Brain Health Part 2: Culinary Culprits to Avoid

Poor Dietary Choices and Mental Function

The previous issue of Staying Healthy (Brain Health Part 1) discussed recent insights into brain protective practices and key strategies for boosting mental function.

This issue focuses on the types of foods that emerging research suggests we should limit or avoid. For the most part they’re the usual suspects associated with risk for cardiovascular disease – unhealthy fats, refined sugars and junk foods, and these dietary habits appear to undermine optimal mental functioning as well. A recent article in Medscape aptly refers to them as potential “culinary culprits” (1).

Avoid Trans Fats to Help Support Good Mood

If you haven’t yet tuned into checking food labels for their trans fatty acid content, now’s a good time to start. It’s well known that these fats pose a risk to the heart, but consistent intake of these fats may also raise the risk for depression. Depression, which affects about 121 million people worldwide, can negatively impact mental clarity.

Looking at the diets of over 12,000 people who were free of depression at the study’s start, researchers in Spain found a robust link between higher intake levels of trans fatty acids and a diagnosis of depression (2).

The way in which trans fats can be harmful to the heart and the brain may be similar, according to the research team. Chronic inflammation and impaired functioning of the endothelium (blood vessel lining) are frequently seen in patients with depression. Pro-inflammatory changes and endothelial dysfunction are also responsible, in part, for the detrimental effects of trans fats in cardiovascular disease.

Trans fats are also thought to raise levels of “bad” LDL cholesterol and reduce “good” HDL cholesterol levels – changes that may negatively impact blood flow to the brain over time.     

Trans fats are created during a process called hydrogenation, which stabilizes polyunsaturated oils to prolong their shelf life and to keep them solid at room temperature. Hydrogenated fats are found in stick margarine, fast foods, baked goods (donuts, cookies, crackers), processed foods, and fried foods.

Limit Fast Foods & Refined Sugar

The same Spanish research team, this time studying nearly 9,000 adults, reports a strong link between “junk food” and cognitive deficits, namely depression. Study participants who frequently consumed fast food were 40% more likely to develop depression than those who mostly steered clear of burgers, pizza, sausage, processed pastries, and the like (3).

The high level of trans fatty acids in fast foods is likely an important contributor to the study’s findings. In addition, people who consistently eat fast food and empty-calorie sugary foods often do so at the expense of foods rich in brain-protective nutrients such as the fats in oily fish and nuts, the B-vitamins, and other plant-derived nutrients.

Higher intake of simple sugar has also been linked to lower mental function and the risk of developing mild cognitive impairment (4,5).

In short, growing evidence suggests that adopting better eating habits may not only support good health overall, but better brain function as well.

References

1. Melville NA. Culinary culprits: Foods that may harm the brain. Medscape Medical News Jan, 30, 2014.
2. Sanchez-Villegas A, et al. Dietary fat intake and the risk of depression: the SUN project. PLoS One. 2011; 6(1): e16268.
3. Sanchez-Villegas A, et al. Fast food and commercial baked good consumption and the risk of depression. Pub Hlth Nutr 15:424-32, 2012.
4. Ye X, et al. Habitual sugar intake and cognitive function among middle-aged and older Puerto Ricans without diabetes. Br J Nutr 106:1423-32, 2011.
5. Roberts RO, et al. Relative intake of macronutrients impacts risk of mild cognitive impairment or dementia. J Alzheimers Dis 32:329-39, 2012.