Carbohydrates Increase Longevity?

Column #157

A recently released, NIH-sponsored nutrition study made headlines all across the nation. Most of the headlines were like this one:

“Moderate Carbohydrate Intake Optimal for Health, Longevity”

Most reviews ran with this quote: “These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to promote healthy aging.”

The conclusion most people gain from this summary is that the best diet is one that restricts meats and animal fats. But is that true? After carefully reading the study, I agree with its conclusion--based on the data--but it is also misleading. Is this another case of blind men describing an elephant?

For starters, I frown on nutritional studies that are based on asking participants what they ate. Even the authors of the report recognize that memories are faulty, exact foods mentioned can be questionable, quantities are guesses, and people can change their preferences over time. For instance, the nutritional characteristics of salads made with iceberg lettuce versus spinach differ significantly. Grain-fed meats are not the same as grass-fed and Omega-3 meats. Macadamia nuts differ from almonds. Corn oil is not like grass-fed beef tallow. Most people don’t understand this.

The study initially consisted of 15,428 participants aged 45–64 years. They were recruited between 1987 and 1989 with six followup visits through 2017. During the study, there were 6,283 deaths from all causes. In 2012 the study included data from eight cohort studies investigating carbohydrate intake adding 432,179 participants with 40,181 deaths reported.

They separated the diets of the participants into groups: Animal-Based Low Carbohydrate, Plant-Based Low Carbohydrate, High Carbohydrate, and 50–55% Carbohydrate Intake. The first three groups had higher mortality rates than the last group. The highest mortality rate was the first group.

The primary foods consumed by the various groups were as follows:

Animal-Based Low Carbohydrate
●    Lower than average intake of vegetables, fruits, and grains;
●    Total protein intake was highest;
●    More servings per day of beef, pork, and lamb as the main dish; beef, pork, and lamb as a side dish; chicken with the skin on; chicken with the skin off; and cheese.

Plant-Based Low Carbohydrate
●    Lower than average intake of vegetables, fruits, and grains;
●    More servings per day of nuts, peanut butter, dark or grain breads, chocolate, and white bread than did higher carbohydrate diets;
●    Higher than average intake of protein from animal sources.

High Carbohydrate Diet
● Tended to be mostly very low-cost foods high in refined carbohydrates, such as white rice, white bread, potatoes, etc.

50–55% Carbohydrate Intake
●    Associated with an average intake of vegetables, fruits, and grains;
●    Average intake of protein from animal sources;
●    Apparently tended to follow USDA MyPlate guidelines.

The authors stated that the results generated by low carbohydrate and high carbohydrate diets versus the balanced diet could well be caused by “differing quantities of bioactive dietary components such as branched-chain amino acids, fatty acids, fibre, phytochemicals, haem iron, and vitamins and minerals.” They hypothesized that low plant and increased animal protein and fat consumption “stimulated inflammatory pathways, biological aging, and oxidative stress.” They assumed the high carbohydrate diet reflected poor food quality and a chronically high glycemic load that leads to negative metabolic consequences.

The authors also stated that the participants who consumed the lowest percentages of total energy from carbohydrates “were more likely to be young, male, a self reported race other than black, college graduates, have high body-mass index, exercise less during leisure time, have high household income, smoke cigarettes, and have diabetes.” These participants may have also been heavy drinkers with overall higher risk lifestyles which could have had a bearing on the study’s all-cause mortality data. Surprisingly it was noted that both low carbohydrate diets were lower in average regular soft drink intake.

The report only mentioned “fatty acids” once. It did not discuss the incident rate of chronic diseases as participants aged nor did it indicate how many were on prescription drugs or under a doctor’s regular care. Other caveats in the report were:
●    The study represents observational data and is not a clinical trial;
●    Randomised trials of low carbohydrate diets on mortality are not practical;
●    Diet was only assessed at the beginning and the 6-year mark of a 25-year study;
●    Any number and combination of dietary components could have been considered and adjusted for in the analysis;
●    Absolute food intakes need to be interpreted cautiously.

My Omega-3 in HUFA (Highly Unsaturated Fatty Acids) score is 64%. That’s right between the scores for Japan and Greenland when their citizens had remarkable health, especially heart health. Today’s average score for Americans is 24%.

