Why do our cells love spinach?

Cells strive to maintain a healthy acid-base balance within the body (3). 

Cells chug along by having rhythmic changes in predetermined intervals. Some of those rhythms recur every few seconds (heart beats, respiratory cycle, brain waves), others are daily (day/night cycles), and still others happen seasonally (for example, hibernation, change in color of the fur).

Cellular rhythms are often due to transient acid fluxes

To create those rhythmic patterns, cells accept signals from the bloodstream and the nervous system. These create transient cytoplasmic acidification. For instance, growth factors and hormones induce a temporary H+ influx into the cytoplasm, after which the cell returns to its steady-state pH  (4, 5, 6).

However, too little or too much acid leads to dysfunction:

• Too little acid, and alkalosis results. This can wreak havoc with calcium-related systems. For example, for those of us who have had problems with hyperventilation, we can experience tingling and muscle spams as a result.
• Too much acid, and cells become prone to aging

Abnormal levels of acid in the cytoplasm will - over time - lead to aging

Chronic excess of acid inside or outside the cell will cause major dysfunction. In fact, experimental acidification of the intracellular or extracellular environment can induce senescence - or aged cells (7). High salt diets in transgenic mice lead to increased cytoplasmic acidification and subsequent early senescence and shortened lifespan  (8).

What is great about spinach is that it has several phytochemicals (quercetin, luteolin, and kaempferol) that have a strong positive effect on acid levels within the cytoplasm. 

Quercetin: 

Quercetin blocks lactate production as well as decreases glucose entry into the cell (9, 10, 11). Furthermore,  quercetin inhibits a receptor that is prominently displayed in cancer cells (Epidermal Growth Factor receptor or EGFR) (12). Blocking this receptor downplays the proliferation of the tumor cells. All in all, quercetin manages to help normal cells cells keep a healthier acid-base balance while encouraging cancer cells to self-destruct (13). 

Luteolin: 

Luteolin decreases aging-related changes in the cell (14). Luteolin also inhibits EGFR signaling leading to the much of the same positive effects as quercetin on decreasing glucose entry into the cell, thus reducing intracellular lactate production (15, 16). 

Kaempferol:

Kaempferol is also an anti-inflammatory and anti-oxidant agent (16). It is also a very strong inhibitor of glucose uptake (16). Anything that inhibits glucose metabolism within the cell that produces lactate (glycolysis) will reverse acidification of the cell (17). 

Thus, compounds - like quercetin, luteolin, and kaempferol - that  inhibit glucose's metabolism into lactate are primed to help control acid production within the cytoplasm.

As noted, not only does spinach prevent acid from accumulating, it blocks glucose entry into the cell. As we can imagine, high levels of fuel fans the fires of acid-producing enzymes within the cytoplasm. 

Thus, spinach creates a double benefit: blocking glucose entry (which is directly linked to a metabolically revved up cell) as well as preventing the processing of glucose into lactate (which acidifies the cytoplasm).

In a way, the phytochemicals in spinach are instructing the cells to chill.

Table: phytochemicals in spinach and their action.

When you have a sprain or a bruise, the body reacts to the cell damage by flooding the area with white blood cells as well as macrophages (scavenger cells). The goal is to jump-start the healing process by helping the housekeeper cells come to the injured area. Unfortunately, many of the proteins produced by those cells create  swelling, muscle spasm, and nerve irritation.  

A common remedy for quick healing as well as reducing inflammation after an injury is to ice as well as raise the affected area. That reduces the blood flow as well as the swelling as well as decreasing the the release of inflammatory molecules (18).

In a similar fashion, the chemicals in spinach act on multiple nodes within the aging cell (2).  They tone down inflammatory molecules. They act as anti-oxidants. And, finally, they block molecules that rev up the cell's metabolism, encouraging the cells to chill.