None of us needs a study to tell us that we feel better after a good night’s sleep. But research is showing that getting enough sleep, between seven and nine hours a night for most people, is one of the pillars of good health, along with exercise, eating plenty of fruit and vegetables, and staying slim. No one study made a big splash in 2007, but the evidence has reached a critical mass.
Studies have linked short and poor sleep to many modern maladies: diabetes, heart disease, high blood pressure, inflammation, stroke.
Short sleep may be a factor in the obesity epidemic: sleep lab studies have shown that it alters the activity of leptin, the “fullness” hormone, and ghrelin, the “appetite” hormone.
Meanwhile, scientists are beginning to understand the sleeping brain and the role it plays in our mental lives and health. One popular theory is that we need sleep to store, and possibly attach meaning to, our memories. So if you make sleep a priority, you might improve your memory and your health.
Eating a healthy diet with ample vitamin C and omega-6 linoleic acid-may make it easier to like what you see in the mirror as you get older. In a new study, UK researchers found those two nutrients stood out in helping prevent the wrinkles, dryness and skin thinning that come with age.
Scientists from Unilever, the European purveyor of foods, beverages and personal products, used data from the US’ first National Health and Nutrition Examination Survey (NHANES I) to examine the relationship between food-based nutrients and skin-aging appearance. NHANES I gathered a huge amount of dietary and lifestyle information between 1971 and 1974-including bodily measurements, supplement intake, diet, physical activity and other habits-on more than 30,000 Americans. For their study, published in the American Journal of Clinical Nutrition, Unilever researchers examined NHANES I data on a total of 4,025 women, ages 40-74.
The researchers focused on dietary intake of nutrients-rather than nutritional supplements-saying that multi-ingredient supplements can make it difficult to determine which nutrient is having an effect. Furthermore, they noted, supplement studies often concentrate on short-term courses of nutrients, and in high dosages. The team claimed that this study is the first skin-aging research to concentrate on daily nutrient intake, rather than supplements.
“Skin aging appearance” was defined as having a wrinkled appearance, senile dryness (dryness as a result of aging) and skin atrophy (skin thinning). Dermatologists conducted clinical examinations of the skin to gauge women’s skin aging appearance.
Women who reported lower intakes of vitamin C in their diets were found to have the highest incidences of wrinkled appearance and senile dryness.
“Vitamin C is an antioxidant that has been shown to play a role in the synthesis of collagen, the protein that helps keep skin elastic,” said lead researcher Maeve C. Cosgrove, PhD. “Our findings add evidence to a predominately supplement and topical application-based hypothesis that what we eat affects our skin-aging appearance.”
Dietary intake of linoleic acid-an omega-6 fatty acid found in abundance in nuts, whole grains, most vegetable oils, eggs and poultry-also proved to be associated with more youthful skin.
On the other hand, higher intakes of fat and carbohydrates had the opposite association: A 17-gram increase in fat and a 50-gram increase in carbohydrate intakes increased the likelihood of a wrinkled appearance and skin atrophy.
The bottom line is good news if you’re already watching what you eat-you may be keeping your skin younger-looking at the same time. As Cosgrove and colleagues put it, “Promoting healthy dietary behaviors may have additional benefit for skin appearance in addition to other health outcomes in the population.”
Though not as well-known as other members of the vitamin alphabet, vitamin K could prove to be a weapon against the inflammation associated with chronic diseases such as osteoporosis and cardiovascular disease. In a new study published in the American Journal of Epidemiology, Tufts researchers linked high blood levels and dietary intakes of vitamin K with decreased levels of 14 inflammatory markers. The researchers studied phylloquinone, also known as vitamin K1, the most common form of the vitamin, which is found in green leafy vegetables.
“Our findings provide one potential alternative mechanism for a putative protective effect of vitamin K in the progression of cardiovascular disease and osteoporosis, since both diseases are characterized by inflammation,” noted lead author KyIa Shea, PhD, of the Vitamin K Laboratory at Tufts’ Jean Mayer Human Nutrition Research Center on Aging (HNRCA). Chronic inflammation, where the body’s natural protective mechanisms over-react or go out of control, has been associated with a range of conditions that also include arthritis, type-2 diabetes, Alzheimer’s disease and cognitive decline.
Previous research led by Sarah Booth, PhD, director of the Vitamin K Laboratory, has connected higher blood levels of phylloquinone with lower risk of osteoarthritis in the hand and knee and high dietary intake with reduced heart-dis ease risk in women.
The latest research relied on data from 1,381 participants in the Framingham Offspring Study, who averaged 59 years old. The Tufts scientists measured blood levels of vitamin K1 as well as dietary intake, and related these to 14 different biological markers (biomarkers) of inflammation.
The study also looked for relationships between vitamin D status and inflammation. While some links were found, overall the results on vitamin D were inconsistent.
The mechanism by which vitamin K1 might combat inflammation isn’t known, the researchers said, adding that further research was warranted. Vitamin K1 is a marker for a healthy diet, so this study may also indicate that other compounds also found in a healthy diet may be the factors that reduce inflammation.
Are you getting enough vitamin K to benefit from its anti-inflammatory powers?
Probably not. In a recent review of studies on vitamin K status among the elderly, Booth reported that although older adults seem to consume more vitamin K than younger adults, many seniors still aren’t getting the recommended daily amount. Vitamin K is found in leafy greens such as spinach and lettuce as well as in kale, cabbage, cauliflower, broccoli, Brussels sprouts, cereals, milk and soybeans. The recommended daily amount is 90 micrograms for adult females and 120 micrograms for adult males.
Tomato and its byproducts are packed with healthful nutrients. Now a new study from Finland says tomatoes may even help improve your cholesterol. The researchers report that people who ate tomato products every day for just three weeks lowered their LDL (”bad”) cholesterol by 13%.
The study, published in the British Journal of Nutrition, focused on 21 healthy volunteers with normal cholesterol readings. They consumed a totally tomato-free diet for the first three weeks, then a three-week “high-tomato” diet that included 30 milligrams of ketchup and 400 milliliters of tomato juice daily. That’s about two tablespoons of ketchip and one and two-third cups of tomato juice.
The subjects’ cholesterol levels were then re-measured and found to have dropped significantly; total cholesterol levels fell nearly 6% on average. Even more encouraging, though, was the drop in LDL cholesterol levels, which decreased nearly 13%.
Further evaluation of the subjects’ blood samples revealed synergistic benefits from their elevated levels of lycopene, betacarotene and gamma-carotene. Marja-Leena Silaste, MSc, from the University of Oulu, and colleagues noted that the subjects’ circulating LDL cholesterol resisted forming oxidized phospholipids, a marker for oxidative stress.
High cholesterol levels have long been associated with a variety of diseases, notably cardiovascular disease, the leading cause of death in the US.
Tomatoes provide the nutrients betacarotene, vitamins C and E, and lycopene, the antioxidant that gives tomatoes their characteristic red color. The FDA has approved a qualified health claim for tomatoes in reducing the risk of prostate, gastric, ovarian and pancreatic cancers.
Although high intake of tomatoes and tomato products had previously also been associated with a reduced risk of cardiovascular disease, scientists didn’t understand why. The new research suggests a possible mechanism, with the tomatoes affecting the body’s cholesterol levels.
