The headline was in Yahoo! News, January 28, 2013.)
In the study to which this article referred, researchers examined 600 cases of breast cancer and matched them to 600 controls. They used serum taken prior to the diagnosis of breast cancer. Among those subjects whose serum was taken within 90 days prior to their diagnosis, those with the lowest levels of serum vitamin D had a 3.3-fold higher risk of breast cancer. (Mohr SB, et al., Serum 25-hydroxyvitamin D and breast cancer in the military: a case-control study utilizing pre-diagnostic serum. Cancer Causes Control. 2013 Jan 8. [Epub ahead of print])
This finding did not quite reach statistical significance, although the trend was quite clear (statistical significance is defined by a less than 5 percent chance that the findings are random, and this trend had a 9 percent chance of being random). The findings can still be significant and they clearly warrant further study. My concern is that the headline might lead someone to ignore the study. The researchers concluded that levels of vitamin D over 50 ng/ml reduced breast cancer risk by 50 percent.
Other life choices also lower cancer risks, including breast cancer. Diet may be particularly protective. This means low-fat diets (especially little or no processed fats and land-animal fats), and consumption of large amounts of fruits, vegetables, whole grains, legumes, seeds, and nuts, all of which are rich in phytochemicals and fiber. A variety of dietary supplements may also help.
Type-2 diabetes, also called “adult onset” diabetes (a misnomer because it is now common in much younger people) may run in families not because of genetics, but because of families often having similar health habits. Chances are high that lifestyle choices (diet, exercise, weight control) play the most significant role in the development of diabetes. However, growing up in industrial societies, with habits that originated mainly in the United States but are now worldwide, makes it difficult for people to change their behaviors, even when confronted with the knowledge that these behaviors lead to disease (including diabetes).
An intensive lifestyle intervention (ILI) can lead to remission of type-2 diabetes (but whether people will stay on such a program for the long term is not clear). Researchers evaluated 4503 US adults with a body mass index (BMI) greater than 25 and type-2 diabetes. They were randomly assigned to receive ILI or diabetes support and education (DSE). They were then followed for four years. (Gregg EW, et al., Association of an intensive lifestyle intervention with remission of type 2 diabetes. JAMA. 2012 Dec 19;308(23):2489-96. doi: 10.1001/jama.2012.67929.)
The ILI (2241 subjects) consisted of weekly group and individual counseling for six months, and then three sessions a month for six months, then twice-monthly contact and regular refresher groups in years 2 and 4. The DSE group (2262 subjects) received three group sessions per year on diet, physical activity, and social support.
Those subjects on ILI lost significantly more weight than DSE participants at year 1 and year 4 and also had greater fitness increases. Partial or complete diabetes remission was significantly more likely in the ILI group than the DSE group. The benefits were less at four years than at one year, which is likely a reflection of the difficulty people have in staying on lifestyle changes for the long term. It does point to the potential for people to control their own health through lifestyle choices. I frequently treat patients with type-2 diabetes with lifestyle changes and dietary supplements, and many of them are able to get off their medications.
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