Over the past few years, trans fats have been a contentious issue. Effectively banned in the US after being declared "Not generally recognised as safe for use in food" by the FDA, this type of fat is on the out in Australia too, with many food manfacturers opting for healthier alternatives.
Without getting too deeply into the science of it, trans fats are polyunsaturated fats that have been modified to behave like saturated fats, generally by a process called hydrogenation. Hydrogenated polyunsaturated fats have a higher melting point, remain solid at room temperature, and are more stable. These properties give food products like biscuits, pastries, and fast food a longer shelf life and greater flavour stability. Most trans fats are produced artificially, but they are also found in trace amounts, naturally, in the milk and meat of ruminant animals like cows, sheep and goats.
A diet high in trans fats is known to raise the levels of LDL (bad) cholesterol, while lowering the levels of HDL (good) cholesterol, and increase levels of blood triglycerides. High blood cholesterol levels are considered to be a major risk factor for heart disease. Diets high in trans fat have also been implicated in obesity, depression and aggressive behaviour.
A new study was recently completed that shows a link between a diet high in trans fats and poor memory. Researchers based this finding on a study that involved close to 1000 healthy men between 20 and 45 years of age with no history of heart disease. The regular dietary habits of these men were analysed, and used to estimate of the amount of trans fats eaten. Participants participated in a visual memory task where they were asked to remember words.
The researchers were stunned by the results, which showed a strong correlation between high consumption of trans fats and poor performance on the memory task, even after the data was corrected for race, education level, and other potentially confounding factors, including depression, which also has a negative impact on cognition.
Researchers have yet to determine a cause, but they have strong ssuspicions this effect may be as a result of oxidative stress or omega-3 levels.
High levels of trans fats, alongside a number of other common environmental stressors like pollution and heavy exercise, are able to exert cell-damaging oxidative stress on the brain tissue, which may affect function. This is why obtaining sufficient dietary antioxidants is so important. Antioxidants are vital to maintain general health and also help the muscles recover after exercise. This is a type of nutrient you don't want to miss out on, and the good news is that there are many potent antioxidant supplements on the market that can fill any gaps in your nutrition.
Omega-3 levels have also been touted as a potential cause for the poor performance in the high trans fats group. Fats are a primary component of brain tissue, and a high ratio of omega-3 fatty acids is known to have a positive effect on brain function. Fish oil supplements are a quick and easy way to boost your omega-3 levels if you don't have the time or inclination to make oily fish a regular meal.
The best way to avoid trans fats is to eat a healthy, balanced diet of fresh food, and to minimise processed and deep fried food and unhealthy takeaway meals. Sometimes this is unavoidable, in which case, supplementary nutrition can help you maintain optimum health.
Golomb B, Bui AK in American Heart Association. Trans Fat Consumption is Linked to Diminished Memory in Working-aged Adults. (2014). American Heart Association Meeting Report Abstract 15572. November 18th 2014.