5 Nutrition ‘Facts’ that are Actually Nutrition Myths

Today’s blog is a follow-up to Nutrition Facts that are Wrong Part One from earlier this year.

Nutritional science is a dynamic field and we are constantly learning more and making discoveries.  As a dietitian, it is my job to stay on top of the most recent evidence and practice based on that. Over time, our understanding evolves and sometimes what we once believed to be true, is no longer. 

Aside from research changing, there’s also the issue of influencers on social media spouting opinion as though it’s fact. Just because someone has a lot of followers, or they say something with what sounds like authority, doesn’t make what they’re saying true. Hint: podcasts are the latest vector for nutrition myth spreading.

‘FACT’: white rice is bad for us 

Rice is a cultural staple for people all over the world, yet we’ve been told for years to avoid ‘white foods,’ including white rice. Embarrassingly, I even told people to avoid white rice in my early years as a dietitian.

While brown rice does have some slight nutritional advantages over white rice (it is a bit higher in fibre and some minerals such as magnesium), a lot of the negative talk about white rice is deeply rooted in the fact that people tend to use Western culture’s idea of ‘healthy food’ as the gold-standard.  This has historically looked like brown rice, mixed vegetables and a piece of fish or chicken breast.

This may work for some people, but it isn’t representative of the diversity of our population.

There are a lot of ways to eat healthily, and our cultural foods should be a part of that.

Food, culture, and identity are deeply rooted, and saying that cultural staples are ‘unhealthy’ is a way of devaluing that culture, which is wrong on so many levels. People should be able to eat and enjoy the food they grew up with, without being made to feel like those foods are ‘bad’ or ‘wrong.’

From a practical standpoint, white rice cooks much faster than brown rice. Rice itself is the perfect vehicle for vegetables and proteins, and it’s inexpensive and can be prepped in advance.

‘FACT’: we don’t need carbs to live 

Carbohydrates have gotten a bad reputation for a long time, but the thinking that carbs are unnecessary is a common nutrition myth mostly perpetuated by followers of low carb and Carnivore diets, especially on social media. People who follow these diets often claim that they have improved their health, lost weight, improved their skin, and gained more energy all by avoiding carbs. I’ve written about the carnivore diet here.

Although technically we can live without carbohydrate, that doesn’t mean that it’s a good idea. Ideally, we are trying to optimize our health versus just trying to survive.

Our brain relies on glucose as its main source of energy. Our bodies can make glucose from other substrates in a process called gluconeogenesis, but that not as efficient a process as just using carbs for glucose.

Again: just because we can, doesn’t mean we should.

There’s nothing wrong with eating a lower-carb diet, but fearing carbs and heavily restricting or avoiding them altogether isn’t health promoting, both physically and emotionally. I’m going to add that fibre is a carb as well, and anyone who claims that fibre is unnecessary or even harmful is not someone who you should be getting your nutrition information from.

Fruit, vegetables, whole grains, beans, and legumes are all nutrient-rich sources of carbohydrates, including fibre. This is important for our gut-health, keeping our cholesterol levels healthy, and can help to stabilize blood sugar in people with diabetes. Research shows us that the healthiest diet is one that contains a lot of plants.

Conversely, there is no research that proves that avoiding plants – or that dramatically restricts carbs – promotes better health. There are always exceptions, but in general, the vast majority of us benefit from including carbohydrates in our diets.

Carb quality matters, too. While there is a role for refined carbohydrates in our diets, the majority of our carb intake should come from whole or minimally processed choices.

‘FACT’: saturated fat is not linked with heart disease 

Guidelines since the 1970’s have been to reduce saturated fat intake to decrease cardiovascular risk, but with evolving science, we’re learning more about how some foods rich in saturated fat may not have a negative impact on heart health after all. However, to say that saturated fat is not linked with heart disease is not true. 

Saturated fat is found in many different foods. Most come from animal sources such as meat, poultry, and dairy products, but tropical fats such as coconut and palm oils also have saturated fat. It’s important to understand that all fats contain a mix of saturated and unsaturated fats in different amounts.

Read my post about seed oils here.

Current guidelines suggest that no more than 10% of our calories per day should be from saturated fat. If there was evidence to suggest that saturated fat was not linked heart disease, these guidelines would have been adjusted by now.

Dairy products have been a popular food group to research about saturated fat and heart health. Cheese has been found to have beneficial effects on our blood fats compared to butter (which, FYI, is only around 63% saturated fat).

