Leafy greens, we all know are one of the healthiest foods on the earth. It offers so much, the benefits are countless, whether it is brain health, heart health or to control your blood sugar levels. But there is always a debate between which one is better. Spinach or kale?

So let's get into it!

Kale, we often must have heard its name listed as a "superfood". The reason is because of the rich nutrients it has to offer. However, both, spinach and kale are powerhouse leafy greens, rich in various nutrients.

If one must break down its nutrients, then we can broadly divide it between the fiber content, vitamin K, vitamin C, vitamin A, calcium, and folate.

Fiber

All leafy greens are rich in dietary fiber and thus is essential for feeding your gut microbiome. This is the community of good bacteria that lives in your gut and supports your digestive health. The recommended daily amount or the RDA of fiber is 25 grams per day. So, if you go for a cup of raw spinach, this gives you around .7 grams of dietary fiber, whereas one cup of raw kale gives you a bit more. It has .9 grams of fiber.

A study published in M J Lifestyle Med titled . Closing America's fiber intake gap: Communication strategies from a food and fiber summit, found that most Americans actually do not get their RDA for fiber met. So, adding spinach and kale could be a great way to give your RDA fiber a start!

Vitamin K

Vitamin K is necessary for blood clotting or lowering blood flow following an injury so that the wound can heal. In addition to calcium and vitamin D, it also supports healthy bones. While some animal products and fermented foods include vitamin K2, a 2020 study titled Vitamin K2 needs an RDI separate from vitamin K1, notes that lush greens like spinach and kale have vitamin K1.

The recommended daily intake of vitamin K is 120 microgrammes (mcg). A cup of raw kale has 82 microgrammes of vitamin K, while a cup of raw spinach contains 145 microgrammes.

Vitamin C

It is a water-soluble vitamin and antioxidant that protect cells from damage and supports immune health. While it is often attributed to citrus fruits like oranges, vitamin C can also be found in leafy greens and both kale and spinach could be a great source. US Food and Drug Administration (FDA) recommends around 80 milligram of daily vitamin C. In one cup of raw spinach, you can get 8.5 milligrams, while kale provides 20 milligrams of daily vitamin C.

Vitamin A

As per the FDA, vitamin A is important not only for your immune system, but also for your eye health. One must have at least 3,000 international units daily. The Office of Dietary Supplements notes that spinach and kale contain compounds called carotenoids, which our bodies convert to a usable form of vitamin A. This way you can have these leafy greens in your diet to fulfill your requirement of vitamin A. In one cup of spinach, you can get 2,810 international units of vitamin A, whereas in one cup of kale, you will find 1,010 international units of vitamin A.

Calcium

Leafy greens are a rich source of calcium, an important nutrient which supports healthy bones and teeth, nerve communication, and muscle movement. The RDA for calcium in adults is 1,300 milligrams and one cup of raw spinach contains 30 milligrams of calcium, whereas in kale, it has 53 milligrams.

Folate

It is a B vitamin which is best known for its important in pregnancy and that provides neural tube defects like spina bifida in fetuses. The RDA for folate is 400 micrograms in pregnant mothers and 600 for those who are lactating. In one cup of spinach, one can get 58.2 micrograms of folate, whereas kale contains 13 micrograms of folate.

How to Decide Your Diet?

Now that you know the nutrients that kale and spinach contain, you make your own decision. This could be decided based on your requirement. The best way to do this is by talking to a healthcare expert, or a nutritionist who can recommend you better based on your body's need.

If you are considering switching from dairy to plant-based alternatives such as oat and almond milk, a new study warns that the move could increase the risk of nutrient deficiencies, particularly among women and children.

Published in The Lancet Planetary Health, the study found that replacing dairy products with unfortified plant-based alternatives could reduce the intake of essential vitamins and minerals.

“With the growing need to address environmental sustainability, many dietary recommendations are focused on plant-based diets and the reduced intake of animal products,” said Dr Katie Nicol, co-author of the study and Research Fellow at the University of Surrey, UK.

Dr Nicol explained that plant-based alternatives may not provide the same micronutrients as dairy products, putting vulnerable groups such as young children and adolescent females at greater risk of deficiencies that could affect their overall health.

