Two studies in the latest “Cell Metabolism” journal are causing ripples through the gerontological and nutrition worlds. They seem to indicate that a high-protein, low-carbohydrate diet shortens your life and increases your risk of cancer.
Hang on a minute. Haven’t people been bombarded with the mantra that carbohydrates are the cause of obesity, early death and disease risk? Wouldn’t we all be better off if we banished them and focused instead on lean, high protein meats and just paid lip service to salad and fruit?
If you’ve read some of my posts on this subject you’ll see that I think this is hogwash and refer to many studies and historical sources to reinforce the idea that carbohydrate, and plant foods in general are our key to a longer, leaner and healthier life. I attack the Atkins Diet, the Glycaemic Index and any other shibboleth that props up the demonisation of carbohydrate and wholesome starchy plant foods like grains and the potato that helped build the first cities and the Pyramids.
The other night I got home after a long day at the gym, clutching a paper bag with complimentary “fast, fresh and balanced” convenience meals inside, courtesy of a concern that was selling them there. I was grateful I did not have to cook and eagerly ripped off the lid of the first meal. A pile of some thin-sliced meaty stuff, a mound of salad and a small container of dressing was my prize. What? Where was the starch – the pasta, rice, cous cous or potato? It dawned on me that “balanced” to these providors meant meat and salad, they were of the anti-carb school. Oh well, what was that stuff, anyway? It sort of looked like mushroom but wasn’t. I guessed it was smoked chicken or turkey breast and gave it a lick. By now my appetite was diminishing. It seemed to taste of processed luncheon meat and with a sigh of disappointment I turned to the next container. These guys were trying to get me to recommend their meals to my clients but so far they were off to a poor start.
The next container revealed another mound of green chopped salad, a small container of dressing and a mound of herb-coated cold, cooked beef strips down one end. They were chewy and over-cooked and both meals went straight into the garbage as I fired up the stove for a quick omellete with some crumbled fetta, baked beans and a couple of slices of toast. Within minutes I had my hot, tasty Bachelor’s Salvation on the table and munched away happily.
My point is that the carbs-as-enemy has permeated society at all levels and I’ve been sitting waiting patiently for the worm to turn as studies move away from weight-loss and focus on metabolic indicators again and redeem us from this narrow, unbalanced mantra of protein and fat good, carbs bad.
It appears the studies are trickling in.
858 mice were fed 25 different diets ranging from high-protein, low-carbohydrate to low-protein, high-carbohydrate. The high-protein group were leaner but lived lives up to 30% shorter. In animals (most likely us as well) animals given unlimited diets will eat until they consume about %10 per cent protein of total energy then stop. A higher protein diet means they eat less overall. There was a direct correlation between lifespan and protein/carb dietary ratio. As protein decreased and carbohydrates went up lifespans increased.
Alright for mice, I hear you say, what about humans? The other study involved 6,381 of them. They’d been surveyed for their eating habits and divided into 3 groups: high-protein (20% or more of total calories), moderate-protein (10-19%), and low-protein (less than 10%). They were followed for eighteen years after the original survey.
From age 50-65 the relative risk of all-cause mortality went up 74% for the high-protein group versus the low-protein group. High-protein eaters were four times as likely to die of cancer than low-protein eaters.
These are just 2 studies but they begin to undermine popular diets and even government-backed nutrition strategies aimed at reducing obesity.
Many studies over the years show that excessively high protein, especially from animal sources can be detrimental. Renal failure and kidney stones shot up in a group of rats studied by the University of Granada in Spain. Yes, they had been put on high-protein.
I find it ridiculous that studies have to be done all over to reinforce former findings in this area. I come from the 80s and 90s era of “complex carbs for energy” era and there was a pie chart on the wall of almost every classroom I sat in, dividing up the major food groups and advocating a balance of each.
I think the global growth in obesity has caused governments to panic and clutch at straws like low-carb diets. Just because we were told to eat “low fat” doesn’t mean people did it. Authorities seem to assume that most people went out and cut fat, yet still gained weight therefore carbohydrates are the villain.
When people really do cut fat (and animal protein) from their diets their health improves dramatically. World Wars One and Two provided coercive models of impact on human nutrition to study, particularly in Scandinavia. During World War One, a British naval blockade of the North Sea caught up neutral Denmark in its net. Over 400,000 Germans died of malnutrition yet the 3 million Danes came out of the War in better health than they entered it.
The Danish government’s food advisor was physician and nutritionist Mikkel Hindhede and manager of the Danish National Laboratory for Nutrition Research. His plan was to switch Denmark from its high-meat diet to one based on starchy grains and vegetables in order to eke out food supplies. Over in Germany they found it impossible to diverge from their “meat is essential for health” mantra with disastrous consequences.
The Danes sold off most of their pigs, dairy cow herds were reduced by one third and alcohol production was limited. The potatoes and barley once intended for stock feed and alcohol production could now be diverted towards humans. Many remaining pigs died of starvation, those left were gobbled up by farmers and never reached the occupants of towns and cities. Beef became a costly luxury affordable only to the rich. Most people lived on bran bread, barley porridge, potatoes, greens, milk and some butter.
And the outcome? Apart from surviving the war, three million Danes emerged well-fed and in improved health. During 1917-1918, the period of most severe restrictions the overall death rate dropped by a staggering 34%! Death rates were the lowest recorded ever, even from before the war.
The result didn’t surprise Professor Hindhede who had been conducting experiments with low-protein (mostly vegetarian) diets. “…I am convinced that over-nutrition, the result of palatable meat dishes, is one of the most common causes of disease.”
After World War Two numerous Scandinavian studies zeroed in on deaths from cardiovascular disease (CVD) and found similar spectacular falls in deaths from CVD. In 1950 Swedish researcher Haqvin Malmros postulated that wartime privations reduced dietary fat from meat and dairy and was the key to reduced cardiac mortality. Direct evidence of reduced arterial pathology followed in numerous studies from Finland, Norway and the Netherlands. Deaths from diabetes similarly plumetted during both World Wars. Malmros hooked up with health researcher Ansel Keyes after his study and the reduction of fat and protein in the diet for cardiovascular health became part of health strategies all over the globe.
What a short memory we have and how soon do we let hard-won knowledge dissipate in the face of popularism and changing trends?
One of the reasons the high-protein/ low-carb approach is popular is that it exploits a metabolic fundamental – that organisms must keep eating until they consume 10% of energy consumed as protein. High-protein diets mean less energy consumption overall. Another trick is that protein fights hunger, but it doesn’t work that way for me. That mound of meat and salad would have had me reaching for the toast. I need starch, and so do you. If you are trying to lose weight stick to a balanced diet, reduce portion sizes and bump your protein up a bit to deal with hunger but don’t overdo it.
It’s ironic that Scandinavia led the way in researching the limits of protein in the human diet for better health outcomes and now they are at the forefront of reducing this knowledge.
Sweden is the first Western country in the world to develop national dietary guidelines that reject low-fat for dieting and embrace a low-carbohydrate, high-fat approach. A 2-year study reviewing 16,000 previous studies and published in 2013 prompted a local Swedish newspaper to declare: “Butter, olive oil, heavy cream and bacon are not harmful foods. Quite the opposite. Fat is the best thing for those who want to lose weight. And there are no connections between a high-fat intake and cardiovascular disease.”
Professor Malmro’s lean body must be spinning in its grave…