Is A Low Carb Diet Safe?
Perhaps you’ve seen the recent new stories: low carb diets lead to an early death. Bad luck if you’ve been banishing the bread, but keeping the butter. You’ve been feeling pretty good since shed a few pounds, although your breath smells pretty bad. But did you say so long to spaghetti, just to fit into a slimmed-down coffin? Is a low carb diet safe?
Before you jettison the courgetti for the doughy delights of white sliced, let’s look at what’s behind those headlines.
It’s true that a recent study has found that following a low carb diet long term may lower life expectancy… but so does a high carb diet.
So let’s look into what the study said in a little bit more detail.
What Was The ‘Is a Low Carb Diet Safe?’ Study Actually About?
Researchers in the field of cardiovascular health at the Boston Brigham and Women’s hospital published findings taken from a long-term study into health outcomes for adults who had been assessed as at high-risk for atherosclerosis.
Atherosclerosis is the building-up of plaque inside the arteries, which over time hardens, narrowing the artery and limiting the flow of oxygen-carrying blood around the body. It can put sufferers at increased risk of heart attack or stroke.
A lot of data had been gathered over twenty-five year period from the 15,400 people enrolled the initial study. This included demographic information (sex, race, level of education) and lifestyle information (smoker/ non-smoker, level of physical activity, diet etc.).
Study participants were also given dietary questionnaires to fill in, asking how often they ate various foods.
The Boston researchers used the these dietary questionnaires in their 2018 ‘is a low carb diet safe’ study. To try to make sure the data wasn’t skewed, they excluded participants who reported extreme calorie restriction or extreme overconsumption from their analysis. They also left out participants whose dietary-questionnaire information was incomplete.
What Did The ‘Is a Low Carb Diet Safe?’ Study Actually Find?
The participants who reported getting less than 30% of their daily calorie intake from carbohydrates tended to die on average four years younger, than those who reported getting 50-55% of their daily intake from carbohydrates.
This was after researchers had adjusted for other factors, like smoking, income and underlying health conditions.
A fifty-year-old enrolled in the atherosclerosis risk study who got less than 30% of their overall energy from carbs could expect on average to live another 29.1 years.
But a fifty-year-old who got between 50-55% of their overall daily energy from carbs could expect to live another 33.1 years.
So does this mean the more carbohydrate, the longer your life expectancy? Is the Fountain of Eternal Youth actually just a bottomless breadstick barrel?
Well no, not exactly. Before you try to Benjamin Button it by shoveling down the spaghetti, the same study also found that the participants who reported getting more than 65% of their daily energy intake in the form of carbohydrates died on average one year earlier than those who reported moderate carbohydrate intake.
So as ever, moderation in all things. Including chip butties.
Is A Low Carb Diet Safe If You’re Vegan?
One of the interesting things about mortality risk for the low-carbohydrate group, was that this risk was moderated in study participants who reported getting most of their dietary protein and fats from non-animal sources.
In the words of the study’s lead author Dr Sara Seidelmann:
“Our data suggests that animal-based low-carbohydrate diets, which are prevalent in North America and Europe, might be associated with shorter overall life span and should be discouraged. Instead, if one chooses to follow a low-carbohydrate diet, then exchanging carbohydrates for more plant-based fats and proteins might actually promote healthy ageing in the long term.”
Bad news for Atkins enthusiasts. But vegans on low-carb diets may less to worry about than those who have swapped out their morning toast for extra rashers of bacon.
Can You Please Just Tell Me Is A Low Carb Diet Safe Or Not?
So are carbs killers or are they the elixir of life?
No, on both counts.
The boring advice remains (boringly) as ever – moderation is usually best.
Following a low-carb diet over a short period of time can be a quick way to shed a few pounds.
If you’ve over-indulged during the festive season, cutting back on the carbs for a week or two in January probably won’t kill you. Reducing carbs can be a straight-forward way to reduce overall calorie intake.
But while studies like this give us a clue as to their possible negatives, we just don’t know that much about low-carb lifestyles long term.
Partly because even initial Atkins and Dukan enthusiasts, often fail to keep up their zeal long term. The call of the carbs is just too much to resist!
At the other extreme, very high-carb diets have historically been associated with poverty and subsistence living. Cheap sources of fat and protein have only recently become widely available. Most people had to survive on monotonous, carb-heavy staples. Rice in much of Asia, barley and rye in parts of Europe and root crops elsewhere in the world.
When people have been able to eat a balanced diet, that’s usually what they opt to do.
Should I Eat Carbs?
Our body uses carbohydrate to meet its short-term energy demands, which is why previous studies have found that eating a carb-containing breakfast improved the performance of healthy, young men in a subsequent exercise task.
Essentially, the Eat-Your-Weetabix hypothesis.
Carbohydrates give you energy and help you feel full and satisfied after a meal.
Of course, not all carbs are created equal. For the equivalent of amount of calories, a bowl of porridge or a baked potato will probably keep you going longer than a couple of slices of white bread.
But unless you’ve been advised otherwise by your doctor or nutritionist, carbohydrates have a place in a balanced diet.