In a recent systematic review and meta-analysis, researchers found that compared to butter, dairy fat eaten in the form of cheese reduced fasting circulating total cholesterol, LDL and HDL. This makes sense given that butter is a completely different food than cheese – cheese is a fermented food and has protein, calcium and many more additional nutrients that you don’t find in butter, which is essentially pure fat.

More research is needed to confirm these findings, and there may also be differences between different types of cheese, such as hard and semi-soft cheeses.

Another more recent area of research has been to look at the chain length of the fatty acids which can be grouped into short, medium, and long chains. Short chain fatty acids are mostly produced in the colon as a biproduct of fibre being fermented. Medium chain fatty acids are found in palm kernel, coconut oil and dairy products. Long chain fatty acids are found in dairy, beef, palm oil, and lard. 

In a systemic review, it was found that long chain fatty acids increased the risk for heart disease, while short and medium chain fats were more neutral. However, since most foods have different types of fatty acids, it becomes hard to make conclusions. 

When looking to reduce saturated fat to improve heart health, what we replace it with is also important. It is generally accepted that replacing saturated fat with polyunsaturated fats is beneficial for our heart health. These fats are found in fatty fish such as salmon and sardines as well as nuts and seeds, tofu and soy beans. Vegetable oils such as canola are also high in polyunsaturated fats. 

Research suggests that replacing saturated fats with refined carbohydrates has a negative effect on heart health. 

‘fact’: we all need calcium supplements for bone health 

It may sound like a no-brainer to supplement a mineral you don’t get enough of from your diet. But when it comes to the research, there are some things to be aware of when it comes to calcium in supplement form.

There have been plenty of studies over the years looking at calcium supplements and bone health, but there isn’t a lot of scientific consensus because the studies have mixed results. 

Most of these studies have been done with post-menopausal women, as this is a time when age-related bone loss tends to accelerate with decreasing estrogen levels. 

Information from the Women’s Health Initiative (WHI) studies suggest that calcium combined with vitamin D is associated with small improvements in bone mineral density, but is not associated with a risk for bone fracture in postmenopausal women.

The US Preventive Services Task Force (USPSTF) had similar findings, and both entities recommend against daily calcium supplementation for the prevention of fractures in postmenopausal women.

There are some risks with calcium supplements. This 2021 meta analysis looked at associations between calcium supplements and heart health. It found that calcium supplements seemed to increase the risk for cardiovascular disease and coronary heart disease, but not cerebrovascular disease. 

Age-related bone loss is a big issue, especially among women. I recommend a lifestyle approach to support bone health that includes eating calcium-rich foods, weight-bearing exercise such as walking and resistance training, and quitting smoking. Get a baseline bone density scan, and follow up as recommended.

‘fact’: everyone should be on a low sodium diet

Sodium is an essential nutrient with roles that include regulating fluid volume and keeping our muscles and nerves working properly.

Blood pressure guidelines and some health professionals have historically recommended a low sodium diet (defined as less than 2300mg of sodium or about 1 tsp of salt) based on the belief that this will reduce blood pressure and in turn, reduce cardiovascular events.

However, these recommendations have recently been challenged due to lack of robust evidence to recommend such a low intake. Average sodium intakes around the world range from 2.3-4.6g (1-2 tsp of salt) per day and some researchers suggest that there is no increased risk of cardiovascular disease by having this amount. The risk increases when sodium intake is over 5g per day. 

Further, there is no research to suggest that low sodium (in the range currently recommended) compared to the average intake is associated with a lower risk of cardiovascular events and mortality. It may even be associated with increased risk. 

Graphic is from: Sodium and health: another challenge to the current dogma | European Heart Journal | Oxford Academic (oup.com) 

The PURE study, which followed 102 000 individuals for 9 years found that a moderate intake (3–5 g/day) of sodium seemed to be optimal for health, with lower and higher intakes being associated with higher mortality and cardiovascular disease.

Isolating one single nutrient in a study is challenging. The effects of sodium are also impacted by how much potassium someone gets which adds to the challenge. That’s okay – most healthy people don’t have to worry about getting too much sodium if they focus on eating a variety of whole foods and limiting ultra-processed foods. 

Nutrition research is evolving. In turn, we should always challenge our beliefs and be open to any progress . Make sure you get your information from credible sources.

There are a lot of people couching their opinions as nutrition facts. Be skeptical of anything that seems extreme or too good to be true, because it probably is.