NASEM: Don’t Trust U.S. Dietary Guidelines

Back to the drawing board

NASEM is the National Academies of Sciences, Engineering, and Medicine. Dr. Andy Harris writes that:

The nation’s senior scientific body recently released a new report raising serious questions about the “scientific rigor” of the Dietary Guidelines for Americans. This report confirms what many in government have suspected for years and is the reason why Congress mandated this report in the first place: our nation’s top nutrition policy is not based on sound science.

Dr. Harris notes that since 1980, when the guidelines were first published, rates of obesity have doubled and diabetes has quadrupled.

Current recommendations to reduce saturated fat consumption and to eat health whole grains do not, after all, reduce rates of cardiovascular disease. That was my conclusion about saturated fat in 2009.

For a mere $68 you can read the NASEM report yourself. Better yet, read Tom Naughton’s thoughts for free.

Steve Parker, M.D.

PS: The diets I’ve designed are contrary to U.S. Dietary Guidelines.

Paleo and Mediterranean Diets Linked to Lower Risk of Death

The Journal of Nutrition in 2017 published a study that looked at baseline diet characteristics of over 21,000 folks, then over the next six years noted who died, and why. Guess how many died?

Here’s a clue. These U.S. study participants were at least 45 years old at the start of the study.

2,513 died. Seems high to me, so I bet the average age was close to 65.

Hank’s not worried about death

I can’t tell for sure from the report’s abstract, but it looks like the researchers were interested in the Mediterranean and caveman diets from the get-go. Study subjects who ate Paleo- or Mediterranean-style were significantly less likely to die over six years. They were less likely to die from any cause or from cancer or from cardiovascular disease.

Composition of the paleo diet is debatable (click for my 2012 definition).

Consider adopting some Mediterranean diet features, too.

Steve Parker, M.D.

Reference:

Paleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with All-Cause and Cause-Specific Mortality in Adults. First published February 8, 2017, doi: 10.3945/​jn.116.241919.

Abstract

Background: Poor diet quality is associated with a higher risk of many chronic diseases that are among the leading causes of death in the United States. It has been hypothesized that evolutionary discordance may account for some of the higher incidence and mortality from these diseases.

Objective: We investigated associations of 2 diet pattern scores, the Paleolithic and the Mediterranean, with all-cause and cause-specific mortality in the REGARDS (REasons for Geographic and Racial Differences in Stroke) study, a longitudinal cohort of black and white men and women ≥45 y of age.

Methods: Participants completed questionnaires, including a Block food-frequency questionnaire (FFQ), at baseline and were contacted every 6 mo to determine their health status. Of the analytic cohort (n = 21,423), a total of 2513 participants died during a median follow-up of 6.25 y. We created diet scores from FFQ responses and assessed their associations with mortality using multivariable Cox proportional hazards regression models adjusting for major risk factors.

Results: For those in the highest relative to the lowest quintiles of the Paleolithic and Mediterranean diet scores, the multivariable adjusted HRs for all-cause mortality were, respectively, 0.77 (95% CI: 0.67, 0.89; P-trend < 0.01) and 0.63 (95% CI: 0.54, 0.73; P-trend < 0.01). The corresponding HRs for all-cancer mortality were 0.72 (95% CI: 0.55, 0.95; P-trend = 0.03) and 0.64 (95% CI: 0.48, 0.84; P-trend = 0.01), and for all-cardiovascular disease mortality they were 0.78 (95% CI: 0.61, 1.00; P-trend = 0.06) and HR: 0.68 (95% CI: 0.53, 0.88; P-trend = 0.01).

Conclusions: Findings from this biracial prospective study suggest that diets closer to Paleolithic or Mediterranean diet patterns may be inversely associated with all-cause and cause-specific mortality.

 

Paleo Diet Reduces Gingivitis and Periodontitis

..at least in a tiny short-term study done in Germany. Only 10 experimental subjects. And the researchers didn’t call it a paleo, Paleolithic, Stone Age, or caveman diet.

