Diet and Exercise

Salt: New Research Says Too Little May Be Unhealthy
Morton Salt

Morton Salt

Salt in the diet is necessary for good health and proper functioning of body processes. Diets consisting largely of unprocessed foods with some added salt for seasoning don’t appear to cause problems; the excess salt problems appear when diets are primarily processed or restaurant food. Since moving away from salty snacks and processed foods like breads, soups, pizza, and fast food both reduces excess salt consumption and has other health benefits, people should still work toward avoiding excess processed and restaurant food.

But the Conventional Wisdom on salt, like on animal fats, was that intake should be reduced as much as possible to lower blood pressure and reduce heart disease. Like many conclusions of past public health medicine, it was based on reduction of a marker for harm caused, not the harm itself — that reducing salt in the diet does reduce blood pressure, and high blood pressure is correlated with heart disease. But there was no real evidence that lowering blood pressure through salt restriction beyond standard dietary levels lowered heart disease or extended lives.

The Wall Street Journal reports on a study which seems to say that too little salt may be as bad as too much, and cause excess deaths due to heart disease and stroke. This is only an association from one urine sampling, and it could easily be true that those who have adopted very low salt diets have done so because their knowledge of pre-existing heart disease issues:

A long-running debate over the merits of eating less salt escalated Wednesday when one of the most comprehensive studies yet suggested cutting back on sodium too much actually poses health hazards.

Current guidelines from U.S. government agencies, the World Health Organization, the American Heart Association and other groups set daily dietary sodium targets between 1,500 and 2,300 milligrams or lower, well below the average U.S. daily consumption of about 3,400 milligrams.

The new study, which tracked more than 100,000 people from 17 countries over an average of more than three years, found that those who consumed fewer than 3,000 milligrams of sodium a day had a 27% higher risk of death or a serious event such as a heart attack or stroke in that period than those whose intake was estimated at 3,000 to 6,000 milligrams. Risk of death or other major events increased with intake above 6,000 milligrams.

The findings, published in the New England Journal of Medicine, are the latest to challenge the benefit of aggressively low sodium targets—especially for generally healthy people. Last year, a report from the Institute of Medicine, which advises Congress on health issues, didn’t find evidence that cutting sodium intake below 2,300 milligrams reduced risk of cardiovascular disease.

The rest of the article reports on the overwhelming evidence that very high salt consumption does lead to heart disease and early death, and the complete lack of a controlled scientific study showing that reducing salt intake as is commonly recommended to below 2300 mg sodium per day has any positive benefits for healthy people.

For more on diet and science-based weight loss:

Getting to Less Than 10% Body Fat Like the Models – Ask Me How!
Starbucks, Jamba Juice Make You Fat
Fat Doesn’t Make You Fat. Government Guidelines Did!
‘Fed Up’ Asks, Are All Calories Equal?
Fructose: The True Villain?
More on “Fed Up”, Sugar Subsidies, and Obesity
Another Study on Diet Drinks
LeBron James Cut Carbs for Lean Look
Why We’re Fat: In-Depth Studies Under Way
Almonds: Superfood, Eat Them Daily for Heart Health
Fish Oil Supplements Ward Off Dementia
More on Diet Drinks: Best Studies Show They Aid Weight Loss
Vani Hari: “Food Babe” and Quack
Cleanses and Detox Diets: Quackery
Sugared Soft Drinks: Health Risk? (and What About Diet Soda?)
Gluten-Free Diets: The Nocebo Effect
Acidic Soft Drinks and Sodas: Demineralization Damages Teeth
Fish and Fish Oil for Better Brain Health
Bulletproof Coffee: Coffee, Oil, and Butter for Breakfast?

Vitamin D: Anti-Dementia?

Vitamin D

Vitamin D


Via Instapundit, “New Study Supports Links Between Dementia And Vitamin D Deficiency” in IFLScience:

Adding to an ever-growing body of evidence, a new study has found that vitamin D deficiency is associated with a substantially increased risk of developing Alzheimer’s and dementia. While previous studies have drawn similar conclusions, this is the largest, most robust study carried out to date. The results have been published in the journal Neurology.

Vitamin D is an essential vitamin that is produced by the body upon exposure of the skin to sunlight, but it can also be found in small amounts in certain foods such as oily fish. It plays a variety of roles in the body and over recent years our understanding of how it helps to maintain optimum health has dramatically increased. For example, it’s thought to reduce the risk of certain bone diseases, bacterial and viral infections and autoimmune diseases.

Interestingly, some studies have hinted that vitamin D may play a neuroprotective role. In support of this idea, several recent studies have found links between vitamin D deficiency and the risk of dementia and cognitive decline. However, one study also found no associations in men.

To find out more, an international team of researchers, headed by scientists at the University of Exeter, enrolled 1,658 adults aged 65 and over who were able to walk unaided and were free from dementia, cardiovascular disease and stroke. Vitamin D levels were assessed at the start of the study and the participants were then followed for six years in order to investigate who went on to develop Alzheimer’s or other forms of dementia.

