In the news: Sleeping Longer May Curb Sugar Intake; Can omega-3 Lower Glaucoma Risk?

Do Dietary Fats Impact Glaucoma Risk?

Poly-unsaturated fatty acids or PUFAs are fatty acids like the omega-6s (e.g. those from meats, dairy) and many vegetable oils) and omega-3s (e.g. those from oily fish and walnuts). Does our intake of these fatty acids impact the risk for glaucoma?

More studies are needed to answer this question, but previous research suggests that the type or amount of PUFAs may affect glaucoma risk. One study found lower levels of omega-3 fatty acids in glaucoma patients. Another linked a higher ratio of dietary omega-6 to omega-3 with increased glaucoma risk.

To shed more light on the possible relationship of PUFAs and this eye disease, UCLA researchers analyzed information on diet and glaucoma prevalence from 3,865 participants in the US National Health and Nutrition Examination Survey (1).

The study found that increased daily levels of the omega-3 PUFAs EPA and DHA were linked to significantly lower odds of having glaucoma.

Higher levels of total PUFAs, however, significantly raised glaucoma risk, which could be due to a high omega-6 to omega-3 ratio, the authors explained.

If these findings were confirmed by further research, the take home message would be to eat a good amount of omega-3 rich foods, while watching overall PUFA intake.

One strategy to achieve this might be to consume a Mediterranean style diet as it contains mono-unsaturated fats (MUFAs) like those in olive oil, and includes seafood ample in omega-3s.

Can Sleeping Longer Curb Sugar Intake?

Evidence increasingly links poor quality or too little sleep with weight gain, obesity and cardio-metabolic disease, which includes heart disease, stroke and type 2 diabetes. Studies show that insufficient sleep can increase appetite, particularly for carb-high calorie-rich snacks.

Researchers from the U.K. recently conducted a pilot randomized controlled trial to see whether increasing sleep time can impact nutrient intake among those who typically sleep for less than the recommended minimum of seven hours nightly (2).

One group received counseling on how to increase sleep that was personalized to each participant’s lifestyle (e.g. no caffeine before bedtime, establishing a relaxing routine, setting a bedtime, etc.). The control group was given no sleep intervention counseling.

Those in the counseled group were able to extend their sleep time – about 86% increased time spent in bed, half extended sleep duration (ranging from 52 to almost 90 minutes), and three participants achieved a week average within the recommended 7-9 hours nightly. No significant differences were seen in the control group.

Participants who received sleep advice also consumed 10 grams less of free sugars compared to levels at the study’s start. There was also a trend toward reduced intake of total carbohydrates, though it didn’t reach statistical significance. Free sugars were those added to foods by manufacturers, or in cooking at home as well as sugars in honey, syrups and fruit juice.

The results suggest that increasing time in bed for an hour or so longer may lead to healthier food choices. This further strengthens the link between short sleep and poorer quality diets that has already been observed by previous studies, according to the study’s lead investigator (3). The researchers are planning longer-term and more detailed studies in the future.

References

1. Wang YE, et al. Association of dietary fatty acid intake with glaucoma in the U.S. JAMA Ophthalmol. 136(2):141-47, 2018.
2. Haya K, et al. Sleep extension is a feasible lifestyle intervention in free-living adults who are habitually short sleepers: a potential strategy for decreasing intake of free sugars? A randomized controlled pilot study. Am J of Clin Nutr, Epub ahead of print, 2018.
3. King's College London. "Sleeping for longer leads to a healthier diet." ScienceDaily. January 9, 2018.