Here’s their description of the food: “..low in carbohydrates, rich in Omega-3 fatty acids, and rich in vitamins C and D, antioxidants and fiber for four weeks.” How low in carbs? To a level “as far as possible to a level < 130 grams/day.” Click the link above for full diet details. By my reading, it qualifies as a paleo diet.

Certified paleo-compliant, plus high omega-3 fatty acids and low-carb

The researchers note in the body of their report that they can’t tell for sure which components of the experimental diet were most helpful, but they suspect it’s 1) the carbohydrate restriction, 2) increased omega-3 fatty acids, and 3) reduced omega-6 consumption.

Those three factors are at play in the both the Paleobetic Diet and Low-Carb Mediterranean Diet.

Here’s the study’s abstract for you science nerds:

Background

The aim of this pilot study was to investigate the effects of four weeks of an oral health optimized diet on periodontal clinical parameters in a randomized controlled trial.

Methods

The experimental group (n = 10) had to change to a diet low in carbohydrates, rich in Omega-3 fatty acids, and rich in vitamins C and D, antioxidants and fiber for four weeks. Participants of the control group (n = 5) did not change their dietary behavior. Plaque index, gingival bleeding, probing depths, and bleeding upon probing were assessed by a dentist with a pressure-sensitive periodontal probe. Measurements were performed after one and two weeks without a dietary change (baseline), followed by a two week transitional period, and finally performed weekly for four weeks.

Results

Despite constant plaque values in both groups, all inflammatory parameters decreased in the experimental group to approximately half that of the baseline values (GI: 1.10 ± 0.51 to 0.54 ± 0.30; BOP: 53.57 to 24.17 %; PISA: 638 mm2 to 284 mm2). This reduction was significantly different compared to that of the control group.

Conclusion

A diet low in carbohydrates, rich in Omega-3 fatty acids, rich in vitamins C and D, and rich in fibers can significantly reduce gingival and periodontal inflammation.

Thanks to BioMed Central for making the entire report available for free.

Reference:

An oral health optimized diet can reduce gingival and periodontal inflammation in humans – a randomized controlled pilot study. BMC Oral Health 2016, 17:28. Published: 26 July, 2016.

Short-Term Benefits of Low-Carb Compared to High-Carb Diet in Type 1 Diabetes

Shrimp Salad

A scientific study published 2017 compared a high-carb (at least 250 grams/day) to low-carb diet (50 grams or less) in 10 patients with type 1 diabetics. The low-carb diet yielded more time in the normal blood sugar range, less hypoglycemia, and less variability of glucose levels.

I assume the low-carb diet required less insulin, but I don’t know since I haven’t seen the full article. Let me know if you can confirm.

In case you’re wondering, the Paleobetic diet provides about 60 grams of carb daily.

Here’s the abstract:

The aim of the present study was to assess the effects of a high carbohydrate diet (HCD) vs a low carbohydrate diet (LCD) on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes. Ten patients (4 women, insulin pump-treated, median ± standard deviation [s.d.] age 48 ± 10 years, glycated haemoglobin [HbA1c] 53 ± 6 mmol/mol [7.0% ± 0.6%]) followed an isocaloric HCD (≥250 g/d) for 1 week and an isocaloric LCD (≤50 g/d) for 1 week in random order. After each week, we downloaded pump and sensor data and collected fasting blood and urine samples. Diet adherence was high (225 ± 30 vs 47 ± 10 g carbohydrates/d; P < .0001). Mean sensor glucose levels were similar in the two diets (7.3 ± 1.1 vs 7.4 ± 0.6 mmol/L; P = .99). The LCD resulted in more time with glucose values in the range of 3.9 to 10.0 mmol/L (83% ± 9% vs 72% ± 11%; P = .02), less time with values ≤3.9 mmol/L (3.3% ± 2.8% vs 8.0% ± 6.3%; P = .03), and less glucose variability (s.d. 1.9 ± 0.4 vs 2.6 ± 0.4 mmol/L; P = .02) than the HCD. Cardiovascular markers were unaffected, while fasting glucagon, ketone and free fatty acid levels were higher at end of the LCD week than the HCD week. In conclusion, the LCD resulted in more time in euglycaemia, less time in hypoglycaemia and less glucose variability than the HCD, without altering mean glucose levels.