Which Nutrients Could Be Lost When Replacing Dairy?

Also read: Can Eating Peanuts Daily Boost Brain Health And Lower Alzheimer's Disease Risk?

The study warned that replacing dairy products, even partially, with unfortified plant-based alternatives could reduce the intake of four essential micronutrients:

• iodine
• calcium
• riboflavin
• vitamin B12.

In the study, the researchers examined the impact of replacing milk, yoghurt and cheese with commercially available plant-based alternatives on micronutrient intake.

They analysed data from more than 3,500 individuals aged between 18 months and 100 years from the National Diet and Nutrition Survey. Using a modelling technique, they assessed how different levels of dairy replacement affected the intake of these four nutrients.

The findings showed that even modest replacements led to marked declines in all four micronutrients, with iodine intake being particularly affected.

Replacing just 20% to 35% of dairy products with plant-based alternatives, under current market fortification levels, increased iodine inadequacy among adolescent females from 54% to 65%. Among women aged 19–49, it rose from 32% to 42%.

With complete replacement, iodine inadequacy increased to 80% among adolescent females and 72% among adolescent males.

Why Is Iodine Particularly Important?

Read More: Too Much Cow’s Milk Linked To Severe Iron Deficiency In Toddlers, Including Three Deaths

Iodine is essential for producing thyroid hormones, which regulate metabolism and support healthy growth and brain development.

“People may also be unaware of the importance of iodine, which is needed to make thyroid hormones to regulate our metabolism, support healthy growth and brain development,” said lead author Dr Sarah Bath, Associate Professor at the University of Surrey.

She added that iodine is particularly important during pregnancy, when requirements increase, but adequate stores are also needed before pregnancy.

Dairy products are a major source of iodine, while unfortified plant-based alternatives contain very little of the mineral.

Can Fortification Prevent Nutrient Deficiencies?

The researchers also assessed whether mandatory fortification of plant-based dairy alternatives could help prevent nutrient deficiencies.

They found that fortifying these alternatives with essential micronutrients prevented declines in their intake when dairy products were replaced. However, iodine inadequacy remained high, affecting 59% of adolescent females.

The study also found that iodine-fortified bread could further improve iodine intake, reducing inadequacy among adolescent females to 37%.

The findings suggest that combining mandatory fortification of plant-based dairy alternatives with iodine-fortified bread could be the most effective strategy to reduce iodine inadequacy.

Eating about two servings of unsalted, skin-roasted peanuts daily may help support brain health, and reduce the risk of Alzheimer's Disease, suggests a study.

The study, conducted in older adults, suggests that eating 60 grams of peanuts daily for 16 weeks improved insulin responsiveness in brain regions involved in memory, a function that can weaken with age and is linked to Alzheimer's Disease.

Published in the peer-reviewed journal Food & Function, the study highlights how daily peanut consumption may influence brain insulin signalling. However, it does not establish that peanuts can prevent Alzheimer's disease.

How Daily Peanut Consumption Improved Brain Insulin Response

The study included 31 healthy adults aged 60 to 75. During the peanut consumption phase, participants ate 60 grams (approximately two servings) of peanuts daily for 16 weeks.

Researchers used a randomized, controlled crossover trial, allowing them to compare the effects of eating peanuts with those of avoiding them.

The elderly who consumed peanuts daily showed improved insulin responsiveness in several brain regions in the right hemisphere. These included parts of the lingual gyrus, hippocampus, parahippocampal gyrus and posterior cingulate gyrus, all involved in memory-related processes.

While insulin is best known for regulating blood sugar, it also plays an important role in the brain. It supports nerve cell growth, survival and communication, helping maintain memory and other cognitive abilities.

Also read: Just Four Days Of High-Fat Diet May Increase Inflammation, Study Finds

Reduced brain responsiveness to insulin with age has been linked to cognitive decline.

"The hormone insulin plays an important role in the brain, where it supports memory and other cognitive processes. As people age, the brain may become less responsive to insulin, which has been linked to age-related cognitive decline," said Dr Peter Joris, associate professor in the Department of Nutrition and Movement Sciences at Maastricht University Medical Center, Netherlands.