The researchers discovered that participants with a moderate vitamin D deficiency had a 53% increased risk of developing any form of dementia, and those with a severe deficiency had a 125% increased risk. Similar results were also found for the risk of developing Alzheimer’s, which is the most common form of dementia. Interestingly, they found that there was a threshold level of 50nmol/L vitamin D in the serum, below which the risk of dementia and Alzheimer’s was markedly increased.

While this shows vitamin D deficiency is associated with increased risk of dementia, it does not prove causation; it’s possible that since oily fish contain lots of D, the Omega-3 fatty acids and other components of fish oil, which has already been shown to reduce dementia, are responsible, since people who regularly eat oily fish won’t suffer D deficiencies. And any number of other cofactors may play a role.

What’s the story on vitamin D supplements? A few years ago, medical professionals themselves were taking 2000-4000 IUDs every day believing these larger doses would be protective against a variety of degenerative diseases. The evidence since is inconclusive. Here are some studies:

Vitamin D and Cardiometabolic Outcomes: A Systematic Review
Vitamin D and calcium: a systematic review of health outcomes.
Vitamin D supplementation for prevention of mortality in adults.
The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis

For more on supplements and life-extending habits:

Getting to Less Than 10% Body Fat Like the Models – Ask Me How!
Low-Dose Aspirin Reduces Pancreatic Cancer
Daily Aspirin Regimen Reduces Cancer Rates
Almonds: Superfood, Eat Them Daily for Heart Health
Fish Oil Supplements Ward Off Dementia
Lower Back Pain: Acetaminophen (Tylenol, Paracetamol) Useless
Cleanses and Detox Diets: Quackery
Gluten-Free Diets: The Nocebo Effect
Scams: Multi-Level Marketing, Herbalife
Fish and Fish Oil for Better Brain Health
Salt: New Research Says Too Little May Be Unhealthy

Fish and Fish Oil for Better Brain Health
Costco Canned Salmon Filet

Costco Canned Salmon Filet

Previously I posted about studies showing regular fish oil supplements could help ward off dementia.

The Atlantic in a “This is Your Brain on Fish” by James Hamblin covers the evidence that regular consumption of baked or broiled fish having similar positive effects on brain tissue and functioning:

Dr. Cyrus Raji, a resident radiologist at UCLA, appreciates value beyond the cosmetics of a thick cerebral cortex. He’s the lead researcher in a new study in the current American Journal of Preventive Medicine that found that people who regularly eat fish have more voluminous brains than those who do not—in such a way that stands to protect them from Alzheimer’s disease.

“Understanding the effects of fish consumption on brain structure is critical for the determination of modifiable factors that can decrease the risk of cognitive deficits and dementia,” Raji and colleagues write. The team has previously shown gainful effects of physical activity and obesity on brain structure.

This study found that eating fish—baked or broiled, never fried—is associated with larger gray matter volumes in brain areas responsible for memory and cognition in healthy elderly people.

“There wasn’t one type of fish that was the best,” Raji told me by phone, probably while eating fish. “All that mattered was the method of preparation.” Fried fish had a unique dearth of benefits to the brain.

People who eat fish at least once a week have larger gray matter volumes in the red/yellow areas. “If you eat fish just once a week, your hippocampus—the big memory and learning center—is 14 percent larger than in people who don’t eat fish that frequently. 14 percent. That has implications for reducing Alzheimer’s risk,” Raji said. “If you have a stronger hippocampus, your risk of Alzheimer’s is going to go down.”

“In the orbital frontal cortex, which controls executive function, it’s a solid 4 percent,” Raji said. “I don’t know of any drug or supplement that’s been shown to do that.”

Speaking of supplements, the researchers initially looked to omega-3 fatty acids as the driver of these benefits. But when they looked at the levels of omega-3s in people’s blood, they didn’t correlate with better brain volumes.

“These findings suggest additional evidence that it is lifestyle factors—in this case, dietary intake of fish,” the researchers write, “and not necessarily the presumed biological factors that can affect the structural integrity of the brain.”

Omega-3 fatty acids have previously been shown to slow cognitive decline. In one study, higher levels of omega-3 fatty acids in people’s blood were associated with lower rates of brain atrophy observable over just a four-year period. We also know that when rats are fed diets low in omega-3 fatty acids, they have increased signs of dementia, possibly mediated by insulin and related buildup of amyloid plaques in their tiny brains.

Eating more omega-3 fatty acids, a lot of fruit, and not much meat, has previously been associated with increased volume throughout the brain’s gray matter. Recent research in the journal Neurology found that elderly people with high levels of omega-3 fatty acids in their blood had better cognitive function than those with lower levels. MRIs of their brains showed larger volumes, too. (The associations also held for vitamins B1, B2, B6, B12, C, D, and E, and folate.)

Drs. Deborah Barnes and Kristine Yaffe at UCSF recently calculated in Lancet Neurology that up to half of cases of Alzheimer’s disease “are potentially attributable” to seven modifiable risk factors: diabetes, midlife high blood pressure, midlife obesity, smoking, depression, cognitive inactivity or low educational attainment, and physical inactivity. Minimal inroads in those areas, they say, could result in millions fewer cases of Alzheimer’s.

