As a result of a study by a UCLA research team in the United States, the level of serotonin, called the ‘happiness substance’, increased
A study has found that frequent consumption of nuts such as walnuts increases the secretion of serotonin, which is called the ‘happiness substance’.
A research team led by Dr. Zhao Ping Li, head of clinical nutrition at the UCLA Nutrition Center in the US, conducted an experiment with 89 obese and overweight adults who participated in a weight management program. The results of this study were published in the latest issue of Nutrients, a renowned academic journal in the field of nutrition, and introduced at the Korea Food Communication Forum.
The researchers gave them a 1.5 ounce (42 g) snack each day for 24 weeks. One group was given mixed nuts (almonds, brazil nuts, pine nuts, walnuts, etc.), and the other group was given pretzels.
As a result, the group that consumed the mixed nuts had a significant increase in serotonin levels. Their blood serotonin concentration was 60.9% when measured 12 weeks following intake and 82.2% at 24 weeks following the experiment period ended. Levels of tryptophan (an amino acid) also increased. Tryptophan is the only ‘raw material’ of serotonin known to help various bodily functions such as mood, sleep, and digestion.
Nuts are an excellent source of protein, unsaturated fat, dietary fiber, minerals, vitamins and phytochemicals. Nuts are well known for their health benefits, including preventing cardiovascular disease and metabolic syndrome. Tryptophan is an essential amino acid that must be consumed through food. It is especially rich in nuts.
The U.S. Food and Drug Administration recommends 1.5 ounces of nuts per day. In terms of calories, this is 135 kcal. One ounce is equivalent to a handful of adult women’s hands, or 12 to 14 half walnuts.
However, nuts also have recommended intake depending on the type. In the case of almonds, it is regarding 23 grains per day. On the other hand, Brazil nuts contain a lot of selenium, which is good for immunity, but excessive intake can cause selenium poisoning symptoms, so it is good to eat only 1-2 pills a day. The recommended intake is less than 5 walnuts per day. Excessive intake has side effects such as diarrhea and abdominal pain.
Donga.com reporter Cho Hye-sun hs87cho@donga.com