Steve Parker, M.D.

If You Resolved to Lose Weight in 2018…

…you need to read my series on preparing for weight loss. It will improve your odds of success.

The answer’s not in this TV infomercial

Merry Christmas!

Credit: Zvonimir Atletic / Shutterstock.com

Even If You’re Old, You Can Preserve Muscle Mass During Weight Loss. Here’s How.

dementia, memory loss, Mediterranean diet, low-carb diet, glycemic index, dementia memory loss

“Honey, please come to the gym with me.”

We’ve known for a while that resistance training helps preserve muscle mass in younger folks during weight-loss programs. I’ve always figured the principle applied to older folks, too. Now we have proof. Average age of these study participants was 67.

From UPI.com:

Seniors who want to lose weight should hit the weight room while they cut calories, a new study suggests.

Older folks who performed resistance training while dieting were able to lose fat but still preserve most of their lean muscle mass, compared with those who walked for exercise, researchers report.

“The thought is if you lose too much lean mass, that this will exacerbate risk of disability in older adults,” said lead researcher Kristen Beavers, an assistant professor of health and exercise science at Wake Forest University in Winston-Salem, N.C. “Our findings show if your treatment goal is to maximize fat loss and minimize lean mass loss, then the resistance training is probably the way to go.”

 

 

Seafood May Contaminate You With Mercury, But Does It Matter?

Dead whole fish aren't very appealing to many folks

Dead whole fish aren’t very appealing to many folks

I advocate consumption of cold-water fatty fish a couple times per week for long-term protection against heart and brain disease. The protective component of fish may be the omega-3 fatty acids.

On the other hand, much seafood is contaminated with mercury, which can be toxic. So, is the mercury in fish actually toxic to brain tissue of folks eating reasonable amounts of fish?

A recent autopsy study answers, “No.”

Read further for details.

Much more appetizing!

From the Journal of the American Medical Association, 2016 Feb 2;315(5):489-97. doi: 10.1001/jama.2015.19451. “Association of Seafood Consumption, Brain Mercury Level, and APOE ε4 Status With Brain Neuropathology in Older Adults.”

IMPORTANCE:Seafood consumption is promoted for its many health benefits even though its contamination by mercury, a known neurotoxin, is a growing concern.

OBJECTIVE:To determine whether seafood consumption is correlated with increased brain mercury levels and also whether seafood consumption or brain mercury levels are correlated with brain neuropathologies.

DESIGN, SETTING, AND PARTICIPANTS:Cross-sectional analyses of deceased participants in the Memory and Aging Project clinical neuropathological cohort study, 2004-2013. Participants resided in Chicago retirement communities and subsidized housing. The study included 286 autopsied brains of 554 deceased participants (51.6%). The mean (SD) age at death was 89.9 (6.1) years, 67% (193) were women, and the mean (SD) educational attainment was 14.6 (2.7) years.

EXPOSURES:Seafood intake was first measured by a food frequency questionnaire at a mean of 4.5 years before death.

