Healthy food and memory
There are 3 foods that may harm your memory. Are they part of your regular diet?
Regular consumption of trans fatty acids, saturated fats or sugar can raise levels of harmful LDL cholesterol and turn on inflammatory genes, raising risk for heart attacks, cancer, dementia and Alzheimer's disease. Many factors influence the development of dementia - but an unhealthy diet and a sedentary lifestyle are major contributors to memory problems.
For instance, a recent study tested the effects of two diets on plasma lipids, insulin levels and visual memory on healthy adults and adults with mild cognitive impairment (MCI). One diet contained high levels of saturated fat and simple carbs, while the other was low in saturated fat with fewer simple carbs. The latter diet was associated with lowered levels of plasma lipids, insulin levels and markers of free radical injury and inflammation in the brain and spinal cord. Not only that, after just one month of the low saturated fat and simple carbs diet, visual memory improved in both healthy adults and adults with MCI. This study has major implications for the effects of diet on quality of life and brain function.
Here are 3 categories of food substances guaranteed to age your brain:
Trans Fatty Acids - are found in processed foods, margarines, salad oils, bakery goods, potato and corn chips, and candies. An average American is estimated to consume 10-30 grams of trans fatty acids every day.
To make trans fatty acids, natural unsaturated vegetable fats - which are liquid at room temperature and are prone to becoming rancid - are heated to a high temperature with a nickel catalyst and hydrogen gas, known as partial hydrogenation. These trans fatty acids have an unnaturally long shelf life. Approximately 70% of the soybean oil in the US has been partially hydrogenated in this manner. In other words, a natural product with no unnatural fats has been converted to an unnatural substance with more than 50% chemically altered fat content.
A 2011 study showed that people who consume diets high in trans fatty acids had less favorable cognitive function and less total cerebral brain volume, along with lower scores on cognitive and memory tests. To avoid consuming trans fatty acids, simply avoid any products with the words 'partially hydrogenated' on the label, including processed and fried foods.
Saturated Fats - are found in the fat on meat, chicken skin, full fat dairy products and butter. A 2012 study showed that regular consumption of saturated fats is associated with a decline in cognitive function and memory over time. Roughly 6,000 women, all over the age of 65, participated in three cognitive function tests every two years for an average of four years. Women who consumed the highest amounts of saturated fat had worse overall cognition and memory compared to those who consumed the lowest amounts. On the other hand, women who ate the most monounsaturated fats (found in olive oil, peanut butter and avocados) had significantly better cognitive scores over time.
Here are five quick tips to reduce the amount of saturated fat in your diet:
- Swap full fat dairy foods for reduced or low-fat dairy foods.
- Swap butter for a margarine spread made from canola, sunflower, olive or dairy blends.
- Trim all visible fat from meat, remove skin from chicken and cut down on processed meat such as sausages and salami.
- Eat 2-3 servings of oily fish every week. Add fish oil capsules and omega-3 enriched foods and drinks to your diet.
- Eat fewer cakes, pastries and biscuits - also limit pastries, pizza, fried fish, hamburgers, hot chips and creamy pasta to once a week.
Sugar, Syrups and Simple Carbs - Sugar, syrups and simple carbs all increase the risk of insulin resistance, obesity and metabolic syndrome. The average American consumes roughly 47 pounds of cane sugar and 35 pounds of high-fructose corn syrup (HFCS) per year, according to the US Department of Agriculture. Cane sugar (sucrose) and high-fructose corn syrup (HFCS), an inexpensive liquid sweetener are major dietary sources of fructose. HFCS is widely added to many processed foods, including soft drinks, condiments, applesauce and baby food.
A UCLA rat study showed how a diet high in fructose slowed down the brain, hampering memory and learning. Rats who consumed fructose solution for six weeks were slower and their brain cells had trouble signaling each other, disrupting their ability to think clearly and recall things they'd learned six weeks earlier. These rats also developed signs of resistance to insulin, a hormone that controls blood sugar and regulates synaptic function in the brain. In other words, eating too much fructose blocked insulin's ability to control how brain cells used and stored sugar for processing thoughts and emotions, affecting memory and learning processes.
Another factor to consider is the glycemic index or GI. Foods that break down quickly during digestion and release glucose rapidly into the blood have a high GI; while those that break down slowly and release glucose gradually have a lower GI. Sugar, syrups and simple carbs have a high GI and release glucose very quickly, causing high, sharp spikes in sugar levels. In response the pancreas releases large amounts of insulin to help liver, muscle and fat cells absorb this excess glucose. Over many years and many such daily sharp spikes in blood sugar and insulin, the sensitivity of these cells to insulin goes down - known as insulin resistance.
Consuming carbohydrate foods with a lower GI means smaller glucose and insulin peaks and slower absorption into the blood. This improves long-term blood glucose control and maintains sensitivity of all the body's cells to insulin, including brain cells. In other words, consuming low-GI foods such as complex carbs and vegetables is likely to reduce the risk of cognitive decline and loss of learning and memory.