"Our study found that daily peanut consumption beneficially affected insulin responsiveness in memory-related brain regions in older adults. These findings suggest that enhanced regional brain insulin responsiveness may contribute to the cognitive benefits of unsalted, skin-roasted peanut intake," he added.

Which Peanut Nutrients May Support Brain Health?

Read More: Peanut Consumption Associated With Lower Type 2 Diabetes Risk: Study Explains

Researchers supplied participants with premeasured packets of skin-roasted peanuts to ensure consistent consumption.

Participants were instructed to eat their peanuts in the morning or afternoon. They could consume the entire portion at once, divide it into smaller servings throughout the day or include the peanuts in their meals.

Researchers believe several peanut components, rather than a single nutrient, may contribute to the observed effects.

"Multiple nutrients present in peanuts, including unsaturated fats, dietary fibre, vitamins and minerals and bioactive phytochemicals, could potentially contribute to the observed brain benefits," said Joris.

"Peanuts are also a good source of plant-based protein and are especially rich in L-arginine. L-arginine is a key precursor of nitric oxide (NO), which has been reported to facilitate learning and memory performance," he added.

Peanut and Improvements in Blood Flow and Verbal Memory

A previous study published in the peer-reviewed journal Clinical Nutrition 2025, found that consuming peanuts for 16 weeks increased overall cerebral blood flow (CBF) by 3.6% and improved verbal memory performance by 5.8%.

Cerebral blood flow measures the amount of blood circulating through the brain, delivering oxygen and nutrients that brain cells need to function. It is also an indicator of brain blood vessel health.

Long-term diet and obesity are known to affect inflammation. A new study from the University of California, San Francisco suggests that even a few days of eating differently can change how strongly the immune system reacts, at least in mice.

What the researchers did

The study was published in Nature on October 28. It was led by Sagar Bapat, a professor of pathology at UCSF and the paper’s corresponding author. Zewen “Owen” Jiang, who did the work as a graduate student at UCSF, was co-first author, according to UCSF.

The team raised mice on either low-fat or high-fat food pellets. They then applied imiquimod, a cream that triggers skin inflammation, to one ear of each mouse. Mice raised on high-fat food and made obese had severe reactions, while mice on low-fat food had mild ones.

Is it the weight or the diet?

Obesity has long been tied to more severe inflammation, but it wasn’t clear why. “We wanted to know whether it was the extra weight or simply the bad diet that was driving the stronger response,” Jiang said.

To find out, the researchers switched normal-weight mice from low-fat to high-fat food for just four days, then applied the cream three days later. These lean mice developed severe ear inflammation, just like the obese mice. In the other direction, obese mice moved to normal food for four days had much milder inflammation.

The paper’s conclusion is that the dietary state around the time inflammation starts, rather than obesity itself, determines how severe the disease gets.

The skin remembered

Weeks later, the normal-weight mice were back on low-fat food and their inflammation had cleared. The researchers applied the cream again to the same ear. The reaction was far stronger than expected.

The researchers found that high-fat food drew rapid-response immune cells into the skin, which amplified the reaction. As the inflammation faded, memory T cells stayed behind in the ear. Together, these changes left the tissue primed for the next flare-up, UCSF reported. The paper also found that the response depends on CD4+ T cells, and that a protein complex called NLRP3 drives the diet-amplified disease.

The team saw a similar heightened response in the lungs after a few days on a high-fat diet.

Also Read: Psoriasis: Understanding The Skin Condition And Ways To Manage Flare-ups

What the scientists said

“Long-term dietary habits absolutely matter for health, but our study unearthed a much more real-time influence of diet,” Bapat said. “Breakfast, lunch, dinner, they all can have a tremendous and rapid impact on the immune system.”

Jiang added a note of caution. “The diet of a laboratory mouse doesn’t map neatly onto what we eat, but it’s striking how quickly the immune system responds to what’s happening in the body right now,” he said. “Diet, exercise, sleep, they could all shape immune health in ways we don’t yet appreciate.”

What this does and doesn’t mean

This was a study in mice, and the high-fat pellets used in the lab are not the same as human meals. The findings don’t show that a single unhealthy meal will worsen a person’s skin or lung conditions. They do suggest that what is eaten around the time inflammation begins may matter more than researchers had assumed, and that the immune system may hold a memory of it.