Preservation of lean muscle mass matters for long term health and function. It is also important to those who want to gain muscle mass so they can look hot and/or awesome. it is also important for strength and for athletic performance. Whatever your interests, here is a report of a recent study on dietary fats and muscle mass.
Dietary Fat and Protein Turnover
Dietary fat may regulate protein turnover. The thought is that dietary fats influence both inflammation and insulin. This study was published in this month’s issue of the Journal of Nutrition. Study subjects were 2,689 women who are part of a study of twins in the UK. Data was collected on:
Percent of Calories obtained from Fat
Fatty acid profile
Fat -free mass in kilograms (an indicator of muscle mass)
Fat-free mass measured by X-Ray absorptiometry
Results of the Dietary Fat and Muscle Study
Women whose diets were higher in polyunsaturated fatty acids had higher fat-free mass (more muscle).
Women who got more of their calories from fat had less fat free mass (less muscle)
Women who ate more saturated fat had less fat free mass (less muscle)
Women who ate more unsaturated fatty acids had less fat free mass (less muscle)
Women who are more transfats had less fat free mass (less muscle)
Women who were in the top 20% for energy intake from polyunsaturated fatty acids had about a pound more muscle mass than women who were at the bottom 20% for polyunsaturated fatty acid. This is about the same difference in muscle mass that would be seen in a 10 year aging period. You could look at this and say that a diet high in polyunsaturated fatty acids saves 10 years of muscle aging. And you might be right. Polyunsaturated fatty acids reduce inflammation and seem to protect against cardiovascular disease and cancer as well. We don’t know what drives age-related muscle loss. It might be related to the same factors that drive cell-aging in general.
The Simple Takeaway for Dietary Fat and Muscle Mass
This is the first study of its kind and more research is needed to figure out what is going on. However, this study supports the idea that a diet higher in polyunsaturated fatty acids is protective against loss of muscle mass. As many are sure to proclaim: correlation is not causation. That claim does not end arguments, although it is often used that way. It simply means that we need to know more. This is an interesting study that should lead to further investigation. Thanks to the team (Alisa Welch, Alex MacGregor, Anne-Marie Minihane, Jane Skinner, Anna Valdes, Tim Spector and Aedin Cassidy) for your hard work.
Welch AA, Macgregor AJ, Minihane AM, Skinner J, Valdes AA, Spector TD, & Cassidy A (2014). Dietary fat and Fatty Acid profile are associated with indices of skeletal muscle mass in women aged 18-79 years. The Journal of nutrition, 144 (3), 327-34 PMID: 24401817
Science 20 December 2013:
Vol. 342 no. 6165 pp. 1440-1441
To Sleep, Perchance to Clean
In work that Science‘s editors named a runner-up for Breakthrough of the Year, researchers studying mice have found experimental evidence that sleep helps to restore and repair the brain.
Why do we sleep?
Questions of biology don’t get much more fundamental than that. This year, neuroscientists took what looks like a major stride toward an answer.
Most researchers agree that sleep serves many purposes, such as bolstering the immune system and consolidating memories, but they have long sought a “core” function common to species that sleep. By tracking colored dye through the brains of sleeping mice, scientists got what they think is a direct view of sleep’s basic purpose: cleaning the brain. When mice slumber, they found, a network of transport channels through the brain expands by 60%, increasing the flow of cerebral spinal fluid. The surge of fluid clears away metabolic waste products such as β amyloid proteins, which can plaster neurons with plaques and are associated with Alzheimer’s disease.
Until this discovery, researchers thought the brain’s only way to dispose of cellular trash was to break it down and recycle it inside cells. If future research finds that many other species undergo this cerebral housekeeping, it would suggest that cleaning is indeed a core function of sleep. The new findings also suggest that sleep deprivation may play a role in the development of neurological diseases. But with a causal role far from certain, it’s too early for anyone to stay awake worrying.
Over the last few years a number of studies have looked at the importance of timing for nutrient intake. A number of studies have looked at the timing of carbohydrate intake and recovery from intense exercise. Others have looked at timing of carbohydrate intake and performance. And of carbohydrate intake and recovery. At least two research groups are now working on the effect of protein intake on protein synthesis while people are asleep. This is important because:
The muscle repair or building boost that happens when people ingest protein right after a workout does not last through the night when growth hormone levels are highest.
A group of researchers from the UK and the Netherlands investigated the effect of protein consumption just before sleep and the rate of protein synthesis.
