A very recent new study was published in The Lancet (one of the world's most prestigious medical journals) on 29th Aug 2017, finding that a higher intake of carbohydrates was associated with a higher risk of earlier death, whereas a higher intake of healthy fats, including saturated fat, actually reduced the risks and incidences of heart disease and other conditions.
The study was admittedly not of a high quality, being based on questionnaires about food intake (carbs vs proteins vs fats), body measurements, lifestyle choices, medicines, and medical history including cardiovascular events (heart attacks, stroke, and other symptoms) and other non-heart related conditions. As such, there is an element of possible inaccuracies about what people may answer in the questionnaires compared to their truth. But the number of people investigated was high - over 135,000 adults from 35-70 years, from low, middle and high income groups in many countries on five continents. Respondents were followed up at 3, 6 and 9 years later, with repeated measurements and questionnaires to assess changes, nutrition, health, deaths and other factors.
People in some countries obtained most of their energy from a very high carbohydrate intake, even up to 70% or more, which is higher than Australia's food guidelines of 45%-65% carbohydrate intake, and certainly higher than what I see in my clients at 50-60% carbohydrate intake. Another issue with the study is that there was no differentiation between "good" carbohydrates of vegetables and fruit, compared to the "bad" carbs of sugar, grain products, alcohol etc. This is a huge flaw in the study, as some people in rural Asian countries eating mostly a plant-based diet with some animal protein and healthy fats (and thus being very healthy) are being seen the same as people in modern Western towns eating a truckload of sugar, bread and alcohol, with massive grain-fed steaks.
Another flaw of the study was the implied assumption that all people from many different countries, cultures, and ethnicities, are somehow all the same and should eat exactly the same foods! Different ethnicities have different genetics, and as such, have different nutritional needs due to different biochemical and metabolic physiologies.
While the attention-grabbing news headlines of the study suggests that eating more carbs and less fats contributes to increased heart disease and death, or that eating more healthy fats leads to less heart disease, the truth (in this study at least) wasn't so exciting.
Some of the findings were:
- Higher carbohydrate intake was linked to increased risk of mortality
- Higher carbohydrate intake was NOT linked to an increased risk of heart disease
- Total fat intake was associated with lower risk of mortality
- Higher saturated fat intake was associated with a lower risk of stroke, but not other heart disease conditions.
Another interesting result from the study was that a higher animal protein intake was associated with a lower risk of mortality, but no association was found with regard to plant protein.
The study concluded with: "Global dietary guidelines should be reconsidered in light of these findings.". No, they shouldn't! As much as I would love to see the dietary guidelines changed, away from their current food industry sponsored/biased advice, to more current scientific evidence as seen in many other better quality published studies, the guidelines shouldn't be changed based on this poor quality and flawed study!
What is my message from this study? Ignore the sensationalist news headlines or articles for this study, as it doesn't tell the full story! There are much better studies showing the association between eating "bad" refined/processed carbs and heart disease, or saturated fat intake not being associated with heart disease.
And for the best nutrition and health advice, see your Nutritionist or Naturopath, who can tailor a nutrition plan specifically for you, taking into account your health history and your health goals!