In this week's news: California takes a hard stance on soft drinks; marketers realize there's more bread to be made in the gluten-free aisle; and an amino acid in spinach gets the spotlight.

Along with several medical experts, a California state senator proposed adding a warning label to the packaging of sodas not unlike what now appears on cigarette packaging. The wording -- developed by a panel of national healthcare leaders -- would read, “STATE OF CALIFORNIA SAFETY WARNING: Drinking beverages with added sugar(s) contributes to obesity, diabetes, and tooth decay." According to data cited, one soda a day raises an adult's chances of being overweight by 27 percent and a child's by 55 percent.

Despite the fact that only about six percent of the population is gluten-sensitive, eleven percent of US families now purchase gluten-free products, and 30 percent say they want to cut back on gluten consumption. According to the New York Times, the gluten-free category is expected to reach $15 billion in annual sales in 2016. There are multiple reasons behind the boom (including a national preoccupation with gut health, according to one analyst) -- and many ramifications, such as increased produce consumption (fruits and veggies are, after all, naturally gluten-free).

Part of the appeal of vitamins lies in their ability to help neutralize free radicals, which can damage cells in the body. And because exercise increases free radical production, it's not uncommon for serious athletes to load up on supplements as part of the recovery regimen. But a new study published in the Journal of Physiology indicates this might not be the best appproach. When 54 male and female volunteers were given pills that contained either a placebo or high levels of vitamins C and E before working out, those taking the supplements showed less improvement in muscular endurance and other health benefits, suggesting there's actually a function for some of the free radicals made in those instances.

The Secret to Popeye’s Spinach Might Be Faster Reflexes

When it comes to reflexes and reactions, who doesn't want a touch of super-speed, whether it's a quick move at the wheel or a pithy 140-character comeback? Now, a team of German researchers think they might have a lead on something that can help: the amino acid tyrosine, commonly found in foods like spinach, eggs and soy. In a double-blind study published in the journal Neuropsychologia, the scientists found that subjects who drank orange juice laced with tyrosine performed better at a computer game designed to measure cognitive and physical reaction time than those who drank the juice with just placebo. Researchers speculated that bumping up intake of the dopamine-driving amino acid might make people less likely to reach for academic performance-enhancers such as Ritalin.

Sara Reistad-Long writes about science, wellness and lifestyle. She is the co-author of  The Big New York Sandwich Book and can be followed on Twitter: @sarareistadlong