The Inuits of Greenland were famous for their traditional diet of seal and walrus which are marine mammals with lots of fat. Seal oil was used for cooking and as a dipping sauce for food. They ate moose, caribou, reindeer, ducks, geese, and little land birds. They also ate lots of crabs and fish such as salmon, whitefish, tomcod, pike, and char.

To their detriment, few Greenlanders still eat an animal-based low carbohydrate diet. Their shift to a more “balanced diet” has increased their rate of diabetes and heart disease. It’s well known that their modern diet is high in carbohydrates which tends to make them quite unhealthy.

The traditional Inuit diet was nutrient dense and diverse, low glycemic, with a 1:1 balanced Omega-6 to Omega-3 essential fatty acid (EFA) ratio. Their modern diet is high glycemic, nutrient lite, with a highly skewed EFA balance that’s well above 4:1. It’s a diet that seems to follow USDA MyPlate guidelines.

The reason why the nutritional shift from traditional foodstuffs to modern foodstuffs is so debilitating is that traditional animal proteins and fat had the green leaf at the bottom of the food chain. Grain and potatoes were rarely eaten. Today modern meats are from GRAIN-fed animals (beef, buffalo, lamb, goat, pork chicken, turkey, and farmed seafood). Grain, seeds, potatoes, nuts, and modern cooking oils are consumed now more than ever before. These foods are overloaded with Omega-6 fatty acids which is why there is an Omega-3 deficiency. Grains, seeds, potatoes (tubers), and most fruits are also high glycemic.

For decades science has shown that Omega-3 EFAs are anti-inflammatory and high carbohydrate diets provide a chronically high glycemic load that can lead to negative metabolic consequences. Grain-fed meats on average have EFA ratios of 15:1. That’s probably why the report hypothesized that “low plant and increased animal protein and fat consumption stimulated inflammatory pathways, biological aging, and oxidative stress.” Grass-Fed and Omega-3 meats would not do that.

I’m convinced that in both the low carbohydrate diet groups and the high carbohydrate diet group, it’s the Omega-3 deficient foods and high glycemic foods that increases their mortality rates. And the 50–55% Carbohydrate Intake group that mimics the USDA guidelines isn’t really much better for preventing disease and death.

I’m quite certain that a low carbohydrate diet consisting of meats and fats that are legitimately grass-fed and Omega-3, wild-caught seafood, and vegetables (emphasizing dark leafy green) results in the lowest all-cause mortality rate. Low glycemic foods with balanced EFAs and dense and diverse nutrient loads more closely approximate the traditional Inuit experience.

This new report is another example of food chemistry being blurred by myopic perspectives that ignores the real elephant in the room. Every assessment in the report is true to a degree, but the big picture was missed. In spite of that, there is one exceptionally good thing about the report. For those of us who understand food chemistry, this report underscores why people who want to follow the ketogenic diet had better make sure their animal proteins and fats have balanced EFAs. If they don’t they are jumping out of the pan into the fire and the report will be dead right for them.

To your health.

Ted Slanker

Ted Slanker has been reporting on the fundamentals of nutritional research in publications, television and radio appearances, and at conferences since 1999. He condenses complex studies into the basics required for health and well-being. His eBook, The Real Diet of Man, is available online.

Don’t miss these links for additional reading:

Moderate Carbohydrate Intake Optimal for Health, Longevity by Alaina Tedesco

Dietary Carbohydrate Intake and Mortality: A Prospective Cohort Study and Meta-Analysis by Sara B Seidelmann, et al.
Pdf on file

Branched-Chain Amino Acids from WebMD

The Inuit Paradox by Patricia Gadsby, Leon Steele from Discover Magazine

Changes In Eskimo Diet Linked To Increase In Heart Disease by Larry Husten from Cardiobrief.org

Increase in the Intake of Refined Carbohydrates and Sugar May Have Led to the Health Decline of the Greenland Eskimos by Dr. James J DiNicolantonio

The Importance of the Ratio of Omega 6 Omega 3 Essential Fatty Acids by Artemis Simopoulos M.D.

Ted Slanker’s Omega-3 Blood Test

Get Your Own Omega-3 Blood Test and use slanker as a code for a discount

Bill Lands’ EFA Education Website

Food Analysis: GI, GL, Fat Ratio, Nutrient Load by Ted Slanker