MAIN OUTCOMES AND MEASURES:Dementia-related pathologies assessed were Alzheimer disease, Lewy bodies, and the number of macroinfarcts and microinfarcts. Dietary consumption of seafood and n-3 fatty acids was annually assessed by a food frequency questionnaire in the years before death. Tissue concentrations of mercury and selenium were measured using instrumental neutron activation analyses.RESULTS:Among the 286 autopsied brains of 544 participants, brain mercury levels were positively correlated with the number of seafood meals consumed per week (ρ = 0.16; P = .02). In models adjusted for age, sex, education, and total energy intake, seafood consumption (≥ 1 meal[s]/week) was significantly correlated with less Alzheimer disease pathology including lower density of neuritic plaques (β = -0.69 score units [95% CI, -1.34 to -0.04]), less severe and widespread neurofibrillary tangles (β = -0.77 score units [95% CI, -1.52 to -0.02]), and lower neuropathologically defined Alzheimer disease (β = -0.53 score units [95% CI, -0.96 to -0.10]) but only among apolipoprotein E (APOE ε4) carriers. Higher intake levels of α-linolenic acid (18:3 n-3) were correlated with lower odds of cerebral macroinfarctions (odds ratio for tertiles 3 vs 1, 0.51 [95% CI, 0.27 to 0.94]). Fish oil supplementation had no statistically significant correlation with any neuropathologic marker. Higher brain concentrations of mercury were not significantly correlated with increased levels of brain neuropathology.

CONCLUSIONS AND RELEVANCE:In cross-sectional analyses, moderate seafood consumption was correlated with lesser Alzheimer disease neuropathology. Although seafood consumption was also correlated with higher brain levels of mercury, these levels were not correlated with brain neuropathology.

Source: Association of Seafood Consumption, Brain Mercury Level, and APOE ε4 Status With Brain Neuropathology in Older Adults. – PubMed – NCBI

Steve Parker, M.D.

Lose Weight With Diet; Maintain Weight Loss With Exercise

Exercise was natural when we were kids

It’s a lesson most of us working in the field learned years ago.

From The New York Times:

It is a question that plagues all who struggle with weight: Why do some of us manage to keep off lost pounds, while others regain them?

Now, a study of 14 participants from the “Biggest Loser” television show provides an answer: physical activity — and much more of it than public health guidelines suggest.

On average, those who managed to maintain a significant weight loss had 80 minutes a day of moderate activity, like walking, or 35 minutes a day of vigorous exercise, like running.

Steve Parker, M.D.

PURE Study: High Carb Consumption Increases Risk of Death

How many innocent lives will be cut short by this tasty but silent killer?

Here’s the abstract of a new epidemiological study that investigated the relationships between diet, cardiovascular disease, and death rates. I don’t have the entire article. My sense is that the 18 countries studied are mostly non-Western:

Background

The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear.

Methods

The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35–70 years (enrolled between Jan 1, 2003, and March 31, 2013) in 18 countries with a median follow-up of 7·4 years (IQR 5·3–9·3). Dietary intake of 135 335 individuals was recorded using validated food frequency questionnaires. The primary outcomes were total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure). Secondary outcomes were all myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality. Participants were categorised into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality. We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random intercepts to account for centre clustering.

paleo diet, paleolithic diet, caveman diet

“Do you understand the words that are coming out of my mouth?”

Findings

During follow-up, we documented 5796 deaths and 4784 major cardiovascular disease events. Higher carbohydrate intake was associated with an increased risk of total mortality (highest [quintile 5] vs lowest quintile [quintile 1] category, HR 1·28 [95% CI 1·12–1·46], ptrend=0·0001) but not with the risk of cardiovascular disease or cardiovascular disease mortality. Intake of total fat and each type of fat was associated with lower risk of total mortality (quintile 5 vs quintile 1, total fat: HR 0·77 [95% CI 0·67–0·87], ptrend<0·0001; saturated fat, HR 0·86 [0·76–0·99], ptrend=0·0088; monounsaturated fat: HR 0·81 [0·71–0·92], ptrend<0·0001; and polyunsaturated fat: HR 0·80 [0·71–0·89], ptrend<0·0001). Higher saturated fat intake was associated with lower risk of stroke (quintile 5 vs quintile 1, HR 0·79 [95% CI 0·64–0·98], ptrend=0·0498). Total fat and saturated and unsaturated fats were not significantly associated with risk of myocardial infarction or cardiovascular disease mortality.

Interpretation

High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.

Source: Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study – The Lancet