Our dietary habits play an important role in shaping our health and well-being, but there are still many unknowns about the diet's ultimate impact on minute biological mechanisms. In this Spotlight feature, we give an overview of some of the best nutrition research published in February 2019.
Last month on Medical News Today, we covered numerous peer-reviewed studies concerned with matters of nutrition.
Each asked and answered questions about how our dietary practices affect our well-being.
And you, our readers, have shown particular interest in which diets are best for health, as well as which foods may have unexpectedly negative effects.
There is no doubt about it and no use denying it: What we eat is at the heart of our daily existence. Food is a necessity for life, and eating well helps us feel well, have more energy, and become more productive.
In the essay "A Room of One's Own," writer Virginia Woolf even forcefully remarks that "One cannot think well, love well, sleep well, if one has not dined well."
But what does it mean to eat well? What should you eat, what should you avoid, and which dietary patterns should you choose?
Researchers are constantly hard at work to get a better understanding of these issues and offer suggestions for better dietary practices.
In this Spotlight feature, we look at some of the most important findings in nutrition research that were published last month.
Best dietary habits for health
Existing studies have suggested that intermittent fasting — in which a person fasts for a set number of hours each day but eats freely in the remaining hours — can help with losing weight and may provide other health benefits, including prolonging a person's lifespan and reducing harmful inflammation.
Essentially, fasting triggers changes in the body — such as stimulating weight loss — by acting on metabolic processes.
Usually, our bodies rely on carbohydrates to produce energy, but when a person fasts and carbohydrates are no longer readily available, the body starts looking for and utilizing other resources.
A study published in the journal Scientific Reports early last month identified some metabolic changes triggered by fasting that researchers had not previously been aware of.
Specifically, the study's authors — who are based at the Okinawa Institute of Science and Technology Graduate University in Japan — found that fasting boosts levels of purine and pyrimidine, two organic compounds that act on gene expression and protein synthesis at a cellular level.
"These [substances] are very important metabolites for maintenance of muscle and antioxidant activity," explains study author Dr. Takayuki Teruya. This means that by increasing levels of purine and pyrimidine, fasting can stimulate rejuvenating processes, potentially keeping the body younger for longer.
Other research published last month sought to debunk long-standing myths about dietary best practices. One such myth is that eating breakfast is important when it comes to achieving weight loss.
Some believe that eating a morning meal helps stimulate the metabolism so that more calories burn faster. Moreover, certain studies have found a correlation between obesity and a tendency to skip breakfast.
However, this not what a study published in the BMJ last month found. The researchers worked with some participants who reported usually having breakfast and others who, more often than not, preferred to skip it.
The team's findings contradict existing notions about breakfast and weight loss, as they indicate that the total daily energy (calorie) intake tends to be higher in people who regularly eat breakfast.
Moreover, the researchers found that individuals who tended to go without breakfast on a daily basis actually had less body weight than breakfast-eaters, on average.
In their study paper, the authors go so far as to warn that "Caution is needed when recommending breakfast for weight loss in adults, as it may have the opposite effect."
The protective effects of common foods
At the same time, researchers have been identifying additional benefits of common natural foods. One example is flaxseed, which many of us use to enrich our smoothies or add some extra crunch to crackers and granola bars.
Now, a new study published in the American Journal of Physiology: Endocrinology and Metabolism suggests that flaxseed fiber can also lower obesity markers.
Flaxseed starts breaking down once it reaches the gut. The research, which the team conducted in a mouse model, showed that the fiber produces changes in the gut microbiota that lead to a more healthy bacterial population.
These changes affect metabolic processes, accelerating the consumption of energy, and thus lowering markers associated with obesity.
In addition to this, they help boost glucose (sugar) tolerance, which may mean that they have a protective effect against features that define other metabolic conditions, such as diabetes, which is characterized by impaired glucose tolerance.
According to other research published last month, onions and garlic, two key ingredients in global cuisines, are also important allies when it comes to safeguarding our health.
In a paper, published in the Asia-Pacific Journal of Clinical Oncology last month, researchers from the First Hospital of China Medical University report that these two vegetables have an anti-cancer effect.
Both garlic and onions belong to the family of allium vegetables, all of which have similarly pungent smells and flavors.
The present study looked at 833 individuals who had been diagnosed with colorectal cancer, assessing how many allium vegetables they tended to consume on a regular basis. The team then matched this group with that of an equal number of cancer-free individuals.
The researchers found that participants who ate the largest quantities of garlic and onions had a 79 percent lower risk of colorectal cancer, compared with people who consumed low quantities of allium vegetables.
Based on these results, the investigators concluded that "The greater the amount of allium vegetables, the better the protection," in the words of senior researcher Dr. Zhi Li.
Another well-loved food item that received positive attention in February is the blueberry. Blueberries are often hailed as a superfood because they are packed with antioxidants, substances that help protect cellular health and fend off disease.
Last month, researchers from King's College London in the United Kingdom found that the anthocyanins — pigments with antioxidant properties — in these berries could help lower a person's risk of cardiovascular problems.
Study participants who ate 200 grams of blueberries per day for a month saw a significant decrease in blood pressure, which, the investigators note, does not usually occur in the absence of specialized medication.
Warnings about dietary choices
February also saw the publication of studies that warned that some dietary choices may be putting our health at risk.
For example, research that appears in JAMA Internal Medicine cautions, once more, that eating ultra-processed foods could be extremely harmful.
This study was conducted by specialists from the Sorbonne University in Paris and the Avicenne Hospital, both in France.
The researchers explain that such foods — which include ready-made meals and processed meats — have high contents of fat, sugar, and sodium (salt) while being low in natural fiber.
This means that, while tasty, they are not nutritious and will cheat our stomachs into feeling satisfied, while failing to offer the real sustenance that we need.
At the same time, the investigators add, ultra-processed foods often contain artificial additives, which could increase our exposure to a range of diseases.
While specialists already understood that such foods exacerbate our vulnerability to disease, the effect on overall mortality risk remained unclear. In the present study, the authors have, for perhaps the first time, concluded that as little as a 10 percent increase in the amount of ultra-processed food that we eat leads to a 14 percent higher mortality risk.
Another study, featured in the journal Stroke, drew some bleak conclusions about the consumption of artificially sweetened diet drinks.
The team that conducted this research was specifically interested in seeing how diet drink consumption affected women over 50, so they analyzed data from 81,714 women in this age category.
The analysis revealed a worrying trend: Women who had two or more diet drinks per day had a 23 percent higher risk of stroke and a 29 percent higher risk of a heart attack or a similar event.
That being the case, the study authors urge us to reconsider whenever we feel tempted to reach out for a low-calorie soft drink and opt for an alternative.
Finally, a team of scientists from Flinders University in Adelaide, Australia, has turned its attention to the harms of alcohol, which, according to the team's new study — published in PLOS ONE — many people still ignore.
The Australian researchers chose to focus on alcohol's well-recognized status as a risk factor for breast cancer. They turned to women aged between 45 and 64, asking them how often and how much they drink and whether they are aware of the risks.
According to lead author Dr. Emma Miller, "There is a low level of awareness about the established link between alcohol and breast cancer," and women continue to actively put themselves at risk.
"[It's] really important to understand the patterns and drivers behind drinking behavior, in order to develop policies and interventions that might reduce the increasing burden on the women and our health system," Dr. Miller stresses.
One message emerges from the studies that top researchers have made available in February, namely: We all need to learn how to make our diets work for us, rather than against us, and make choices for which our bodies will be grateful.