Protein intake and exercise study protocol (very brief)
Two groups of eight recreational athletes (All young men. Total = 16)
Subjects did leg extensions and leg presses at weights close to each individual’s limit of ability
All subjects received same diet during the study
8 were given 40 grams of protein just before bed. Eight were not.
Muscle biopsies were taken at the time of protein intake, and 7.5 hours later. After sleeping.
Protein intake and exercise study results
Rate of protein synthesis was higher in subjects who received protein just before sleeping. This is an important finding because:
It confirms that protein ingested just before sleep is digested and used to make muscle in humans.
Throws doubt on that old adage that you shouldn’t eat for several hours before bed
Protein intake before bed may may mean faster recovery for athletes
Protein intake before bed may help slow or prevent natural loss of strength and muscle mass in middle aged adults.
Protein intake before bed may help the elderly avoid muscle wasting. This is a major factor limiting quality of life for the elderly.
Taking it to the next level
The second research group (Groen et al. 2012) also looked at the effect of night time protein intake on muscle synthesis. The gave a group of elderly men protein at night, directly to the stomach, while they were actually asleep. Protein synthesis increased in this group too. Few athletes, even devoted CrossFit men (or CrossFit women) will want to go to this extreme. You never know. It may be a very good news for elderly people with muscle wasting.
Res PT, Groen B, Pennings B, Beelen M, Wallis GA, Gijsen AP, Senden JM, & VAN Loon LJ (2012). Protein ingestion before sleep improves postexercise overnight recovery. Medicine and science in sports and exercise, 44 (8), 1560-9 PMID: 22330017
Groen BB, Res PT, Pennings B, Hertle E, Senden JM, Saris WH, & van Loon LJ (2012). Intragastric protein administration stimulates overnight muscle protein synthesis in elderly men. American journal of physiology. Endocrinology and metabolism, 302 (1) PMID: 21917635
You can only be as healthy as your cells. A major marker of cell health is telomere length. Telomeres cap the ends of chromosomes. They protect DNA from deteriorating. They also protect DNA from accidental fusion with other chromosomes. You need the caps. Caps, however, tend to wear out (they get shorter) with repeated cell divisions. Once a telomere suffers enough wear the cell can no longer divide. Other things can wear out telomeres too. Things like oxidative stress and inflammation. Telomere shortening and wear is thought to play a major role in aging. Preserving telomere length may be a way to prolong life. Speeding telomere wear may cause faster aging.
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Short to Medium Chain Saturated Fatty Acids
A diet rich in short to medium chain saturated fatty acids may damage telomeres. A new paper published in the Journal of Nutrition reports on diet, fat intake and telomere length. Subjects were part of the Women’s Health Initiative study. Women who ate a lot of short and medium chain saturated fatty acids had shorter telomeres. Women with the lowest intake of short and medium chain saturated fatty acids had the longest telomeres. Long-chain saturated fats, monounsaturated fats and polyunsaturated fats had no effect on telomeres.
Nutrition take away.
A diet high in short to medium chain fatty acids may speed aging. A lot of people in CrossFit follow the Paleo Diet. Or The Paleolithic Diet. The Paleo diet and a lot of its followers advocate consumption of coconut oil. Medium chain fatty acids do have some nice qualities. Medium chain fatty acids have been associated with reduced risk of metabolic syndrome. Medium chain fatty acids are easy to digest. They may reduce appetite and feelings of hunger. And they pack a lot of calories. Having a source of calories is important. The research reported here shows you are probably better off sticking to long chain, and unsaturated fats. Drink olive oil. Eat walnuts. Future research may report something different. Few people, after all, eat lots of coconut oil. And there may have been other factors involved with the women in the Women’s Health Initiative study that might also have caused their telomeres to shorten.
Foods High in Short or Medium Chain Saturated Fatty Acids
Coconut oil: 66% medium chain saturated fatty acids
Palm Kernal Oil
Song Y, You NC, Song Y, Kang MK, Hou L, Wallace R, Eaton CB, Tinker LF, & Liu S (2013). Intake of Small-to-Medium-Chain Saturated Fatty Acids Is Associated with Peripheral Leukocyte Telomere Length in Postmenopausal Women. The Journal of nutrition PMID: 23616516
Nagao K, & Yanagita T (2010). Medium-chain fatty acids: functional lipids for the prevention and treatment of the metabolic syndrome. Pharmacological research : the official journal of the Italian Pharmacological Society, 61 (3), 208-12 PMID: 19931617
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