People who ate fish once per week were just as well off as those who ate it more frequently.
Researchers at the University of Pittsburgh School of Medicine corroborate, “Our research has consistently shown that it is the interactions among these risk factors with the patho-biological cascade of Alzheimer’s disease that determine the likelihood of a clinical expression as dementia or mild cognitive impairment.”

Specific suspects in the fish-brain benefit paradigm are omega-3s docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which seem to increase the size of the amygdala and anterior cingulate gyrus, and possibly overall brain volume. DHA and EPA can also affect the way neural synapses fire.

I have a can of Costco salmon filet every day for lunch; it’s an easy, delicious way to both meet protein needs and consume the healthy fish oils that protect and increase brain power.

Fish Oil Supplements Ward Off Dementia

For more on good supplements and life-extending habits:

Getting to Less Than 10% Body Fat Like the Models – Ask Me How!
Low-Dose Aspirin Reduces Pancreatic Cancer
Daily Aspirin Regimen Reduces Cancer Rates
Almonds: Superfood, Eat Them Daily for Heart Health
Fish Oil Supplements Ward Off Dementia
Lower Back Pain: Acetaminophen (Tylenol, Paracetamol) Useless
Cleanses and Detox Diets: Quackery
Gluten-Free Diets: The Nocebo Effect
Scams: Multi-Level Marketing, Herbalife
Vitamin D: Anti-Dementia?
Salt: New Research Says Too Little May Be Unhealthy

Pre-Exhaustion Weightlifting Routines: Study Shows No Improvement
Squats - the best compound exercise!

Squats – the best compound exercise!

Most studies of weightlifting are done on students or relative beginners; naturally the untrained will show a larger response than subjects who have been training for years.

Trainers have come up with a variety of complex routines to get experienced lifters past a plateau where they seem to be unable to make further gains. One of the more logical of these is Pre-Exhaustion (PreEx) training, which targets the strongest link muscle of a compound exercise with isolation exercise before the compound exercise, with the goal of saving the weak link muscles so that the compound exercise will fully exhaust the already-trained stronger muscle.

A new study, “The effects of pre-exhaustion, exercise order, and rest intervals in a full-body resistance training intervention” by James Peter Fisher, Luke Carlson, James Steele, and Dave Smith blows that out of the water. Fully-trained subjects were given either routines in proper order for PreEx training or routines not in such order. The result was that the order of exercise made no significant difference in gains or performance.

It is generally true that compound exercises are more time-efficient, and a series of compound exercises (like pullups, squats, or deadlifts) done with intensity and to exhaustion is likely to produce better gains in less workout time than a mix of isolation and compound exercises. There are reasons to do isolation exercises — when you do have a weak link needing further strengthening to catch up, or when injury reduces ability to do compound exercises — but they should not occupy much of your gym time.

Abstract:

Pre-exhaustion (PreEx) training is advocated on the principle that immediately preceding a compound exercise with an isolation exercise can target stronger muscles to pre-exhaust them to obtain greater adaptations in strength and size. However, research considering PreEx training method is limited. The present study looked to examine the effects of a PreEx training programme. Thirty-nine trained participants (male = 9, female = 30) completed 12 weeks of resistance training in 1 of 3 groups: a group that performed PreEx training (n = 14), a group that performed the same exercise order with a rest interval between exercises (n = 17), and a control group (n = 8) that performed the same exercises in a different order (compound exercises prior to isolation). No significant between-group effects were found for strength in chest press, leg press, or pull-down exercises, or for body composition changes. Magnitude of change was examined for outcomes also using effect size (ES). ESs for strength changes were considered large for each group for every exercise (ranging 1.15 to 1.62). In conclusion, PreEx training offers no greater benefit to performing the same exercises with rest between them compared with exercises performed in an order that prioritises compound movements.

Further discussion of PreEx:

Pre-exhaustion (PreEx) training is an advanced resistance training (RT) method where 2 or more sequential exercises are performed in immediate succession. Whilst Jones (1970) is often credited for the hypothesis and application of PreEx RT, he suggests that the original concept existed prior to his description. The PreEx method is based upon the hypothesis that a point of momentary muscular failure (MMF) in a compound exercise occurs when the weakest muscles involved are no longer able to apply the required force to continue the exercise (Jones 1970). As such the “target” muscles can be “pre-exhausted” with an isolation exercise before moving immediately to a compound exercise. For example, the biceps might be the “weak-link” in a pulling exercise though the target might be to train the latissimus muscles. With this in mind, it is suggested to pre-exhaust the target muscles using an isolation exercise immediately prior to a compound exercise. It is hypothesised that this provides greater stimulation to the target muscles. Jones (1970) notes that “during the brief period while your weak-link muscles are actually stronger than your target muscles, you can take advantage of that momentary condition to use the strength of the weak-link muscles to train the target muscles much harder than would otherwise be possible.”1 Since evidence suggests training to MMF maximally recruits motor units and produces greatest gains in muscular strength (Fisher et al. 2011) and hypertrophy (Fisher et al. 2013a), the notion of attaining a greater fatigue to maximise adaptation appears logical.